Focal disruption of temporal cortex in macaque during midbrain-induced neglect

Abstract

Spatial neglect is a common clinical syndrome involving disruption of the brains attention-related circuitry, including the dorsocaudal temporal cortex. While neglect is readily modeled in macaques, the absence of evidence for temporal cortex involvement has suggested a fundamental difference from humans. To map the neurological expression of spatial neglect in macaques, we measured attention-related fMRI activity across the cerebral cortex during experimental induction of neglect through reversible inactivation of the superior colliculus. During inactivation, monkeys exhibited hallmark attentional deficits of neglect in tasks using either moving or static stimuli. The behavioral deficits were accompanied by marked reductions in fMRI attentional modulation that were strongest in a small region on the floor of the superior temporal sulcus. Notably, direct inactivation of this mid-STS cortical region caused similar neglect-like spatial attention deficits. These results identify a putative macaque homolog to temporal cortex structures known to play a central role in human neglect.\n\nHighlightsO_LIDuring neglect the mid-STS cortex shows largest reduction in attentional modulation\nC_LIO_LIThe mid-STS cortex is selectively affected with static as well as dynamic stimuli\nC_LIO_LIMid-STS cortex is affected during neglect caused by SC or FEF inactivation\nC_LIO_LIInactivation of mid-STS cortex itself causes neglect without eye movement deficits\nC_LI\n\nIn BriefUsing fMRI in macaques performing attention tasks combined with reversible inactivations, Bogadhi et al. provide causal evidence that a region on the floor of the superior temporal sulcus is a crucial node in the cortical control of covert selective attention and a putative homolog to temporal cortex regions in humans implicated in spatial neglect.