Temporoparietal junction

From Wikipedia, the free encyclopedia

Temporoparietal junction
Side view of the human brain. TPJ is indicated by red circle.
Side view of the human brain. TPJ is indicated by red circle.
Identifiers
Acronym(s)	TPJ

The temporoparietal junction (TPJ) is an area of the brain where the temporal and parietal lobes meet, at the posterior end of the Sylvian fissure. The TPJ incorporates information from the thalamus and the limbic system, as well as from the visual, auditory, and somatosensory systems. The TPJ also integrates information from both the external environment as well as from within the body. The TPJ is responsible for collecting all of this information and then processing it. This area is also known to play a crucial role in self-other distinctions processes and theory of mind (ToM). Furthermore, damage to the TPJ has been implicated in having adverse effects on an individual’s ability to make moral decisions and has been known to produce out-of-body experiences (OBEs). Electromagnetic stimulation of the TPJ can also cause these effects. Apart from these diverse roles that the TPJ plays, it is also known for its involvement in a variety of widespread disorders including amnesia, Alzheimer's disease, and schizophrenia.

Anatomy and function

Animation. Both left and right temporoparietal junctions are shown in red.

The brain contains four main lobes: temporal lobe, parietal lobe, frontal lobe and the occipital lobe. The temporoparietal junction lies in the region between the temporal and parietal lobes, near the Sylvian fissure. Specifically, it is composed of the inferior parietal lobule and the caudal parts of the superior temporal sulcus. There are two halves to the temporoparietal junction, with each component in their respective hemispheres of the brain. Each half of the TPJ pertains to various aspects of cognitive function. Often, however, the separate halves of the TPJ will work in coordination. The TPJ is mainly involved in information processing and perception.

Right temporoparietal junction

The right temporoparietal junction (rTPJ) is involved in the processing of information in terms of the ability of an individual to pay attention. Evidence from neuroimaging studies as well as lesion studies revealed that the rTPJ plays a pivotal role in analyzing signals from self-produced actions as well as with signals from the external environment. For example, an individual with lesions in their rTPJ would more than likely exhibit a sense of hemi-neglect, wherein they would no longer be able to pay attention to anything they observe on the left. So, if someone were to have a lesion in their rTPJ, then over time the awareness of the left limbs may fade without treatment. Visual signals provide the sensory information necessary for the brain to process spatial recognition of the world. When vision is limited, knowledge of existence begins to fade away since as far as the brain is concerned the object does not exist. Furthermore, the rTPJ plays a role in the way individuals observe and process information, thus impacting social interaction. Empathy and sympathy require an individual to simultaneously distinguish between different possible perspectives on the same situation. Imaging studies show that this ability depends upon the coordinated interaction of the rTPJ to identify and process the social cues presented to it. This rapid process allows for an individual to quickly react to situations.

Left temporoparietal junction

The left temporoparietal junction (lTPJ) contains both Wernicke's area and the angular gyrus, both prominent anatomical structures of the brain that are involved in language cognition, processing, and comprehension of both written and spoken language. This is the region of the brain wherein “Mentalese”, a term coined by Steven Pinker to explain the brain’s language that translates itself into written and spoken language, is processed. According to Pinker, “knowing a language is knowing how to translate Mentalese into a string of words and vice versa.” The lTPJ succeeds in this matter by taking in observations from external environments, such as conversations, making connections in the brain regarding past memories or incidents and then converting those thoughts and connections to written and spoken language. Pinker explains this in detail in The Language Instinct: How the Mind Creates Language. The lTPJ also plays an important role in reasoning of other’s beliefs, intentions, and desires. Activation of the lTPJ was observed in patients processing mental states such as beliefs when an fMRI was used on patients as they were asked to make inferences regarding the mental states of others such as lying. This study was further supplemented by a study which identified that lesions to the left TPJ can impair cognitive processes specifically involved in the inference of someone else's belief, intention, or desire. Individuals with lesions in the lTPJ were no longer able to correctly identify when someone was lying or insinuating a false sense of belief or desire. The lTPJ is also involved in the processing of associating and remembering the names of individuals and objects.

Disorders

The dopaminergic-serotonergic system mediates our ability to distinguish and understand others beliefs as well as predict their behavior in light of that understanding. In certain disorders, involving the dopaminergic-serotonergic system, this mentalizing process is disrupted and part or all of the process is impaired; this includes amnesia and Alzheimer's disease, and schizophrenia.

Amnesia

Amnesia is a deficit in memory caused by brain damage, disease, or physiological trauma. Amnesia is best understood via Henry Molaison, or patient H.M. Molaison, who suffered from severe epilepsy and eventually had a temporal lobectomy. After surgery, his epilepsy improved but then he had anterograde amnesia, wherein long-term memory formation is inhibited. Short-term memory remained normal except that he could never remember anything that had happened after his surgery for very long. Based on general known roles of the TPJ, it is known that the TPJ is involved in the memory processing system of the body. Studies have also revealed that certain types of epileptic amnesia could be attributed to TPJ. fMRI studies indicated that there was lower activation of the rTPJ in patients with epileptic amnesia. Furthermore, it was noticed the autobiographical memories were affected in these patients. As such, the rTPJ along with the right cerebellum were identified as core components of autobiographical memory.

In terms of treatment, most forms of amnesia fix themselves without actually undergoing treatment. However, options such as cognitive therapy or occupational therapy have proved to help. Therapy will focus on various methods to improve a patient’s memory and with repetition over time, a patient’s memory as a whole will improve and eventually become close to normal.

Alzheimer's disease

Alzheimer’s disease is the most common form of dementia and is also the sixth leading cause of death in the United States. This disease has no known cure and is a disease that worsens as it progresses and eventually leads to death. Reduced metabolism in the TPJ, along with the superior frontal sulcus, correlates with Alzheimer’s patients’ inability to perceive themselves as others do (with a third-person point of view); the discrepancy between a patients’ understanding of their own cognitive impairment and the actual extent of their cognitive impairment increases as metabolism in the TPJ decreases. Additionally, the TPJ contains the praxicon, a dictionary of representations of different human actions, which is necessary to distinguishing between actions of the self and other people. Because Alzheimer’s patients, as well as patients with other forms of dementia, with anosognosia are unable to distinguish between the normal actions of other people and their own diminished abilities, it is expected that there must be damage to the TPJ that is arresting this cognitive function.

