An objective neural measure of the effect of wearing facemasks on single-glance human face identity recognition.

As highlighted during and since the COVID-19 pandemic, wearing facemasks significantly impacts human social interactions, notably by hindering facial recognition. Here we measured the reduction of single-glance facial identity recognition associated with wearing facemasks with an objective implicit approach. Electroencephalographic (EEG) recordings were conducted in a group of participants presented with the same unfamiliar face identity photograph at a 6 Hz frequency, interrupted by different face identities every 5 stimuli. For faces wearing a mask, the neural face identity recognition response at 1.2 Hz and harmonics was significantly reduced by about 40 % over the bilateral occipito-temporal cortex. This reduction was specific to upright faces, with the lower signal to inverted faces being unaffected by facemasks. Overall, these findings suggest a significant impact of mask-wearing on single-glance face identity recognition underpinned both by a direct alteration of diagnostic cues provided by the bottom half of the face and an indirect decreased diagnosticity of the top face half typically provided by holistic face perception.