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Friday, June 26, 2026

Market failure

From Wikipedia, the free encyclopedia
While factories and refineries provide jobs and wages, they are also an example of a market failure, as they impose negative externalities on the surrounding region via their airborne pollutants.

In neoclassical economics, market failure is a situation in which the allocation of goods and services by a free market is not Pareto efficient, often leading to a net loss of economic value. The first known use of the term by economists was in 1958, but the concept has been traced back to the Victorian writers John Stuart Mill and Henry Sidgwick. Market failures are often associated with public goodstime-inconsistent preferencesinformation asymmetriesfailures of competition, principal–agent problems, externalitiesunequal bargaining power, behavioral irrationality (in behavioral economics), and macro-economic failures (such as unemployment and inflation).

The neoclassical school attributes market failures to the interference of self-regulatory organizations, governments or supra-national institutions in a particular market, although this view is criticized by heterodox economists. Economists, especially microeconomists, are often concerned with the causes of market failure and possible means of correction. Such analysis plays an important role in many types of public policy decisions and studies.

However, government policy interventions, such as taxes, subsidies, wage and price controls, and regulations, may also lead to an inefficient allocation of resources, sometimes called government failure. Most mainstream economists believe that there are circumstances (like building codes, fire safety regulations or endangered species laws) in which it is possible for government or other organizations to improve the inefficient market outcome. Several heterodox schools of thought disagree with this as a matter of ideology.

An ecological market failure exists when human activity in a market economy is exhausting critical non-renewable resources, disrupting fragile ecosystems, or overloading biospheric waste absorption capacities. In none of these cases does the criterion of Pareto efficiency obtain.

Categories

Different economists have different views about what events are the sources of market failure. Mainstream economic analysis widely accepts that there are several causes of market failures. These include if the market is "monopolised" or a small group of businesses hold significant market power resulting in a "failure of competition"; if production of the good or service results in an externality (external costs or benefits); if the good or service is a "public good"; if there is a "failure of information" or information asymmetry; if there is unequal bargaining power; if there is bounded rationality or irrationality; and if there are macro-economic failures such as unemployment or inflation.

Failure of competition

Agents in a market can gain market power, allowing them to block other mutually beneficial gains from trade from occurring. This can lead to inefficiency due to imperfect competition, which can take many different forms, such as monopoliesmonopsonies, or monopolistic competition, if the agent does not implement perfect price discrimination.

In small countries like New Zealand, electricity transmission is a natural monopoly. Due to enormous fixed costs and small market size, one seller can serve the entire market at the downward-sloping section of its average cost curve, meaning that it will have lower average costs than any potential entrant.

It is then a further question about what circumstances allow a monopoly to arise. In some cases, monopolies can maintain themselves where there are "barriers to entry" that prevent other companies from effectively entering and competing in an industry or market. Or there could exist significant first-mover advantages in the market that make it difficult for other firms to compete. Moreover, monopoly can be a result of geographical conditions created by huge distances or isolated locations. This leads to a situation where there are only few communities scattered across a vast territory with only one supplier. Australia is an example that meets this description. A natural monopoly is a firm whose per-unit cost decreases as it increases output; in this situation it is most efficient (from a cost perspective) to have only a single producer of a good. Natural monopolies display so-called increasing returns to scale. It means that at all possible outputs marginal cost needs to be below average cost if average cost is declining. One of the reasons is the existence of fixed costs, which must be paid without considering the amount of output, what results in a state where costs are evenly divided over more units leading to the reduction of cost per unit.

Public goods

Some markets can fail due to the nature of the goods being exchanged. For instance, some goods can display the attributes of public goods or common goods, wherein sellers are unable to exclude non-buyers from using a product, as in the development of inventions that may spread freely once revealed, such as developing a new method of harvesting. This can cause underinvestment because developers cannot capture enough of the benefits from success to make the development effort worthwhile. This can also lead to resource depletion in the case of common-pool resources, whereby the use of the resource is rival but non-excludable, there is no incentive for users to conserve the resource. An example of this is a lake with a natural supply of fish: if people catch the fish faster than the fish can reproduce, then the fish population will dwindle until there are no fish left for future generations.

Externalities

A good or service could also have significant externalities, where gains or losses associated with the product, production or consumption of a product, differ from the private cost. These gains or losses are imposed on a third-party that did not take part in the original market transaction. These externalities can be innate to the methods of production or other conditions important to the market.

"The Problem of Social Cost" illuminates a different path towards social optimum showing the Pigouvian tax is not the only way towards solving externalities. It is hard to say who discovered externalities first since many classical economists saw the importance of education or a lighthouse, but it was Alfred Marshall who wanted to explore this more. He wondered why long-run supply curve under perfect competition could be decreasing so he founded "external economies". Externalities can be positive or negative depending on how a good/service is produced or what the good/service provides to the public. Positive externalities tend to be goods like vaccines, schools, or advancement of technology. They usually provide the public with a positive gain. Negative externalities would be like noise or air pollution. Coase shows this with his example of the case Sturges v. Bridgman involving a confectioner and doctor. The confectioner had lived there many years and soon the doctor several years into residency decides to build a consulting room; it is right by the confectioner's kitchen which releases vibrations from his grinding of pestle and mortar. The doctor wins the case by a claim of nuisance so the confectioner would have to cease from using his machine. Coase argues there could have been bargains instead the confectioner could have paid the doctor to continue the source of income from using the machine hopefully it is more than what the Doctor is losing. Vice versa the doctor could have paid the confectioner to cease production since he is prohibiting a source of income from the confectioner. Coase used a few more examples similar in scope dealing with social cost of an externality and the possible resolutions.

Congested Times Square in Midtown Manhattan, New York City, which leads the world in urban automobile traffic congestion, but which has implemented congestion pricing in January 2025 to address the problem

Traffic congestion is an example of market failure that incorporates both non-excludability and externality. Public roads are common resources that are available for the entire population's use (non-excludable), and act as a complement to cars (the more roads there are, the more useful cars become). Because there is very low cost but high benefit to individual drivers in using the roads, the roads become congested, decreasing their usefulness to society. Furthermore, driving can impose hidden costs on society through pollution (externality). Solutions for this include public transportation, congestion pricing, tolls, and other ways of making the driver include the social cost in the decision to drive.

Perhaps the best example of the inefficiency associated with common/public goods and externalities is the environmental harm caused by pollution and overexploitation of natural resources.

Coase theorem

The Coase theorem, developed by Ronald Coase and labeled as such by George Stigler, states that private transactions are efficient as long as property rights exist, only a small number of parties are involved, and transactions costs are low. Additionally, this efficiency will take place regardless of who owns the property rights. This theory comes from a section of Coase's Nobel prize-winning work The Problem of Social Cost. While the assumptions of low transactions costs and a small number of parties involved may not always be applicable in real-world markets, Coase's work changed the long-held belief that the owner of property rights was a major determining factor in whether or not a market would fail. The Coase theorem points out when one would expect the market to function properly even when there are externalities.

A market is an institution in which individuals or firms exchange not just commodities, but the rights to use them in particular ways for particular amounts of time. [...] Markets are institutions which organize the exchange of control of commodities, where the nature of the control is defined by the property rights attached to the commodities.

As a result, agents' control over the uses of their goods and services can be imperfect, because the system of rights which defines that control is incomplete. Typically, this falls into two generalized rights – excludability and transferability. Excludability deals with the ability of agents to control who uses their commodity, and for how long – and the related costs associated with doing so. Transferability reflects the right of agents to transfer the rights of use from one agent to another, for instance by selling or leasing a commodity, and the costs associated with doing so. If a given system of rights does not fully guarantee these at minimal (or no) cost, then the resulting distribution can be inefficient. Considerations such as these form an important part of the work of institutional economics. Nonetheless, views still differ on whether something displaying these attributes is meaningful without the information provided by the market price system.

Information failures

Information asymmetry is considered a leading type of market failure. This is where there is an imbalance of information between two or more parties to a transaction. One example is incomplete markets, for example where second hand car buyers know there is a risk a car may break down, and systematically under-pay to discount this risk: this leads to fewer cars being sold overall; or where insurers know that some policyholders will withhold information, and systematically refuse to insure certain groups because of this risk. This may result in economic inefficiency, but also have a possibility of improving efficiency through market, legal, and regulatory remedies. From contract theory, decisions in transactions where one party has more or better information than the other is considered "asymmetry". This creates an imbalance of power in transactions which can sometimes cause the transactions to go awry. Examples of this problem are adverse selection and moral hazard. Most commonly, information asymmetries are studied in the context of principal–agent problems. George Akerlof, Michael Spence, and Joseph E. Stiglitz developed the idea and shared the 2001 Nobel Prize in Economics.

Unequal bargaining power

In The Wealth of Nations Adam Smith explored how an employer had the ability to "hold out" longer in a dispute over pay with workers because workers were more likely to go hungry more quickly, given that the employer has more property, and have fewer obstacles in organising. Unequal bargaining power has been used as a concept justifying economic regulation, particularly for employment, consumer, and tenancy rights since the early 20th century. Thomas Piketty in Capital in the Twenty-First Century explains how unequal bargaining power undermines "conditions of "pure and perfect" competition" and leads to a persistently lower share of income for labor, and leads to growing inequality. While it was argued by Ronald Coase that bargaining power merely affects distribution of income, but not productive efficiency, the modern behavioural evidence establishes that distribution or fairness of exchange does affect motivation to work, and therefore unequal bargaining power is a market failure. Notably, the price of labour was excluded from the scope of the original charts on supply and demand by their inventor, Fleeming Jenkin, who considered that the wages of labour could not be equated with ordinary markets for commodities such as corn, because of labour's unequal bargaining power.

Bounded rationality

In Models of Man, Herbert A. Simon points out that most people are only partly rational, and are emotional/irrational in the remaining part of their actions. In another work, he states "boundedly rational agents experience limits in formulating and solving complex problems and in processing (receiving, storing, retrieving, transmitting) information" (Williamson, p. 553, citing Simon). Simon describes a number of dimensions along which "classical" models of rationality can be made somewhat more realistic, while sticking within the vein of fairly rigorous formalization. These include:

  • limiting what sorts of utility functions there might be.
  • recognizing the costs of gathering and processing information.
  • the possibility of having a "vector" or "multi-valued" utility function.

Simon suggests that economic agents employ the use of heuristics to make decisions rather than a strict rigid rule of optimization. They do this because of the complexity of the situation, and their inability to process and compute the expected utility of every alternative action. Deliberation costs might be high and there are often other, concurrent economic activities also requiring decisions.

