Alpha and theta oscillations during the cognitive reappraisal of aversive pictures: A spatio-temporal qEEG investigation

Emotion regulation is a set of processes responsible for controlling, evaluating and adjusting reactions to achieve a goal. Results derived from magnetic resonance imaging agreed on the involvement of frontal and limbic structures in this process. Findings using cognition and physiology interactions are still scarce but suggest a role of alpha rhythm in emotional induction and for theta in regulation. Our goal was to investigate alpha and theta rhythm during the reappraisal of aversive stimuli. We hypothesized that an implication of alpha rhythm in emotional induction only and an increase in prefrontal theta rhythm positively correlated with successful regulation. Twenty-four healthy participants were recorded with 64 EEG electrodes while asked to watch or reappraise negative pictures passively. Theta and alpha rhythms were compared across maintain, decrease and increase regulation conditions, and a source localization estimated the generators. Theta activity was consistently higher in the upregulation than in the maintenance condition (p = .04) for the entire control period, but mainly at the beginning of regulation (1–3 s) for low-theta and later (5–7 s) for high-theta. Moreover, our results confirm that a low-theta generator correlated with mainly the middle frontal gyrus and the anterior dorsal cingulate cortex during upregulation. Theta was sensitive to emotion upregulation, whereas the alpha oscillation was non-sensitive to emotion induction and regulation. Theta rhythm was involved explicitly in emotion upregulation processes that occur at a definite time during reappraisal, whereas the alpha rhythm was not altered by emotion induction and regulation.