THE ASSESSMENT OF RESIDUAL EFFECTS OF A SINGLE-DOSE OF DIAZEPAM ON VISUALLY-DEFINED EEG PATTERNS

The aim of this single-blind study was to evaluate the residual effect s of a IO-mg dose of diazeparn on cortical activation 11h after oral i ntake. The electroencephalographic segments (from O-1-O-2) delimited b y a sequence of photic stimuli presented every 10 sec during a simple reaction-time task (36 min duration) were arbitrarily classified into nine cerebral patterns (EEGP). EEGP segment classifications were group ed into six peri-stimulus transitions expressed in percentages: alpha- blockade; alpha-persistence; beta-persistence; alpha-induction; activa tion and deactivation. A sample of 42 young healthy university student s (21 females and 21 males) each underwent three counterbalanced exper imental conditions (control, placebo and diazepam). Diazepam affected all the subjects, although the women showed a greater number of EEGP t ransitions which indicated deactivation, than did the men. The results show that this type of visual EEG analysis is a useful technique for detecting the residual effects of benzodiazepines.