The concept of bounded rationality was significantly expanded through behavioral economics research, suggesting that people are systematically irrational in day-to-day decisions. Daniel Kahneman in Thinking, Fast and Slow explored how human beings operate as if they have two systems of thinking: a fast "system 1" mode of thought for snap, everyday decisions which applies rules of thumb but is frequently mistaken; and a slow "system 2" mode of thought that is careful and deliberative, but not as often used in making ordinary decisions to buy and sell or do business.

Macro-economic failures

"Unemployment, inflation and "disequilibrium" are considered a category of market failure at a "macro economic" or "whole economy" level. These symptoms (of high job loss, or fast rising prices or both) can result from a financial crash, a recession or depression, and the market failure is evident in the sustained underproduction of an economy, or a tendency not to recover immediately. Macroeconomic business cycles are a part of the market. They are characterized by constant downswings and upswings which influence economic activity. Therefore, this situation requires some kind of government intervention.

Persistent labor shortages

Widespread and persistent domestic labour shortages in various countries are examples of market failure, whereby excessively low salaries (relative to the domestic cost of living) and adverse working conditions (excessive workload and working hours) in low-wage industries (hospitality and leisure, education, health care, rail transportation, warehousing, aviation, retail, manufacturing, food, construction, elderly care), collectively lead to occupational burnout and attrition of existing workers, insufficient incentives to attract the inflow supply of domestic workers, short-staffing and regular shift work at workplaces and further exacerbation (positive feedback) of staff shortages. Poor job quality and artificial shortages perpetuated by salary-paying employers, deter workers from entering or remaining in these roles.

Labour shortages occur broadly across multiple industries within a rapidly expanding economy, whilst labour shortages often occur within specific industries (which generally offer low salaries) even during economic periods of high unemployment. In response to domestic labour shortages, business associations such as chambers of commerce, trade associations or employers' organizations would generally lobby to governments for an increase of the inward immigration of foreign workers from countries which are less developed and have lower salaries. In addition, business associations have campaigned for greater state provision of child care, which would enable more women to re-enter the labour workforce at a lower wage rate to achieve economic equilibrium. However, as labour shortages in the relevant low-wage industries are often widespread globally throughout many countries in the world, immigration would only partially address the chronic labour shortages in the relevant low-wage industries in developed countries (whilst simultaneously discouraging local labour from entering the relevant industries) and in turn cause greater labour shortages in developing countries.

Interpretations and policy examples

The above causes represent the mainstream view of what market failures mean and of their importance in the economy. This analysis follows the lead of the neoclassical school, and relies on the notion of Pareto efficiency, which can be in the "public interest", as well as in interests of stakeholders with equity. This form of analysis has also been adopted by the Keynesian or new Keynesian schools in modern macroeconomics, applying it to Walrasian models of general equilibrium in order to deal with failures to attain full employment, or the non-adjustment of prices and wages.

Policies to prevent market failure are already commonly implemented in the economy. For example, to prevent information asymmetry, members of the New York Stock Exchange agree to abide by its rules in order to promote a fair and orderly market in the trading of listed securities. The members of the NYSE presumably believe that each member is individually better off if every member adheres to its rules – even if they have to forego money-making opportunities that would violate those rules.

A simple example of policies to address market power is government antitrust policies. As an additional example of externalities, municipal governments enforce building codes and license tradesmen to mitigate the incentive to use cheaper (but more dangerous) construction practices, ensuring that the total cost of new construction includes the (otherwise external) cost of preventing future tragedies. The voters who elect municipal officials presumably feel that they are individually better off if everyone complies with the local codes, even if those codes may increase the cost of construction in their communities.

CITES is an international treaty to protect the world's common interest in preserving endangered species – a classic "public good" – against the private interests of poachers, developers and other market participants who might otherwise reap monetary benefits without bearing the known and unknown costs that extinction could create. Even without knowing the true cost of extinction, the signatory countries believe that the societal costs far outweigh the possible private gains that they have agreed to forego.

Some remedies for market failure can resemble other market failures. For example, the issue of systematic underinvestment in research is addressed by the patent system that creates artificial monopolies for successful inventions.

Objections

Public choice

Economists such as Milton Friedman from the Chicago school and others from the Public Choice school, argue that market failure does not necessarily imply that the government should attempt to solve market failures, because the costs of government failure might be worse than those of the market failure it attempts to fix. This failure of government is seen as the result of the inherent problems of democracy and other forms of government perceived by this school and also of the power of special-interest groups (rent seekers) both in the private sector and in the government bureaucracy. Conditions that many would regard as negative are often seen as an effect of subversion of the free market by coercive government intervention. Beyond philosophical objections, a further issue is the practical difficulty that any single decision maker may face in trying to understand (and perhaps predict) the numerous interactions that occur between producers and consumers in any market.

Austrian

Some advocates of laissez-faire capitalism, including many economists of the Austrian School, argue that there is no such phenomenon as "market failure". Israel Kirzner states that, "Efficiency for a social system means the efficiency with which it permits its individual members to achieve their individual goals." Inefficiency only arises when means are chosen by individuals that are inconsistent with their desired goals. This definition of efficiency differs from that of Pareto efficiency, and forms the basis of the theoretical argument against the existence of market failures. However, providing that the conditions of the first welfare theorem are met, these two definitions agree, and give identical results. Austrians argue that the market tends to eliminate its inefficiencies through the process of entrepreneurship driven by the profit motive; something the government has great difficulty detecting, or correcting.

Marxian

Objections also exist on more fundamental bases, such as Marxian analysis. Colloquial uses of the term "market failure" reflect the notion of a market "failing" to provide some desired attribute different from efficiency – for instance, high levels of inequality can be considered a "market failure", yet are not Pareto inefficient, and so would not be considered a market failure by mainstream economics. In addition, many Marxian economists would argue that the system of private property rights is a fundamental problem in itself, and that resources should be allocated in another way entirely. This is different from concepts of "market failure" which focuses on specific situations – typically seen as "abnormal" – where markets have inefficient outcomes. Marxists, in contrast, would say that markets have inefficient and democratically unwanted outcomes – viewing market failure as an inherent feature of any capitalist economy – and typically omit it from discussion, preferring to ration finite goods not exclusively through a price mechanism, but based upon need as determined by society expressed through the community.

Ecological

In ecological economics, the concept of externalities is considered a misnomer, since market agents are viewed as making their incomes and profits by systematically 'shifting' the social and ecological costs of their activities onto other agents, including future generations. Hence, externalities is a modus operandi of the market, not a failure: The market cannot exist without constantly 'failing'.

The fair and even allocation of non-renewable resources over time is a market failure issue of concern to ecological economics. This issue is also known as 'intergenerational fairness'. It is argued that the market mechanism fails when it comes to allocating the Earth's finite mineral stock fairly and evenly among present and future generations, as future generations are not, and cannot be, present on today's market. In effect, today's market prices do not, and cannot, reflect the preferences of the yet unborn. This is an instance of a market failure passed unrecognized by most mainstream economists, as the concept of Pareto efficiency is entirely static (timeless). Imposing government restrictions on the general level of activity in the economy may be the only way of bringing about a more fair and even intergenerational allocation of the mineral stock. Hence, Nicholas Georgescu-Roegen and Herman Daly, the two leading theorists in the field, have both called for the imposition of such restrictions: Georgescu-Roegen has proposed a minimal bioeconomic program, and Daly has proposed a comprehensive steady-state economy. However, Georgescu-Roegen, Daly, and other economists in the field agree that on a finite Earth, geologic limits will inevitably strain most fairness in the longer run, regardless of any present government restrictions: Any rate of extraction and use of the finite stock of non-renewable mineral resources will diminish the remaining stock left over for future generations to use.

Another ecological market failure is presented by the overutilisation of an otherwise renewable resource at a point in time, or within a short period of time. Such overutilisation usually occurs when the resource in question has poorly defined (or non-existing) property rights attached to it while too many market agents engage in activity simultaneously for the resource to be able to sustain it all. Examples range from over-fishing of fisheries and over-grazing of pastures to over-crowding of recreational areas in congested cities. This type of ecological market failure is generally known as the 'tragedy of the commons'. In this type of market failure, the principle of Pareto efficiency is violated the utmost, as all agents in the market are left worse off, while nobody are benefitting. It has been argued that the best way to remedy a 'tragedy of the commons'-type of ecological market failure is to establish enforceable property rights politically – only, this may be easier said than done.

The issue of climate change presents an overwhelming example of a 'tragedy of the commons'-type of ecological market failure: The Earth's atmosphere may be regarded as a 'global common' exhibiting poorly defined (non-existing) property rights, and the waste absorption capacity of the atmosphere with regard to carbon dioxide is presently being heavily overloaded by a large volume of emissions from the world economy. Historically, the fossil fuel dependence of the Industrial Revolution has unintentionally thrown mankind out of ecological equilibrium with the rest of the Earth's biosphere (including the atmosphere), and the market has failed to correct the situation ever since. Quite the opposite: The unrestricted market has been exacerbating this global state of ecological dis-equilibrium, and is expected to continue doing so well into the foreseeable future. This particular market failure may be remedied to some extent at the political level by the establishment of an international (or regional) cap and trade property rights system, where carbon dioxide emission permits are bought and sold among market agents.

The term 'uneconomic growth' describes a pervasive ecological market failure: The ecological costs of further economic growth in a so-called 'full-world economy' like the present world economy may exceed the immediate social benefits derived from this growth.

Zerbe and McCurdy

Zerbe and McCurdy connected criticism of market failure paradigm to transaction costs. Market failure paradigm is defined as follows:

"A fundamental problem with the concept of market failure, as economists occasionally recognize, is that it describes a situation that exists everywhere."

Transaction costs are part of each market exchange, although the price of transaction costs is not usually determined. They occur everywhere and are unpriced. Consequently, market failures and externalities can arise in the economy every time transaction costs arise. There is no place for government intervention. Instead, government should focus on the elimination of both transaction costs and costs of provision.

Emotion and memory

From Wikipedia, the free encyclopedia

Emotion can have a powerful effect on humans and animals. Numerous studies have shown that the most vivid autobiographical memories tend to be of emotional events, which are likely to be recalled more often and with more clarity and detail than neutral events.

The activity of emotionally enhanced memory retention can be linked to human evolution; during early development, responsive behavior to environmental events would have progressed as a process of trial and error. Survival depended on behavioral patterns that were repeated or reinforced through life and death situations. Through evolution, this process of learning became genetically embedded in humans and all animal species in what is known as flight or fight instinct.