In terms of treatment options for managing the symptoms of Alzheimer’s, current options include pharmaceuticals, psychosocial intervention, caregiving, and feeding tubes. Current pharmaceuticals are either acetylcholinesterase inhibitors or an NMDA receptor antagonist. Psychosocial interventions are used to supplement pharmaceutical usage as it can take some time to get used to. Since Alzheimer’s disease does eventually lead to death with the condition worsening over time, all family members can really do is provide care for those afflicted and try to make their lives as easy as possible as the situation worsens.

Autism spectrum disorder

There is a connection between the temporoparietal junction and the ability to recognize socially awkward situations in individuals with autism spectrum disorder. Both neurotypical and autism spectrum disorder participants were asked to watch socially-awkward situations (a full-length episode of the sitcom The Office) under an fMRI which measured their brain activity. During this experiment several brain regions should be activated which involve social cognition and perception such as superior temporal gyrus, frontal gyrus, temporoparietal junction, parietal lobe, and amygdala. However, participants with autism spectrum disorder displayed a difference in activation when compared to the neurotypical individuals in their temporoparietal junction during the fMRI. Thus, participants with autism spectrum disorder have a hard time identifying socially- awkward situations since the temporoparietal junctions plays a role in social cognition and perception.  Recently, an analysis of a huge multi-centre dataset confirmed significant differences at this and other locations.

Schizophrenia

The decreased ability for schizophrenia patients to function in social situations has been related to a deficit within the theory of mind process. There have been relatively few studies that have examined the role of theory of mind in schizophrenia patients; the findings of these studies as they relate to the activation of the TPJ are varied. Some studies have found decreased activation of the TPJ in schizophrenia patients who were asked to make inferences about other peoples' social intentions based on cartoons; other studies, however, performed similar assessments of schizophrenia patients and found that the TPJ actually became hyperactive, compared to control individuals without schizophrenia, in the TPJ. This indicates that there is abnormal activation of the TPJ in these patients while performing tasks that involving understanding social intention of others, but the directionality of this abnormal activity is not clear, or possibly not universal throughout schizophrenia patients. It was found that the changes in activation in the TPJ were lateralized; they found that there was reduced activity in only the right TPJ and proposed that based on previous research about the different roles of the right and left TPJ the findings indicated that there was a more general deficit in the overall mentalizing process for these patients, but their ability to understand other individuals' basic social intentions through observing interaction is not impaired.

A study found that there was a connection between the auditory hallucinations in schizophrenia and the TPJ; the TPJ has been determined as a critical node in the auditory-verbal hallucination system. This study found that there was a significant decrease in the connectivity between the left TPJ and the right hemispheric homotope of the Broca's area, which is related to the production of language that is also characteristic of AVH events. This aspect of impairment seen in schizophrenia patients may also be related to the involvement of the TPJ with producing out of body experiences.

Anxiety Disorders

A recent study showed reduced activity in the TPJ of adolescents compared to adults during an extinction task, suggesting a role for the TPJ in anxiety disorders.

Future of possible treatments

Vasopressin is a neuropeptide that is involved in regulating social behaviors, including social memory and recognition. One study examined the connection between vasopressin and cortical areas that are involved in processing social interactions including the TPJ. This study looked specifically at the brain regions that were active in men who were given vasopressin and tested based on familiarity related tasks. They found that the introduction of vasopressin caused a localized specific change in social recognition-related activity in the left TPJ/Brodmann area 39; the presence of vasopressin diminishes the heightened activity in the left TPJ that is present upon exposure to an unfamiliar social stimulus indicating that the presence of vasopressin leads individuals to associate an unfamiliar face with a familiar category more readily. While recognizing that this is the first study that has looked into this connection, the authors propose that it has potential to lead into further research about regulating the TPJ with vasopressin or a similar compound, which could allow pharmacologists to target this area of the brain and help with certain disorders including autism, social anxiety disorder. Perhaps such an approach could also be used to treat certain symptoms of schizophrenia or other disorders with know social cognitive impairments.

Current research

Current research involving the TPJ is extensive, ranging from issues of physiology to issues of mental state. A wide range of cognitive processes rely on the TPJ and as such gaining information about it is crucial. Research is conducted by studying the role TPJ plays both with and without lesions when stimulated. Research concerns various issues such as theory of mind, out-of-body experiences, temporal order judgments, morality, etc. This is a growing field due to the prevalence of ailments that involve TPJ as well as because of the importance of perception in everyday life.

Theory of mind

Theory of mind requires the collaboration of functionally related regions of the brain to form the distinction between self and other mental states and to create a comprehensive understanding of those mental states so that we may recognize, understand, and predict behavior. In general the theory of mind process is mediated by the dopaminergic-serotonergic system, which involves the TPJ as well as other associative regions necessary for mentalizing. Recent studies suggest that both the left TPJ, working in conjunction with the frontal cortex, and the right TPJ are involved in the representation of mental states; furthermore they suggest that the TPJ is particularly active in making the distinction between the mental states of self and others. A study in Nature Neuroscience from 2004 describes how the TPJ is involved in processing socially relevant cues including gaze direction and goal-directed action and also explains that results from the study show that lesions to this area of the brain result in an impaired ability to detect another persons belief. Moreover, studies have reported an increase in activity in the TPJ when patients are absorbing information through reading or images regarding other peoples' beliefs but not while observing information about physical control stimuli. Some studies, however, have shown that the TPJ, along with the cingulate cortex, is more specifically involved with attributing beliefs, but the process of mentalizing more generally is associated more with the medial prefrontal cortex. Another study in Current Biology from 2012 identifies the importance of the TPJ in both low-level, such as simple discrimination, and high-level, such as the ability to empathize, sociocognitive operations. In July 2011, a review from Neuropsychologia presented a model of the mentalizing network that established that mental states are first detected in the TPJ. The TPJ is composed of two discrete anatomical regions, the inferior parietal lobule (IPL) and the caudal parts of the superior temporal sulcus (pSTS), and both are active in the process of distinction between mental states of different individuals; thus, it is probable that this detection is the outcome of the combination and coordination of these two parts. Additionally, the right TPJ is involved in the ventral attention stream and contributes to the ability to focus attention on a particular stimuli or objective. It has also been observed that the interaction and communication between the dorsal and ventral streams involves the TPJ.

