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Saturday, April 3, 2021

Metacognition

From Wikipedia, the free encyclopedia

Metacognition is "cognition about cognition", "thinking about thinking", "knowing about knowing", becoming "aware of one's awareness" and higher-order thinking skills. The term comes from the root word meta, meaning "beyond", or "on top of". Metacognition can take many forms; it includes knowledge about when and how to use particular strategies for learning or problem-solving. There are generally two components of metacognition: (1) knowledge about cognition and (2) regulation of cognition.

Metamemory, defined as knowing about memory and mnemonic strategies, is an especially important form of metacognition. Academic research on metacognitive processing across cultures is in the early stages, but there are indications that further work may provide better outcomes in cross-cultural learning between teachers and students.

Writings on metacognition date back at least as far as two works by the Greek philosopher Aristotle (384–322 BC): On the Soul and the Parva Naturalia.

Definitions

This higher-level cognition was given the label metacognition by American developmental psychologist John H. Flavell (1976).

The term metacognition literally means 'above cognition', and is used to indicate cognition about cognition, or more informally, thinking about thinking. Flavell defined metacognition as knowledge about cognition and control of cognition. For example, a person is engaging in metacognition if they notice that they are having more trouble learning A than B, or if it strikes them that they should double-check C before accepting it as fact. J. H. Flavell (1976, p. 232). Andreas Demetriou's theory (one of the neo-Piagetian theories of cognitive development) used the term hyper-cognition to refer to self-monitoring, self-representation, and self-regulation processes, which are regarded as integral components of the human mind. Moreover, with his colleagues, he showed that these processes participate in general intelligence, together with processing efficiency and reasoning, which have traditionally been considered to compose fluid intelligence.

Metacognition also involves thinking about one's own thinking process such as study skills, memory capabilities, and the ability to monitor learning. This concept needs to be explicitly taught along with content instruction.

Metacognitive knowledge is about one's own cognitive processes and the understanding of how to regulate those processes to maximize learning.

Some types of metacognitive knowledge would include:

  • Content knowledge (declarative knowledge) which is understanding one's own capabilities, such as a student evaluating their own knowledge of a subject in a class. It is notable that not all metacognition is accurate. Studies have shown that students often mistake lack of effort with understanding in evaluating themselves and their overall knowledge of a concept. Also, greater confidence in having performed well is associated with less accurate metacognitive judgment of the performance.
  • Task knowledge (procedural knowledge), which is how one perceives the difficulty of a task which is the content, length, and the type of assignment. The study mentioned in Content knowledge also deals with a person's ability to evaluate the difficulty of a task related to their overall performance on the task. Again, the accuracy of this knowledge was skewed as students who thought their way was better/easier also seemed to perform worse on evaluations, while students who were rigorously and continually evaluated reported to not be as confident but still did better on initial evaluations.
  • Strategic knowledge (conditional knowledge) which is one's own capability for using strategies to learn information. Young children are not particularly good at this; it is not until students are in upper elementary school that they begin to develop an understanding of effective strategies.

Metacognition is a general term encompassing the study of memory-monitoring and self-regulation, meta-reasoning, consciousness/awareness and autonoetic consciousness/self-awareness. In practice these capacities are used to regulate one's own cognition, to maximize one's potential to think, learn and to the evaluation of proper ethical/moral rules. It can also lead to a reduction in response time for a given situation as a result of heightened awareness, and potentially reduce the time to complete problems or tasks.

In the domain of experimental psychology, an influential distinction in metacognition (proposed by T. O. Nelson & L. Narens) is between Monitoring—making judgments about the strength of one's memories—and Control—using those judgments to guide behavior (in particular, to guide study choices). Dunlosky, Serra, and Baker (2007) covered this distinction in a review of metamemory research that focused on how findings from this domain can be applied to other areas of applied research.

In the domain of cognitive neuroscience, metacognitive monitoring and control has been viewed as a function of the prefrontal cortex, which receives (monitors) sensory signals from other cortical regions and implements control using feedback loops (see chapters by Schwartz & Bacon and Shimamura, in Dunlosky & Bjork, 2008).

Metacognition is studied in the domain of artificial intelligence and modelling. Therefore, it is the domain of interest of emergent systemics.

Components

Metacognition is classified into three components:

  1. Metacognitive knowledge (also called metacognitive awareness) is what individuals know about themselves and others as cognitive processors.
  2. Metacognitive regulation is the regulation of cognition and learning experiences through a set of activities that help people control their learning.
  3. Metacognitive experiences are those experiences that have something to do with the current, on-going cognitive endeavor.

Metacognition refers to a level of thinking that involves active control over the process of thinking that is used in learning situations. Planning the way to approach a learning task, monitoring comprehension, and evaluating the progress towards the completion of a task: these are skills that are metacognitive in their nature.

Metacognition includes at least three different types of metacognitive awareness when considering metacognitive knowledge:

  1. Declarative knowledge: refers to knowledge about oneself as a learner and about what factors can influence one's performance. Declarative knowledge can also be referred to as "world knowledge".
  2. Procedural knowledge: refers to knowledge about doing things. This type of knowledge is displayed as heuristics and strategies. A high degree of procedural knowledge can allow individuals to perform tasks more automatically. This is achieved through a large variety of strategies that can be accessed more efficiently.
  3. Conditional knowledge: refers to knowing when and why to use declarative and procedural knowledge. It allows students to allocate their resources when using strategies. This in turn allows the strategies to become more effective.

Similar to metacognitive knowledge, metacognitive regulation or "regulation of cognition" contains three skills that are essential.

  1. Planning: refers to the appropriate selection of strategies and the correct allocation of resources that affect task performance.
  2. Monitoring: refers to one's awareness of comprehension and task performance
  3. Evaluating: refers to appraising the final product of a task and the efficiency at which the task was performed. This can include re-evaluating strategies that were used.

Similarly, maintaining motivation to see a task to completion is also a metacognitive skill. The ability to become aware of distracting stimuli – both internal and external – and sustain effort over time also involves metacognitive or executive functions. The theory that metacognition has a critical role to play in successful learning means it is important that it be demonstrated by both students and teachers.

Students who underwent metacognitive training including pretesting, self evaluation, and creating study plans performed better on exams. They are self-regulated learners who utilize the "right tool for the job" and modify learning strategies and skills based on their awareness of effectiveness. Individuals with a high level of metacognitive knowledge and skill identify blocks to learning as early as possible and change "tools" or strategies to ensure goal attainment. Swanson (1990) found that metacognitive knowledge can compensate for IQ and lack of prior knowledge when comparing fifth and sixth grade students' problem solving. Students with a high-metacognition were reported to have used fewer strategies, but solved problems more effectively than low-metacognition students, regardless of IQ or prior knowledge. In one study examining students who send text messages during college lectures, it was suggested that students with higher metacognitive abilities were less likely than other students to have their learning affected by using a mobile phone in class.

The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.

Metacognologists are aware of their own strengths and weaknesses, the nature of the task at hand, and available "tools" or skills. A broader repertoire of "tools" also assists in goal attainment. When "tools" are general, generic, and context independent, they are more likely to be useful in different types of learning situations.

Another distinction in metacognition is executive management and strategic knowledge. Executive management processes involve planning, monitoring, evaluating and revising one's own thinking processes and products. Strategic knowledge involves knowing what (factual or declarative knowledge), knowing when and why (conditional or contextual knowledge) and knowing how (procedural or methodological knowledge). Both executive management and strategic knowledge metacognition are needed to self-regulate one's own thinking and learning.

Finally, there is no distinction between domain-general and domain-specific metacognitive skills. This means that metacognitive skills are domain-general in nature and there are no specific skills for certain subject areas. The metacognitive skills that are used to review an essay are the same as those that are used to verify an answer to a math question.

Social metacognition

Although metacognition has thus far been discussed in relation to the self, recent research in the field has suggested that this view is overly restrictive. Instead, it is argued that metacognition research should also include beliefs about others' mental processes, the influence of culture on those beliefs, and on beliefs about ourselves. This "expansionist view" proposes that it is impossible to fully understand metacognition without considering the situational norms and cultural expectations that influence those same conceptions. This combination of social psychology and metacognition is referred to as social metacognition.

