Task-related dissociation of EEG β enhancement and suppression

Previous investigations of EEG beta processes can be divided into two categories: one in which beta enhancement is obtained and one in which beta suppression is obtained. The current study investigated the beta band range (14-30 Hz) by subdividing the signal into 2 Hz sub -bands. We presented participants with photographs of faces expressing happy, angry, sad or neutral expressions under two primary tasks in which participants judged the emotion the individual was expressing, or how the way the other person feels makes the participant feel. Results revealed a pattern of both suppression and enhancement that appeared to depend on whether the task required first -person emotional experience (self -task) or perspective -taking (other -task). Specifically, the self task was associated with enhancement while the other -task was associated with suppression. While some previous research has reported beta enhancement to emotion -inducing stimuli, other research has reported beta suppression in tasks also associated with mu suppression. To our knowledge, the current data are the first to reveal both beta enhancement and suppression within a single experiment and suggests a neurocognitive dissociation of enhancement and suppression within the beta band range. (C) 2015 Elsevier B.V. All rights reserved.