Out-of-body experiences

The TPJ is also a crucial structure for self-processing. Several neuro-imaging studies have shown an activation of the TPJ during different aspects of self-processing such as visuo-spatial perspective, self-other distinction, mental own body imagery, and vestibular and multi sensory integration. Damage in the TPJ has been linked to out-of-body experiences (OBEs), the feeling that one’s self is located outside one’s physical body.

An OBE is defined by the presence of three characteristics: disembodiment, the impression of seeing the world from a distant and elevated visuo-spatial perspective, and the impression of seeing one’s own body from this elevated perspective. OBEs mostly occur to people with epilepsy or migraines, but approximately 10% of the healthy population also experience OBEs once or twice in a lifetime. They usually occur spontaneously and are of short duration, making OBEs hard to study. Here is an example of a patient describing what he or she experienced during an OBE:

I was in bed and about to fall asleep when I had the distinct impression that “I” was at the ceiling level looking down at my body in the bed. I was very startled and frightened; immediately [afterward] I felt that, I was consciously back in the bed again.

It is suggested that OBEs are caused by multi-sensory disintegration in the TPJ disrupting different aspects of self-processing such as illusory reduplication, illusory self-location, and illusory perspective. The brain integrates different sensory inputs to create a representation of one’s body and its location in its surrounding. Some inhibition of discrepant inputs is required to have coherency, but in some cases, those discrepant inputs are so strong and come from more than one sensory source that it leads to two different representations of one’s own body. This multi-sensory disintegration at the TPJ leads to OBEs. An electromagnetic stimulation to the right TPJ of an patient with epilepsy induced an OBE. The author also states that these experiences are closely related to schizophrenia and phantom limb.

Temporal order judgement

Temporal order is the arrangement of events in time. By judging this, one can understand how we process things. Temporal order judgments require an individual to determine the relative timing between two spatially separate events. One study revealed that subjects had to determine the order of appearance of two objects as well as which object fit a certain property better. What was learned from this study was that when identifying the order or appearance, fMRI studies showed that there was bilateral activation of the TPJ. Meanwhile, when it comes to object characterization based on a property, it was noticed that there was only activation of the lTPJ. As such, it is evident that TPJ is involved in the “when” pathway of the brain.

Morality

Morality is the differentiation in intention between choosing between what is good and what is bad. Connections made at the TPJ help an individual understand their emotions and make decisions based on them. The TPJ allows the association of emotions to events or individuals, aiding in the decision making process. However, errors in this emotional processing can arise when patients have lesions in the TPJ or when the brain is electrically stimulated. transcranial magnetic stimulation (TMS) can be used to disrupt neural activity in the rTPJ right before a patient had to make a moral decision as well as during the decision making process, constituting to two different testing environments. Then, when presented with a moral dilemma, patients’ ability to make morally-sound decisions was deterred. TMS to the rTJ affects the ability of an individual to use mental states to make moral decisions. Studies also show that there is a relation between theory of mind and moral judgment, once again signifying the role of the rTPJ in morality.

Ventromedial prefrontal cortex

From Wikipedia, the free encyclopedia

Ventromedial prefrontal cortex
Ventromedial prefrontal cortex shown on medial and ventral views of the brain, reflecting approximate location of damage in patients with decision making deficits.
Medial surface of the brain with Brodmann's areas numbered.
Details
Identifiers
Latin	Cortex praefrontalis ventromedialis
Anatomical terms of neuroanatomy

The ventromedial prefrontal cortex (vmPFC) is a part of the prefrontal cortex in the mammalian brain. The ventral medial prefrontal is located in the frontal lobe at the bottom of the cerebral hemispheres and is implicated in the processing of risk and fear. It also plays a role in the inhibition of emotional responses, and in the process of decision making and self control. It is also involved in the cognitive evaluation of morality.

Anatomy

While the ventromedial prefrontal cortex does not have a universally agreed on demarcation, in most sources, it is equivalent to the ventromedial reward network of Ongur and Price. This network includes Brodmann area 10, Brodmann area 14, Brodmann area 25, and Brodmann area 32, as well as portions of Brodmann area 11, Brodmann area 12, and Brodmann area 13. However, not all sources agree on the boundaries of the area. Different researchers use the term ventromedial prefrontal cortex differently. Sometimes, the term is saved for the area above the medial orbitofrontal cortex, while at other times, 'ventromedial prefrontal cortex' is used to describe a broad area in the lower (ventral) central (medial) region of the prefrontal cortex, of which the medial orbitofrontal cortex constitutes the lowermost part. This latter, broader area, corresponds to the area damaged in patients with decision-making impairments investigated by António Damásio and colleagues (see diagram, and below).

To get a rough idea of where the ventromedial prefrontal cortex is, recall that the left and right hemispheres of the brain are separated [by the longitudinal cerebral fissure]. Now imagine you could take your hand and starting at the anterior brain (where your forehead is) insert it into this gap until you reached the insula (a structure that is beneath the frontal lobe). Your palm would be touching a part of the prefrontal cortex, which is in the front part of the brain and the lower part of your palm would be touching the ventral medial prefrontal cortex.

The ventromedial prefrontal cortex is connected to and receives input from the ventral tegmental area, amygdala, the temporal lobe, the olfactory system, and the dorsomedial thalamus. It, in turn, sends signals to many different brain regions including; The temporal lobe, amygdala, the lateral hypothalamus, the hippocampal formation, the cingulate cortex, and certain other regions of the prefrontal cortex.^[4] This huge network of connections affords the vmPFC the ability to receive and monitor large amounts of sensory data and to affect and influence a plethora of other brain regions, particularly the amygdala.

Function

Functional differences between the orbitofrontal and ventromedial areas of the pre-frontal cortex have not yet been clearly established, although the areas of the ventromedial cortex superior to the orbitofrontal cortex are much less associated with social functions and more with pure emotion regulation. Research in developmental neuroscience also suggested that neural networks in the ventromedial prefrontal cortex are rapidly developing during adolescence and young adulthood supporting emotion regulation through the amygdala, being associated with a decrease in cortisol levels.

There are only a few reports of people with early-onset vmPFC damage during childhood, but these individuals tend to have severe antisocial behavior and impaired moral judgment. Compared to individuals with damage later in life, their behavior pattern is similar but more severe.

