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Abstract:
Abstract: We used fMRI in 8 healthy volunteers to examine
cerebral activations related to the perception of a monetary gain
or loss. Subjects were instructed to depress a response key as
quickly as possible in order to either win money, avoid losing
money, or to keep the task running. At the beginning of each block
condition, three distinct cues informed the subject of the
potential outcome for the ten following trials: "win"(triangle),
"lose" (circle), "nothing" (square). Pairs of conditions were
alternated during six runs : reward-lose, reward-nothing,
lose-nothing, lose-wining, nothing-winning, nothing-losing. When
compared to "nothing", "reward" and "lose" activated predominantly
within the right hemisphere, a common set of structures, including:
medial temporal areas, temporal pole, basal ganglia, lateral and
orbito-frontal cortex , cingular gyrus, and premotor areas. The
direct contrast between 'lose' and 'reward' yielded isolated
bilateral focal activations in the temporal poles. Regression
analysis using increasing gains within each block showed
activations of the left inferior temporal gyrus and right
prefrontal areas while increasing loss involved activation of the
mesial and orbital frontal cortex. These results suggest that while
competing for monetary incentive activates a large network of
cerebral regions, working to maximize gains and attempting to
minimize losses involves different preferential activation sites in
the frontal and temporal lobes.
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