OVERNIGHT EFFECTS OF TRIAZOLAM ON COGNITIVE FUNCTION - AN EVENT-RELATED POTENTIALS STUDY

The effects of triazolam on cognitive function and vigilance on the mo rning following a nocturnal administration were investigated using eve nt-related potentials (ERP) measurement and a sleep latency test (SLT) , We previously reported a significant reducing effect on target NI am plitude on the morning following triazolam administration, suggesting a residual effect of triazolam. In order to demonstrate, which aspect of cognitive function alteration caused the reducing effect on N1 ampl itude, we added the ignore condition for ERP measurement, which enable d us to separate mismatch negativity (MMN) from other subcomponents ov erlapping NI, As a result, MMN was attenuated and sleep latency was sh ortened on the morning following triazolam administration. Two possibi lities were suggested for the mechanism of MMN attenuation. One is GAB Aergic activation caused by the residual effect of triazolam per se, a nd the other is the lowered vigilance level demonstrated in the SLT, F urther studies are necessary to determine whether this alteration in p hysiological bases underlying mismatch detection is specific to triazo lam and/or other benzodiazepines or related to nonspecific vigilance l evel.