Decision making

Patients with bilateral lesions of the vmPFC develop severe impairments in personal and social decision-making even though most of their intellectual ability is preserved. For instance, they have difficulties in choosing between options with uncertain outcomes, whether the uncertainty is in the form of a risk or of an ambiguity. After their lesion, these patients have an impaired capacity to learn from their mistakes, making the same decisions again and again even though they lead to negative consequences. These patients choose alternatives that give immediate rewards, but seem to be blind to the future consequences of their actions. However, the underlying mechanisms of this behaviour are not yet fully understood.

Damage to the ventromedial prefrontal cortex (especially in the right hemisphere) has been connected with deficits in detecting irony, sarcasm, and deception. Subjects with damage in this area have been found to be more easily influenced by misleading advertising. This has been attributed to a disruption of a "false tagging mechanism" which provides doubt and skepticism of new beliefs.

People with damage to the ventromedial prefrontal cortex still retain the ability to consciously make moral judgments without error, but only in hypothetical situations presented to them. There is a gap in reasoning when applying the same moral principles to similar situations in their own lives. The result is that people make decisions that are inconsistent with their self professed moral values. People with early damage to the ventromedial prefrontal cortex are more likely to endorse self-serving actions that break moral rules or cause harm to others. This is especially true for patients whose damage occurred the earliest in life.

Emotions and an understanding of social norms are used to provide reasoning of the moral nature on our behaviors, beliefs, and the people around us. The vmPFC works as the neural basis in allowing emotion to influence moral judgement. The trolley dilemma is a classic situation testing emotional involvement in moral judgment. In the trolley dilemma, participants imagine a runaway trolley heading toward five people who will be killed if the trolley is to continue. The participant is to decide whether to allow the trolley to run its course, or to shunt the trolley off to another track where it will only kill one person. Most people choose to throw the switch, concluding that it is moral to save five by sacrificing the life of one. In a variation, there is no switch at hand to shunt the trolley, instead the participant has the option to push someone on the trolley tracks to stop it from moving. Most people are repulsed at the idea of pushing the man to his death, even though outcome is the same as the first dilemma, with five people surviving and one person dying. The more personal nature of pushing someone onto the tracks discourages this response, and the role of emotion is proposed to be the difference in the reasoning. In functional imaging studies, increased activity in the vmPFC is associated with thinking of these personal moral situations, while making harmless decisions does not. Patients with vmPFC lesions made the same decision in impersonal and personal dilemmas. Dysfunction of the vmPFC causes failure in using correct moral emotion, which explains why these patients showed less emotional responses when facing these dilemmas.

Regulation of emotion

The vmPFC plays an important role in regulating and inhibiting our response to emotions. VmPFC seems to use our emotional reactions to model our behavior and control emotional reactions in certain social situations. The inputs of the vmPFC provide it with information from the environment and the plans of the frontal lobe, and its outputs allow the vmPFC to control different physiological responses and behaviors. The role of the vmPFC is especially highlighted in people with damage to this region. A damaged vmPFC causes impairments of behavioral control and decision making, consequences which are rooted in emotional dysregulation. The first and most famous case of someone with defects to this region was Phineas Gage, a railroad construction foreman who had his vmPFC bilaterally destroyed in an accident in 1848. Before his accident, Gage was described as “serious, industrious and energetic. Afterward he became childish, irresponsible, and thoughtless of others.” Another patient with vmPFC damage wasted away his life savings on foolish investments and failed to make appropriate decisions in his personal life. In patients with vmPFC damage, evidence shows that there is a correlation between emotional dysregulation and dysfunction in real world competencies.

The amygdala plays a significant role in instigating the emotional reactions associated with anger and violence. With the vmPFC’s outputs to the amygdala, the vmPFC plays a part in preventing such behavior. Evidence has shown that impulsive murderers have decreased activity in the prefrontal cortex and increased activity in subcortical areas such as the amygdala. This imbalance can enhance actions that are created by negative emotions and limit the ability of the prefrontal cortex to control these emotions. Lower activation in the prefrontal cortex is also correlated with antisocial behavior. The dysfunction of the ventromedial cortex seems to, in part, be caused by lower levels of serotonin release.

The vmPFC also is involved in courage. In experiments with participants allowing snakes to come near or away from them, acts of courage correlated with activation in the vmPFC, specifically the subgenual anterior cingulate cortex.

Activation of the vmPFC is associated with successful suppression of emotional responses to a negative emotional signal. Patients with vmPFC lesions show defects both in emotional response and emotion regulation. Their emotional responsivity is generally diminished and they show markedly reduced social emotions such as compassion, shame and guilt. These are emotions that are closely associated with moral values. Patients also exhibit poorly regulated anger and frustration tolerance in certain circumstances.

Patients with focal lesions in the vmPFC show personality changes such as lack of empathy, irresponsibility, and poor decision making. These traits are similar to psychopathic personality traits. In addition, a correlation between individuals with a history of physical violence and decreased grey matter density in the vmPFC has been evidenced.

The right half of the ventromedial prefrontal cortex was associated with regulating the interaction of cognition and affect in the production of empathic responses. Hedonic (pleasure) responses were also associations to orbitofrontal cortex activity level by Morten Kringelbach. This finding contributes findings suggesting ventromedial prefrontal cortex being associated with preference judgement, possibly assigning the ventromedial prefrontal cortex a key role in constructing one's self. Studies with Posttraumatic Stress Disorder (PTSD) also supported the idea that the ventromedial prefrontal cortex is an important component for reactivating past emotional associations and events, therefore essentially mediating pathogenesis of PTSD. Dysfunction of the vmPFC has also been identified as playing a role in PTSD-affected parents' response to their own children's mental states. Treatments geared to the activation of the ventromedial prefrontal cortex were therefore suggested for individuals and parent-child relationships affected by PTSD. The right half of the ventrolateral prefrontal cortex, being active during emotion regulation, was activated when participants were offered an unfair offer in a scenario. Specific deficits in reversal learning and decision-making have led to the hypothesis that the ventromedial prefrontal cortex is a major locus of dysfunction in the mild stages of the behavioural variant of frontotemporal dementia.

The capacity for mature defense mechanisms such as intellectualization, compensation, reaction formation, and isolation has been tied to proper functioning of the right ventromedial prefrontal cortex, while more primitive defense mechanisms such as projection, splitting, verbal denial, and fantasy have been found to rely on other regions, primarily in the left hemisphere .

