Cognitive control and midline theta adjust across multiple timescales

This study used measures of behavior, EEG, and a simple quantitative model to test the hypothesis that conflict control at the block level is not exclusively driven by the control adjustments over successive trials. Young adults performed an auditory Simon task, and the base rate of compatible vs. incompatible trials was manipulated in separate blocks (25, 50, 75% compatible). EEG data were analyzed using independent component analysis (ICA) to define cortical mechanisms of any base rate and trial-by-trial sequence effects. Reaction time measures had both sequence and base rate effects. Two fronto-medial ICA components indexed sequence and base rate effects, with specific profiles for evoked potentials and oscillations in the theta and alpha frequency bands. Predictive modeling showed that sequence effects accounted for a minority of the variance on behavioral and ICA measures (all <36%). The results strongly suggest that the base rate manipulation affected behavior and many neural measures in addition to the influences of sequence effects.

Source: Neuropsychologia - February 2, 2018 Category: Neurology Source Type: research