Inconsistencies between human and macaque lesion data can be resolved with a stimulus-computable model of the ventral visual stream.

Abstract

Decades of neuroscientific research has sought to understand medial temporal lobe (MTL) involvement in perception. Apparent inconsistencies in the literature have led to competing interpretations of the available evidence; critically, findings from human participants with naturally occurring MTL damage appear to be inconsistent with findings from monkeys with surgical lesions. Here we leverage a 'stimulus-computable' proxy for the primate ventral visual stream (VVS), which enables us to formally evaluate perceptual demands across stimulus sets, experiments, and species. With this approach, we analyze a series of experiments administered to monkeys with surgical, bilateral damage to perirhinal cortex (PRC), a MTL structure implicated in visual object perception. Across experiments, PRC-lesioned subjects showed no impairment on perceptual tasks; this originally led us (Eldridge et al., 2018) to conclude that PRC is not involved in perception. Here we find that a 'VVS-like' model predicts both PRC-intact and -lesioned choice behaviors, suggesting that a linear readout of the VVS should be sufficient for performance on these tasks. Evaluating these data alongside findings from human experiments, we suggest that results from Eldridge et al., 2018 alone can not be used as evidence against PRC involvement in perception. These data suggest that the experimental findings from human and non-human primate literature are consistent, and apparent discrepancies between species was due to reliance on informal accounts of perceptual processing.