Social metacognition can include ideas and perceptions that relate to social cognition. Additionally, social metacognition can include judging the cognition of others, such as judging the perceptions and emotional states of others. This is in part because the process of judging others is similar to judging the self. However, individuals have less information about the people they are judging; therefore, judging others tends to be more inaccurate. Having similar cognitions can buffer against this inaccuracy and can be helpful for teams or organizations, as well as interpersonal relationships.

Social metacognition and the self concept

An example of the interaction between social metacognition and self-concept can be found in examining implicit theories about the self. Implicit theories can cover a wide range of constructs about how the self operates, but two are especially relevant here; entity theory and incrementalist theory. Entity theory proposes that an individual's self-attributes and abilities are fixed and stable, while incrementalist theory proposes that these same constructs can be changed through effort and experience. Entity theorists are susceptible to learned helplessness because they may feel that circumstances are outside their control (i.e. there's nothing that could have been done to make things better), thus they may give up easily. Incremental theorists react differently when faced with failure: they desire to master challenges, and therefore adopt a mastery-oriented pattern.  They immediately began to consider various ways that they could approach the task differently, and they increase their efforts. Cultural beliefs can act on this as well. For example, a person who has accepted a cultural belief that memory loss is an unavoidable consequence of old age may avoid cognitively demanding tasks as they age, thus accelerating cognitive decline. Similarly, a woman who is aware of the stereotype that purports that women are not good at mathematics may perform worse on tests of mathematical ability or avoid mathematics altogether. These examples demonstrate that the metacognitive beliefs people hold about the self - which may be socially or culturally transmitted - can have important effects on persistence, performance, and motivation.

Attitudes as a function of social metacognition

The way that individuals think about attitude greatly affects the way that they behave. Metacognitions about attitudes influence how individuals act, and especially how they interact with others.

Some metacognitive characteristics of attitudes include importance, certainty, and perceived knowledge, and they influence behavior in different ways. Attitude importance is the strongest predictor of behavior and can predict information seeking behaviors in individuals. Attitude importance is also more likely to influence behavior than certainty of the attitude. When considering a social behavior like voting a person may hold high importance but low certainty. This means that they will likely vote, even if they are unsure whom to vote for. Meanwhile, a person who is very certain of who they want to vote for, may not actually vote if it is of low importance to them. This also applies to interpersonal relationships. A person might hold a lot of favorable knowledge about their family, but they may not maintain close relations with their family if it is of low importance.

Metacognitive characteristics of attitudes may be key to understanding how attitudes change. Research shows that the frequency of positive or negative thoughts is the biggest factor in attitude change. A person may believe that climate change is occurring but have negative thoughts toward it such as "If I accept the responsibilities of climate change, I must change my lifestyle". These individuals would not likely change their behavior compared to someone that thinks positively about the same issue such as "By using less electricity, I will be helping the planet".

Another way to increase the likelihood of behavior change is by influencing the source of the attitude. An individual's personal thoughts and ideas have a much greater impact on the attitude compared to ideas of others. Therefore, when people view lifestyle changes as coming from themselves, the effects are more powerful than if the changes were coming from a friend or family member. These thoughts can be re-framed in a way that emphasizes personal importance, such as "I want to stop smoking because it is important to me" rather than "quitting smoking is important to my family". More research needs to be conducted on culture differences and importance of group ideology, which may alter these results.

Social metacognition and stereotypes

People have secondary cognitions about the appropriateness, justifiability, and social judgability of their own stereotypic beliefs. People know that it is typically unacceptable to make stereotypical judgments and make conscious efforts not to do so. Subtle social cues can influence these conscious efforts. For example, when given a false sense of confidence about their ability to judge others, people will return to relying on social stereotypes. Cultural backgrounds influence social metacognitive assumptions, including stereotypes. For example, cultures without the stereotype that memory declines with old age display no age differences in memory performance.

When it comes to making judgments about other people, implicit theories about the stability versus malleability of human characteristics predict differences in social stereotyping as well. Holding an entity theory of traits increases the tendency for people to see similarity among group members and utilize stereotyped judgments. For example, compared to those holding incremental beliefs, people who hold entity beliefs of traits use more stereotypical trait judgments of ethnic and occupational groups as well as form more extreme trait judgments of new groups. When an individual's assumptions about a group combine with their implicit theories, more stereotypical judgments may be formed. Stereotypes that one believes others hold about them are called metastereotypes.

Animal metacognition

In nonhuman primates

Chimpanzees

Beran, Smith, and Perdue (2013) found that chimpanzees showed metacognitive monitoring in the information-seeking task. In their studies, three language-trained chimpanzees were asked to use the keyboard to name the food item in order to get the food. The food in the container was either visible to them or they had to move toward the container to see its contents. Studies shown that chimpanzees were more often to check what was in the container first if the food in the container was hidden. But when the food was visible to them, the chimpanzees were more likely to directly approach the keyboard and reported the identity of the food without looking again in the container. Their results suggested that chimpanzees know what they have seen and show effective information-seeking behavior when information is incomplete.

Rhesus macaques (Macaca mulatta)

Morgan et al. (2014) investigated whether rhesus macaques can make both retrospective and prospective metacognitive judgments on the same memory task. Risk choices were introduced to assess the monkey’s confidence about their memories. Two male rhesus monkeys (Macaca mulatta) were trained in a computerized token economy task first in which they can accumulate tokens to exchange food rewards. Monkeys were presented with multiple images of common objects simultaneously and then a moving border appearing on the screen indicating the target. Immediately following the presentation, the target images and some distractors were shown in the test. During the training phase, monkeys received immediate feedback after they made responses. They can earn two tokens if they make correct choices but lost two tokens if they were wrong.

In Experiment 1, the confidence rating was introduced after they completed their responses in order to test the retrospective metamemory judgments. After each response, a high-risk and a low-risk choice were provided to the monkeys. They could earn one token regardless of their accuracy if they choose the low-risk option. When they chose high-risk, they were rewarded with three tokens if their memory response was correct on that trial but lost three tokens if they made incorrect responses. Morgan and colleagues (2014) found a significant positive correlation between memory accuracy and risk choice in two rhesus monkeys. That is, they were more likely to select the high-risk option if they answered correctly in the working memory task but select the low-risk option if they were failed in the memory task.

Then Morgan et al. (2014) examine monkeys’ prospective metacognitive monitoring skills in Experiment 2. This study employed the same design except that two monkeys were asked to make low-risk or high-risk confidence judgment before they make actual responses to measure their judgments about future events. Similarly, the monkeys were more often to choose high-risk confidence judgment before answering correctly in working memory task and tended to choose the low-risk option before providing an incorrect response. These two studies indicated that rhesus monkeys can accurately monitor their performance and provided evidence of metacognitive abilities in monkeys.

In rats

In addition to nonhuman primates, other animals are also shown metacognition. Foote and Crystal (2007) provided the first evidence that rats have the knowledge of what they know in a perceptual discrimination task. Rats were required to classify brief noises as short or long. Some noises with intermediate durations were difficult to discriminate as short or long. Rats were provided with an option to decline to take the test on some trials but were forced to make responses on other trials. If they chose to take the test and respond correctly, they would receive a high reward but no reward if their classification of noises was incorrect. But if the rats decline to take the test, they would be guaranteed a smaller reward. The results showed that rats were more likely to decline to take the test when the difficulty of noise discrimination increased, suggesting rats knew they do not have the correct answers and declined to take the test to receive the reward. Another finding is that the performance was better when they had chosen to take the test compared with if the rats were forced to make responses, proving that some uncertain trials were declined to improve the accuracy.

These responses pattern might be attributed to actively monitor their own mental states. Alternatively, external cues such as environmental cue associations could be used to explain their behaviors in the discrimination task. Rats might have learned the association between intermediate stimuli and the decline option over time. Longer response latencies or some features inherent to stimuli can serve as discriminative cues to decline tests. Therefore, Templer, Lee, and Preston (2017) utilized an olfactory-based delayed match to sample (DMTS) memory task to assess whether rats were capable of metacognitive responding adaptively. Rats were exposed to sample odor first and chose to either decline or take the four-choice memory test after a delay. The correct choices of odor were associated with high reward and incorrect choices have no reward. The decline options were accompanied by a small reward.

