We explored the relation between neuropsychological (attention tests
involving time constraints) and neurophysiological (N2 and P3
event-related potential (ERP) latencies) indices of slowness of
information processing after closed head injury (CHI). A group of 44
CHI patients performed worse than healthy controls on most
neuropsychological indices, and had significantly longer ERP latencies.
Significant correlations between neuropsychological measures and ERP
latencies were found only for the 3 subtasks of the Stroop test. In
additional multiple regression analyses P3 latency appeared the best
predictor in Stroop Color only. A possible explanation is that stimulus
evaluation processes comprise a relatively large part of performance on
this subtask. In Stroop Color-Word, response related processes are
supposed to play a greater role, reducing the role of the preceding
input related processes. The absence of significant correlations
between P3 latency and scores on the other attention tests suggests a
relatively small role of stimulus evaluation processes in these tasks,
implying that these tasks are not sensitive to slowness of these
processes. The Stroop test appears to be the only attention test
administered in which slowness in stimulus evaluation processes
requiring selective attention contributes significantly to the delay in
final performance on the task. (JINS, 2004, 10,
851–861.)