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Abstract:
Clinical depression is characterized by a tendency to
selectively attend to and remember failure experiences. The present
study investigates what neural regions are activated differently by
depressed and healthy controls during success and failure
experiences. We used fMRI to determine brain activity during a
visual response time task in which 15 depressed and 12
non-depressed volunteers received positive, negative and neutral
performance feedback. Blocks of 80% negative, 80% positive and 80%
neutral feedback were presented regardless of actual performance.
At the end of the scan session, participants estimated the
percentage of positive, negative and neutral feedback they received
during the task. Initial analyses suggest that the depressed
individuals overestimated the amount of negative feedback they
received, while non-depressed individuals did not. Functional brain
images were acquired using a gradient echo T2*-weighted spiral scan
(TR=3 s; TE=30 ms; flip angle=83; FOV=24 cm). In the depressed
population, visual processing areas are most active in the positive
and least active in the negative feedback conditions, suggesting
that they are paying less attention to the task itself the more
negative feedback they receive. For the control population, the
same areas are most active in the negative feedback condition,
suggesting they are paying the most attention to the task under
this condition. These results support the idea that depressed
individuals selectively process negative feedback.
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