Perceptual dominance of oriented faces mirrors the distribution of orientation tunings in inferotemporal neurons

Abstract

In three experiments participants viewed pairs of overlapping transparent faces, with one face upright and the other oriented, and they reported which face was dominant. In each trial, an upright face was presented with a face at 45, 90, 135 or 180°, with transparency set using a linear weighted algorithm, so that relative contrast across faces was biased in favour of oriented faces. Exposure duration was restricted in experiment 1 to 250, 500 or 1000 ms, but was unlimited in experiments 2 and 3. Adults were tested in experiments 1 and 2 and children aged 6–9 years of age were tested in experiment 3. Irrespective of exposure duration, the results showed the probability of dominance being ceded by oriented faces to upright faces was a function of orientation. In comparable conditions, the function found with young children was flatter than with adults. These patterns, and those of earlier perceptual studies, can be explained by the distribution of different orientation tunings found in physiological studies of inferotemporal cortex in macaques.