Archive for February 14th, 2010

14/02/2010

Short review: Silvia A. Bunge, Itamar Kahn, Jonathan D. Wallis, Earl K. Miller, Anthony D. Wagner, Neural Circuits Subserving the Retrieval and Maintenance of Abstract Rules, Journal of Neurophysiology, 2003, 90, pp. 3419-3428.

Short review:

Silvia A. Bunge, Itamar Kahn, Jonathan D. Wallis, Earl K. Miller, Anthony D. Wagner, Neural Circuits Subserving the Retrieval and Maintenance of Abstract Rules, Journal of Neurophysiology, 2003, 90, pp. 3419-3428.

1. Summary

(a)    Theses:

Thesis 1: Ventrolateral PFC (VLPFC) is correlated with controlled retrieval and maintenance of abstract rule representations.

Thesis 2: Temporal cortex is correlated with an abstract rule retrieval.

Thesis 3: Left anterior and posterior VLPFC interact with temporal cortices to retrieve the rule, FPC reformulates the rule into a form that can be used to guide behaviour more specifically, and posterior VLPFC and parietal cortices interact to maintain the relevant response contingencies.

(b)   Experimental setting:

Experiment: First, subjects learned to associate each of four verbal and nonverbal cues with one of four rules: match, non-match, go left or go right. Non of the cues had preexperimental associations (verbal cues were pronounceable nonwords, e.g. ‘pohu’, and the nonverbal cues were unfamiliar shapes). Then, participants were asked to perform a task while being fMRI scanned. During the task, a cue was presented for 1 s, followed by a variable delay (ranging from 7 s to 15 s). After the delay, a picture was presented (the sample) and was followed by a second picture (the probe) that was either identical to or different from the sample. Two white circles apperead below the second picture, indicating that the participant should make a response by pressing one of two buttons with their left hand. On match trials, subjects were to press the left button if the probe matched the sample and the right button if it did not match. On non-match trials, subjects were to press the left button if the probe did not match the sample and the right button if it matched. On go trials, subjects were to press either left or right button depending on the cue. The fMRI scanning revealed that left VLPFC, parietal, temporal, and posterior dorsolateral (DLPFC) regions were active during cue period. Left posterior VLPFC and parietal regions were active during both cue period and delay period.

2. Critical comments:

1)      The rules which were applied by participants, appeared to them as a response to a certain stimuli, verbal or nonverbal, which was associated with this stimuli. The participants did not enter any explicit process of reasoning, which, at least in some contexts, seems to be crucial in applying abstract rules in novel cirtumstances.

2)      The rules used by participants in the experiment could be described as technical (match, non match, go left, go right). It would be interesting to see, whether different kinds of rules, especially moral norms, activate the same regions in the brain.

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14/02/2010

Short review: Jorge Moll, Ricardo de Oliveira-Souza, Paul J. Eslinger, Ivanei E. Bramati, Janaina Mourao-Miranda, Pedro Angelo Andreiuolo, Luiz Pessoa The Neural Correlates of Moral Sensitivity: A Functional Magnetic Resonance Imaging Investigation of Basic Moral Emotions, Journal of Neuroscience, 2002, 22 (7), pp. 2730-2736.

Short review:

Jorge Moll, Ricardo de Oliveira-Souza, Paul J. Eslinger, Ivanei E. Bramati, Janaina Mourao-Miranda, Pedro Angelo Andreiuolo, Luiz Pessoa The Neural Correlates of Moral Sensitivity: A Functional Magnetic Resonance Imaging Investigation of Basic Moral Emotions, Journal of Neuroscience, 2002, 22 (7), pp. 2730-2736.

1. Summary

(a)    Theses:

Thesis 1: Moral emotions play a key role in assigning moral values, being an implicit social behaviour in humans.

Thesis 2: Orbital and medial sectors of the prefrontal cortex and the superior temporal sulculus (STS) are critical regions for moral appraisal.

