Decision-making following closed-head injury: can response speed be retrained?

The present study was designed to assess the extent to which the effects of feed-back (FB) and time windows, on the RTs of closed-head-injured outpatients, might carry-over when these external cues were removed. RT and evoked potentials were recorded while 12 closed-head-injured outpatients and 12 matched controls performed an auditory discrimination task. The FB and time windows were provided on three trials, then gradually removed. Following the removal of the FB and windows, patient RTs remained significantly faster and were approximately equal to the RTs of controls prior to the presentation of the cues. As in controls, the RTs of patients following removal of the cues occurred at approximately the same time as their P300s (the latency of this event-related potential component is thought to index stimulus evaluation time). To this extent, patient RTs did not appear to be exaggerated beyond the time needed for stimulus evaluation. The results obtained, therefore, provided tentative evidence that the experimental manipulation might have a lasting effect on CHI patient RTs.