Neural selectivity in anterior inferotemporal cortex for morphed photographic images during behavioral classification or fixation.

Anterior inferotemporal cortex (aIT) contributes to the ability to discriminate and classify complex images. To determine whether and what proportion of single neurons in aIT cortex can yield enough information to classify complex images, we recorded from aIT neurons during the presentation of morphed photographic images in sessions in which monkeys classified images in a two alternative forced-choice--delayed-match-to-sample (2AFC-DMS) task or in sessions in which they performed a fixation task. The sample stimuli were chosen from a sequence in which one image was gradually morphed into another in a pair, while the original pair of images served as choices. Responses of many individual neurons in aIT cortex during the behavioral classification of the images, decoded using an ideal observer analysis, were sufficiently selective to account for the observed behavioral classification of the images. The responses of a separate population of neurons in aIT cortex recorded in subsequent sessions while the monkeys viewed the same images, were less selective than neural responses measured during sessions in which the 2AFC-DMS task was performed. Our findings show that many neurons in aIT could provide sensory information sufficient for the classification of images when a 2AFC-DMS task was performed.