(b)   Experimental setting:

Experiment: Subjects were presented with six categories of pictures: (1) moral pictures portraying emotionally charged, unpleasant social scenes, representing moral violations; (2) unpleasant pictures of aversive scenes not conveying moral connotations; (3) pleasant pictures, including scenes of people and landscapes; (4) ‘interesting’ pictures, which were visually arousing but less emotional; (5) neutral pictures, including people and landscapes; (6) scrambled images. The goal of the experiment was to investigate spontaneus brain responses triggered by the perception of this visual stimuli. The results showed an increased activation of the right medial orbital prefrontal cortex (OFC) and the medial frontal gyrus (MedFG) and the cortex surrounding the right STS while viewing moral in comparison with nonmoral scenes.

2. Critical comments:

1)      The experiment revealed that viewing moral and nonmoral unpleasant visual stimuli activated very similar brain regions. Effects of the moral stimuli cannot be explained on the basis of emotional valence or visual arousal alone. Moral emotions differ from basic emotions in that they are interpersonal. However, if it is so, moral emotions are similar to basic ones, only in the aspect of being a quick and automatic response to a certain situation. Apart from this emotional aspect of moral emotions, they seem to require mechanism specific to moral domain, that enables to recognize certain situation as moral.

2)      Because the experiment consisted only in presenting visual stimuli to participants, it exhausts only one mode of presentation of moral situations. However, subjects may encounter ‘moral content’ in other ‘forms’. For example, it was shown that explicit moral reasoning activates additional prefrontal regions to OFC, MedFG and STS.

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14/02/2010

Short review: Jorge Moll, Paul J. Eslinger, Ricardo de Oliveira Sousa, Frontopolar and anterior temporal cortex activation in a moral judgement task: a preliminary functional MRI results in normal subjects, Arq. Neuropsiquiatr, 59, pp. 657-664.

Short review:

Jorge Moll, Paul J. Eslinger, Ricardo de Oliveira Sousa, Frontopolar and anterior temporal cortex activation in a moral judgement task: a preliminary functional MRI results in normal subjects, Arq. Neuropsiquiatr, 59, pp. 657-664.

1. Summary

(a)    Theses:

Thesis 1: Frontopolar cortex (FPC) and anterior temporal cortex (ATC) play a critical role in the mediation of complex judgement processes according to moral constraints.

Thesis 2: Anterior temporal lobe is involved in emotional valence of moral judgements.

Thesis 3: FPC is involved in the organisation of behaviours grounded on moral knowledge.

(b)   Experimental setting:

Experiment 1: Moral and factual sentences were auditorily presented to the participants. Subjects were asked to think about each statement and to judge whether they found them right or wrong. Furthermore, subjects were instructed to think over the content of each sentence until the presentation of the next one. After the first scanning session, the whole list was presented a second time. Subjects were instructed to recall to their impressions and to rate each sentence on a 4 point scale asright or wrong, as well as the degree of moral content, emotional valence, and judgement difficulty. Comparing brain activity during moral and factual judgements, the most consistently activated regions across subjects were the FPC and the medial frontal gyrus. Right anterior temporal lobe was also extensively activated.

Experiment 2: The above mentioned results were adjusted to the effects of emotional valence. The frontopolar and medial frontal activations remained almost unchanged, still being the largest areas of activation. However, there was reduction in activation of the anterior temporal lobe.

2. Critical comments

1)      The role of FPC in moral judgement was not stated explicitly. The results of the experiment, show that this region is extensively active during the making of moral judgement, however, it is not clear whether FPC is a cognitive, emotional or a different kind of mechanism that regulates moral behaviour.

2)      It would be interesting to see, whether FPC is active during processing of moral and conventional norms. The ability to distinguish between moral and conventional norms is important to be recognized as a moral agent, therefore the role of FPC in moral behaviour could be strenghtened or weakened, depending on the results of such an experiment.

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14/02/2010

Short review: S. Berthoz, J.L. Armony, R.J.R. Blair, R.J. Dolan, An fMRI study of intentional and unintentional (embarassing) violations of social norms, Brain, 2002, Vol. 125, pp. 1696-1708.

Short review:

S. Berthoz, J.L. Armony, R.J.R. Blair, R.J. Dolan, An fMRI study of intentional and unintentional (embarassing) violations of social norms, Brain, 2002, Vol. 125, pp. 1696-1708.

1. Summary

(a)    Theses:

Thesis 1: Brain regions involved in the representation of the mental state of others (medial prefrontal cortex, temporo-parietal regions, temporal lobe) are activated during situations of violation of social norms.

