EEG correlates of working memory for action
Edmund Wascher1, Bianca Zickerig1, Stephan Getzmann1, Stefan Arnau1, Sven Thönes1, Daniel Schneider1; 1Leibniz Research Centre for Working Environments and Human Factors
Working memory (WM) reflects an interface between perception, long-term memory and action. Either stimulus information or an anticipated response can be stored. Supramodal mechanisms of WM are performed by a wide-spread cortical network including the dorsolateral prefrontal cortex. Additionally, modality specific processing can be assumed, processed not in early sensory but in higher level regions that reflect specific representations of the information that has to be stored. While there is substantial literature regarding the comparison of different sensory modalities, WM for action is hardly ever directly compared to semantic and sensory WM. We evaluated a new approach to WM-functions allowing to differentiate between remembering a stimulus and remembering a response, based on the same stimulus material. A sequence of digits (1-6) was presented continuously. Participants had to make an odd-even decision on either the actual digit (Task: N0), the preceding digit (N-1) or the sum of the actual and the preceding digit (S-1). In S-1, the current digit had to be remembered because no response could be assigned to a single element. Sustained frontal negativity indicated that the digit was maintained in a verbal loop. In N-1, the participants could evaluate the stimulus in advance and store the response until the next stimulus. A modulation of mu- and beta oscillatory activity in the ERSPs was observed that indicated continuing response storage. Moreover, mu- and beta activity varied with the efficiency of response preparation. We thus argue that modulations in mu- and beta- activity provide cortical correlates for WM for action.
Topic Area: EXECUTIVE PROCESSES: Working memory