Somatic marker hypothesis

One particularly notable theory of vmPFC function is the somatic marker hypothesis, accredited to António Damásio. By this hypothesis, the vmPFC has a central role in adapting somatic markers—emotional associations, or associations between mental objects and visceral (bodily) feedback—for use in natural decision making. This account also gives the vmPFC a role in moderating emotions and emotional reactions because whether the vmPFC decides the markers are positive or negative affects the appropriate response in a particular situation. However, a critical review of this hypothesis concluded that there is a need for additional empirical data to support the somatic marker theory.

Extinction

Another role that the vmPFC plays is in the process of extinction, the gradual weakening and eventual cessation of a conditioned response, as studies have shown increased activation of the vmPFC after extinction training. The specific role played by the vmPFC concerning extinction is not well understood, but it is believed that it plays a necessary role in the recall of extinction learning after a long period of time. Studies show that it aids in the consolidation of extinction learning. A separate study has implicated the correlation between the cortical thickness of the vmPFC and the degree of extinction memory. Patients with larger vmPFCs tended to have lower responses to the extinct conditioned stimulus, therefore suggesting a superior extinction memory. In general, the ventromedial prefrontal cortex plays a major role in the later stages of memory consolidation.

Gender specific social cues

Ventromedial prefrontal cortex lesions were also associated with a deficit in processing gender specific social cues. One experiment tested the ability of patients with vmPFC lesions to categorize gender-specific names, attributes, and attitudes compared to patients with dorsolateral prefrontal cortex lesions and control subjects. Whereas the patients with dorsolateral prefrontal cortex lesions performed similarly to the control subjects on tests indicating gender stereotypes, patients with ventromedial prefrontal cortex lesions demonstrated impaired stereotypic social knowledge.

Cocaine abuse

Frequent cocaine users have been shown to have lower than normal activity in the ventromedial prefrontal cortex. When asked to perform certain tasks that rely heavily on activation of this area of the brain, the cocaine users perform worse and have less prefrontal cortex activation than the control subjects. The quantity of cocaine used was found to be inversely proportional to the level of activation.

The prefrontal cortex is also physically affected by cocaine use. Chronic use has been shown to lead to a decrease in the amount of gray matter in the ventromedial prefrontal cortex. The decrease in gray matter and effect on behavior is analogous to a person having lesions throughout their medial prefrontal cortex. Specifically, the pyramidal cells of the ventromedial prefrontal cortex are known to be linked with drug seeking behaviors. Both an increased and decreased level of activity in these pyramidal cells has shown to lead to extinction of cocaine-seeking behaviors depending on when the activation takes place. Inactivation of these cells was needed to inhibit cocaine-seeking behavior after a longer duration of time, whereas activation was required to reduce the behavior soon after using cocaine.

Morality

From Wikipedia, the free encyclopedia

Allegory with a portrait of a Venetian senator (Allegory of the morality of earthly things), attributed to Tintoretto, 1585

Morality (from Latin: moralis, lit. 'manner, character, proper behavior') is the differentiation of intentions, decisions and actions between those that are distinguished as proper and those that are improper. Morality can be a body of standards or principles derived from a code of conduct from a particular philosophy, religion or culture, or it can derive from a standard that a person believes should be universal. Morality may also be specifically synonymous with "goodness" or "rightness".

Moral philosophy includes moral ontology, which is the origin of morals; and moral epistemology, which studies the knowledge of morals. Different systems of expressing morality have been proposed, including deontological ethical systems which adhere to a set of established rules, and normative ethical systems which consider the merits of actions themselves. An example of normative ethical philosophy is the Golden Rule, which states that: "One should treat others as one would like others to treat oneself."

Immorality is the active opposition to morality (i.e. opposition to that which is good or right), while amorality is variously defined as an unawareness of, indifference toward, or disbelief in any particular set of moral standards or principles.

Philosophy

Ethics

Immanuel Kant introduced the categorical imperative: "Act only according to that maxim whereby you can, at the same time, will that it should become a universal law".

Ethics (also known as moral philosophy) is the branch of philosophy which addresses questions of morality. The word "ethics" is "commonly used interchangeably with 'morality,' and sometimes it is used more narrowly to mean the moral principles of a particular tradition, group, or individual." Likewise, certain types of ethical theories, especially deontological ethics, sometimes distinguish between ethics and morals: "Although the morality of people and their ethics amounts to the same thing, there is a usage that restricts morality to systems such as that of Immanuel Kant, based on notions such as duty, obligation, and principles of conduct, reserving ethics for the more Aristotelian approach to practical reasoning, based on the notion of a virtue, and generally avoiding the separation of 'moral' considerations from other practical considerations."

Descriptive and normative

In its descriptive sense, "morality" refers to personal or cultural values, codes of conduct or social mores from a society that provides these codes of conduct in which it applies and is accepted by an individual. It does not connote objective claims of right or wrong, but only refers to that which is considered right or wrong. Descriptive ethics is the branch of philosophy which studies morality in this sense.

In its normative sense, "morality" refers to whatever (if anything) is actually right or wrong, which may be independent of the values or mores held by any particular peoples or cultures. Normative ethics is the branch of philosophy which studies morality in this sense.

Realism and anti-realism

Philosophical theories on the nature and origins of morality (that is, theories of meta-ethics) are broadly divided into two classes:

• Moral realism is the class of theories which hold that there are true moral statements that report objective moral facts. For example, while they might concede that forces of social conformity significantly shape individuals' "moral" decisions, they deny that those cultural norms and customs define morally right behavior. This may be the philosophical view propounded by ethical naturalists, however not all moral realists accept that position (e.g. ethical non-naturalists);
• Moral anti-realism, on the other hand, holds that moral statements either fail or do not even attempt to report objective moral facts. Instead, they hold that moral sentences are either categorically false claims of objective moral facts (error theory); claims about subjective attitudes rather than objective facts (ethical subjectivism); or else not attempts to describe the world at all but rather something else, like an expression of an emotion or the issuance of a command (non-cognitivism).

Some forms of non-cognitivism and ethical subjectivism, while considered anti-realist in the robust sense used here, are considered realist in the sense synonymous with moral universalism. For example, universal prescriptivism is a universalist form of non-cognitivism which claims that morality is derived from reasoning about implied imperatives, and divine command theory and ideal observer theory are universalist forms of ethical subjectivism which claim that morality is derived from the edicts of a god or the hypothetical decrees of a perfectly rational being, respectively.

