Diazepam-induced changes in EEG oscillations during performance of a sustained attention task

The primary aim of the present study was to test diazepam (DZ) effect, a benzodiazepine (BDZ) usually prescribed to reduce anxiety and to induce sleep, on EEG activity while performing a visual sustained attention task. The EEG activity was recorded in a double-blind placebo experiment, and prestimulus spectral power and inter- and intrahemispheric temporal coupling were assessed during visual sustained attention task performance. A single DZ dose (5 mg) was enough to increase reaction times during visual sustained attention task responses. DZ decreased prestimulus EEG power in the 1- to 6-, 8- to 12-, and 19- to 35-Hz bands and disrupted right intrahemispheric temporal coupling in the α-frequency range (8-12 Hz). The combined reduction in power and temporal coupling suggests both local and interregional DZ-induced disruption of neuronal synchronicity especially in the right hemisphere in agreement with the prominent attention-related networks in this hemisphere. These data support the notion that the influence of DZ on behavior goes beyond sedative effects and can potentially compromise higher cognitive functions with negative consequences to daily life situations.