The progress on this protocol has been severely hampered by lack of access to adequate testing facilities in the NIMH outpatient clinic. Nevertheless, we have published this year in Biological Psychology a report of seasonal effects on the amplitude of cognitive ERP components (Kosmidis et al., 1999). In preparation at this time are reports of the effects of clonidine on ERPs in normal subjects, the effects of closed head injuries on ERPs in attention-demanding tasks, as well as a comparison among normal controls and two groups of patients with seizure disorders. The latter study indicated that ERPs in patients with temporal lobe seizures resemble in most respects those seen in normal control subjects; in contrast, ERPs in patients with absence epilepsy show reduced amplitudes of cognitive components, especially P300 and slow wave. The differences were seen primarily in the processing of auditory signals. We are hoping to reactivate this project in the coming year, in conjunction with colleagues at the Uniformed Services University of the Health Sciences. A manuscript describing the effects of closed head injuries on ERPs in attention-demanding tasks has been submitted to the journal Psychophysiology. The findings indicate that changes in the N200 component, concerned with identification and classification of stimuli, is altered in these patients, particularly in the auditory modality.