Anthropology

Tribal and territorial

Celia Green made a distinction between tribal and territorial morality. She characterizes the latter as predominantly negative and proscriptive: it defines a person's territory, including his or her property and dependents, which is not to be damaged or interfered with. Apart from these proscriptions, territorial morality is permissive, allowing the individual whatever behaviour does not interfere with the territory of another. By contrast, tribal morality is prescriptive, imposing the norms of the collective on the individual. These norms will be arbitrary, culturally dependent and 'flexible', whereas territorial morality aims at rules which are universal and absolute, such as Kant's 'categorical imperative' and Geisler's graded absolutism. Green relates the development of territorial morality to the rise of the concept of private property, and the ascendancy of contract over status.

In-group and out-group

Some observers hold that individuals apply distinct sets of moral rules to people depending on their membership of an "in-group" (the individual and those they believe to be of the same group) or an "out-group" (people not entitled to be treated according to the same rules). Some biologists, anthropologists and evolutionary psychologists believe this in-group/out-group discrimination has evolved because it enhances group survival. This belief has been confirmed by simple computational models of evolution. In simulations this discrimination can result in both unexpected cooperation towards the in-group and irrational hostility towards the out-group. Gary R. Johnson and V.S. Falger have argued that nationalism and patriotism are forms of this in-group/out-group boundary. Jonathan Haidt has noted that experimental observation indicating an in-group criterion provides one moral foundation substantially used by conservatives, but far less so by liberals.

Comparing cultures

Peterson and Seligman approach the anthropological view looking across cultures, geo-cultural areas and across millennia. They conclude that certain virtues have prevailed in all cultures they examined. The major virtues they identified include wisdom / knowledge; courage; humanity; justice; temperance; and transcendence. Each of these includes several divisions. For instance humanity includes love, kindness, and social intelligence.

Fons Trompenaars, author of Did the Pedestrian Die?, tested members of different cultures with various moral dilemmas. One of these was whether the driver of a car would have his friend, a passenger riding in the car, lie in order to protect the driver from the consequences of driving too fast and hitting a pedestrian. Trompenaars found that different cultures had quite different expectations, from none to definite.

John Newton, author of Complete Conduct Principles for the 21st Century compared the Eastern and the Western cultures about morality. As stated in Complete Conduct Principles for the 21st Century, "One of the important objectives of this book is to blend harmoniously the fine souls regarding conduct in the Eastern and the Western cultures, to take the result as the source and then to create newer and better conduct principles to suit the human society of the new century, and to introduce a lot of Chinese fine conduct spirits to the Western world. It is hoped that this helps solve lots of problems the human society of the 21st century faces, including (but not limited to the Eastern and the Western cultures) what a single culture cannot."

Evolution

The development of modern morality is a process closely tied to sociocultural evolution. Some evolutionary biologists, particularly sociobiologists, believe that morality is a product of evolutionary forces acting at an individual level and also at the group level through group selection (although to what degree this actually occurs is a controversial topic in evolutionary theory). Some sociobiologists contend that the set of behaviors that constitute morality evolved largely because they provided possible survival or reproductive benefits (i.e. increased evolutionary success). Humans consequently evolved "pro-social" emotions, such as feelings of empathy or guilt, in response to these moral behaviors.
On this understanding, moralities are sets of self-perpetuating and biologically-driven behaviors which encourage human cooperation. Biologists contend that all social animals, from ants to elephants, have modified their behaviors, by restraining immediate selfishness in order to improve their evolutionary fitness. Human morality, although sophisticated and complex relative to the moralities of other animals, is essentially a natural phenomenon that evolved to restrict excessive individualism that could undermine a group's cohesion and thereby reducing the individuals' fitness.

On this view, moral codes are ultimately founded on emotional instincts and intuitions that were selected for in the past because they aided survival and reproduction (inclusive fitness). Examples: the maternal bond is selected for because it improves the survival of offspring; the Westermarck effect, where close proximity during early years reduces mutual sexual attraction, underpins taboos against incest because it decreases the likelihood of genetically risky behaviour such as inbreeding.

The phenomenon of reciprocity in nature is seen by evolutionary biologists as one way to begin to understand human morality. Its function is typically to ensure a reliable supply of essential resources, especially for animals living in a habitat where food quantity or quality fluctuates unpredictably. For example, some vampire bats fail to feed on prey some nights while others manage to consume a surplus. Bats that did eat will then regurgitate part of their blood meal to save a conspecific from starvation. Since these animals live in close-knit groups over many years, an individual can count on other group members to return the favor on nights when it goes hungry (Wilkinson, 1984)
Marc Bekoff and Jessica Pierce (2009) have argued that morality is a suite of behavioral capacities likely shared by all mammals living in complex social groups (e.g., wolves, coyotes, elephants, dolphins, rats, chimpanzees). They define morality as "a suite of interrelated other-regarding behaviors that cultivate and regulate complex interactions within social groups." This suite of behaviors includes empathy, reciprocity, altruism, cooperation, and a sense of fairness. In related work, it has been convincingly demonstrated that chimpanzees show empathy for each other in a wide variety of contexts. They also possess the ability to engage in deception, and a level of social politics prototypical of our own tendencies for gossip and reputation management.

Christopher Boehm (1982) has hypothesized that the incremental development of moral complexity throughout hominid evolution was due to the increasing need to avoid disputes and injuries in moving to open savanna and developing stone weapons. Other theories are that increasing complexity was simply a correlate of increasing group size and brain size, and in particular the development of theory of mind abilities.

Moral cognition

Moral cognition refers to cognitive processes that allow a person to act or decide in morally permissible ways. It consists of several domain-general cognitive processes, ranging from perception of a morally-salient stimuli to reasoning when faced with a moral dilemma. While it’s important to mention that there is not a single cognitive faculty dedicated exclusively to moral cognition, characterizing the contributions of domain-general processes to moral behavior is a critical scientific endeavor to understand how morality works and how it can be improved.

Cognitive psychologists and neuroscientists investigate the inputs to these cognitive processes and their interactions, as well as how these contribute to moral behavior by running controlled experiments. In these experiments putatively moral versus nonmoral stimuli are compared to each other, while controlling for other variables such as content or working memory load. Often, the differential neural response to specifically moral statements or scenes, are examined using functional neuroimaging experiments.

