Fig. 1.

Stimulus context alters visual processing in IT (example neuron). A: stimulus presentation paradigm. Monkeys fixated a stream of visual stimuli presented on the screen. Each stimulus was presented for 250 ms, with a 250-ms interstimulus interval. Monkeys needed to maintain fixation for 2 s to receive a reward; however, they could continue fixating to receive an additional reward every 2 s. In the face condition, 20 views of a single face were presented as stimuli; in the mixed condition stimuli were a mixture of face and nonface images. B: visual response of an exemplar IT neuron to stimulus presentation, averaged across all 20 face stimuli, for the face condition (red) and the mixed condition (blue). Average visual response (70–320 ms; gray bar) is enhanced in the face condition. The activity prior to stimulus-evoked response (0–70 ms) is also greater in the face condition. Inset: area of inferotemporal cortex from which recordings were made (sts, superior temporal sulcus; amts, anterior middle temporal sulcus; ots, occipitotemporal sulcus). C: polar plot showing tuning of example neuron for viewing angle in face condition (red) and mixed condition (blue).