A neural marker of rapid discrimination of facial expression in 3.5 and 7-month-old infants

Little is known about infants' ability to rapidly discriminate a facial expression against many others. Here, we investigated the development of facial expression discrimination in infancy with fast periodic visual stimulation coupled with scalp electroencephalography (EEG). EEG was recorded in 3.5- and 7-month-old infants (n=18 per group) displayed with an expressive (disgust or happy) or neutral female face at a base stimulation frequency of 6 Hz. Pictures of the same individual randomly expressing other expressions (either anger, disgust, fear, happiness, sadness, or neutrality) were introduced every 6 stimuli (i.e., at 6/6 = 1 Hz) to directly isolate a discrimination response between th…