abstract Clio Janssens

Clio Janssens (Department of Experimental Psychology, Ghent University, Belgium)

Alpha power in visual brain areas reveals attentional modulations during stimulus and response incongruent trials

Cognitive control is essential for performing goal-oriented actions. Its neural basis includes at least two main components. A mid-frontal area signals the need for control; other cortical areas subsequently implement control by biasing sensory areas, boosting or suppressing activity in areas processing task-relevant or task-irrelevant information, respectively. Classical cognitive control theories state that control is a serial and thus slow process, while more recent associative models hypothesize that control can be implemented much more rapidly (Janssens et al. 2016; Verguts & Notebaert 2008). EEG allows studying such rapid control. To obtain spatial specificity, earlier EEG research (Appelbaum et al. 2011) used a flanker task with incongruent flankers in only one hemifield (congruent flankers in the other hemifield). ERPs revealed modulations specifically in visual areas processing incongruent stimuli. However, this study did not distinguish between stimulus incongruency (SI, visual dissimilarity) and response incongruency (RI). Moreover, interpretation of the ERP modulation is difficult since it can imply both increased and decreased neural activity. In the current study, we applied a similar paradigm but included both a SI and RI condition. We show the ERP modulations observed by Appelbaum et al. (2011) in both SI and RI conditions. Importantly, we show that alpha power suppression after stimulus presentation, which is linked to increased metabolic activity (Laufs et al. 2003) and attention (Worden et al. 2000), is more pronounced in areas processing incongruent (SI or RI) flankers than in areas processing congruent flankers. This indicates fast, within-trial attentional suppression for distracting information.