Emotion arousal but not valence is strongly represented in aperiodic EEG activity stemming from thalamocortical interactions

Oscillatory EEG signals contain both periodic and aperiodic (1/f components), segregating which is important for gaining insights into the underlying neural computations. Several studies have explored the periodic features underlying neural basis of emotion processing, while 1/f component is less explored. Hence, the present study sought to determine whether seeing emotionally laden music video clips have an impact on aperiodic components along with the periodic components and their underlying basis by conceptualizing a biophysically realistic computational model. Using the publicly available Data for Emotional Analysis using Physiological Signals (DEAP) dataset we elucidate that there is a significant increase in exponent and offset of aperiodic background during high arousal compared to low arousal trials. In contrast, there were no discernible variations between the aperiodic components during the high and low valence categories. In high arousal, we also discovered reduction in alpha power in line with previous studies. Finally, to elucidate the underlying mechanisms, we employed a biophysically realistic and previously established thalamo-cortical model of neural field activity, which which allowed us to characterize that heightened emotional arousal appears emerge from an increased cooperation in information communication between neuronal populations in reticular and relay nuclei of thalamus.