Artificially inducing this instinct through traumatic physical or emotional stimuli essentially creates the same physiological condition that heightens memory retention by exciting neuro-chemical activity affecting areas of the brain responsible for encoding and recalling memory. This memory-enhancing effect of emotion has been demonstrated in many laboratory studies, using stimuli ranging from words to pictures to narrated slide shows, as well as autobiographical memory studies. However, as described below, emotion does not always enhance memory.

Arousal and valence in memory

One of the most common frameworks in the emotions field proposes that affective experiences are best characterized by two main dimensions: arousal and valence. The dimension of valence ranges from highly positive to highly negative, whereas the dimension of arousal ranges from calming or soothing to exciting or agitating.

The majority of studies to date have focused on the arousal dimension of emotion as the critical factor contributing to the emotional enhancement effect on memory. Different explanations have been offered for this effect, according to the different stages of memory formation and reconstruction. Memory has been shown to be better with arousal linked with emotion than without emotion. The use of a PET scan has allowed scientists to see that pictures with an "emotional-stimulus" have significantly larger amount of activity in the amygdala. In a study using fluoro-2-deoxyglucose (FDG-PET) to examine the brain during recall of films that were both neutral and aversive, there was a positive correlation between the brain glucose and metabolic rate in the amygdala. The activity in the amygdala is part of the episodic memory that was being created due to the adverse stimuli. Most recently, an intracranial EEG study found that the amygdala triggered more pronounced hippocampal sharp-wave ripples after the encoding of more arousing experiences, which are believed to play a critical role in memory consolidation.

However, a growing body of research is dedicated to the emotional valence dimension and its effects on memory. It has been claimed that this is an essential step towards a more complete understanding of emotion effects on memory. The studies that did investigate this dimension have found that emotional valence alone can enhance memory; that is, nonarousing items with positive or negative valence can be better remembered than neutral items.

Emotion and encoding

From an information processing perspective, encoding refers to the process of interpreting incoming stimuli and combining the processed information. At the encoding level the following mechanisms have been suggested as mediators of emotion effects on memory:

Selectivity of attention

Easterbrook's (1959) cue utilization theory predicted that high levels of arousal will lead to attention narrowing, defined as a decrease in the range of cues from the stimulus and its environment to which the organism is sensitive. According to this hypothesis, attention will be focused primarily on the arousing details (cues) of the stimulus, so that information central to the source of the emotional arousal will be encoded while peripheral details will not.

Accordingly, several studies have demonstrated that the presentation of emotionally-arousing stimuli (compared to neutral stimuli) results in enhanced memory for central details (details central to the appearance or meaning of the emotional stimuli) and impaired memory for peripheral details. Also consistent with this hypothesis are findings of weapon focus effect, in which witnesses to a crime remember the gun or knife in great detail but not other details such as the perpetrator's clothing or vehicle. In laboratory replications it was found that participants spend a disproportionate amount of time looking at a weapon in a scene, and this looking time is inversely related to the likelihood that individuals will subsequently identify the perpetrator of the crime. Other researchers have suggested arousal may also increase the duration of attentional focusing on the arousing stimuli, thus delaying the disengagement of attention from it. Ochsner (2000) summarized the different findings and suggested that by influencing attention selectivity and dwell time, arousing stimuli are more distinctively encoded, resulting in more accurate memory of those stimuli.

While these previous studies focused on how emotion affects memory for emotionally arousing stimuli, in their arousal-biased competition theory, Mather and Sutherland (2011) argue that how arousal influences memory for non-emotional stimuli depends on the priority of those stimuli at the time of the arousal. Arousal enhances perception and memory of high priority stimuli but impairs perception and memory of low priority stimuli. Priority can be determined by bottom-up salience or by top-down goals.

Prioritized processing

Emotional items also appear more likely to be processed when attention is limited, suggesting a facilitated or prioritized processing of emotional information. This effect was demonstrated using the attentional blink paradigm in which 2 target items are presented in close temporal proximity within a stream of rapidly presented stimuli.

The typical finding is that participants often miss the second target item, as if there were a "blink" of attention following the first target's presentation, reducing the likelihood that the second target stimulus is attended. However, when the second target stimulus elicits emotional arousal (a "taboo" word), participants are less likely to miss the target's presentation, which suggests that under conditions of limited attention, arousing items are more likely to be processed than neutral items.

Additional support for the prioritized processing hypothesis was provided by studies investigating the visual extinction deficit. People suffering from this deficit can perceive a single stimulus in either side visual field if it is presented alone but are unaware of the same stimulus in the visual field opposed to the lesional side, if another stimulus is presented simultaneously on the lesional side.

Emotion has been found to modulate the magnitude of the visual extinction deficit, so that items that signal emotional relevance (e.g., spiders) are more likely to be processed in the presence of competing distractors than nonemotional items (e.g., flowers).

Emotion and storage

In addition to its effects during the encoding phase, emotional arousal appears to increase the likelihood of memory consolidation during the retention (storage) stage of memory (the process of creating a permanent record of the encoded information). A number of studies show that over time, memories for neutral stimuli decrease but memories for arousing stimuli remain the same or improve.

Others have discovered that memory enhancements for emotional information tend to be greater after longer delays than after relatively short ones. This delayed effect is consistent with the proposal that emotionally-arousing memories are more likely to be converted into a relatively permanent trace, whereas memories for nonarousing events are more vulnerable to disruption.

A few studies have even found that emotionally arousing stimuli enhance memory only after a delay. The most famous of these was a study by Kleinsmith and Kaplan (1963) that found an advantage for numbers paired with arousing words over those paired with neutral words only at delayed test, but not at immediate test. As outlined by Mather (2007), the Kleinsmith and Kaplan effects were most likely due to a methodological confound. However, Sharot and Phelps (2004) found better recognition of arousing words over neutral words at a delayed test but not at an immediate test, supporting the notion that there is enhanced memory consolidation for arousing stimuli. According to these theories, different physiological systems, including those involved in the discharge of hormones believed to affect memory consolidation, become active during, and closely following, the occurrence of arousing events.

Another possible explanation for the findings of the emotional arousal delayed effect is post-event processing regarding the cause of the arousal. According to the post stimulus elaboration (PSE) hypothesis, an arousing emotional experience may cause more effort to be invested in elaboration of the experience, which would subsequently be processed at a deeper level than a neutral experience. Elaboration refers to the process of establishing links between newly-encountered information and previously-stored information.

It has long been known that when individuals process items in an elaborative fashion, such that meaning is extracted from items and inter-item associations are formed, memory is enhanced. Thus, if a person gives more thought to central details in an arousing event, memory for such information is likely to be enhanced. However, these processes could also disrupt consolidation of memories for peripheral details. Christianson (1992) suggested that the combined action of perceptual, attentional, and elaborative processing, triggered by an emotionally arousing experience, produces memory enhancements of details related to the emotion laden stimulus, at the cost of less elaboration and consolidation of memory for the peripheral details.

Emotion and elaboration

The processes involved in this enhancement may be distinct from those mediating the enhanced memory for arousing items. It has been suggested that in contrast to the relatively automatic attentional modulation of memory for arousing information, memory for non-arousing positive or negative stimuli may benefit instead from conscious encoding strategies, such as elaboration. This elaborative processing can be autobiographical or semantic.

Autobiographical elaboration is known to benefit memory by creating links between the processed stimuli, and the self, for example, deciding whether a word would describe the personal self. Memory formed through autobiographical elaboration is enhanced as compared to items processed for meaning, but not in relation to the self.

Since words such as "sorrow" or "comfort" may be more likely to be associated with autobiographical experiences or self-introspection than neutral words such as "shadow", autobiographical elaboration may explain the memory enhancement of non-arousing positive or negative items. Studies have shown that dividing attention at encoding decreases an individual's ability to utilize controlled encoding processes, such as autobiographical or semantic elaboration.

Thus, findings that participants' memory for negative non-arousing words suffers with divided attention, and that the memory advantage for negative, non-arousing words can be eliminated when participants encode items while simultaneously performing a secondary task, has supported the elaborative processing hypothesis as the mechanism responsible for memory enhancement for negative non-arousing words.

Emotion and retrieval

Retrieval is a process of reconstructing past experiences; this phenomenon of reconstruction is influenced by a number of different variables described below.

Trade-off between details

Kensinger argues there are two trade-offs: central/peripheral trade-off of details and a specific/general trade-off. Emotional memories may include increased emotional details often with the trade-off of excluding background information. Research has shown that this trade-off effect cannot be explained exclusively by overt attention (measured by eye-tracking directed to emotional items during encoding) (Steinmetz & Kensinger, 2013).

Contextual effects of emotion on memory

Contextual effects occur as a result of the degree of similarity between the encoding context and the retrieval context of an emotional dimension. The main findings are that the current mood we are in affects what is attended, encoded and ultimately retrieved, as reflected in two similar but subtly different effects: the mood congruence effect and mood-state dependent retrieval. Positive encoding contexts have been connected to activity in the right fusiform gyrus. Negative encoding contexts have been correlated to activity in the right amygdala (Lewis & Critchley, 2003). However, Lewis and Critchley (2003) claim that it is not clear whether involvement of the emotional system in encoding memory differs for positive or negative emotions, or whether moods at recall lead to activity in the corresponding positive or negative neural networks.

Mood congruence effect

The mood congruence effect refers to the tendency of individuals to retrieve information more easily when it has the same emotional content as their current emotional state. For instance, being in a depressed mood increases the tendency to remember negative events (Drace, 2013).

This effect has been demonstrated for explicit retrieval as well as implicit retrieval.

Mood-state dependent retrieval

Another documented phenomenon is the mood-state dependent retrieval, a type of context-dependent memory. The retrieval of information is more effective when the emotional state at the time of retrieval is similar to the emotional state at the time of encoding.

Thus, the probability of remembering an event can be enhanced by evoking the emotional state experienced during its initial processing. These two phenomena, the mood congruity effect, and mood-state dependent retrieval, are similar to the context effects which have been traditionally observed in memory research. It may also relate to the phenomena of state-dependent memory in neuropsychopharmacology.

