Visual Scan Patterns of Rhesus Monkeys Viewing Faces

Abstract

Two rhesus monkeys viewed black/white photographic slides depicting rhesus, human, chimpanzee, and schematic faces with direct gazes. Eye-track apparatus was used to assign visual fixations to one of four facial regions: the two eyes, nose, or mouth. Results showed that the eyes of stimulus faces received a disproportionate number of fixations from both observers across all stimulus face types. Stimulus faces depicting rhesus and human facial gestures shifted scan patterns somewhat, but did not disrupt the preoccupation with eyes. When the features of schematic faces were rearranged into non-facelike configurations, fixations directed to schematic stimuli were typically reduced in number.