In experiment 2, some “no-sample” trials were added in the memory test in which no odor was provided before the test. They hypothesized that rats would decline more often when there was no sample odor presented compared with odor presented if rats could internally assess the memory strength. Alternatively, if the decline option was motivated by external environmental cues, the rats would be less likely to decline the test because no available external cues were presented. The results showed that rats were more likely to decline the test in no-sample trials relative to normal sample trials, supporting the notion that rats can track their internal memory strength.

To rule out other potential possibilities, they also manipulated memory strength by providing the sampled odor twice and varying the retention interval between the learning and the test. Templer and colleagues (2017) found rats were less likely to decline the test if they had been exposed to the sample twice, suggesting that their memory strength for these samples was increased. Longer delayed sample test was more often declined than short delayed test because their memory was better after the short delay. Overall, their series of studies demonstrated that rats could distinguish between remembering and forgetting and rule out the possibilities that decline use was modulated by the external cues such as environmental cue associations.

In pigeons

Research on metacognition of pigeons has shown limited success. Inman and Shettleworth (1999) employed the delayed match to sample (DMTS) procedure to test pigeons’ metacognition. Pigeons were presented with one of three sample shapes (a triangle, a square, or a star) and then they were required to peck the matched sample when three stimuli simultaneously appeared on the screen at the end of the retention interval. A safe key was also presented in some trials next to three sample stimuli which allow them to decline that trial. Pigeons received a high reward for pecking correct stimuli, a middle-level reward for pecking the safe key, and nothing if they pecked the wrong stimuli. Inman and Shettleworth's (1999) first experiment found that pigeons’ accuracies were lower and they were more likely to choose the safe key as the retention interval between presentation of stimuli and test increased. However, in Experiment 2, when pigeons were presented with the option to escape or take the test before the test phase, there was no relationship between choosing the safe key and longer retention interval. Adams and Santi (2011) also employed the DMTS procedure in a perceptual discrimination task during which pigeons were trained to discriminate between durations of illumination. Pigeons did not choose the escape option more often as the retention interval increased during initial testing. After extended training, they learned to escape the difficult trials. However, these patterns might be attributed to the possibility that pigeons learned the association between escape responses and longer retention delay.

In addition to DMTS paradigm, Castro and Wasserman (2013) proved that pigeons can exhibit adaptive and efficient information-seeking behavior in the same-different discrimination task. Two arrays of items were presented simultaneously in which the two sets of items were either identical or different from one another. Pigeons were required to distinguish between the two arrays of items in which the level of difficulty was varied. Pigeons were provided with an “Information” button and a “Go” button on some trials that they could increase the number of items in the arrays to make the discrimination easier or they can prompt to make responses by pecking the Go button. Castro and Wasserman found that the more difficult the task, the more often pigeons chose the information button to solve the discrimination task. This behavioral pattern indicated that pigeons could evaluate the difficulty of the task internally and actively search for information when is necessary.

In dogs

Dogs have shown a certain level of metacognition that they are sensitive to information they have acquired or not. Belger & Bräuer (2018) examined whether dogs could seek additional information when facing uncertain situations. The experimenter put the reward behind one of the two fences in which dogs can see or cannot see where the reward was hidden. After that, dogs were encouraged to find the reward by walking around one fence. The dogs checked more frequently before selecting the fence when they did not see the baiting process compared with when they saw where the reward was hidden. However, contrary to apes, dogs did not show more checking behaviors when the delay between baiting the reward and selecting the fence was longer. Their findings suggested that dogs have some aspect of information-searching behaviors but less flexibly compared to apes.

In dolphins

Smith et al. (1995) evaluated whether dolphins have the ability of metacognitive monitoring in an auditory threshold paradigm. A bottlenosed dolphin was trained to discriminate between high-frequency tones and low-frequency tones. An escape option was available on some trials associated with a small reward. Their studies showed that dolphins could appropriately use the uncertain response when the trials were difficult to discriminate.

Debate

There is consensus that nonhuman primates, especially great apes and rhesus monkeys, exhibit metacognitive control and monitoring behaviors. But less convergent evidence was found in other animals such as rats and pigeons. Some researchers criticized these methods and posited that these performances might be accounted for by low-level conditioning mechanisms. Animals learned the association between reward and external stimuli through simple reinforcement models. However, many studies have demonstrated that the reinforcement model alone cannot explain animals’ behavioral patterns. Animals have shown adaptive metacognitive behavior even with the absence of concrete reward.

Strategies

Metacognitive-like processes are especially ubiquitous when it comes to the discussion of self-regulated learning. Self-regulation requires metacognition by looking at one's awareness of their learning and planning further learning methodology. Attentive metacognition is a salient feature of good self-regulated learners, but does not guarantee automatic application. Reinforcing collective discussion of metacognition is a salient feature of self-critical and self-regulating social groups. The activities of strategy selection and application include those concerned with an ongoing attempt to plan, check, monitor, select, revise, evaluate, etc.

Metacognition is 'stable' in that learners' initial decisions derive from the pertinent facts about their cognition through years of learning experience. Simultaneously, it is also 'situated' in the sense that it depends on learners' familiarity with the task, motivation, emotion, and so forth. Individuals need to regulate their thoughts about the strategy they are using and adjust it based on the situation to which the strategy is being applied. At a professional level, this has led to emphasis on the development of reflective practice, particularly in the education and health-care professions.

Recently, the notion has been applied to the study of second language learners in the field of TESOL and applied linguistics in general (e.g., Wenden, 1987; Zhang, 2001, 2010). This new development has been much related to Flavell (1979), where the notion of metacognition is elaborated within a tripartite theoretical framework. Learner metacognition is defined and investigated by examining their person knowledge, task knowledge and strategy knowledge.

Wenden (1991) has proposed and used this framework and Zhang (2001) has adopted this approach and investigated second language learners' metacognition or metacognitive knowledge. In addition to exploring the relationships between learner metacognition and performance, researchers are also interested in the effects of metacognitively-oriented strategic instruction on reading comprehension (e.g., Garner, 1994, in first language contexts, and Chamot, 2005; Zhang, 2010). The efforts are aimed at developing learner autonomy, interdependence and self-regulation.

Metacognition helps people to perform many cognitive tasks more effectively. Strategies for promoting metacognition include self-questioning (e.g. "What do I already know about this topic? How have I solved problems like this before?"), thinking aloud while performing a task, and making graphic representations (e.g. concept maps, flow charts, semantic webs) of one's thoughts and knowledge. Carr, 2002, argues that the physical act of writing plays a large part in the development of metacognitive skills.

Strategy Evaluation matrices (SEM) can help to improve the knowledge of cognition component of metacognition. The SEM works by identifying the declarative (Column 1), procedural (Column 2) and conditional (Column 3 and 4) knowledge about specific strategies. The SEM can help individuals identify the strength and weaknesses about certain strategies as well as introduce them to new strategies that they can add to their repertoire.

A regulation checklist (RC) is a useful strategy for improving the regulation of cognition aspect of one's metacognition. RCs help individuals to implement a sequence of thoughts that allow them to go over their own metacognition. King (1991) found that fifth-grade students who used a regulation checklist outperformed control students when looking at a variety of questions including written problem solving, asking strategic questions, and elaborating information.

Examples of strategies that can be taught to students are word analysis skills, active reading strategies, listening skills, organizational skills and creating mnemonic devices.

Walker and Walker have developed a model of metacognition in school learning termed Steering Cognition, which describes the capacity of the mind to exert conscious control over its reasoning and processing strategies in relation to the external learning task. Studies have shown that pupils with an ability to exert metacognitive regulation over their attentional and reasoning strategies used when engaged in maths, and then shift those strategies when engaged in science or then English literature learning, associate with higher academic outcomes at secondary school.

Metastrategic knowledge

"Metastrategic knowledge" (MSK) is a sub-component of metacognition that is defined as general knowledge about higher order thinking strategies. MSK had been defined as "general knowledge about the cognitive procedures that are being manipulated". The knowledge involved in MSK consists of "making generalizations and drawing rules regarding a thinking strategy" and of "naming" the thinking strategy.

The important conscious act of a metastrategic strategy is the "conscious" awareness that one is performing a form of higher order thinking. MSK is an awareness of the type of thinking strategies being used in specific instances and it consists of the following abilities: making generalizations and drawing rules regarding a thinking strategy, naming the thinking strategy, explaining when, why and how such a thinking strategy should be used, when it should not be used, what are the disadvantages of not using appropriate strategies, and what task characteristics call for the use of the strategy.