When recalling a memory, if someone is recalling an event by themselves or within a group of people, the emotions that they remember may change as well recall of specific details. Individuals recall events with stronger negative emotions than when a group is recalling the same event. Collaborative recall, as it can be referred to, causes strong emotions to fade. Emotional tone changes as well, with a difference of individual or collaborative recall so much that an individual will keep the tone of what was previously felt, but the group will have a more neutral tone. For example, if someone is recalling the negative experience of taking a difficult exam, then they will talk in a negative tone. However, when the group is recalling taking the exam, they will most likely recount it in a positive tone as the negative emotions and tones fade. Detail recount is also something that changed based on the emotion state a person is in when they are remembering an event. If an event is being collaboratively recalled the specific detail count is higher than if an individual is doing it. Detail recall is also more accurate when someone is experiencing negative emotion; Xie and Zhang (2016) conducted a study in which participants saw a screen with five colors on it and when presented with the next screen were asked which color was missing. Those who were experiencing negative emotions were more precise than those in the positive and neutral conditions. Aside from emotional state, mental illness like depression relates to people's ability to recall specific details. Those who are depressed tend to overgeneralize their memories and are not able to remember as many specific details of any events as compared to those without depression.

Thematic vs. sudden appearance of emotional stimuli

A somewhat different contextual effect stemmed from the recently made distinction between thematical and sudden appearance of an emotionally arousing event, suggesting that the occurrence of memory impairments depends on the way the emotional stimuli are induced. Laney et al. (2003) argued that when arousal is induced thematically (i.e., not through the sudden appearance of a discrete shocking stimulus such as a weapon but rather through involvement in an unfolding event plot and empathy with the victim as his or her plight becomes increasingly apparent), memory enhancements of details central to the emotional stimulus need not come at the expense of memory impairment of peripheral details.

Laney et al. (2004) demonstrated this by using an audio narrative to give the presented slides either neutral or emotional meaning, instead of presenting shockingly salient visual stimuli. In one of the experiments, participants in both the neutral and emotional conditions viewed slides of a date scenario of a woman and man at a dinner date. The couple engaged in conversation, then, at the end of the evening, embraced. The event concluded with the man leaving and the woman phoning a friend.

The accompanying audio recording informed participants in the neutral condition that the date went reasonably well, while participants in the emotional condition heard that, as the evening wore on, the man displayed some increasingly unpleasant traits of a type that was derogatory to women, and the embrace at the end of the evening was described as an attempt to sexually assault the woman.

As expected, the results revealed that details central to the event were remembered more accurately when that event was emotional than when neutral, However, this was not at the expense of memory for peripheral (in this case, spatially peripheral or plot-irrelevant) details, which were also remembered more accurately when the event was emotional. Based on these findings it has been suggested that the dual enhancing and impairing effects on memory are not an inevitable consequence of emotional arousal.

Neurobiological mechanisms of emotional memory enhancement

The neural mechanism underlying emotional memory enhancement involves the interaction between the amygdala and the hippocampus, as well as several other factors that prioritize the encoding of emotional experiences. When an emotional experience occurs, the amygdala becomes highly active, signaling the hippocampus to strengthen the encoding and consolidation of these memories. This process is facilitated by the release of stress hormones and neurotransmitters, which modulate synaptic plasticity and enhance neural connectivity. Multiple mechanisms have been proposed to explain this prioritized encoding, including the neuromodulatory effects on plasticity and the dynamic interplay between the amygdala and the hippocampus. Intracranial EEG studies have shown that the amygdala triggers pronounced hippocampal sharp-wave ripples after encoding emotional experiences, further reinforcing the consolidation of these memories during both awake and sleep. This coordinated activity between the amygdala and hippocampus ensures that emotionally significant events are prioritized in long-term memory storage, leveraging both immediate neurochemical changes and enduring structural adaptations in neural circuits.

Memory of felt emotion

Many researchers use self-report measures of felt emotion as a manipulation check. This raises an interesting question and a possible methodological weakness: are people always accurate when they recall how they felt in the past? Several findings suggest this is not the case. For instance, in a study of memory for emotions in supporters of former U.S. presidential candidate Ross Perot, supporters were asked to describe their initial emotional reactions after Perot's unexpected withdrawal in July 1992 and again after the presidential election that November.

Between the two assessment periods, the views of many supporters changed dramatically as Perot re-entered the race in October and received nearly a fifth of the popular vote. The results showed that supporters recalled their past emotions as having been more consistent with their current appraisals of Perot than they actually were.

Another study found that people's memories for how distressed they felt when they learned of the 9/11 terrorist attacks changed over time and moreover, were predicted by their current appraisals of the impact of the attacks (Levine et al., 2004). It appears that memories of past emotional responses are not always accurate, and can even be partially reconstructed based on their current appraisal of events.

Studies have shown that as episodic memory becomes less accessible over time, the reliance on semantic memory to remember past emotions increases. In one study Levine et al. (2009) primes of the cultural belief of women being more emotional than men had a greater effect on responses for older memories compared to new memories. The long-term recall of emotions was more in line with the primed opinions, showing that long-term recall of emotions was heavily influenced by current opinions.

Emotion regulation effects on memory

An interesting issue in the study of the emotion-memory relationship is whether our emotions are influenced by our behavioral reaction to them, and whether this reaction—in the form of expression or suppression of the emotion—might affect what we remember about an event. Researchers have begun to examine whether concealing feelings influences our ability to perform common cognitive tasks, such as forming memories, and found that the emotion regulation efforts do have cognitive consequences. In the seminal work on negative affect arousal and white noise, Seidner found support for the existence of a negative affect arousal mechanism through observations regarding the devaluation of speakers from other ethnic origins."

In a study of Richards and Gross (1999) and Tiwari (2013), participants viewed slides of injured men that produced increases in negative emotions, while information concerning each man was presented orally with his slide. The participants were assigned to either an expressive suppression group (where they were asked to refrain from showing emotion while watching the slides) or to a control group (where they were not given regulatory instructions at all). As predicted by the researchers, suppressors showed significantly worse performance on a memory test for the orally presented information.

In another study, it was investigated whether expressive suppression (i.e., keeping one's emotions subdued) comes with a cognitive price. They measured expressive suppression when it spontaneously occurred while watching a movie of surgeries. After the movie, memory was tested and was found to be worse with a higher usage of suppression. In a second study, another movie was shown of people arguing. Memory of the conversation was then measured. When gauging the magnitude of cognitive cost, expressive suppression was compared with self-distraction, which was described as simply not trying to think about something. It was concluded that experimentally-induced suppression was associated with worse memory.

There is evidence that emotion enhances memory but is more specific towards arousal and valence factors. To test this theory, arousal and valence were assessed for over 2,820 words. Both negative and positive stimuli were remembered higher than neutral stimuli. Arousal also did not predict recognition memory. In this study, the importance of stimulus controls and experimental designs in research memory was highlighted. Arousal-related activities when affiliated with heightened heart rate (HR) stimulate prediction of memory enhancement. It was hypothesized that tonic elevations in HR (meaning revitalization in HR) and phasic HR (meaning quick reaction) declaration to help the memory. Fifty-three men's heart rates were measured while looking at unpleasant, neutral, and pleasant pictures and their memory tested two days later. It was concluded that tonic elevations created more accurate memory recall.

Several related studies have reached similar results. It was demonstrated that the effects of expressive suppression on memory generalize to emotionally positive experiences and to socially relevant contexts.

One possible answer to the question "why does emotion suppression impair memory?" might lay in the self monitoring efforts invested in order to suppress emotion (thinking about the behavior one is trying to control). A recent study found heightened self- monitoring efforts among suppressors relative to control participants.

That is, suppressors were more likely to report thinking about their behavior and the need to control it during a conversation. Increases in self-monitoring predicted decreases in memory for what was said, that is, people who reported thinking a lot about controlling their behavior had particularly impoverished memories. However, additional research is needed to confirm whether self-monitoring actually exerts a causal effect on memory

Emotion-induced forgetting

Emotionally arousing stimuli can lead to retrograde amnesia for preceding events and anterograde amnesia for subsequent events. This has been demonstrated in lab studies with lists of words or pictures, in which people show impaired memory for stimuli appearing before or after arousing stimuli.

Depression and memory

Memory recall tends to be congruent with one's current mood, with depressed people more likely to recall negative events from the past. In addition, depression is often associated with poor memory in general, as outlined here.

Dementia and emotional memory

Several studies have demonstrated emotional memory enhancement in Alzheimer's patients suggesting that emotional memory enhancement might be used in the daily management of Alzheimer's patients. One study found that objects are recalled significantly better in Alzheimer's patients if they were presented as birthday presents to AD patients.

Aging and emotional memory

The enhancing effects of emotional arousal on later memory recall tend to be maintained among older adults and the amygdala shows relatively less decline than many other brain regions. However, older adults also show somewhat of a shift towards favoring positive over negative information in memory, leading to a positivity effect.

Emotional memory and sleep

Emotional memory and sleep has been a well-researched association. Emotional memories are consolidated greater during sleep, rather than neutral memories. Studies have investigated high valence and arousing words, in comparison to neutral words. Sleep enhances the consolidation of the high valence and arousing words and therefore these are remembered more post-sleep. This concept has been demonstrated in many studies using a variety of media such as pictures, film clips, and words.

Memories of 'future relevance' are also consolidated greater during sleep. In a study by Wilhelm et al., 2011, memories of items that participants knew were needed for the future (for the testing session) were remembered more after sleep. Sleep consolidated these memories of future relevance to a greater extent. Memories that are emotionally significant and relevant for the future are therefore preferentially consolidated during sleep. This can translate to mean that memories that are more meaningful or valuable to a person are consolidated more.

The concept of emotional memory and sleep can be applied to real-life situations e.g. by developing more effective learning strategies. One could integrate the memorization of information that possesses high emotional significance (highly salient) with information that holds little emotional significance (low salience), prior to a period of sleep.

Cognition

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Cognition

Cognition encompasses mental processes that deal with knowledge. It includes psychological activities that acquire, store, retrieve, transform, or apply information. Cognitions are a pervasive part of mental life, helping individuals understand and interact with the world.

Cognitive processes are typically categorized by their function. Perception organizes and interprets sensory information, such as light and sound, to construct a coherent experience of objects and events. Attention prioritizes specific aspects while filtering out irrelevant information. Memory is the ability to retain, store, and retrieve information, including working memory and long-term memory. Thinking encompasses psychological activities in which concepts, ideas, and mental representations are considered and manipulated. It includes reasoning, concept formation, problem-solving, and decision-making. Many cognitive activities deal with language, including language acquisition, comprehension, and production. Metacognitive processes deal with information about other mental processes, such as knowing that one can recall a specific memory. Classifications also distinguish between conscious and unconscious processes and between controlled and automatic ones.

There are many theories of the nature of cognition. Classical computationalism posits that cognitive processes manipulate symbols according to formal rules, similar to how computers execute algorithms. Connectionism models the mind as a complex network of nodes where information flows as they communicate with each other. Representationalism and anti-representationalism disagree about whether cognitive processes operate on internal representations of the world.

