Abstract # 2452 Poster # 49:

Scheduled for Thursday, June 19, 2008 05:00 PM-07:00 PM: Session 4 (Ball Rooms A and B) Poster Presentation

Macaques’ neonatal imitation responses depend on internal sensorimotor mechanisms and not on attentional factors

D. Hipp, A. Paukner, A. Ruggiero, P. F. Ferrari and S. J. Suomi
Laboratory of Comparative Ethology, Dickerson, MD, USA
     The interindividual variability observed in neonatal macaques’ ability to respond to facial gestures with matching facial gestures has been hypothesized to be based on differences in sensitivity and reactivity of sensorimotor systems to external social cues. Here we test an alternative hypothesis that interindividual differences in neonatal imitation might be related to differences in attention paid to the modeled gesture. We coded the amount of time infant rhesus macaques (Macaca mulatta, N=23) aged 1 day to 7 days looked at an experimenter who modeled facial gestures during a neonatal imitation task. The modeled gestures (lip smacking and tongue protrusion) attracted more attention than the experimenter’s still face. We further analyzed whether the phase in which infants paid the most attention coincided with the phase in which infants responded most frequently with a matching facial gesture. Results show that there was no association between the amount of attention directed at facial gestures and the frequency of matching facial gestures [Binomial Sign Test, a=0.05]. These results suggest that the observed interindividual variability in neonatal imitation is not attributable to attentional processes, and further support the view that differences in infants’ ability to match facial gestures are related to differences in sensorimotor development.