MSK deals with the broader picture of the conceptual problem. It creates rules to describe and understand the physical world around the people who utilize these processes called higher-order thinking. This is the capability of the individual to take apart complex problems in order to understand the components in problem. These are the building blocks to understanding the "big picture" (of the main problem) through reflection and problem solving.

Action

Both social and cognitive dimensions of sporting expertise can be adequately explained from a metacognitive perspective according to recent research. The potential of metacognitive inferences and domain-general skills including psychological skills training are integral to the genesis of expert performance. Moreover, the contribution of both mental imagery (e.g., mental practice) and attentional strategies (e.g., routines) to our understanding of expertise and metacognition is noteworthy. The potential of metacognition to illuminate our understanding of action was first highlighted by Aidan Moran who discussed the role of meta-attention in 1996. A recent research initiative, a research seminar series called META funded by the BPS, is exploring the role of the related constructs of meta-motivation, meta-emotion, and thinking and action (metacognition).

Mental illness

Sparks of interest

In the context of mental health, metacognition can be loosely defined as the process that "reinforces one's subjective sense of being a self and allows for becoming aware that some of one's thoughts and feelings are symptoms of an illness". The interest in metacognition emerged from a concern for an individual's ability to understand their own mental status compared to others as well as the ability to cope with the source of their distress. These insights into an individual's mental health status can have a profound effect on overall prognosis and recovery. Metacognition brings many unique insights into the normal daily functioning of a human being. It also demonstrates that a lack of these insights compromises 'normal' functioning. This leads to less healthy functioning. In the autism spectrum, there is a profound deficit in Theory of Mind. In people who identify as alcoholics, there is a belief that the need to control cognition is an independent predictor of alcohol use over anxiety. Alcohol may be used as a coping strategy for controlling unwanted thoughts and emotions formed by negative perceptions. This is sometimes referred to as self medication.

Implications

Adrian Wells' and Gerald Matthews' theory proposes that when faced with an undesired choice, an individual can operate in two distinct modes: "object" and "metacognitive". Object mode interprets perceived stimuli as truth, where metacognitive mode understands thoughts as cues that have to be weighted and evaluated. They are not as easily trusted. There are targeted interventions unique of each patient, that gives rise to the belief that assistance in increasing metacognition in people diagnosed with schizophrenia is possible through tailored psychotherapy. With a customized therapy in place clients then have the potential to develop greater ability to engage in complex self-reflection. This can ultimately be pivotal in the patient's recovery process. In the obsessive–compulsive spectrum, cognitive formulations have greater attention to intrusive thoughts related to the disorder. "Cognitive self-consciousness" are the tendencies to focus attention on thought. Patients with OCD exemplify varying degrees of these "intrusive thoughts". Patients also suffering from generalized anxiety disorder also show negative thought process in their cognition.

Cognitive-attentional syndrome (CAS) characterizes a metacognitive model of emotion disorder (CAS is consistent with the attention strategy of excessively focusing on the source of a threat). This ultimately develops through the client's own beliefs. Metacognitive therapy attempts to correct this change in the CAS. One of the techniques in this model is called attention training (ATT). It was designed to diminish the worry and anxiety by a sense of control and cognitive awareness. ATT also trains clients to detect threats and test how controllable reality appears to be.

Works of art as metacognitive artifacts

The concept of metacognition has also been applied to reader-response criticism. Narrative works of art, including novels, movies and musical compositions, can be characterized as metacognitive artifacts which are designed by the artist to anticipate and regulate the beliefs and cognitive processes of the recipient, for instance, how and in which order events and their causes and identities are revealed to the reader of a detective story. As Menakhem Perry has pointed out, mere order has profound effects on the aesthetical meaning of a text. Narrative works of art contain a representation of their own ideal reception process. They are something of a tool with which the creators of the work wish to attain certain aesthetical and even moral effects.

Mind wandering

There is an intimate, dynamic interplay between mind wandering and metacognition. Metacognition serves to correct the wandering mind, suppressing spontaneous thoughts and bringing attention back to more "worthwhile" tasks.

Human–animal communication

From Wikipedia, the free encyclopedia

Human–animal communication is the communication observed between humans and other animals, from non-verbal cues and vocalizations through to the use of language.

Introduction

Human–animal communication may be observed in everyday life. The interactions between pets and their owners, for example, reflect a form of spoken, while not necessarily verbal dialogue. A dog being scolded is able to grasp the message by interpreting cues such as the owner's stance, tone of voice, and body language. This communication is two-way, as owners can learn to discern the subtle differences between barks and meows, and there is a clear difference between the bark of an angry dog defending its home and the happy bark of the same animal while playing. Communication (often nonverbal) is also significant in equestrian activities such as dressage.

One scientific study has found that 30 bird species and 29 mammal species share the same pattern of pitch and speed in basic messages, so humans and those 59 species can understand each other when they express "aggression, hostility, appeasement, approachability, submission and fear.

Birds

Parrots are able to use words meaningfully in linguistic tasks. In particular, the grey parrot Alex learned 100 words, and after training used English words to answer questions about color, shapes, size and numbers correctly about 80% of the time. He also, without training, said where he wanted to be taken, such as his cage or the back of a chair, and protested when taken elsewhere, or when hidden objects were not where he thought they were. He asked a question, what color he himself was, which has been called the only question so far asked by a non-human animal. Scientific American editor Madhusree Mukerjee described these abilities as creativity and reasoning comparable to nonhuman primates or cetaceans, while expressing concern that extensive language use resulted in feather-plucking behavior, a possible sign of stress.

Most bird species have at least six calls which humans can learn to understand, for situations including danger, distress, hunger, and the presence of food.

Pigeons can identify different artists. Pigeons can learn to recognize up to 58 four-letter English words, with an average of 43, though they were not taught any meanings to associate with the words.

Java Sparrows chose music by sitting on a particular perch, which determined which music was played. Two birds preferred Bach and Vivaldi over Schoenberg or silence. The other two birds had varying preferences among Bach, Schoenberg, white noise and silence.

The greater honeyguide has a specific call to alert humans that it can lead them to honey, and also responds to a specific human call requesting such a lead, by leading humans to honeybee hives so it can eat the discarded honeycomb wax after humans collect the honey. The human call varies regionally, so the honeyguide's response is learned in each area, not instinctive.

Crows identify and respond differently to different human faces.

Fictional portrayals of sentient talking parrots and similar birds are common in children's fiction, such as the talking, loud-mouth parrot Iago of Disney's Aladdin.

Primates

Chimpanzees can make at least 32 sounds with distinct meanings for humans.

Chimpanzees, bonobos, gorillas and orangutans have used sign language, physical tokens, keyboards and touch screens to communicate with humans in numerous research studies. The research showed that they understood multiple signals and produced them to communicate with humans. There is some disagreement whether they can re-order them to create distinct meanings.

Baboons can learn to recognize an average of 139 4-letter English words (maximum of 308), though they were not taught any meanings to associate with the words.

Primates also have been trained to use touch screens to tell a researcher their musical preferences. In Toronto, for hundreds of songs in random order, orangutans were given one 30-second segment of a song, and then chose between repeating that segment or 30 seconds of silence. Different orangutans chose to replay from 8% to 48% of the segments, and all exhibited stress throughout the trials. There was no pattern of selections by genre, and the researchers did not look for other attributes which were shared by the orangutans' chosen segments. No comparison was available of how many 30-second segments humans would repeat in the same situation. In another experiment the orangutans did not distinguish between music played in its original order and music sliced into half-second intervals which were played in random order. Chimpanzees can hear higher frequencies than humans; if orangutans can too, and if these overtones are present in the recordings, the overtones would affect their choices.

Cetaceans

Lilly

In the 1960s, John C. Lilly sponsored English lessons for one bottlenose dolphin (Tursiops truncatus). The teacher, Margaret Howe Lovatt, lived with the dolphin for ​2 12 months in a house on the shore of the Virgin Islands. The house was partially flooded and allowed them to be together for meals, play, language lessons, and sleep. Lilly thought of this as a mother-child dyad, though the dolphin was 5–6 years old. Lilly said that he had heard other dolphins repeating his own English words, and believed that an intelligent animal would want to mimic the language of its captors, to communicate. The experiment ended in the third month and did not restart, because Howe found the two-room lab and constant bumping from the dolphin too constricting.