Thesis 2: Processing social violations involves structures (lateral orbitofrontal and medial prefrontal cortices) associated with the representation of aversive emotional reactions in others, particularly others’ anger.

(b)   Experimental setting:

Experiment 1: Four types of a personal (the story protagonist is ‘you’) and impersonal verbal material (the story protagonist is a character) were presented to the participants: (1) description of normal behaviour; (2) description of an embarassing situation for the story protagonist (unintentional transgression of the social norm); (3) description of a situation where the story protagonist’s behaviour is a violation of social norms (intentional transgression); (4) sentences of ‘unrelated words’. The participants were asked to rate: (1) how embarassing they thought the situation is; (2) how inappropriate they thought the behaviour is; (3) how funny they thought the story is. No difference between the personal and impersonal ratings was found.

Experiment 2: Normal stories were used as a reference condition to measure the activity of brain regions. Both violation of social norms and embarassing stories activated left medial, middle and inferior prefrontal gyrus, left orbitofrontal cortex, anterior and middle temporal lobe.

2. Critical comments

1)      The results doesn’t show, were there any differences in brain activity, when participants were dealing with personal and impersonal stories. This seems to be important because we can assume that personal violations of the social norms (both intentional and unintentional) can trigger increased activity in brain regions involved with representation of aversive emotional reactions in others as compared to the impersonal violations.

2)      The personal/impersonal distinction of the stories is questionable as experimental scenarios seem to describe situations where the action of the protagonist is rather voluntary or involuntary. Intentionality is only an element of voluntariness (others being: ability to recognize the important chararacteristics of the action, ability to control the action).

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14/02/2010

Short review: Joshua Greene, Leigh E. Nystrom, Andrew D. Engell, John M. Darley, Jonathan Cohen, The Neural Bases of Cognitive Conflict and Control in Moral Judgement, Neuron, 2004, Vol. 44, 389-400.

Short review:

Joshua Greene, Leigh E. Nystrom, Andrew D. Engell, John M. Darley, Jonathan Cohen, The Neural Bases of Cognitive Conflict and Control in Moral Judgement, Neuron, 2004, Vol. 44, 389-400.

1. Summary

(a)    Theses

Thesis 1: Both cognitive and emotional processes play crucial and sometimes mutually competitive roles in moral judgment.

Thesis 2: Difficult personal moral dillemas involve increased reasoning and cognitive control.

Thesis 3:  Cognitive processes favor utilitarian moral judgments.

(b)   Experimental setting

Experiment 1: Participants were asked to respond to a difficult moral dilemma (the crying baby dilemma) and an easy moral dilemma (infanticide dilemma) while having their brains scanned by fMRI. Difficult, as compared to easy personal dillema, involved increased activity bilaterally in both the anterior dorsolateral prefrontal cortex (DLPFC), associated with abstract reasoning processes and cognitive control and anterior cingulate cortex (ACC) associated with cognitive conflict.

Experiment 2: Neural activity associated with utilitarian judgements (accepting a personal moral violation in favor of a greater good) was compared to neural activity associated with nonutilitarian judgements (prohibiting a personal moral violation despite its utilitarian value). For utilitarian judgments, increased activity in the anterior DLPFC was found.

2. Critical comments

1)      The results of the experiments do not show that utilitarian judgements are wholly associated with cognition whereas nonutilitarian judgements are associated only with emotions. Therefore, it is difficult to state what is the exact role of cognition and emotions in those judgments.

2)      It would be interesting to see, how persons with lesions to DLPFC and ACC structures respond to easy (“infanticide”) and difficult (“the crying baby”) moral dilemmas. Particularly, it is interesting whether persons with the aforementioned lesions respond to these dilemmas in a nonutilitarian way.

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14/02/2010

Short review: Jonathan Haidt, Sumio Imada, Laura Lowery, Paul Rozin, The CAD Triad Hypothesis: A Mapping Between Three Moral Emotions (Contempt, Anger, Disgust) and Three Moral Codes (Community, Autonomy, Divinity), Journal of Personality and Social Psychology 1999, Vol. 76, No. 4, 574-586.