Many disciplines explore cognition, including psychology, neuroscience, and cognitive science. They examine different levels of abstraction and employ distinct methods of inquiry. Some scientists study cognitive development, investigating how mental abilities grow from infancy through adulthood. While cognitive research mostly focuses on humans, it also explores how animals acquire knowledge and how artificial systems can emulate cognitive processes. The study of cognition has its roots in antiquity and has gained particular interdisciplinary prominence since the cognitive revolution starting in the 1950s.

Definition

Cognitions are mental processes that deal with knowledge, involving the acquisition, transformation, storage, retrieval, and use of information. For example, these processes occur when reading an article, as sensory input about the text is acquired and preexisting linguistic knowledge is retrieved to interpret the text's meaning. This content is then transformed as different ideas are linked, resulting in the storage of information as memories and beliefs are formed.

Cognitions are a pervasive part of mental life, and many cognitive processes happen simultaneously. They are essential for understanding and interacting with the world by making individuals aware of their environment and helping them plan and execute appropriate responses. Thought is a characteristic form of cognition. It considers ideas, analyzes information, draws inferences, solves problems, and forms beliefs. However, cognition is not limited to abstract reasoning and encompasses diverse psychological processes, including perception, attention, memory, language, and decision-making. It is debated whether or under what conditions feelings, emotions, and other affects qualify as cognitions. Some controversial views associated with cognitivism argue that all mental phenomena are cognitions.

Cognitive activities can happen consciously, like when a person deliberately analyzes a problem step by step. They can also take place unconsciously, such as automatic mechanisms responsible for language processing and facial recognition. Many fields of inquiry study cognition, including psychology, cognitive science, neuroscience, and philosophy. While research focuses primarily on the human mind, cognition is not limited to humans and encompasses animal and artificial forms.

The term cognition originates from the Indo-European root gnō-, meaning 'to know'. This root is present in the Latin term gnōscere, also meaning 'to know', which led to the formation of the verb cognōscere, meaning 'to learn, to understand'. Through its perfect participle cognitus, the Latin verb entered Middle English as cognicioun. The earliest documented use occurred in 1447, eventually evolving into the modern English word cognition.

Types of cognitive processes

Cognitive processes encompass various types, each managing different information and performing distinct functions within the human mind. They are sometimes divided into basic processes, like perception and memory, and higher-order processes, like thinking. This distinction rests on the idea that higher-order processes could not occur without basic processes.

Perception and attention

Diagram of cognitive processes associated with perception and memory
Simplified model of cognitive processes associated with perception and memory

Perception is the organization and interpretation of sensory information about the world. It is a complex mental activity that involves the interplay of diverse cognitive processes, many of which occur automatically and unconsciously. It starts with physical stimuli, such as light or sound, which are detected by receptors and transmitted to the brain as electrical signals. These signals are processed in various brain regions to construct a coherent experience of distinct objects and events while situating them in a spatial-temporal framework.

Certain cognitive processes are responsible for detecting basic features in sensory data, such as edges, colors, and pitches, while others process spatial location. Object recognition is another function that compares this information with stored representations in search of known patterns, such as recognizing a familiar landmark or identifying a specific melody. Some cognitive faculties are specialized for tasks only relevant to particular perceptual contents, such as face recognition and language processing.

Cognitive processes responsible for perception rely on various heuristics to simplify problems and reduce cognitive labor. For example, visual perception often assumes that the size, shape, and color of objects remain constant to ensure a consistent view despite changes in perspective or lighting. Heuristics sometimes lead to inaccurate or illusory perceptions.

Different forms of perception are associated with distinct types of stimuli and receptors. Visual perception—the detection and interpretation of light—is a primary source of knowledge about the external environment for humans. Other forms of perception include hearing, touch, smell, and taste. Data from these different modalities are integrated by higher-order cognitive processes to form a unified and coherent experience of the world. Although sensory data is a central factor of perceptual experience, it is not the only factor, and various other forms of information influence the underlying cognitive operations. For instance, memories from earlier experiences determine which objects are experienced as familiar. Other factors include the expectations, goals, background knowledge, and belief system of the individual.

Attention is a central aspect of mental processes that focuses cognitive resources on certain stimuli or features. It involves the selection or prioritization of specific aspects while filtering out irrelevant information. For example, attention is responsible for the cocktail party effect, in which the brain isolates a single conversation while relegating surrounding noise to the background. The selection process is crucial since the total amount of information is typically too vast for the brain to process all at once. It ensures that the most important features are prioritized. Attention is not limited to perception but is also present in other cognitive processes, such as remembering and thinking.

Memory and learning

Memory is the ability to retain, store, and retrieve information. It includes the capacity to consciously recall past experiences and is central to many other cognitive activities that rely on stored data to process information and coordinate behavior. Memory processes have three stages: an input phase where new information is acquired, a storage phase preserving the information for future access, and an output phase retrieving the information and making it available to other cognitive operations. Different types of memory are distinguished by the function they perform and the type of information they operate on.

Working memory stores information temporarily, making it available to other cognitive processes while allowing manipulation of the stored information. During mental arithmetic, for example, the working memory holds and updates intermediate results while calculations are performed. The term is sometimes used interchangeably with the term short-term memory, which is defined by brief retention without the emphasis on dynamic manipulation. Long-term memory, by contrast, retains information for long periods, in some cases indefinitely. During storage, the information is not actively considered. However, it remains available for retrieval, like when recalling a childhood memory. Passive exposure to information is usually not sufficient for the effective formation and retrieval of long-term memories. Relevant factors include the level and type of engagement with the content: for example, the attention, emotion, mood, and context in which the information is processed.

Long-term memory is typically divided into episodic, semantic, and procedural memory based on the type of information involved. Episodic memory deals with information about past personal experiences and events. New memories are stored as a person undergoes experiences and can be accessed later, either by accessing factual information about the events or by mentally reliving them. For example, remembering one's last holiday trip involves episodic memory. Semantic memory deals with organized knowledge about the world not linked to specific experiences, such as general knowledge about facts and concepts. For instance, the information that water freezes at 0 °C is stored in semantic memory.

Procedural memory handles practical knowledge of how to do things. It encompasses learned skills that can be executed, like the ability to ride a bicycle or to type on a keyboard. As a form of know-how, procedural memory is distinct from the capacity to verbally describe the exact procedure involved in the execution, like explaining how to maintain balance on a bicycle. For this reason, procedural memory is categorized as non-declarative or implicit memory, which operates automatically and cannot be consciously accessed. Episodic and semantic memory, by contrast, belong to declarative or explicit memory, which encompasses information that can be consciously recalled and described.

The different forms of memory play a central role in learning, which involves the acquisition of novel information, skills, or habits, as well as refining existing knowledge and skills. Learning occurs through experience and enables individuals to adapt to their environment. It happens either intentionally, such as through studying or practicing, or unintentionally as an unconscious side effect of engaging in other tasks. A central aspect of effective learning is the formation of memory connections, which link different pieces of information and facilitate their retrieval.

Thinking

Thinking is a mental activity in which concepts, ideas, and mental representations are considered and manipulated. Many cognitive processes fall into this category, including reasoning, concept formation, problem solving, and decision-making.

Logical reasoning deals with information in the form of statements by inferring a conclusion from a set of premises. It proceeds in a rigorous and norm-governed manner to ensure that the conclusion is rationally convincing and supported by the premises. Logical reasoning encompasses deductive and non-deductive reasoning. Deductive reasoning follows strict rules of inference, providing the strongest support: the conclusion of a deductive inference cannot be false if all the premises are true. An example is the syllogism from the premises "all men are mortal" and "Socrates is a man" to the conclusion "Socrates is mortal". Non-deductive reasoning aims to make a conclusion rationally convincing but does not guarantee its truth. For instance, inductive reasoning infers a general law from many individual observations, like concluding that all ravens are black based on observations of numerous black ravens. Abductive reasoning, another type of non-deductive reasoning, seeks the best explanation of a phenomenon. For example, a doctor uses abductive reasoning when they infer that a child has chickenpox as an explanation of the child's skin rash and fever.

Diagram of several trees with arrows to one more tree
Through concept formation, the mind learns to identify common patterns among diverse instances.

Problem-solving is a goal-directed activity that aims to overcome obstacles and arrive at a pre-defined objective. This happens, for instance, when determining the best route for an upcoming trip. Problem-solving starts with comprehending the problem, which typically involves an understanding of the initial state, the goal state, and the obstacles or constraints that hinder progress. Some problems are well-structured and have precise solution paths. For ill-structured problems, by contrast, it is not possible to determine which exact steps will be successful. Divergent thinking is an approach to problem-solving that generates many possible solutions. It is usually combined with convergent thinking, which evaluates the different options and eliminates unfeasible ones. Thought often relies on heuristics or general rules to find and compare possible solutions. A common heuristic is to divide a problem into several simpler subproblems. Another heuristic is to adapt strategies that were successful for similar problems encountered earlier.

Closely related to problem-solving, decision-making is the cognitive process of choosing between courses of action. To determine the best alternative, it weighs the different options by assessing their advantages and disadvantages—for example, by considering their positive and negative consequences. According to expected utility theory, a decision is rational if it selects the option with the highest expected benefit, which is determined by the probability and the value of each consequence. To assess the probability of an outcome, people use various heuristics, such as the representativeness heuristic (judging by similarity to prototypes), the availability heuristic (privileging easily accessible information), and anchoring (relying on reference points).

Different forms of thinking rely on concepts, which are general ideas or mental representations to sort objects into classes, like the concepts animal and table. Concept formation is the process of acquiring a new concept by learning to identify its instances and grasping its relation to other concepts. This process helps individuals organize information and make sense of the world. Psychologists distinguish between logical and natural concepts. Logical concepts have precise definitions and rules of application, like the concept triangle. Natural concepts, by contrast, are based on resemblance but lack exact definitions or clear-cut boundaries, like the concept table.

Language

A language, such as English, Japanese, or American Sign Language, is a structured communication system based on symbols and rules to share information and coordinate action. Language plays a central role in everyday life and influences other cognitive processes, but there are disagreements about the extent of these influences. The Whorfian hypothesis and the thesis of linguistic relativity propose pervasive influences, arguing that language shapes thought patterns and that speakers of distinct languages think differently. Many cognitive processes are involved in the acquisition, comprehension, and production of linguistic expressions.

