Intensity of the stimulus rather than its affective meaning elicts changes in EEG recorded frontal alpha asymmetry

Abstract

A constantly growing body of literature has so far not reached a common understanding of which aspects of the affective state modulate frontal EEG alpha asymmetry. To explore these effects the monetary incentives delay paradigm was modified to enable direct comparison between the most prominent dimensions of emotion (valence, approach-avoidance, motivational intensity). The intensity of the stimulus was varied through a separate independent variable indicating the stakes (high/low) participants were playing for. The results showed no emotion dimension having a significant effect on the changes in the EEG recorded frontal alpha asymmetry scores during stimulus presentation. Analysis did however reveal the stimulus intensity having a significant effect on the change in asymmetry scores remaining even after accounting for stable and situational individual differences. These results lead to the conclusion that emotional stimulus intensity rather than their affective meaning can affect the changes in frontal alpha asymmetry scores elicited by an emotional stimulus.