Fearful Events Induce Sustained Changes in Spontaneous Aperiodic EEG

Dysregulation of the fear response can impair well-being, making it crucial to understand the brain mechanisms underpinning maladaptive and sustained fear responses. Electrophysiological studies of fear usually focus on evoked or oscillatory activity, overlooking the role of aperiodic neural activity. In this study, we examined EEG spectral changes following exposure to emotionally charged stimuli to shed light on the neural correlates of persisting fear responses. Thirty-six participants watched video clips with neutral or fearful content, each followed by a closed eyes resting period. Spectral parametrization analysis of resting-state EEG data revealed no significant changes in oscillatory power between neutral and fearful conditions. However, we found that the overall power spectrum had a significantly shallower slope after exposure to fearful stimuli, characterized by reduced aperiodic exponents and offsets. These findings suggest that aperiodic EEG parameters can track physiological responses and emotional arousal following fear, providing novel insights into the neural dynamics of lingering fear responses.