Detrimental effects of a high-dose alcohol intoxication on sequential cognitive flexibility are attenuated by...

It is well-known that alcohol impairs behavioral control and motor response inhibition, but it has remained rather unclear whether it also impairs cognitive inhibition. As automatized behavior is less vulnerable towards the detrimental effects of alcohol than cognitive control processes, potential cognitive inhibition deficits might however improve with training. We investigated the effect of an acute, binge-like alcohol intoxication in a balanced within-subjects design, asking n=32 healthy young males to perform a backward inhibition paradigm once sober and once while intoxicated (~1.1 ‰). To identify the underlying neurophysiological mechanisms, we analyzed stimulus- and response selection-related processes in neurophysiological data after Residue Iteration Decomposition (RIDE). Alcohol generally impaired behavioral task performance (accuracy and response times) during task switching. This was associated with impaired attentional processing of the task-relevant cue (reflected by reduced P1 and N1 amplitudes), which likely resulted in a larger need for reactive control at the later stage of response selection and control (reflected by increased fronto-central theta power). Without prior practice (~30 minutes), the intoxicated participants further struggled to overcome the cognitive inhibition of a previously relevant task set (reflected by a larger backward inhibition effect). This was linked to reduced posterior theta power, which reflects alcohol-induced impairments in working memory capacity and task set-relevant memory retrieval. As individuals with ~30 min task practice did not show the same alcohol-related deficit, it may be deduced that (partial) task set automatization via stimulus-response associations may help to reduce the detrimental effects of alcohol on cognitive inhibition during task switching.