Poster D34, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
Variations in alpha oscillatory power during rule switching
Paolo Medrano1, Robert Ross1; 1University of New Hampshire
Cognitive control allows for goal-directed selection of the appropriate action within a given context. Rule-switching is a cognitive control process related to flexibly switching tasks, a process which may require the retrieval of information from long-term memory. Previous research utilizing EEG has associated oscillatory activity in the alpha (8-12 Hz) and beta (13-30 Hz) frequencies with cognitive processes. In particular, suppression of alpha oscillatory activity has been linked with better task switching performance, as well as long-term memory retrieval. This study aims to further the current literature by investigating differences in oscillatory power during a rule-switching task. EEG and behavioral data were collected from 73 healthy young adult participants. Participants were asked to differentiate stimuli based on two rules: color (red or green) or shape (square or circle). Cues presented prior to stimulus presentation determined what rule the participant followed, and changed every few trials. Trials where cues changed were labeled switch trials, while trials that repeated the previous cue were labeled maintain trials. Behavioral analyses revealed significantly greater accuracy and faster reaction times for maintain trials compared to switch trials. Oscillatory analyses revealed a large decrease in alpha oscillatory power in a right lateral inferior region for switch trials, with the significant decrease sustained from 500-2500 ms post-cue presentation. This sustained decrease in alpha power occurring may be linked to memory retrieval processes that aid the reinstatement of a previous rule.
Topic Area: EXECUTIVE PROCESSES: Goal maintenance & switching