Resting-state electroencephalography in participantswith sensory overresponsiveness: An exploratory study

OBJECTIVE. People with sensory overresponsiveness (SOR) perceive nonpainful stimuli as noxious and demonstrate hyperalgesia and lingering sensation to laboratory pain stimuli. Electroencephalography (EEG) of cortical activity at rest is widely used to explore endophenotypes but has not yet been tested in people with SOR. Therefore, we investigated the characteristics of resting-state EEG in participants with SOR. METHOD. Resting-state EEG (5-min, eyes-closed recording) was compared in participants with (n = 9) and without (n = 12) SOR. RESULTS. Participants with SOR demonstrated a global reduction of the EEG activity, including significantly lower u and a1 activity as well as faster peak a frequency. Higher sensory-responsiveness scores were associated with high peak a power in participants without SOR. CONCLUSION. Reduced a activity is commonly interpreted as an electrophysiological indicator of arousal and sensitivity to pain. The EEG pattern of response may partly explain the reported ongoing daily alertness to environmental stimuli in participants with SOR.