After several weeks, a concerted effort by the dolphin to imitate the instructor's speech was evident, and human-like sounds were apparent, and recorded. It was able to perform tasks such as retrieval of aurally indicated objects without fail. Later in the project the dolphin's ability to process linguistic syntax was made apparent, in that it could distinguish between commands such as "Bring the ball to the doll," and "Bring the doll to the ball." This ability not only demonstrates the bottlenose dolphin's grasp of basic grammar, but also implies the dolphins' own language might include syntactical rules. The correlation between length and 'syllables' (bursts of the dolphin's sound) with the instructor's speech also went from essentially zero at the beginning of the session to almost a perfect correlation by its completion, so that when the human spoke 5 or 10 syllables, the dolphin also spoke 5 or 10 'syllables' or bursts of sound.

Two experiments of this sort are explained in detail in Lilly's book, Mind of the Dolphin. The first experiment was more of a test run to check psychological and other strains on the human and cetacean participants, determining the extent of the need for other human contact, dry clothing, time alone, and so on. Despite tensions after several weeks, Howe Lovatt agreed to the ​2 12 months isolated with the dolphin.

Experiments by the research team of Louis Herman, a former collaborator and student of Lilly's, demonstrated that dolphins could understand human communication in whistles and respond with the same whistles.

A female bottlenose dolphin, Phoenix, understood at least 34 whistles. Whistles created a system of 2-way communication. By having separate whistles for object and action, Herman could reorder commands without fresh teaching (take hoop to ball). Successful communication was shown when Herman used new combinations, and the dolphin understood and did what he asked without further training 80-90% of the time.

In 1980, Herman had taught 6 whistles to a female bottle-nose dolphin, Kea, to refer to three objects and three actions, and the dolphin followed his instructions. He wrote, "In addition to mouthing the three familiar training objects in the presence of the mouth name, Kea correctly mouthed on their first appearance a plastic water pipe, a wooden disc, and the experimenter's open hand. The same type of immediate response generalization occurred for touch and fetch."

Richards, Wolz and Herman (1984) trained a dolphin to make distinct whistles for objects, "so that, in effect, the dolphin gave unique vocal labels to those objects."

Herman's later publications do not discuss the whistle communication. Herman started getting US Navy funding in 1985, so further expansion of the 2-way whistle language would have been in the classified United States Navy Marine Mammal Program, a black project.

Herman also studied the crossmodal perceptual ability of dolphins. Dolphins typically perceive their environment through sound waves generated in the melon of their skulls, through a process known as echolocation (similar to that seen in bats, though the mechanism of production is different). The dolphin's eyesight however is also fairly good, even by human standards, and Herman's research found that any object, even of complex and arbitrary shape, identified either by sight or sound by the dolphin, could later be correctly identified by the dolphin with the alternate sense modality with almost 100 per cent accuracy, in what is classically known in psychology and behaviorism as a match-to-sample test. The only errors noted were presumed to have been a misunderstanding of the task during the first few trials, and not an inability of the dolphin's perceptual apparatus. This capacity is strong evidence for abstract and conceptual thought in the dolphin's brain, wherein an idea of the object is stored and understood not merely by its sensory properties; such abstraction may be argued to be of the same kind as complex language, mathematics, and art, and implies a potentially very great intelligence and conceptual understanding within the brains of tursiops and possibly many other cetaceans. Accordingly, Lilly's interest later shifted to whale song and the possibility of high intelligence in the brains of large whales, and Louis Herman's research at the now misnomered Dolphin Institute in Honolulu, Hawaii, focuses exclusively on the Humpback whale.

Other researchers

  • Batteau (1964, video) developed machines for the US Navy, which translated human voices to higher frequencies for dolphins to hear and translated dolphin voices to lower frequencies for humans to hear. The work continued at least until 1967 when the Navy classified its dolphin research. Batteau died, also in 1967, before he published results.
  • Reiss and McCowan (1993) taught dolphins 3 whistles (ball, ring, rub), which the 2 dolphins produced, and even combined, when playing with the ball and/or ring, or getting a rub.
  • Delfour and Marten (2005) gave dolphins a touchscreen to show they recognized a musical note
  • Kuczaj (2006) used an underwater keyboard, which humans and dolphins can touch to signal an action.
  • Amundin et al. (2008) had dolphins point narrow echolocation beams onto an array of hydrophones which acted like a touchscreen to communicate with the researchers.
  • Reiss (2011) used an underwater keyboard which dolphins could press. A dolphin defined a key as "I want a small fish" and Reiss (2011, p. 100) understood, but ignored it.
  • Herzing (2013) used an underwater keyboard in the open ocean which dolphins and humans could press to choose a plaything.
  • Herzing (2014) created 3 whistles for "play objects (Sargassum... scarf, and rope)", and found that wild dolphins understand them, but has not found if dolphins produce the whistles.

Historical

From Roman times to modern Brazil, dolphins have been known to drive fish toward fishermen waiting on shore, and signal to the fishermen when to throw their nets, even when water is too murky for the fishermen to see the arrival of the fish. The dolphins catch unnetted fish disoriented by the net.

From about 1840-1920 orcas smacked the water off Twofold Bay in New South Wales to signal to human whalers that the orcas were herding large baleen whales nearby, so the humans would send boats to harpoon the whales, killing them faster and more assuredly than the orcas could. The orcas ate the tongues and lips, leaving the blubber and bones for the humans.

Dogs

Dogs communicating to humans

Bonnie Bergin trained dogs to go to specific text on the wall to ask clearly for "water, treat or pet me." Dogs were able to learn English or Japanese text. She says service dogs can learn to find EXIT signs, bathroom gender signs, and report what disease they smell in a urine sample by going to a sign on the wall naming that disease.

Police and private dogs can be trained to "alert" when they find certain scents, including drugs, explosives, mines, scent of a suspect, fire accelerants, and bed bugs. The alert can be a specific bark or position, and can be accepted as evidence in court.

Stanley Coren identifies 56 signals which untrained dogs make and people can understand, including 10 barks, 5 growls, 8 other vocalizations, 11 tail signals, 5 ear and eye positions, 5 mouth signals and 12 body positions. Faragó et al. describe research that humans can accurately categorize barks from unseen dogs as aggressive, playful, or stressed, even if they do not own a dog. This recognizability has led to machine learning algorithms to categorize barks, and commercial products and apps such as Bow Lingual, Talk With Your Dog, and Talk Dog.

Humans communicating to dogs

Dogs can be trained to understand hundreds of spoken words, including Chaser (1,022 words), Betsy (340 words), Rico (200 words), and others. They can react appropriately when a human uses verbs and nouns in new combinations, such as "fetch ball" or "paw frisbee."

Bergin trained dogs to obey 20 written commands on flashcards, in Roman or Japanese characters, including 🚫 to keep them away from an area.

Shepherds and others have developed detailed commands to tell herding dogs when to move, stop, collect or separate herd animals.

Other animal training

Humans teach animals specific responses for specific conditions or stimuli. Training may be for purposes such as companionship, detection, protection, research and entertainment. During training humans communicate their wishes with positive or negative reinforcement. After training is finished the human communicates by giving signals with words, whistles, gestures, body language, etc.

APOPO has trained Southern giant pouched rats to communicate to humans the presence of land mines, by scratching the ground, and tuberculosis in medical samples. They identify 40% more cases of tuberculosis than clinics do, an extra 12,000 cases from 2007-2017. They have identified 100,000 mines from 2003-2017, certifying 2,200 hectares (5,400 acres) as mine-free. They are accurate enough that the human trainers run on the land after removing the mines which rats have identified.

Rats (Wistar, Rattus norvegicus) have been taught to distinguish and respond differently to different human faces.

Patricia McConnell found that handlers around the world, speaking 16 languages, working with camels, dogs, donkeys, horses and water buffalo, all use long sounds with a steady pitch to tell animals to go more slowly (whoa, euuuuuu), and they use short repeated sounds, often rising in pitch, to speed them up or bring them to the handler (Go, Go, Go, claps, clicks). Chimpanzees, dogs, gulls, horses, rats, roosters, sheep and sparrows all use similar short repeated sounds to tell others of the same species to come closer.

Even fish, which lack a neocortex, have been taught to distinguish and respond differently to different human faces (archerfish) or styles of music (goldfish and koi).

