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Abstract:
The ability to inhibit inappropriate responses is often
compromised following traumatic brain injury (TBI). Event-related
potentials (ERPs) were recorded from normal and TBI participants
while performing a task requiring responses to be withheld to rare
(one in nine) numerical targets. The TBI group made more errors to
NoGo targets compared to the control group. Stimulus-locked ERPs
revealed a centrally distributed late positive component (450 to
550 ms post-stimulus) that was larger in amplitude for correct and
incorrect responses to the NoGo targets compared to correct
responses to Go stimuli in both groups. These components were
attenuated in the TBI group, suggesting deficient stimulus
categorization and response selection following TBI. Subtraction of
response-locked ERPs to correct responses from those of incorrect
responses revealed a clear negative-positive complex that has been
associated with error detection and compensation. The centrally
distributed negative wave (90 ms post-response) did not differ for
TBI and control groups whereas the centroparietally distributed
positive wave (300 ms post-response) was attenuated in the TBI
group compared to the control group. Although TBI patients may
detect errors normally, they seem less able to adopt compensatory
strategies following these errors.
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