Critically, the specific cognitive processes that are involved depend on the prototypical situation that a person encounters. For instance, while situations that require an active decision on a moral dilemma may require active reasoning, an immediate reaction to a shocking moral violation may involve quick, affect-laden processes. Nonetheless certain cognitive skills such as being able to attribute mental states—beliefs, intents, desires, emotions to oneself, and to others is a common feature of a broad range of prototypical situations. In line with this, a meta-analysis found overlapping activity between moral emotion and moral reasoning tasks, suggesting a shared neural network for both tasks. The results of this meta-analaysis, however, also demonstrated that the processing of moral input is affected by task demands.

Neuroscience

The brain areas that are consistently involved when humans reason about moral issues have been investigated by a quantitative large-scale meta-analysis of the brain activity changes reported in the moral neuroscience literature. In fact, the neural network underlying moral decisions overlapped with the network pertaining to representing others' intentions (i.e., theory of mind) and the network pertaining to representing others' (vicariously experienced) emotional states (i.e., empathy). This supports the notion that moral reasoning is related to both seeing things from other persons' points of view and to grasping others' feelings. These results provide evidence that the neural network underlying moral decisions is probably domain-global (i.e., there might be no such things as a "moral module" in the human brain) and might be dissociable into cognitive and affective sub-systems.

Brain areas

An essential, shared component of moral judgment involves the capacity to detect morally salient content within a given social context. Recent research implicated the salience network in this initial detection of moral content. The salience network responds to behaviorally salient events and may be critical to modulate downstream default and frontal control network interactions in the service of complex moral reasoning and decision-making processes.

The explicit making of moral right and wrong judgments coincides with activation in the ventromedial prefrontal cortex (VMPC) while intuitive reactions to situations containing implicit moral issues activates the temporoparietal junction area.

Stimulation of the VMPC by transcranial magnetic stimulation, has been shown to inhibit the ability of human subjects to take into account intent when forming a moral judgment. According to this investigation, TMS did not disrupt participants' ability to make any moral judgment. On the contrary, moral judgments of intentional harms and non-harms were unaffected by TMS to either the RTPJ or the control site; presumably, however, people typically make moral judgments of intentional harms by considering not only the action's harmful outcome but the agent's intentions and beliefs. So why were moral judgments of intentional harms not affected by TMS to the RTPJ? One possibility is that moral judgments typically reflect a weighted function of any morally relevant information that is available at the time. On the basis of this view, when information concerning the agent's belief is unavailable or degraded, the resulting moral judgment simply reflects a higher weighting of other morally relevant factors (e.g., outcome). Alternatively, following TMS to the RTPJ, moral judgments might be made via an abnormal processing route that does not take belief into account. On either account, when belief information is degraded or unavailable, moral judgments are shifted toward other morally relevant factors (e.g., outcome). For intentional harms and non-harms, however, the outcome suggests the same moral judgment as the intention. Thus, the researchers suggest that TMS to the RTPJ disrupted the processing of negative beliefs for both intentional harms and attempted harms, but the current design allowed the investigators to detect this effect only in the case of attempted harms, in which the neutral outcomes did not afford harsh moral judgments on their own.

Similarly VMPC-impaired persons will judge an action purely on its outcome and are unable to take into account the intent of that action.

Mirror neurons

Mirror neurons are neurons in the brain that fire when another person is observed doing a certain action. The neurons fire in imitation of the action being observed, causing the same muscles to act minutely in the observer as are acting grossly in the person actually performing the action. Research on mirror neurons, since their discovery in 1996, suggests that they may have a role to play not only in action understanding, but also in emotion sharing empathy. Cognitive neuro-scientist Jean Decety thinks that the ability to recognize and vicariously experience what another individual is undergoing was a key step forward in the evolution of social behavior, and ultimately, morality. The inability to feel empathy is one of the defining characteristics of psychopathy, and this would appear to lend support to Decety's view.

Psychology

Kohlberg Model of Moral Development

In modern moral psychology, morality is considered to change through personal development. A number of psychologists have produced theories on the development of morals, usually going through stages of different morals. Lawrence Kohlberg, Jean Piaget, and Elliot Turiel have cognitive-developmental approaches to moral development; to these theorists morality forms in a series of constructive stages or domains. In the Ethics of care approach established by Carol Gilligan, moral development occurs in the context of caring, mutually responsive relationships which are based on interdependence, particularly in parenting but also in social relationships generally. Social psychologists such as Martin Hoffman and Jonathan Haidt emphasize social and emotional development based on biology, such as empathy. Moral identity theorists, such as William Damon and Mordechai Nisan, see moral commitment as arising from the development of a self-identity that is defined by moral purposes: this moral self-identity leads to a sense of responsibility to pursue such purposes. Of historical interest in psychology are the theories of psychoanalysts such as Sigmund Freud, who believe that moral development is the product of aspects of the super-ego as guilt-shame avoidance.

Because we are naturally prone to be empathic and moral, we have a sense of responsibility to pursue moral purposes, we still, at least occasionally, engage in immoral behavior. Such behaviors jeopardize our moral self-image; however, when we engage in immoral behaviors we still feel as though we are moral individuals. Moral self-licensing attempts to explain this phenomenon and proposes that self-image security increases our likelihood to engage in immoral behavior. When our moral self-image is threatened, we can gain confidence from our past moral behavior. The more confident we are, the less we will worry about our future behavior which actually increases the likelihood that we will engage in immoral behaviors. Monin and Miller (2001) examined the moral self-licensing effect and found that when participants established credentials as non-prejudiced persons, they were more willing to express politically incorrect opinions despite the fact that the audience was unaware of their credentials.

As an alternative to viewing morality as an individual trait, some sociologists as well as social- and discursive psychologists have taken upon themselves to study the in-vivo aspects of morality by examining how persons conduct themselves in social interaction.

Politics

If morality is the answer to the question 'how ought we to live' at the individual level, politics can be seen as addressing the same question at the social level, though the political sphere raises additional problems and challenges. It is therefore unsurprising that evidence has been found of a relationship between attitudes in morality and politics. Jonathan Haidt and Jesse Graham have studied the differences between liberals and conservatives, in this regard. Haidt found that Americans who identified as liberals tended to value care and fairness higher than loyalty, respect and purity. Self-identified conservative Americans valued care and fairness less and the remaining three values more. Both groups gave care the highest over-all weighting, but conservatives valued fairness the lowest, whereas liberals valued purity the lowest. Haidt also hypothesizes that the origin of this division in the United States can be traced to geo-historical factors, with conservatism strongest in closely knit, ethnically homogenous communities, in contrast to port-cities, where the cultural mix is greater, thus requiring more liberalism.