Language acquisition happens naturally in early childhood through exposure to a linguistic environment. It is a complex process since the system of spoken language is made up of several layers. At the fundamental level are basic sounds or sound units. They usually do not have linguistic meaning themselves but are combined into words, which refer to diverse things and ideas. Words are combined into sentences by following the rules of grammar. This system makes it possible to form and comprehend an infinite number of sentences based on knowledge of a finite number of words and rules. The exact meaning of sentences usually depends also on the context in which they are used. Although distinct languages can differ significantly in their general structure, there are some universal cognitive patterns that underlie all human languages.

Language comprehension is the process of understanding spoken, written, and signed language. It involves the coordination of various cognitive skills to recognize words, consult memory to access their meanings, analyze sentence structures, and use contextual information to interpret their implications. Additional difficulties come from lexical and structural ambiguities, in which a word or a sentence can be associated with multiple meanings. To resolve ambiguities, individuals rely on background knowledge about the overall topic and the speaker to discern the intended meaning. As a result, language comprehension depends not only on bottom-up processes, which start with sensory information, but also on top-down processes, which integrate general knowledge and expectations. For example, expectations cause longer processing times if a familiar word occurs in a context where the audience did not expect it.

While language comprehension seeks to uncover the meaning of pre-existing linguistic messages, language production involves the inverse process of generating linguistic expressions to convey thoughts. Before a statement can be precisely formulated, speakers construct a general idea of what they wish to express, and a rough sentence pattern of how to communicate it. Speakers then cognitively search for words that match the concepts they wish to convey. This activity, known as lexicalization, is divided into two stages: the identification of an abstract idea of the intended meaning, followed by the retrieval of the phonological form needed to pronounce the word. As speakers string together words to generate a sentence, they consider the grammatical category of each word, like the contrast between nouns and adjectives, to align with the intended overall sentence structure. Additionally, the context of the conversation and the assumed background knowledge of the audience influence the selection of words and sentence structures.

Others

Cognitive processes can be conscious or unconscious. Conscious processes, such as attentively solving a math problem step by step or recalling a vivid memory, involve active awareness. Unconscious processes, such as the low-level processes underlying face recognition and language processing, operate automatically without the individual's awareness. Phenomenal consciousness involves a qualitative experience of mental phenomena, whereas access consciousness is an awareness of information that is available for use but not actively experienced at the moment. Various theories of the cognitive function of consciousness have been proposed. One asserts that consciousness integrates diverse forms of data and makes information widely available to different subsystems. Other theories argue that consciousness improves social interaction by fostering self-awareness in social contexts or that consciousness allows for increased flexibility and control, particularly in novel situations.

A related distinction is between controlled and automatic processes. Controlled processes are actively guided by the individual's intentions, like when a person deliberately shifts attention from one object of perception to another. These processes are flexible and adaptable to new situations but require more cognitive resources. Automatic processes, by contrast, happen unconsciously, are effortless, and require fewer cognitive resources. By becoming familiar with a task, a process that was initially controlled can become automatic, freeing up resources for other activities. For example, as a novice driver becomes experienced, they can automatically handle the car and adapt to road and traffic conditions while gaining the ability to engage in a conversation at the same time.

Diagram of a brain thinking about a brain
Metacognitive processes deal with information about other cognitive processes.

Consciousness is closely related to metacognition, which encompasses any knowledge or cognitive process that deals with information about cognition. Some forms of metacognition only manage or store information about other aspects of cognition, like knowing that one can recall a specific memory. Others play an active role in monitoring and regulating ongoing processes, like changing a problem-solving strategy upon realizing that the previous one was ineffective. Metacognitive skills tend to improve the performance of other cognitive skills, particularly when dealing with complex tasks.

Social cognitions are mental activities through which individuals make sense of social phenomena. They include diverse types, such as the recognition of faces and facial expressions, the interpretation of intentions and behavior, and the evaluation of social cues and dynamics. A central topic in this field is theory of mind—the ability to understand others as mental beings with emotions, desires, and beliefs different from one's own. This ability allows individuals to think about and respond to the mental states of others. Moral cognitions are a type of social cognition that make individuals aware of the moral significance of situations. They occur when people recognize and appreciate altruistic behavior or disapprove of malicious and harmful actions. Cognitive psychologists also study the relation between cognition and emotion, for example, how emotions influence mental operations like attention and decision-making.

Cognitive processes do not always function as they should, and can lead to inaccuracies, either because of natural errors associated with cognitive biases or as a result of pathological impairments from cognitive disorders. Cognitive biases are systematic ways in which human thinking deviates from ideal norms of rationality. They are common patterns that affect most people, leading to misinterpretations of reality and suboptimal decisions. Cognitive biases are often caused by heuristics or mental shortcuts, which the brain uses to increase speed and reduce cognitive load. For instance, people typically rely on information that easily comes to mind when assessing a situation while disregarding more relevant information that is harder to retrieve.

Cognitive disorders involve a more pronounced deviation from typical mental functioning. High-level cognitive abilities usually require the interaction of many low-level processes. Impairments affecting a specific subprocess often result in a partial malfunction of the high-level process while leaving its other functions intact. For example, prosopagnosia is a perceptual disorder in which individuals struggle to recognize faces, although their other visual abilities remain unaffected. Similarly, anterograde amnesia is an impaired ability to form and recall new memories but leaves long-term memory intact. Disorders can affect a wide range of mental functions, including thought and language. Some disorders involve a general cognitive decline that is not limited to one specific function. For instance, Alzheimer's disease is associated with a widespread, gradual impairment of memory, reasoning, and language.

Theories

Various theories of the nature of cognition have been proposed. They provide conceptualizations and models to represent cognitive processes, explain empirical data, and predict experimental outcomes. Some theories propose interpretations of the overall cognitive architecture of the mind, seeking to explain cognition as a whole. Others suggest more limited models intended only for specific mental activities, such as theories of visual attention.

Classical computationalism

Computationalism asserts that cognition is a type of computation, highlighting the similarities between minds and computers. In its classical form, it argues that the brain represents information through strings of symbols. It treats thought as symbol manipulation: cognitions operate on strings to create new strings. A key feature of this model is that cognitive processes follow mechanical rules that depend on the syntactic structure of symbol strings without considering what the symbols represent. In this regard, individual processes work similarly to an electronic calculator that transforms the string "3 + 7" into the result "10" according to the mechanical rules of arithmetic without grasping the meaning of these numerals. Theories extend this symbol-based approach with more sophisticated devices of knowledge representation, such as semantic nets, schemata, and frames, to explain how the mind handles complex data involving many entities and relations.

According to classical computationalism, any cognitive activity is at its fundamental level a formal symbol manipulation, including perception, reasoning, planning, and language processing. Researchers using this perspective analyze and distinguish cognitive processes by examining the types of representations involved and the mechanical rules followed. The tri-level hypothesis divides this study into three levels of abstraction. The highest level analyzes the goal or purpose of a process, identifying the information it receives, the problem it aims to solve, and the result it produces. The intermediary level decomposes the process into individual steps, analyzing how the computation is performed or which algorithm is used. The most concrete level explores how the algorithm is implemented on a material level through neurological systems.

Classical computationalism is closely related to the information-processing approach, which assumes that most cognitive activities are complex processes arising from the interaction of several subprocesses. Each process is characterized by the function it performs, which is connected to the input information it obtains, how it transforms this information, and the output it generates. Interaction happens when the output of one subprocess acts as the input for another. This approach is associated with serial models in which complex computations are divided into sequences of calculations where intermediary results are computed and transmitted until a final output is produced. It typically divides the mind into a small number of high-level systems responsible for different tasks, such as perception, memory, and reasoning. Information-processing models often rely on a hierarchical cognitive architecture where a central system integrates information from other units and formulates overall goals.

The language of thought hypothesis is a version of classical computationalism arguing that thought happens through the medium of an internal linguistic system, termed mentalese, similar to natural languages such as English. According to this view, internal symbols and their combination into strings are like words and sentences composed according to the rules of grammar. The language of thought hypothesis suggests that mental states like beliefs and desires are realized as mentalese sentences and that cognitive operations manipulate these sentences according to specific rules to transform or extract information.

Some symbol-based approaches use formal logic as a model of cognition. According to this view, internal representations have the form of statements, similar to declarative sentences. Computational processes are conceptualized as rules of inference, which take one or more sentences as input and produce a new sentence as output. For example, modus ponens is a rule of inference that, when applied to the premises "if it rains, then the ground is wet" and "it rains", yields the conclusion "the ground is wet".

A similar approach interprets cognition as the application of if–then rules to generate new representations. According to this outlook, a cognitive system is made up of many rules, each defined by one or more conditions together with an output procedure. If information stored in the working memory satisfies all the conditions of a rule then its output procedure is triggered and transfers a new representation to the working memory. This change may, in turn, prompt the execution of another rule, leading to a dynamic sequence of operations that can solve complex computational tasks. The cognitive architecture Soar is an example of this approach.

Connectionism

Diagram of a neural network consisting of several layers
Connectionism analyzes cognition through complex neural networks consisting of several layers of nodes.

Connectionism is another form of computationalism that differs from classical computationalism in various ways. It agrees that cognitions are computations but proposes a different cognitive architecture based on a complex network of nodes. The nodes are locally linked to each other, and the activity of each node depends on the inputs it receives from connected nodes. The nodes are organized into layers, with information flowing in one direction from input to output layers. The initial input layer of nodes receives information, such as sensory data, and passes it on to intermediary layers, where the main computation takes place. At the end of the process is an output layer, which transmits the result to other systems. The behavior of each individual node is usually relatively simple: it receives the input values from the nodes of the previous layer, uses this information to compute its own activation level, and transmits this value to nodes in the subsequent layer. Complex computations emerge as numerous nodes operate in parallel and interact across layers.

Connectionists typically reject the serial and hierarchical models common in classical computationalism. Instead, they argue that cognition happens in parallel as countless neurons work simultaneously without a central control system guiding the process. Another difference is that connnectionism focuses on non-symbolic processes: the activations of individual nodes perform computations without the use of symbols. Accordingly, connectionism and classical computationalism are often characterized as competing paradigms that propose incompatible cognitive architectures. However, they do not necessarily exclude each other. For example, implementation connectionism argues that non-symbolic processes can implement symbolic processes. This view holds that the cognitive system functions as a neural network at the fundamental level and as a symbol-processor at a higher level of abstraction. Radical connectionism, by contrast, asserts that symbol-based approaches are fundamentally flawed and misconstrue the nature of cognition.

