title: Distinct EEG amplitude suppression to facial gestures as evidence for a mirror mechanism in newborn monkeys.
abstract: At birth, human infants and newborns of other primate species demonstrate the capacity to attend and to respond to facial stimuli provided by a caregiver. Newborn infants are also capable of exhibiting a range of facial expressions. Identification of the neural underpinnings of these capacities represents a formidable challenge in understanding social development. One possible neuronal substrate is the mirror-neuron system assumed to activate shared motor cortical representations for both observation and production of actions. We tested this hypothesis by recording scalp EEG from 1- to 7-day-old newborn rhesus macaques who were observing and producing facial gestures. We found that 5-6 Hz EEG activity was suppressed both when the infants produced facial gestures and while they were observing facial gestures of a human experimenter, but not when they were observing nonbiological stimuli. These findings demonstrate the presence of neural reactivity for biological, communicatively relevant stimuli, which may be a likely signature of neuronal mirroring. The basic elements of the mirror-neuron system appear to operate from the very first days of life and contribute to the encoding of socially relevant stimuli.
authors.affiliation: Dipartimento di Neuroscienze, Università di Parma, Via Volturno 39, Parma, Italy. pierfrancesco.ferrari@unipr.it
authors.forename: Pier Francesco
authors.initials: PF
authors.lastname: Ferrari
authors.forename: Ross E
authors.initials: RE
authors.lastname: Vanderwert
authors.forename: Annika
authors.initials: A
authors.lastname: Paukner
authors.forename: Seth
authors.initials: S
authors.lastname: Bower
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Suomi
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Fox
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D056344:Executive Function; D005145:Face; D005149:Facial Expression; D005260:Female; D007839:Functional Laterality; D005868:Gestures; D007100:Imitative Behavior / Q000502:physiology*; D008253:Macaca mulatta / Q000502:physiology*; D008297:Male; D009433:Neural Inhibition / Q000502:physiology*; D010775:Photic Stimulation; D014741:Video Recording