Tuesday, November 25, 2008

The role of emotion in decision-making: Evidence from neurological patients with orbitofrontal damage

The role of emotion in decision-making: Evidence
from neurological patients with orbitofrontal damage

Most theories of choice assume that decisions derive from an assessment of the future outcomes of various options and alternatives
through some type of cost-benefit analyses. The influence of emotions on decision-making is largely ignored. The studies of
decision-making in neurological patients who can no longer process emotional information normally suggest that people make
judgments not only by evaluating the consequences and their probability of occurring, but also and even sometimes primarily at a
gut or emotional level. Lesions of the ventromedial (which includes the orbitofrontal) sector of the prefrontal cortex interfere with
the normal processing of ‘‘somatic’’ or emotional signals, while sparing most basic cognitive functions. Such damage leads to
impairments in the decision-making process, which seriously compromise the quality of decisions in daily life.


OK, so here they focused on decision making in frontal lobe impaired subjects. They make the point that in real life, you don't always know what the results of your actions will be, so you have to estimate. They had subjects choose from two decks of cards: cards with a modest, but fairly certain, payoff, and another deck which was a losing deck, but with some big payoffs spread inside. Normal people tended towards the sure thing, while frontal lobe impaired patients chose from the risky deck. They tied this in to emotions, by studying skin response to view emotional responses. They found that both groups of patients felt emotions when they won or lost, but that normal patients felt emotions before picking, especially from the risky deck. Impaired patients seemed blind to this, and just made their choices and THEN felt the emotion. They also show that different halves of the brain focus on negative or positive rewards. So depending on the damaged lobe, right or left, the subject might be totally focused on positive rewards, ignoring negative consequences, or totally focused on negative rewards, ignoring the positive. Either way leads to impaired decision making skills. Authors are also trying to point out the role emotion plays in decision making, especially when results are uncertain, as they are in most scenarios in real life.

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