Molluscs, with totally different brain designs, have been taught to distinguish and respond to symbols (cuttlefish and octopus), and have been taught that food behind a clear barrier cannot be eaten (squid).

A harbor seal, Hoover learned to speak several phrases in understandable English as a pup from his human foster parent and used these in appropriate circumstances during his later life at the New England Aquarium until he died in 1985. Other talking animals have been studied, though they did not always use their phrases in meaningful contexts.

Animal communication as entertainment

Poster for Toby the Sapient pig

Though animal communication has always been a topic of public comment and attention, for a period in history it surpassed this and became sensational popular entertainment. From the late 18th century through the mid 19th century, a succession of "learned pigs" and various other animals were displayed to the public in for-profit performances, boasting the ability to communicate with their owners (often in more than one language), write, solve math problems, and the like. One poster dated 1817 shows a group of "Java sparrows" who are advertised as knowing seven languages, including Chinese and Russian.

Cetacean intelligence

From Wikipedia, the free encyclopedia

Cetacean intelligence is the cognitive ability of the infraorder Cetacea of mammals. This order includes whales, porpoises, and dolphins.

Brain size

Brain size was previously considered a major indicator of the intelligence of an animal. However, many other factors also affect intelligence, and recent discoveries concerning bird intelligence have called into question the influence of brain size. Since most of the brain is used for maintaining bodily functions, greater ratios of brain to body mass may increase the amount of brain mass available for more complex cognitive tasks. Allometric analysis indicates that in general, mammalian brain size scales at approximately the ​23 or ​34 exponent of body mass. Comparison of actual brain size with the size expected from allometry provides an encephalization quotient (EQ) that can be used as a more accurate indicator of an animal's intelligence.

  • Sperm whales (Physeter macrocephalus) have the largest known brain mass of any extant animal, averaging 7.8 kg in mature males.
  • Orcas (Orcinus orca) have the second largest known brain mass of any extant animal. (5.4-6.8 kg) 
  • Bottlenose dolphins (Tursiops truncatus) have an absolute brain mass of 1,500–1,700 grams. This is slightly greater than that of humans (1,300–1,400 grams) and about four times that of chimpanzees (400 grams).
  • The brain to body mass ratio (not the encephalization quotient) in some members of the odontocete superfamily Delphinoidea (dolphins, porpoises, belugas, and narwhals) is greater than modern humans, and greater than all other mammals (there is debate whether that of the treeshrew might be second in place of humans). In some dolphins, it is less than half that of humans: 0.9% versus 2.1%. This comparison seems more favorable if one excludes the large amount of insulating blubber (15-20% of mass).
  • The encephalization quotient varies widely between species. The La Plata dolphin has an EQ of approximately 1.67; the Ganges river dolphin of 1.55; the orca of 2.57; the bottlenose dolphin of 4.14; and the tucuxi dolphin of 4.56; In comparison to other animals, elephants have an EQ ranging from 1.13 to 2.36; chimpanzees of approximately 2.49; dogs of 1.17; cats of 1.00; and mice of 0.50.
  • The majority of mammals are born with a brain close to 90% of the adult brain weight. Humans are born with 28% of the adult brain weight, chimpanzees with 54%, bottlenose dolphins with 42.5%, and elephants with 35%.

Spindle cells (neurons without extensive branching) have been discovered in the brains of the humpback whale, fin whale, sperm whale, killer whale, bottlenose dolphins, Risso's dolphins, and beluga whales. Humans, great apes, and elephants, species all well known for their high intelligence, are the only others known to have spindle cells. Spindle neurons appear to play a central role in the development of intelligent behavior. Such a discovery may suggest a convergent evolution of these species.

Brain structure

Elephant brains also show a complexity similar to dolphin brains, and are also more convoluted than that of humans, and with a cortex thicker than that of cetaceans. It is generally agreed that the growth of the neocortex, both absolutely and relative to the rest of the brain, during human evolution, has been responsible for the evolution of human intelligence, however defined. While a complex neocortex usually indicates high intelligence, there are exceptions. For example, the echidna has a highly developed brain, yet is not widely considered very intelligent, though preliminary investigations into their intelligence suggest that echidnas are capable of more advanced cognitive tasks than were previously assumed.

In 2014, it was shown for the first time that a species of dolphin, the long-finned pilot whale, has more neocortical neurons than any mammal studied to date including humans. Unlike terrestrial mammals, dolphin brains contain a paralimbic lobe, which may possibly be used for sensory processing. The dolphin is a voluntary breather, even during sleep, with the result that veterinary anaesthesia of dolphins would result in asphyxiation. All sleeping mammals, including dolphins, experience a stage known as REM sleep. Ridgway reports that EEGs show alternating hemispheric asymmetry in slow waves during sleep, with occasional sleep-like waves from both hemispheres. This result has been interpreted to mean that dolphins sleep only one hemisphere of their brain at a time, possibly to control their voluntary respiration system or to be vigilant for predators. This is also given as explanation for the large size of their brains.

Dolphin brain stem transmission time is faster than that normally found in humans, and is approximately equivalent to the speed in rats. The dolphin's greater dependence on sound processing is evident in the structure of its brain: its neural area devoted to visual imaging is only about one-tenth that of the human brain, while the area devoted to acoustical imaging is about 10 times as large. Sensory experiments suggest a great degree of cross-modal integration in the processing of shapes between echolocative and visual areas of the brain. Unlike the case of the human brain, the cetacean optic chiasm is completely crossed, and there is behavioral evidence for hemispheric dominance for vision.

Brain evolution

The evolution of encephalization in cetaceans is similar to that in primates. Though the general trend in their evolutionary history increased brain mass, body mass, and encephalization quotient, a few lineages actually underwent decephalization, although the selective pressures that caused this are still under debate. Among cetaceans, Odontoceti tend to have higher encephalization quotients than Mysticeti, which is at least partially due to the fact that Mysticeti have much larger body masses without a compensating increase in brain mass. As far as which selective pressures drove the encephalization (or decephalization) of cetacean brains, current research espouses a few main theories. The most promising suggests that cetacean brain size and complexity increased to support complex social relations. It could also have been driven by changes in diet, the emergence of echolocation, or an increase in territorial range.

Problem-solving ability

Some research shows that dolphins, among other animals, understand concepts such as numerical continuity, though not necessarily counting. Dolphins may be able to discriminate between numbers.

Several researchers observing animals' ability to learn set formation tend to rank dolphins at about the level of elephants in intelligence, and show that dolphins do not surpass other highly intelligent animals in problem solving. A 1982 survey of other studies showed that in the learning of "set formation", dolphins rank highly, but not as high as some other animals.

Behavior

Pod characteristics

Dolphin group sizes vary quite dramatically. River dolphins usually congregate in fairly small groups from 6 to 12 in number or, in some species, singly or in pairs. The individuals in these small groups know and recognize one another. Other species such as the oceanic pantropical spotted dolphin, common dolphin and spinner dolphin travel in large groups of hundreds of individuals. It is unknown whether every member of the group is acquainted with every other. However, large packs can act as a single cohesive unit – observations show that if an unexpected disturbance, such as a shark approach, occurs from the flank or from beneath the group, the group moves in near-unison to avoid the threat. This means that the dolphins must be aware not only of their near neighbors but also of other individuals nearby – in a similar manner to which humans perform "audience waves". This is achieved by sight, and possibly also echolocation. One hypothesis proposed by Jerison (1986) is that members of a pod of dolphins are able to share echolocation results with each other to create a better understanding of their surroundings.

Resident orcas living in British Columbia, Canada, and Washington, United States live in extremely stable family groups. The basis of this social structure is the matriline, consisting of a mother and her offspring, who travel with her for life. Male orcas never leave their mothers' pods, while female offspring may branch off to form their own matriline if they have many offspring of their own. Males have a particularly strong bond with their mother, and travel with them their entire lives, which can exceed 50 years.

Relationships in the orca population can be discovered through their vocalizations. Matrilines who share a common ancestor from only a few generations back share mostly the same dialect, comprising a pod. Pods who share some calls indicate a common ancestor from many generations back, and make up a clan. The orcas use these dialects to avoid inbreeding. They mate outside the clan, which is determined by the different vocalizations. There is evidence that other species of dolphins may also have dialects.

