EFFECTS OF PEMOLINE ON SPONTANEOUS AND EVENT-RELATED ELECTRICAL-ACTIVITY OF THE BRAIN

The effect of pemoline on the electrical activity of the brain (electr oencephalogram, EEG) was studied in relation to time since sleep and t ime of day in 6 healthy subjects carrying out periods of work lasting 18 h. Power of the spontaneous EEG increased with time since sleep and amplitude of the P3 event-related response decreased. The changes may be interpreted as the reduction in alertness with time awake. In cont rast, pemoline decreased power of the spontaneous EEG and increased th e amplitude the P3 response, effects that are consistent with improved alertness. The changes in brain activity were paralleled by effects o n performance, in terms of percentage of correct responses and reactio n time. Performance decreased with time awake, and was improved by pem oline compared with placebo. The drug counteracted the adverse effects of time since sleep, with the beneficial effect of the drug persistin g over the 18-hour period of work. The findings emphasise that spontan eous and event-related activity of the EEG may be used both to complem ent measures of performance in the laboratory and to assess behaviour in occupational situations where performance testing is impractical.