P300 event-related potential decrements in well-functioning university students with mild head injury

We compared the performance of 10 well-functioning university students who had experienced a mild head injury (MHI) an average of 6.4 years previously and IZ controls on a series of standard psychometric tests of attention, m emory, and thinking and on a series of auditory oddball vigilance tasks to which we also took event-related potentials (ERPs). The MHI and Control gro ups performed equivalently on all the psychometric tasks and on self-report questionnaires of everyday memory and attention difficulties. The MHI grou p performed more slowly and with lower accuracy on only the most difficult of the oddball tasks, yet they showed substantially and significantly reduc ed P300 amplitudes and subsequent attentuation on all the oddball tasks. bo th easy and difficult. There were no alterations of N1. P2. and N2 componen ts. These data suggest that despite excellent behavioral recovery, subtle i nformation processing deficits involving attention nevertheless may persist long after the original injury and may not he apparent on a variety of sta ndard psychometric measures. (C) 2001 Academic Press.