In bottlenose dolphin studies by Wells in Sarasota, Florida, and Smolker in Shark Bay, Australia, females of a community are all linked either directly or through a mutual association in an overall social structure known as fission-fusion. Groups of the strongest association are known as "bands", and their composition can remain stable over years. There is some genetic evidence that band members may be related, but these bands are not necessarily limited to a single matrilineal line. There is no evidence that bands compete with each other. In the same research areas, as well as in Moray Firth, Scotland, males form strong associations of two to three individuals, with a coefficient of association between 70 and 100. These groups of males are known as "alliances", and members often display synchronous behaviors such as respiration, jumping, and breaching. Alliance composition is stable on the order of tens of years, and may provide a benefit for the acquisition of females for mating. The complex social strategies of marine mammals such as bottlenose dolphins, "provide interesting parallels" with the social strategies of elephants and chimpanzees.

Complex play

Dolphins are known to engage in complex play behavior, which includes such things as producing stable underwater toroidal air-core vortex rings or "bubble rings". There are two main methods of bubble ring production: rapid puffing of a burst of air into the water and allowing it to rise to the surface, forming a ring; or swimming repeatedly in a circle and then stopping to inject air into the helical vortex currents thus formed. The dolphin will often then examine its creation visually and with sonar. They also appear to enjoy biting the vortex-rings they have created, so that they burst into many separate normal bubbles and then rise quickly to the surface. Certain whales are also known to produce bubble rings or bubble nets for the purpose of foraging. Many dolphin species also play by riding in waves, whether natural waves near the shoreline in a method akin to human "body-surfing", or within the waves induced by the bow of a moving boat in a behavior known as bow riding.

Cross-species cooperation

There have been instances in captivity of various species of dolphin and porpoise helping and interacting across species, including helping beached whales. Also they have been known to live alongside resident (fish eating) orca whales for limited amounts of time. Dolphins have also been known to aid human swimmers in need, and in at least one instance a distressed dolphin approached human divers seeking assistance.

Creative behavior

Aside from having exhibited the ability to learn complex tricks, dolphins have also demonstrated the ability to produce creative responses. This was studied by Karen Pryor during the mid-1960s at Sea Life Park in Hawaii, and was published as The Creative Porpoise: Training for Novel Behavior in 1969. The two test subjects were two rough-toothed dolphins (Steno bredanensis), named Malia (a regular show performer at Sea Life Park) and Hou (a research subject at adjacent Oceanic Institute). The experiment tested when and whether the dolphins would identify that they were being rewarded (with fish) for originality in behavior and was very successful. However, since only two dolphins were involved in the experiment, the study is difficult to generalize.

Starting with the dolphin named Malia, the method of the experiment was to choose a particular behavior exhibited by her each day and reward each display of that behavior throughout the day's session. At the start of each new day Malia would present the prior day's behavior, but only when a new behavior was exhibited was a reward given. All behaviors exhibited were, at least for a time, known behaviors of dolphins. After approximately two weeks Malia apparently exhausted "normal" behaviors and began to repeat performances. This was not rewarded.

According to Pryor, the dolphin became almost despondent. However, at the sixteenth session without novel behavior, the researchers were presented with a flip they had never seen before. This was reinforced. As related by Pryor, after the new display: "instead of offering that again she offered a tail swipe we'd never seen; we reinforced that. She began offering us all kinds of behavior that we hadn't seen in such a mad flurry that finally we could hardly choose what to throw fish at".

The second test subject, Hou, took thirty-three sessions to reach the same stage. On each occasion the experiment was stopped when the variability of dolphin behavior became too complex to make further positive reinforcement meaningful.

The same experiment was repeated with humans, and it took the volunteers about the same length of time to figure out what was being asked of them. After an initial period of frustration or anger, the humans realised they were being rewarded for novel behavior. In dolphins this realisation produced excitement and more and more novel behaviors – in humans it mostly just produced relief.

Captive orcas have displayed responses indicating they get bored with activities. For instance, when Paul Spong worked with the orca Skana, he researched her visual skills. However, after performing favorably in the 72 trials per day, Skana suddenly began consistently getting every answer wrong. Spong concluded that a few fish were not enough motivation. He began playing music, which seemed to provide Skana with much more motivation.

At the Institute for Marine Mammal Studies in Mississippi, it has also been observed that the resident dolphins seem to show an awareness of the future. The dolphins are trained to keep their own tank clean by retrieving rubbish and bringing it to a keeper, to be rewarded with a fish. However, one dolphin, named Kelly, has apparently learned a way to get more fish, by hoarding the rubbish under a rock at the bottom of the pool and bringing it up one small piece at a time.

Use of tools

As of 1984, scientists have observed wild bottlenose dolphins in Shark Bay, Western Australia using a basic tool. When searching for food on the sea floor, many of these dolphins were seen tearing off pieces of sponge and wrapping them around their rostra, presumably to prevent abrasions and facilitate digging.

Communication

Whale song is the sounds made by whales and which is used for different kinds of communication.

Dolphins emit two distinct kinds of acoustic signals, which are called whistles and clicks:

  • Clicks – quick broadband burst pulses – are used for echolocation, although some lower-frequency broadband vocalizations may serve a non-echolocative purpose such as communication; for example, the pulsed calls of orcas. Pulses in a click train are emitted at intervals of ≈35–50 milliseconds, and in general these inter-click intervals are slightly greater than the round-trip time of sound to the target.
  • Whistles – narrow-band frequency modulated (FM) signals – are used for communicative purposes, such as contact calls, the pod-specific dialects of resident orcas, or the signature whistle of bottlenose dolphins.

There is strong evidence that some specific whistles, called signature whistles, are used by dolphins to identify and/or call each other; dolphins have been observed emitting both other specimens' signature whistles, and their own. A unique signature whistle develops quite early in a dolphin's life, and it appears to be created in imitation of the signature whistle of the dolphin's mother. Imitation of the signature whistle seems to occur only among the mother and its young, and among befriended adult males.

Xitco reported the ability of dolphins to eavesdrop passively on the active echolocative inspection of an object by another dolphin. Herman calls this effect the "acoustic flashlight" hypothesis, and may be related to findings by both Herman and Xitco on the comprehension of variations on the pointing gesture, including human pointing, dolphin postural pointing, and human gaze, in the sense of a redirection of another individual's attention, an ability which may require theory of mind.

The environment where dolphins live makes experiments much more expensive and complicated than for many other species; additionally, the fact that cetaceans can emit and hear sounds (which are believed to be their main means of communication) in a range of frequencies much wider than humans can means that sophisticated equipment, which was scarcely available in the past, is needed to record and analyse them. For example, clicks can contain significant energy in frequencies greater than 110 kHz (for comparison, it is unusual for a human to be able to hear sounds above 20 kHz), requiring that equipment have a sampling rates of at least 220 kHz; MHz-capable hardware is often used.

In addition to the acoustic communication channel, the visual modality is also significant. The contrasting pigmentation of the body may be used, for example with "flashes" of the hypopigmented ventral area of some species, as can the production of bubble streams during signature whistling. Also, much of the synchronous and cooperative behaviors, as described in the Behavior section of this entry, as well as cooperative foraging methods, likely are managed at least partly by visual means.

Experiments have shown that they can learn human sign language and can use whistles for 2-way human–animal communication. Phoenix and Akeakamai, bottlenose dolphins, understood individual words and basic sentences like "touch the frisbee with your tail and then jump over it" (Herman, Richards, & Wolz 1984). Phoenix learned whistles, and Akeakamai learned sign language. Both dolphins understood the significance of the ordering of tasks in a sentence.

A study conducted by Jason Bruck of the University of Chicago showed that bottlenose dolphins can remember whistles of other dolphins they had lived with after 20 years of separation. Each dolphin has a unique whistle that functions like a name, allowing the marine mammals to keep close social bonds. The new research shows that dolphins have the longest memory yet known in any species other than humans.

Self-awareness

Self-awareness, though not well defined scientifically, is believed to be the precursor to more advanced processes like meta-cognitive reasoning (thinking about thinking) that are typical of humans. Scientific research in this field has suggested that bottlenose dolphins, alongside elephants and great apes, possess self-awareness.

The most widely used test for self-awareness in animals is the mirror test, developed by Gordon Gallup in the 1970s, in which a temporary dye is placed on an animal's body, and the animal is then presented with a mirror.

