EFFECTS OF ALPRAZOLAM AND BROMAZEPAM ON VISUAL-SEARCH AND VERBAL RECOGNITION MEMORY IN HUMANS - A STUDY WITH EVENT-RELATED BRAIN POTENTIALS

The effects of two benzodiazepines (alprazolam and bromazepam) on perf ormance and event-related brain potentials (ERPs) in visual search and verbal recognition memory paradigms were tested in a placebo-controll ed double-blind paradigm employing 12 young healthy subjects. Both dru gs exerted similar effects on performance and electrophysiological mea sures. Reaction times and hit rates were adversely affected in both pa radigms. The ERP pattern in the visual search experiment suggested an impairment in selective attention (reduction of N1 component) and of a utomatic feature registration (posterior N2 reduction). In the world r ecognition experiment a dramatic reduction of the N400 component was s een under benzodiazepines. This is interpreted as reflecting an impair ed ability to perform context integration processes.