Short review:

Jonathan Haidt, Sumio Imada, Laura Lowery, Paul Rozin, The CAD Triad Hypothesis: A Mapping Between Three Moral Emotions (Contempt, Anger, Disgust) and Three Moral Codes (Community, Autonomy, Divinity), Journal of Personality and Social Psychology 1999, Vol. 76, No. 4, 574-586.

1. Summary

(a)    Theses

Thesis 1: Contempt, anger and disgust are emotions which are triggered by the violation of the rules of specific part of the moral domain.

Thesis 2: Contempt is, most likely, triggered by the violation of the ethics of community; anger is, most likely, triggered by the violation of the ethics of autonomy; divinity is, most likely, triggered by the violation of the ethics of divinity

(b)   Experimental setting

Experiment 1: American and Japanese participants of the experiment read a list of moral violations and then chose the most appropriate face that an onlooker would make (contempt, anger, or disgust) or the most appropriate emotion word to describe an onlooker’s feelings (contempt, anger, or disgust). The situations represented violations of the three moral codes: community (community/hierarchy violations), autonomy (individual freedom/rights violations) and divinity (divinity/purity violations). In all but two cases, the predicted emotion was chosen more frequently than the sum of other two.

Experiment 2: American and Japanes participants of the experiment were to decide which moral system (individual freedom/rights; community/hierarchy; divinity/purity) was violated in the situations presented to them. The exact same list was used as in experiment 1. In 19/27 situations, the dominant moral code was greater or equal than the sum of the other two classifications.

Experiment 3: The participants were asked to read each of the situations of the moral rules violation from experiment 1 and produce the face that was appropriate to the situation. 13 of the 14 correlations were positive.

2. Critical comments

1)      It is sometimes suggested, that contempt is not a fundamental but a derived class of other-directed moral emotions. On such view, contempt is a blend of anger and disgust. This thesis is plausible because community can be thought of as an organized, dynamic system of individuals, where each person has a particular place. In this respect, community is like nature. Therefore,  violations of community rules can be thought of as violations of autonomy and divinity rules.

2)      It would be interesting to see which brain structures are most active when persons perform the experimental task. Especially, it is interesting whether there is a significant difference between the activity in the structures associated with the “cognitive” processes and “emotional” responses.

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14/02/2010

Short review: Hanna Damasio, Disorder of Social Conduct Following Damage to Prefrontal Cortices, [in:] J.-P. Changeaux, A.R. Damasio, W. Singer, Y. Christen (eds.), Neurobiology of Human Values, Springer 2005, pp. 37-46.

Short review:

Hanna Damasio, Disorder of Social Conduct Following Damage to Prefrontal Cortices, [in:] J.-P. Changeaux, A.R. Damasio, W. Singer, Y. Christen (eds.), Neurobiology of Human Values, Springer 2005, pp. 37-46.

1. Summary

(a)    Theses

Thesis 1: Certain disorders of social conduct in which ethical rules are violated can be related to specific brain systems (ventromedial prefrontal cortices – VMPFC) and accounted for by neural dysfunction in the absence of causative sociocultural factors.

Thesis 2: Abnormal emotional function seems to play a critical role in disorders of social conduct.

Thesis 3: VMPFC region is necessary for triggering most of salient social emotions.

(b)   Experimental setting

Experiment 1: Normal subjects and patients with an adult-onset damage to VMPFC region were presented with The Iowa Gambling Task (IGT). The task involves selection of cards from four decks (A, B, C and D). The subjects is told that each card selection can result in a money gain or loss. The subject is given $2.000. The subject does not know that: (1) the rewards in A and B are always $100, whereas in C and D are $50; (2) the penalties in A and B are up to $1200, whereas in C and D up to $300; (3) the game lasts for 100 turns; (4) turning cards from A and B leads to an overall loss, in spite of immediate high rewards, whereas turning cards from C and D is profitable. VMPFC patients turn more cards from A and B decks, ending in their bankruptcy. Normal subjects turn more cards from decks C and D.

