Ricerc@Sapienza

The present mini-review was aimed at exploring the frontal EEG asymmetry of mood.
With respect to emotion, interpreted as a discrete affective process, mood is more
controllable, more nebulous, and more related to mind/cognition; in addition, causes
are less well-defined than those eliciting emotion. Therefore, firstly, the rational for the
distinction between emotion and mood was provided. Then, the main frontal EEG
asymmetry models were presented, such as the motivational approach/withdrawal,
valence/arousal, capability, and inhibition asymmetric models. Afterward, the frontal EEG
asymmetry of mood was investigated following three research lines, that is considering
studies involving different mood induction procedures, dispositional mood (positive and
negative affect), and mood alterations in both healthy and clinical populations. In general,
results were found to be contradictory, no model is unequivocally supported regardless
the research line considered. Different methodological issues were raised, such as: the
composition of samples used across studies, in particular, gender and age were found
to be critical variables that should be better addressed in future studies; the importance
of third variables that might mediate the relationship between frontal EEG asymmetries
and mood, for example bodily states and hormonal responses; the role of cognition,
namely the interplay between mood and executive functions. In light of these issues,
future research directions were proposed. Amongst others, the need to explore the neural
connectivity that underpins EEG asymmetries, and the need to include both positive and
negative mood conditions in the experimental designs have been highlighted.