To reduce complexity, cognitive scientists often rely on idealized models that focus on activation levels and connections between nodes. These models typically ignore the underlying neurophysiological mechanisms in the brain. In this regard, there are various parallels between connectionist models of the mind and the neural networks employed in the field of artificial intelligence, for example, concerning the application of node networks to solve specific cognitive tasks and the problem of learning algorithms. Computational neuroscience, by contrast, directly integrates neurological data about the electrochemical activity of neurons into theories, which usually results in more complex models.

Representationalism and anti-representationalism

Both classical computationalism and some forms of connectionism accept representationalism, which holds that information is stored in representations that depict the state of the world. Representations can take various forms, such as symbols, images, and concepts, as well as non-symbolic patterns used to model higher-level structures. Representationalists examine how cognitive systems encode, manipulate, and decode representations to construct internal models of the environment and predict changes.

Anti-representationalists reject the idea that cognition is about representing the world through internal models. They assert that intelligence arises from the interaction between an organism and its environment rather than from internal processes alone. For example, some approaches in behaviorism and situated robotics suggest a more immediate link between perception and action: environmental stimuli are directly processed and translated into behavior following stimulus–response patterns without constructing detailed internal representations. This outlook suggests that intelligent behavior emerges if an entity has stimulus–response patterns that match the external situation, even if the cognitive system responsible for these patterns has no representations of what the environment is like.

Anti-representationalism is closely related to 4E cognition, a family of views critical of prioritizing internal representations. 4E cognition examines the relation between mind, body, and environment through four approaches: embodied, embedded, extended, and enactive cognition. Embodied cognition is the idea that cognitive processes are grounded in bodily experience and cannot be understood in isolation from the organism's sensorimotor capacities. Embedded cognition asserts that cognitive effort and efficiency depend on physical and social environments. Extended cognition claims that the environment not only influences cognition but forms part of it, meaning that cognitive processes extend beyond internal neural activity to include external events. Enactive cognition asserts that cognition arises from the interaction between organism and environment.

Other theories

The modularity of mind is an approach that analyzes the cognitive system in terms of independent mental modules. Each module is an inborn mechanism that deals only with a specific type of information while being mostly unaware of the activities of other modules. Mental modules are primarily used to explain low-level cognitive activities, such as edge detection in visual perception. The massive modularity hypothesis, by contrast, asserts that the mind is entirely composed of modules. According to this view, mental modules are also responsible for high-level cognitive processes by linking and integrating the outputs of low-level cognitive processes.

Bayesianism uses probability theory to model cognitive activities such as learning, vision, and motor control. Its central idea is that representations of the environment have degrees of uncertainty. It uses probability theory to deal with this uncertainty and handle incoming information. Bayesianism is sometimes combined with predictive models. According to these, the brain predicts outcomes, checks them against reality, and updates its internal model accordingly.

Dual process theory relies on the distinction between automatic and controlled processes to analyze cognitive phenomena. It conceptualizes them as two systems and proposes different models of their interaction. According to the default-interventionist model, the automatic system generates intuitive judgments while the controlled system monitors them and intervenes if it detects problems. The parallel-competitive model, by contrast, suggests that each system generates its own type of knowledge and that the outputs of the different systems compete with each other.

Various theories of cognition are discussed in ancient Indian philosophy, often inspired by Vedic scriptures that were composed roughly between 1500–600 BCE. Many propose that the mind is divided into different faculties that deal with specific cognitive processes. For example, manas is often understood as the sensory mind responsible for receiving and interpreting information from the external senses, while buddhi is typically described as the intellect engaged in judgment, reasoning, and decision-making. Related debates address the sources of knowledge, called pramana, such as perception, inference, and testimonyAncient Chinese thought emphasized the connection between cognition and behavior. These ideas originated prior to the Qin period (i.e., before 221 BCE) and anticipated later theories of enactive cognition.

Development

Photo of a man with white hair and glasses, wearing a suit
Jean Piaget divided the cognitive development of children into four stages.

Cognitive development is the progressive growth of mental abilities from infancy through adulthood as individuals acquire and improve cognitive skills and learn from experience. Some changes occur continuously as gradual improvements over extended periods. Others involve discontinuous transitions in the form of abrupt reorganizations resulting in qualitative changes. They are typically conceptualized as stages through which the individual passes.

Various theories of the general mechanisms and stages of cognitive development have been proposed. Jean Piaget (1896–1980) divided the process into four stages, each marked by an increasing capacity for abstraction and systematic understanding. In the initial sensory-motor stage, from birth to about two years, children explore sensory impressions and motor capacities, learning that things continue to exist when not observed. During the pre-operational stage, up to about age seven, children begin to understand and use symbols intuitively. In the following stages of concrete and formal operation, children first apply logical reasoning to concrete physical objects and then, from around age twelve, also to abstract ideas.

In contrast to Piaget's approach, Lev Vygotsky (1896–1934) argued that social interaction is the primary driver of cognitive development without clearly demarcated stages. This theory holds that children learn new skills by engaging in tasks under the guidance of knowledgeable others. It emphasizes the role of language acquisition, suggesting that children internalize language and use it in private speech as a tool for planning, self-regulation, and problem solving. Other approaches examine the role of different types of representation in cognitive development. For example, Annette Karmiloff-Smith (1938–2016) proposed that cognitive development involves a shift from implicit to explicit representations, making knowledge more complex and easier to access. A further theory, proposed by Robert S. Siegler (born 1949), asserts that children use multiple cognitive strategies to solve problems and become more adept at selecting effective strategies as they develop.

Some influences on cognitive development occur before birth, due to factors like nutrition, maternal stress, and harmful substances like alcohol during pregnancy. Developments are most rapid during childhood and affect all major cognitive faculties, including perception, memory, thinking, and language. Cognitive changes also happen during adulthood but are less pronounced. In old age, overall cognition declines, affecting reasoning, comprehension, novel problem solving, and memory.

The nature versus nurture debate addresses the causes of cognitive development, contrasting the influences of inborn dispositions with the effects of environment and experience. Empiricists identify environment and experience as the main factors. This view is inspired by John Locke's idea that the mind of an infant is a blank slate that initially knows nothing of the world. According to this outlook, children learn through sense data by associating and generalizing impressions. Nativists, by contrast, argue that the mind has innate knowledge of abstract patterns. They suggest that this inborn framework organizes sensory information and guides learning. Contemporary approaches integrate ideas from both perspectives, moving beyond a polarizing opposition between empiricism and nativism.

Non-human

Animal

Photo of a bonobo using a stick to fish for termites
The ability to employ tools is an example of animal cognition, such as a bonobo fishing for termites with a stick.

Animal cognition encompasses the mechanisms by which animals acquire, process, and use information to guide flexible, goal-directed behavior. Animals use cognitive abilities for many daily tasks, for example, to find and recognize food, navigate territory, seek shelter, hunt prey, avoid predators, interact socially, communicate, learn new habits, and form long-term memories. Researchers examine cognition across diverse species, including mammals, birds, fish, and insects. The cognitive abilities of different species are usually tied to the specific ecological and social challenges they encounter in life. More general abilities are primarily found in animals with larger brains and incur higher energetic costs, posing a trade-off between energy investment and behavioral flexibility.

Researchers examine various areas of animal cognition. To study the ability to form abstract concepts, they examine whether an animal can grasp a category through generalization and apply it to cases not encountered before. For instance, chimpanzees can learn concepts of different numbers. As a result, they acquire various number-related abilities, like identifying collections containing a specific number of items. Another often-studied capacity is the ability to form and remember a spatial map of the environment. This enables animals, such as jays, to navigate efficiently and choose the shortest route to a shelter or a feeding site. Research also addresses imitation, in which an animal copies the behavior of another animal. This facilitates the spread of useful skills, including tool use. Beyond animal cognition, some researchers also examine plant cognition as a form of information processing resulting in adaptive, flexible, or goal-directed responses to the environment. For example, maple trees use plant communication: they release airborne chemicals to warn nearby trees of a herbivore attack, helping them prepare defensive responses. The extent of the cognitive capacities of plants is disputed and researchers are typically skeptical about the presence of higher functions like consciousness.

Comparative cognition is the study of the similarities and differences in cognitive abilities across species. It is an interdisciplinary field of inquiry that also considers evolutionary factors. For example, researchers investigate which cognitive traits are required to solve particular socioecological problems and how these traits evolved in different species. A key topic in this field is the problem of anthropomorphism or the tendency to ascribe human cognitive qualities to animals. For instance, researchers have to decide whether social behavior in chimpanzees indicates the human-like ability to understand the mental states of other individuals or can be explained through simpler mechanisms. These challenges relate closely to anthropocentrism—the tendency to regard human cognition as exceptional and superior to that of other animals.

Artificial

Artificial cognition uses computational systems to emulate and model cognitive processes, like perception and reasoning, with central applications in artificial intelligence and robotics. Artificial and human cognition have different strengths and weaknesses. For example, artificial cognition excels at rapidly processing vast datasets according to predefined algorithms. Human cognition, by contrast, is typically better suited to assess emotional significance and to find and evaluate solutions that require novel and creative thinking. These differences affect how the two forms of cognition are integrated with each other. For some applications, artificial cognition is used to assist human cognition. In aviation, for example, automated systems monitor flight parameters and analyze environmental conditions, including turbulence prediction, allowing human pilots to focus on decision-making rather than data analysis. However, there are also cases where artificial cognition replaces human cognition, such as autonomous vehicle navigation.

The field of artificial cognitive systems explores the possibility of autonomous machines with human-like cognition. This encompasses not only artificial intelligence at the level of individual tasks, such as object detection or language translation, but also the integration of diverse cognitive processes. The aim is an embodied system that can autonomously interact with its environment in real time. An artificial cognitive system can navigate its surroundings, set goals, devise means to achieve them, anticipate outcomes, adapt to circumstances, execute action plans, and learn from experience.[97] Artificial general intelligence, a closely related concept, refers to hypothetical systems that possess or surpass the full range of human mental abilities. It is controversial whether such a system can be fully realized since it would include not only computational capacities associated with logical reasoning but also emotion and phenomenal consciousness.

In various fields

Many fields of inquiry study cognition, including psychology, neuroscience, and cognitive science. They examine different aspects of cognition, ranging from high-level computational processes to low-level neural mechanisms, and employ distinct methods to reach their conclusions. There is substantial overlap among these disciplines, and researchers from one field often rely on conceptual models or empirical findings from another.

Psychology

Cognitive psychology examines mental activities responsible for cognitive phenomena and intelligent behavior. It uses the scientific method to study cognitive processes like perception, memory, reasoning, and language. Although mental activities mediate between stimuli and responses, they are not directly observable, which poses a methodological challenge for researchers. It typically forces them to rely on indirect methods for empirical validation, usually in the form of models or theories that have testable predictions. For example, if a theory predicts a specific behavior in a particular situation, then empirical observations can determine if outcomes align with those predictions.

