Abstract
High density electrical mapping was used to index event-related brain activity in subjects performing parametric variations of the 'AX'-type continuous performance task (AX-CPT) that differentially challenge control, and informative control conditions. In the AX-CPT, subjects must use context, created by a cue stimulus, to guide response to a target. Diseases such as schizophrenia and attention deficit hyperactivity disorder (ADHD) are associated with impaired AX-CPT performance. Event-related potentials (ERP) were analyzed as a function of both global and local stimulus context. The topographical analysis revealed that well-defined ERP are elicited under conditions where subjects must override a prepotent response. Activation patterns related to overriding a prepotent response (Go to No-Go) differed markedly from those associated with overriding a prepotent non-response (No-Go to Go). Dipole source mapping suggested that withholding a prepotent response is reflected primarily in anterior cingulate/dorsolateral prefrontal cortex activity during the 350-450 ms latency range following presentation of the No-Go. In contrast, preparing to respond is reflected in parietal (including area BA 40) activity during the same latency range, followed by a prolonged frontal negativity (contingent negative variation; CNV). Similar patterns of activation were observed whether the changes in preparation were triggered by cue or target stimuli, though target-elicited potentials peaked earlier.
Original language | English (US) |
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Pages (from-to) | 701-715 |
Number of pages | 15 |
Journal | Cerebral Cortex |
Volume | 13 |
Issue number | 7 |
DOIs | |
State | Published - Jul 1 2003 |
ASJC Scopus subject areas
- Cognitive Neuroscience
- Cellular and Molecular Neuroscience