Prestimulus Alpha Oscillations as an Index of Increased Cognitive Control Under the Auditory Condensation Task

Abstract

Attentional lapses are usually viewed as a result of deterioration in cognitive control. Current theories suggest that deterioration in the cognitive control may be related to an increase in alpha rhythm power, although it is not clear whether this notion can be generalized outside of the visual task modality. In the current study power of prestimulus alpha-band oscillations was analyzed during performance of the modified auditory condensation task, which creates high attentional load. Prestimulus lower alpha-band power was found to decrease before erroneous responses, which can be viewed as attentional lapses related to decreased cognitive control, compared with correct responses. Prestimulus lower alpha-band power also gradually increased within continuous sequences of distractor stimuli separating adjacent target stimuli, thus reflecting gradual increase in the level of cognitive control mirroring increasing expectancy of the target stimuli. These findings demonstrate that the relation of alpha power to cognitive control level critically depends on the experimental task modality, and under conditions of the auditory attentional task higher alpha power may be an index of increased rather than decreased level of cognitive control.