Experiment 2: The IGT can be played while skin conductance responses (SCR) are monitored. SCRs occur immediately after a punishment or reward (,,consequent” SCR) and in the 5 sec interval preceding the actual choice of a card (,,anticipatory” SCR). Both normal subjects  and VMPFC patients show similar consequent SCR amplitudes (higher after a punishment, lower after a reward). However, normal subjects show anticipatory SCRs that discriminate between the decks (higher amplitudes for ,,bad” decks A and B, lower amplitude for ,,good” decks C and D), whereas VMPFC patients anticipatory SCRs show very low amplitude for all decks.

Experiment 3: The VMPFC patients perform normally in tests measuring their cognitive and social problem-solving abilities.

Experiment 4:  Patients with an early-onset damage to VMPFC region were studied (lesions acquired between the age of 1 and 7). Such patients perform abnormally on all tests probing their social problem-solving abilities, on which the adult-onset group perform normally.

Experiment 5: Both groups of VMPFC patients behave abnormally in real-life social situations, showing severe impairment in their social emotions recognition (shame, embarrassment, compassion). However, the behavior in such situations is especially abnormal for patients with an early-onset damage to VMPFC region.

2. Critical comments:

1)      Although VMPFC region seems to be a necessary structure for normal, real-life decision making in situations when some ethical rules are evaluated, it is plausible to assume that other brain structures also play an important role in the process of making such decisions. In particular, it seems that structures responsible for cognitive functions are a necessary element while making such decisions.

2)      It would be interesting to examine which of the other brain regions are necessary for making the aforementioned decisions.

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14/02/2010

Short review: Giacomo Rizolatti and Laila Craighero, Mirror Neuron: a Neurological Approach to Empathy, [in:] J.-P. Changeaux, A.R. Damasio, W. Singer, Y. Christen (eds.), Neurobiology of Human Values, Springer 2005, pp. 107-124.

Short review:

Giacomo Rizolatti and Laila Craighero, Mirror Neuron: a Neurological Approach to Empathy, [in:] J.-P. Changeaux, A.R. Damasio, W. Singer, Y. Christen (eds.), Neurobiology of Human Values, Springer 2005, pp. 107-124.

1. Summary

(a)    Theses

Thesis 1: There is a neural mechanism (,,mirror mechanism’’) that enables individuals to understand the meaning of actions done by others, their intentions, and their emotions, through activation of internal representations coding motorically the observed actions and emotions.

Thesis 2: This neural mechanism played a fundamental role in evolution of altruism, supporting moral norms based on a general concept of ,,The Golden Rule”.

(b)   Experimental setting

Experiment 1: Mirror neurons were recorded while monkey was observing a ,,noisy” action (e.g., ripping a piece of paper) and then it was presented with the same noise without seeing the action. The results showed that a large number of mirror neurons, responsive to the observation of noisy action, also responded to the presentation of the sound proper of that action, alone. Response to the white sound or to the sound of other actions were absent or much weaker than responses to the preferred action.

Experiment 2: Mirror neurons were tested by introducing a screen between the monkey and the location of an object. The monkeys were tested in four conditions: (1) the experimenter is grasping an object; (2) the experimenter is miming grasping, and (3) and (4) the monkey observes the actions of (1) and (2) but the final critical part of them (hand-object interaction) is hidden by a screen. The results showed that more than half of the tested neurons discharged in the hidden condition. Mirror neurons typically do not fire during the observation of mimed actions.

Experiment 3: Functional imaging study in humans consisted of olfactory and visual runs. In the olfactory runs, individual inhaled disgusting and pleasant odorants. In the visual runs, the same participants viewed video-clips of individuals smelling a glass containing disgusting, pleasant and neutral odorants and expressing their emotions. The results showed that the same sector within the anterior insula that was activated by the exposure to disgusting odorants was also activated by the observation of disgust in others.

2. Critical comments

1) The idea that when individuals observe others, they enact their actions inside themselves and share their emotions is a plausible one. However, it seems that possessing the above-mentioned biological mechanism is not a sufficient condition of acting altruistically. The presence of an unhappy person may compel some individuals to eliminate the unpleasant feeling determined by that presence, by acting in a way that is not necessary pleasant for the unhappy person.

2) Despite the fact that disgust is usually understood as an emotion that is correlated with a breach of moral rules, in the experimental setting this emotion was not correlated with such an action. It would be interesting to see if the same results were acquired when such an experiment is carried out.

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