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Abstract:
Several studies demonstrated that cingulate cortex is
involved in depression. The error-related negativity (ERN) is an
event-related potential (ERP) associated with error processing. Its
generator is possibly located in the anterior cingulate cortex. We
used a computerized version of the Eriksen flanker task to evoke
the ERN in depressed patients and healthy controls.8 right-handed
depressed patients and 8 matched healthy controls took part in the
study. For each trial subjects got feedback according to their
performance. EEG was recorded from 64 channels mounted in a cap.
ERPs were extracted by averaging correct and incorrect responses
separately. ERPs were averaged, synchronous to both the response,
and the feedback. Patients were rated with Brief Psychiatric Rating
Scale (BPRS), Hamilton Depression Scale (HAMD), Hamilton Anxiety
Scale (HAMA), and Yale Brown Obsession Scale (Y BOCS). As expected,
trials with incorrect responses elicited a more negative ERP in
both the response- and feedback-locked averages than correct
responses. In the response-locked condition, the negativity peaked
at about 100 ms at central electrodes. In accordance with earlier
studies we identified this negativity to incorrect responses as an
ERN. However, depressed patients showed decreased amplitude of the
ERN. Differences in the ERN between depressed patients and control
subjects suggest a dysfunction of anterior cingulate cortex in
depression. Hence, the ERN appears to be sensitive to
psychopathological states.
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