In 1995, Marten and Psarakos used television to test dolphin self-awareness. They showed dolphins real-time footage of themselves, recorded footage, and another dolphin. They concluded that their evidence suggested self-awareness rather than social behavior. While this particular study has not been repeated since then, dolphins have since passed the mirror test. However, some researchers have argued that evidence for self-awareness has not been convincingly demonstrated.

Further reading

  • Dolphin Communication and Cognition: Past, Present, and Future, edited by Denise L. Herzing and Christine M. Johnson, 2015, MIT Press

Memory protection

From Wikipedia, the free encyclopedia

Memory protection is a way to control memory access rights on a computer, and is a part of most modern instruction set architectures and operating systems. The main purpose of memory protection is to prevent a process from accessing memory that has not been allocated to it. This prevents a bug or malware within a process from affecting other processes, or the operating system itself. Protection may encompass all accesses to a specified area of memory, write accesses, or attempts to execute the contents of the area. An attempt to access unauthorized memory results in a hardware fault, e.g., a segmentation fault, storage violation exception, generally causing abnormal termination of the offending process. Memory protection for computer security includes additional techniques such as address space layout randomization and executable space protection.

Methods

Segmentation

Segmentation refers to dividing a computer's memory into segments. A reference to a memory location includes a value that identifies a segment and an offset within that segment.

The x86 architecture has multiple segmentation features, which are helpful for using protected memory on this architecture. On the x86 architecture, the Global Descriptor Table and Local Descriptor Tables can be used to reference segments in the computer's memory. Pointers to memory segments on x86 processors can also be stored in the processor's segment registers. Initially x86 processors had 4 segment registers, CS (code segment), SS (stack segment), DS (data segment) and ES (extra segment); later another two segment registers were added – FS and GS.

Paged virtual memory

In paging the memory address space or segment is divided into equal-sized blocks called pages. Using virtual memory hardware, each page can reside in any location at a suitable boundary of the computer's physical memory, or be flagged as being protected. Virtual memory makes it possible to have a linear virtual memory address space and to use it to access blocks fragmented over physical memory address space.

Most computer architectures which support paging also use pages as the basis for memory protection.

A page table maps virtual memory to physical memory. There may be a single page table, a page table for each process, a page table for each segment, or a hierarchy of page tables, depending on the architecture and the OS. The page tables are usually invisible to the process. Page tables make it easier to allocate additional memory, as each new page can be allocated from anywhere in physical memory.

It is impossible for an unprivileged application to access a page that has not been explicitly allocated to it, because every memory address either points to a page allocated to that application, or generates an interrupt called a page fault. Unallocated pages, and pages allocated to any other application, do not have any addresses from the application point of view.

A page fault may not necessarily indicate an error. Page faults are not only used for memory protection. The operating system may manage the page table in such a way that a reference to a page that has been previously swapped out to disk causes a page fault. The operating system intercepts the page fault, loads the required memory page, and the application continues as if no fault had occurred. This scheme, known as virtual memory, allows in-memory data not currently in use to be moved to disk storage and back in a way which is transparent to applications, to increase overall memory capacity.

On some systems, the page fault mechanism is also used for executable space protection such as W^X.

Protection keys

A memory protection key (MPK) mechanism divides physical memory into blocks of a particular size (e.g., 4 KiB), each of which has an associated numerical value called a protection key. Each process also has a protection key value associated with it. On a memory access the hardware checks that the current process's protection key matches the value associated with the memory block being accessed; if not, an exception occurs. This mechanism was introduced in the System/360 architecture. It is available on today's System z mainframes and heavily used by System z operating systems and their subsystems.

The System/360 protection keys described above are associated with physical addresses. This is different from the protection key mechanism used by architectures such as the Hewlett-Packard/Intel IA-64 and Hewlett-Packard PA-RISC, which are associated with virtual addresses, and which allow multiple keys per process.

In the Itanium and PA-RISC architectures, translations (TLB entries) have keys (Itanium) or access ids (PA-RISC) associated with them. A running process has several protection key registers (16 for Itanium, 4 for PA-RISC). A translation selected by the virtual address has its key compared to each of the protection key registers. If any of them match (plus other possible checks), the access is permitted. If none match, a fault or exception is generated. The software fault handler can, if desired, check the missing key against a larger list of keys maintained by software; thus, the protection key registers inside the processor may be treated as a software-managed cache of a larger list of keys associated with a process.

PA-RISC has 15–18 bits of key; Itanium mandates at least 18. Keys are usually associated with protection domains, such as libraries, modules, etc.

In the x86, the protection keys architecture allows tagging virtual addresses for user pages with any of 16 protection keys. All the pages tagged with the same protection key constitute a protection domain. A new register contains the permissions associated with each of the protection domain. Load and store operations are checked against both the page table permissions and the protection key permissions associated with the protection domain of the virtual address, and only allowed if both permissions allow the access. The protection key permissions can be set from user space, allowing applications to directly restrict access to the application data without OS intervention. Since the protection keys are associated with a virtual address, the protection domains are per address space, so processes running in different address spaces can each use all 16 domains.

Protection rings

In Multics and systems derived from it, each segment has a protection ring for reading, writing and execution; an attempt by a process with a higher ring number than the ring number for the segment causes a fault. There is a mechanism for safely calling procedures that run in a lower ring and returning to the higher ring. There are mechanisms for a routine running with a low ring number to access a parameter with the larger of its own ring and the caller's ring.

Simulated segmentation

Simulation is the use of a monitoring program to interpret the machine code instructions of some computer architectures. Such an instruction set simulator can provide memory protection by using a segmentation-like scheme and validating the target address and length of each instruction in real time before actually executing them. The simulator must calculate the target address and length and compare this against a list of valid address ranges that it holds concerning the thread's environment, such as any dynamic memory blocks acquired since the thread's inception, plus any valid shared static memory slots. The meaning of "valid" may change throughout the thread's life depending upon context. It may sometimes be allowed to alter a static block of storage, and sometimes not, depending upon the current mode of execution, which may or may not depend on a storage key or supervisor state.

It is generally not advisable to use this method of memory protection where adequate facilities exist on a CPU, as this takes valuable processing power from the computer. However, it is generally used for debugging and testing purposes to provide an extra fine level of granularity to otherwise generic storage violations and can indicate precisely which instruction is attempting to overwrite the particular section of storage which may have the same storage key as unprotected storage.

Capability-based addressing

Capability-based addressing is a method of memory protection that is unused in modern commercial computers. In this method, pointers are replaced by protected objects (called capabilities) that can only be created using privileged instructions which may only be executed by the kernel, or some other process authorized to do so. This effectively lets the kernel control which processes may access which objects in memory, with no need to use separate address spaces or context switches. Only a few commercial products used capability based security: Plessey System 250, IBM System/38, Intel iAPX 432 architecture and KeyKOS. Capability approaches are widely used in research systems such as EROS and Combex DARPA browser. They are used conceptually as the basis for some virtual machines, most notably Smalltalk and Java. Currently, the DARPA-funded CHERI project at University of Cambridge is working to create a modern capability machine that also supports legacy software.

Dynamic tainting

Dynamic tainting is a technique for protecting programs from illegal memory accesses. When memory is allocated, at runtime, this technique taints both the memory and the corresponding pointer using the same taint mark. Taint marks are then suitably propagated while the program executes and are checked every time a memory address m is accessed through a pointer p; if the taint marks associated with m and p differ, the execution is stopped and the illegal access is reported.

SPARC M7 processors (and higher) implement dynamic tainting in hardware. Oracle markets this feature as Silicon Secured Memory (SSM) (previously branded as Application Data Integrity (ADI)).

The lowRISC CPU design includes dynamic tainting under the name Tagged Memory.

Measures

The protection level of a particular implementation may be measured by how closely it adheres to the principle of minimum privilege.

Memory protection in different operating systems

Different operating systems use different forms of memory protection or separation. Although memory protection was common on most mainframes and many minicomputer systems from the 1960s, true memory separation was not used in home computer operating systems until OS/2 (and in RISC OS) was released in 1987. On prior systems, such lack of protection was even used as a form of interprocess communication, by sending a pointer between processes. It is possible for processes to access System Memory in the Windows 9x family of Operating Systems.

Some operating systems that do implement memory protection include:

On Unix-like systems, the mprotect system call is used to control memory protection.

Algorithmic information theory

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