Emotional expressions modulate low α and β oscillations in a cortically blind patient

• We investigate the EROs of a male patient with affective blindsight.
• We compare the electrophysiological response of fearful, happy and neutral faces.
• Positive vs. negative emotions affect frequencies in the lower α-band.
• Emotional content of a face modified frequencies in the low β-band
• Both effects occurred between 100 and 400 ms after the cue onset.

Studies of cortical blindness have suggested that some residual visual function may persist without perceptual awareness, a condition known as blindsight. To investigate electrophysiological evidence of unconscious processing of emotional stimuli, we examined the event-related oscillations (EROs) in a 62 year-old male patient (TN) with affective blindsight during random stimulation of three facial expressions (fearful, happy and neutral).Spectral power analysis in response to the different emotions revealed significant differences between fearful and happy faces over the right frontal regions at 7–8 Hz (low α), and between emotional and neutral faces over the left frontal sites at 12–13 Hz (low β) in a time period between 100–400 ms after visual stimulus onset.These results demonstrate that emotional face processing occurs very early in time in the absence of any functional striate cortex, and further reveals the existence of specific oscillatory frequencies that reflect unconscious processing of facial expressions in affective blindsight.