Looking behaviour of control (dark grey) and FAE (light grey) infant vervets at dynamic audiovisual presentations of macaque calls in Experiment 1.

<p>A. Spectrograms of the rhesus monkey coo and grunt. Inset shows one frame of the peak of the corresponding facial expression. B. The percentage of total looking time that the subjects spent looking at the matching face. C. The mean duration of looking time at the matching and nonmatching faces. D. The mean duration of the longest single look at the matching and nonmatching faces. Error bars represent ±1 SEM.