Cognitive psychologists use diverse methods to gather data for empirical validation. Experimental methods create controlled situations in which certain factors, called independent variables, can be changed. The main interest is in how these factors influence individuals in the situation. By measuring the effects, called dependent variables, researchers aim to identify causal relations between independent and dependent variables. Correlational methods, by contrast, measure the degree of association between two variables without proving that one causes the other. Cognitive psychologists also integrate methods from other disciplines, including neuroimaging techniques and computational simulations. Early cognitive psychologists, such as Wilhelm Wundt, made extensive use of introspection, in which researchers examine and reflect on their own experiences to understand mental processes. The choice of method depends on the studied cognitive process and can differ markedly between areas like perception and memory.

Neuroscience

fMRI image showing the brain from a top view with active areas colored in orange
fMRI is a neuroimaging technique that can measure regional brain activity corresponding to specific cognitive tasks.

Cognitive neuroscience investigates how the nervous system gives rise to cognition. It is particularly interested in the brain, covering both micro-scale studies of individual neurons and synapses as well as the macro-scale analyses of interactions between brain regions. For example, cognitive neuroscientists study the brain areas responsible for processes like memory and decision-making, exploring how they represent and transform information and communicate with each other on a biological level. They also examine how these processes are influenced by neurotransmitterssignalling molecules that affect information exchange between neurons.

Cognitive neuroscientists employ neuroimaging techniques to study brain activity, including electroencephalography (EEG), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI). These techniques visualize neural processes by measuring phenomena such as electrical or magnetic changes and blood flow across different brain areas, indicating local activity levels. Researchers compare the activation patterns associated with specific mental tasks to learn how regional brain activity correlates with cognitive demands. Another method examines patients with brain damage to infer the role of a brain area by observing how cognition changes when the area is impaired.

A different approach, common in computational or theoretical neuroscience, is to design computational or mathematical models of cognitive systems. This approach explores possible explanations of observed mental phenomena and neural activities by modeling and simulating underlying brain mechanisms.

Cognitive science

Cognitive science is an interdisciplinary field informed by psychology, neuroscience, philosophy, linguistics, and artificial intelligence. It seeks to integrate the insights of these disciplines and provide a unified perspective. To this end, it adopts a common conceptualization of minds as information processors, understanding cognition as the manipulation of internal representations.

To bridge disciplinary and methodological divides between the different fields, it identifies distinct levels of analysis corresponding to different degrees of abstraction. For example, neuroscientific analysis of the electrochemical activity of brain areas belongs to a concrete level that deals with the biological mechanisms performing computations. By contrast, the psychological study of the roles of and interactions between high-level processes, such as perception, memory, and reasoning, adopts an abstract perspective. Cognitive scientists seek to connect experimental findings with explanations and models to produce testable theories that link the different levels.

Other fields

Many fields of inquiry have subareas dedicated to cognitive phenomena. For example, cognitive linguistics is a subarea of linguistics that investigates the relation between language and cognition. It studies the cognitive processes responsible for grammar, conceptualization, language comprehension, and language production. Similarly, cognitive anthropology examines the connection between culture and cognition, conceptualizing culture as a system of knowledge, beliefs, and values. It analyzes and compares cultural systems from this perspective to identify distinctive features of particular societies and the universal patterns shared by all. Cognitive sociology, a related field, explores how sociocultural factors shape cognitive activity. Other fields include cognitive archaeology and cognitive biology.

Various branches of philosophy address cognition, including philosophy of mind and epistemology. Philosophers of mind examine the nature of cognition and related concepts, such as mind, representation, and consciousness. They are particularly interested in the relation between the mind and the body and the problem of how physical states can give rise to conscious experience. Epistemologists seek to understand the nature and limits of knowledge. They further ask under what conditions cognitive processes, like perception and reasoning, lead to knowledge. Philosophers also reflect on the fields of inquiry studying cognition. They explore how psychologists, neuroscientists, and cognitive scientists conduct research and ask about the fundamental concepts and background assumptions underlying these fields.

Education studies examines the nature, purposes, practices, and outcomes of education. It investigates the cognitive development of children and studies how knowledge is transmitted, acquired, and organized. This discipline overlaps with cognitive psychology and cognitive science because of its interest in learning, covering diverse cognitive processes and skills, such as conceptual change, metacognition, mental models, logical reasoning, and problem solving. Cognitive learning theories conceptualize learning in terms of information processing. They analyze how information is encoded, retrieved, and transformed, often with the goal of devising educational practices that optimize learning. For example, cognitive load theory identifies limitations of working memory as a bottleneck that impedes learning and proposes educational practices to avoid cognitive overload.

Psychometrics examines how mental attributes can be measured. It includes the discussion of cognitive tests, which are methods designed to assess cognitive abilities. IQ tests estimate overall cognitive performance by measuring how individuals perform on tasks involving logical reasoning, verbal comprehension, spatial thinking, and working memory. The Montreal Cognitive Assessment and the mini–mental state examination are tests to detect cognitive impairment, such as deficits in memory, attention, and language.

Cognitive enhancement encompasses diverse ways to improve mental performance, including biochemical, behavioral, and physical factors. Biochemical approaches include balanced nutrition and psychoactive substances like caffeine and amphetamine. Behavioral enhancements cover physical exercise, sufficient sleep, meditation, and cognitive strategies, such as mnemonics. Physical enhancements encompass invasive and non-invasive brain stimulation as well as neurofeedback and wearable devices.

Cognitive behavior therapy is a psychotherapy that analyzes psychological problems in terms of cognitive processes. It argues that maladaptive automatic thoughts, cognitive distortions, and unhealthy core beliefs lead to inaccurate interpretations of events, emotional distress, and problematic behavior. For example, if a person has an unconscious core belief that they are fundamentally inadequate, they may misinterpret a neutral interaction as a rejection. Cognitive behavior therapists seek to restructure problematic attitudes by helping clients modify dysfunctional thought patterns and maladaptive behavior.

Many topics in computer science are relevant to cognition, particularly for approaches that understand cognition in terms of computation and information processing. Theories of computation examine the nature of computation and explore which problems can be solved computationally. Computer architecture has parallels with cognitive architecture, providing models of how different components interact to form a functional system. Another overlap concerns the field of knowledge representation, in which computer scientists explore formal data structures that make knowledge accessible to computational processes. Artificial intelligence is the capacity of certain computer systems to perform tasks requiring intelligence, such as reasoning and problem-solving. It includes the field of machine learning, through which computer systems acquire new abilities not explicitly coded by programmers. The field of cognitive robotics integrates insights from these subfields to create intelligent robots.

History

Oil painting of a man with gray hair wearing a brown attire
John Locke argued that humans have no inborn knowledge and need to learn everything from experience.

Cognitive research has its roots in ancient philosophy. Early work took the form of reflections on the nature and sources of knowledge, proposed divisions of the mind into separate faculties, and analyzed specific cognitive processes, like perception and deductive reasoning. Plato (c. 428–347 BCE) examined how knowledge of abstract principles is possible. His student Aristotle (384–322 BCE) explored the nature of perception, studying how the mind integrates sensory data with memory and imagination. He also devised a formal logical system to describe logical reasoning. Inspired by Aristotle, Avicenna (980–1037 CE) and Thomas Aquinas (1225–1274 CE) developed faculty psychologies that organized the mind into distinct faculties and analyzed their functions and interactions. In early modern philosophy, rationalists like René Descartes (1596–1650) and Gottfried Wilhelm Leibniz (1646–1716) argued that the mind has innate knowledge of the world. This view was opposed by empiricists, like John Locke (1632–1704), who saw the mind as a blank slate that learns everything from experience. Immanuel Kant (1724–1804) introduced the idea of innate categories that organize all experience and understanding.

Experimental research into cognitive processes began in the late 19th century with Wilhelm Wundt (1832–1920) and his student Edward Bradford Titchener (1867–1927). They laid the foundations of scientific psychology by introducing controlled laboratory experiments, such as measuring responses and reaction times to stimuli, combined with a rigorous introspective method. Hermann Ebbinghaus (1850–1909) and Mary Whiton Calkins (1863–1930) pioneered experimental studies of memory. William James (1842–1910) approached psychological research from a pragmatist perspective, studying everyday experience. In the early 20th century, Max Wertheimer (1880–1943), Kurt Koffka (1886–1941), and Wolfgang Köhler (1887–1967) formulated Gestalt psychology. In contrast to earlier experimental approaches that analyzed individual elements, they focused on larger patterns that emerge as the mind actively organizes information into coherent wholes.[134] Frederic Bartlett (1886–1969) was also interested in how the mind actively transforms information, examining how this process introduces systematic errors into memory.

Difficulties in measuring internal cognitive events led to the rise of behaviorism, which sought to explain observable conduct through stimulus–response patterns without reference to unobservable mental states. Initially developed by John B. Watson (1878–1958), it dominated psychological research in the first half of the 20th century. Challenges in explaining complex human behavior prompted a paradigm shift in the 1950s—the cognitive revolution. Instead of studying stimulus–response patterns, researchers examined how the mind receives, stores, and transforms information, placing cognition at the center of psychological research and resulting in the emergence of cognitive subfields across disciplines.

Jean Piaget (1896–1980) applied these ideas to developmental psychology and proposed a series of cognitive stages through which children pass as they gradually acquire the capacity for abstract thinking. Donald Broadbent (1926–1993) integrated ideas from the information theory of communication, developed by Claude Shannon (1916–2001) and Warren Weaver (1894–1978), to analyze how perception transmits and filters information. Allen Newell (1927–1992) and Herbert A. Simon (1916–2001) helped establish the field of artificial intelligence while demonstrating how computers can model and simulate human problem-solving. In linguistics, Noam Chomsky (b. 1928) examined how the brain processes language, identifying universal patterns of language mechanisms.

These developments across several fields of inquiry led to the formation of cognitive science in the 1970s. David Marr (1945–1980) helped unify this interdisciplinary field with the tri-level hypothesis, proposing that the distinct disciplines work on different levels of abstraction but are fundamentally concerned with the same phenomena. The advent of neuroimaging techniques such as fMRI and PET revolutionized the neuroscientific study of cognition, enabling the examination of regional, task-specific brain activity. Concurrently, advances in computational power and artificial intelligence made possible the design of increasingly complex simulations of cognition and intelligent systems that rival and surpass human cognition in specific tasks.

Openness to experience

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