Эмоциялар мен шешім қабылдау: Соматикалық маркерлер гипотезасы

Hypothesis that emotional processes guide or bias decision making

The somatic marker hypothesis, formulated by Antonio Damasio and associated researchers, proposes that emotional processes guide (or bias) behavior, particularly decision making. "Somatic markers" are feelings in the body that are associated with emotions, such as the association of rapid heartbeat with anxiety or of nausea with disgust. According to the hypothesis, somatic markers strongly influence subsequent decision making. Within the brain, somatic markers are thought to be processed in the ventromedial prefrontal cortex (vmPFC) and the amygdala. The hypothesis has been tested in experiments using the Iowa gambling task.

In economic theory, human decision making is often modeled as being devoid of emotions, involving only logical reasoning based on cost benefit calculations. In contrast, the somatic marker hypothesis proposes that emotions play a critical role in the ability to make fast, rational decisions in complex and uncertain situations. vmPFC patients also have difficulty expressing and experiencing appropriate emotions. This led Antonio Damasio to hypothesize that decision making deficits following vmPFC damage result from the inability to use emotions to help guide future behavior based on past experiences. Consequently, vmPFC damage forces those affected to rely on slow and laborious cost benefit analyses for every given choice situation.

Antonio Damasio (António Damásio) is a Portuguese American neuroscientist. He is currently the David Dornsife Professor of Neuroscience, Psychology and Philosophy at the University of Southern California and an adjunct professor at the Salk Institute. Damasio heads the Brain and Creativity Institute, and has authored several books: his most recent work, Feeling and Knowing: Making Minds Conscious (2021), explores the relationship between the brain, feelings and consciousness. Damasio's research in neuroscience has shown that emotions play a central role in social cognition and decision making.

When individuals make decisions, they must assess the incentive value of the choices available to them, using cognitive and emotional processes. When the individuals face complex and conflicting choices, they may be unable to decide using only cognitive processes, which may become overloaded. Emotions, consequently, are hypothesized to guide decision making. Emotions, as defined by Damasio, are changes in both body and brain states in response to stimuli.

Damasio has posited that the ability of humans to perform abstract thinking quickly and efficiently coincides with both the development of the vmPFC and with the use of somatic markers to guide human behavior during evolution. When this idea was tested in individuals who were infected with HIV and were substance dependent, differences were found between persons who scored well in the Iowa gambling test, and those who scored poorly. The high scorers showed a correlation between the amount of distress they reported having over their HIV status, and their acceptance of risk during sexual behavior – the greater the distress, the greater the risk that these people would take. The low scorers, on the other hand, showed no such correlation. These results were interpreted as indicating that persons with intact decision making abilities are better able to rely on past emotional experiences when weighing risks, than are persons who are deficient in such abilities, and that acceptance of risk serves to ameliorate emotional distress. Researchers analyzed the neuroendocrine responses of substance dependent individuals and healthy individuals after being shown pleasant or unpleasant images. In response to unpleasant images, drug users showed decreased levels of several neuroendocrine markers, including norepinephrine, cortisol, and adrenocorticotropic hormone. Addicts showed lesser responses to both pleasant and unpleasant images, suggesting that they may have a diminished emotional response. Neuroimaging studies utilizing fMRI indicate that drug related stimuli have the ability to activate brain regions involved in emotional evaluation and reward processing. When shown a film of people smoking cocaine, cocaine users showed greater activation of the anterior cingulate cortex, the right inferior parietal lobe, and the caudate nucleus than did non users. Conversely, the cocaine users showed lesser activation when viewing a sex film than did non users.

Some researchers believe that the use of somatic markers (i. e., afferent feedback) would be a very inefficient method of influencing behavior. Damasio's notion of the as if experience dependent feedback route, whereby bodily responses are re represented utilizing the somatosensory cortex (postcentral gyrus), also proposes an inefficient method of affecting explicit behavior. Rolls (1999) stated that; "it would be very inefficient and noisy to place in the execution route a peripheral response, and transducers to attempt to measure that peripheral response, itself a notoriously difficult procedure" (p. 73). This process can occur via implicit or explicit processes. While the Iowa gambling task has proven to be an ecologically valid measure of decision making impairment, there exist three assumptions that need to hold true. First, the claim that it assesses implicit learning as the reward/punishment design is inconsistent with data showing accurate knowledge of the task possibilities and that mechanisms such as working memory appear to have a strong influence. Second, the claim that this knowledge occurs through preventive marker signals is not supported by competing explanations of the psychophysiology generated profile. Lastly, the claim that the impairment is due to a 'myopia for the future' is undermined by more plausible psychological mechanisms explaining deficits on the tasks such as reversal learning, risk taking, and working memory deficits. There may also be more variability in control performance than previously thought, thus complicating the interpretation of the findings. Furthermore, although the somatic marker hypothesis has accurately identified many of the brain regions involved in decision making, emotion, and body state representation, it has failed to clearly demonstrate how these processes interact at a psychological and evolutionary level. There are many experiments that could be implemented to further test the somatic marker hypothesis. One way would be to develop variants of the Iowa gambling task that control some of the methodological issues and interpretation ambiguities generated. It may be a good idea to include removing the reversal learning confound, which would make the task more difficult to consciously comprehend. Additionally, causal tests of the somatic marker hypothesis could be practiced more insistently in a greater range of populations with altered peripheral feedback, like on patients with facial paralysis. In conclusion, the somatic marker hypothesis needs to be tested in more experiments. Until a wider range of empirical approaches are employed in order to test the somatic marker hypothesis, it appears that the framework is simply an intriguing idea that is in need of some better supporting evidence. Despite these issues, the somatic marker hypothesis and the Iowa gambling task reestablish the notion that emotion has the potential to be a benefit as well as a problem during the decision making process in humans.