Group morality develops from shared concepts and beliefs and is often codified to regulate behavior within a culture or community. Various defined actions come to be called moral or immoral. Individuals who choose moral action are popularly held to possess "moral fiber", whereas those who indulge in immoral behavior may be labeled as socially degenerate. The continued existence of a group may depend on widespread conformity to codes of morality; an inability to adjust moral codes in response to new challenges is sometimes credited with the demise of a community (a positive example would be the function of Cistercian reform in reviving monasticism; a negative example would be the role of the Dowager Empress in the subjugation of China to European interests). Within nationalist movements, there has been some tendency to feel that a nation will not survive or prosper without acknowledging one common morality, regardless of its content. Political Morality is also relevant to the behavior internationally of national governments, and to the support they receive from their host population. Noam Chomsky states that

... if we adopt the principle of universality : if an action is right (or wrong) for others, it is right (or wrong) for us. Those who do not rise to the minimal moral level of applying to themselves the standards they apply to others—more stringent ones, in fact—plainly cannot be taken seriously when they speak of appropriateness of response; or of right and wrong, good and evil. In fact, one of the, maybe the most, elementary of moral principles is that of universality, that is, If something's right for me, it's right for you; if it's wrong for you, it's wrong for me. Any moral code that is even worth looking at has that at its core somehow.

Religion

Religion and morality are not synonymous. Morality does not depend upon religion although for some this is "an almost automatic assumption". According to The Westminster Dictionary of Christian Ethics, religion and morality "are to be defined differently and have no definitional connections with each other. Conceptually and in principle, morality and a religious value system are two distinct kinds of value systems or action guides."

Positions

Within the wide range of moral traditions, religious value systems co-exist with contemporary secular frameworks such as consequentialism, freethought, humanism, utilitarianism, and others. There are many types of religious value systems. Modern monotheistic religions, such as Islam, Judaism, Christianity, and to a certain degree others such as Sikhism and Zoroastrianism, define right and wrong by the laws and rules set forth by their respective scriptures and as interpreted by religious leaders within the respective faith. Other religions spanning pantheistic to nontheistic tend to be less absolute. For example, within Buddhism, the intention of the individual and the circumstances should be accounted for to determine if an action is right or wrong. A further disparity between the values of religious traditions is pointed out by Barbara Stoler Miller, who states that, in Hinduism, "practically, right and wrong are decided according to the categories of social rank, kinship, and stages of life. For modern Westerners, who have been raised on ideals of universality and egalitarianism, this relativity of values and obligations is the aspect of Hinduism most difficult to understand".

Religions provide different ways of dealing with moral dilemmas. For example, there is no absolute prohibition on killing in Hinduism, which recognizes that it "may be inevitable and indeed necessary" in certain circumstances. In monotheistic traditions, certain acts are viewed in more absolute terms, such as abortion or divorce. Religion is not always positively associated with morality. Philosopher David Hume stated that, "the greatest crimes have been found, in many instances, to be compatible with a superstitious piety and devotion; Hence it is justly regarded as unsafe to draw any inference in favor of a man's morals, from the fervor or strictness of his religious exercises, even though he himself believe them sincere."

Religious value systems can diverge from commonly-held contemporary moral positions, such as those on murder, mass atrocities, and slavery. For example, Simon Blackburn states that "apologists for Hinduism defend or explain away its involvement with the caste system, and apologists for Islam defend or explain away its harsh penal code or its attitude to women and infidels". In regard to Christianity, he states that the "Bible can be read as giving us a carte blanche for harsh attitudes to children, the mentally handicapped, animals, the environment, the divorced, unbelievers, people with various sexual habits, and elderly women", and notes morally suspect themes in the Bible's New Testament as well. Christian apologists address Blackburn's viewpoints and construe that Jewish laws in the Jewish Bible showed the evolution of moral standards towards protecting the vulnerable, imposing a death penalty on those pursuing slavery and treating slaves as persons and not property. Elizabeth Anderson holds that "the Bible contains both good and evil teachings", and it is "morally inconsistent". Humanists like Paul Kurtz believe that we can identify moral values across cultures, even if we do not appeal to a supernatural or universalist understanding of principles - values including integrity, trustworthiness, benevolence, and fairness. These values can be resources for finding common ground between believers and nonbelievers.

Empirical analyses

A number of studies have been conducted on the empirics of morality in various countries, and the overall relationship between faith and crime is unclear. A 2001 review of studies on this topic found "The existing evidence surrounding the effect of religion on crime is varied, contested, and inconclusive, and currently no persuasive answer exists as to the empirical relationship between religion and crime." Phil Zuckerman's 2008 book, Society without God, based on studies conducted during a 14-month period in Scandinavia in 2005-2006, notes that Denmark and Sweden, "which are probably the least religious countries in the world, and possibly in the history of the world", enjoy "among the lowest violent crime rates in the world [and] the lowest levels of corruption in the world".

Dozens of studies have been conducted on this topic since the twentieth century. A 2005 study by Gregory S. Paul published in the Journal of Religion and Society stated that, "In general, higher rates of belief in and worship of a creator correlate with higher rates of homicide, juvenile and early adult mortality, STD infection rates, teen pregnancy, and abortion in the prosperous democracies," and "In all secular developing democracies a centuries long-term trend has seen homicide rates drop to historical lows" with the exceptions being the United States (with a high religiosity level) and "theistic" Portugal. In a response, Gary Jensen builds on and refines Paul's study. His conclusion is that a "complex relationship" exists between religiosity and homicide "with some dimensions of religiosity encouraging homicide and other dimensions discouraging it". On April 26, 2012, the results of a study which tested their subjects' pro-social sentiments were published in the Social Psychological and Personality Science journal in which non-religious people had higher scores showing that they were more inclined to show generosity in random acts of kindness, such as lending their possessions and offering a seat on a crowded bus or train. Religious people also had lower scores when it came to seeing how much compassion motivated participants to be charitable in other ways, such as in giving money or food to a homeless person and to non-believers.