Ultra-high-resolution fMRI of Human Ventral Temporal Cortex Reveals Differential Representation of Categories and Domains

Abstract

Human ventral temporal cortex (VTC) is critical for visual recognition. It is thought that this ability is supported by large-scale patterns of activity across VTC that contain information about visual categories. However, it is unknown how category representations in VTC are organized at the submillimeter scale and across cortical depths. To fill this gap in knowledge, we measured BOLD responses in medial and lateral VTC to images spanning 10 categories from five domains (written characters, bodies, faces, places, and objects) at an ultra-high spatial resolution of 0.8 mm using 7 Tesla fMRI in both male and female participants. Representations in lateral VTC were organized most strongly at the general level of domains (e.g., places), whereas medial VTC was also organized at the level of specific categories (e.g., corridors and houses within the domain of places). In both lateral and medial VTC, domain-level and category-level structure decreased with cortical depth, and downsampling our data to standard resolution (2.4 mm) did not reverse differences in representations between lateral and medial VTC. The functional diversity of representations across VTC partitions may allow downstream regions to read out information in a flexible manner according to task demands. These results bridge an important gap between electrophysiological recordings in single neurons at the micron scale in nonhuman primates and standard-resolution fMRI in humans by elucidating distributed responses at the submillimeter scale with ultra-high-resolution fMRI in humans.

Extensive individual differences of category information in ventral temporal cortex in the congenitally blind

“…For sighted subjects viewing video stimuli, we found the typical cortical patterns of category selectivity in VTC (Grill-Spector and Weiner et al, 2014;Margalit et al, 2020). This is visible in the representative example sighted subject ( Fig.…”

Direct comparison of contralateral bias and face/scene selectivity in human occipitotemporal cortex

“…Here, we investigate the relative strength of retinotopy and category-selectivity directly by presenting face and scene stimuli to either the left or right visual field, thereby making the stimuli exclusively available (initially) to one hemisphere at a time. Although only providing a limited sampling of the dimensions of space and category, we chose these particular categories and visual field positions because these provide a strong test of interaction between category and visual field positions: visual cortex is known to contain multiple face and scene preferring regions with divergent and strong preferences between these categories (Julian et al 2012;Weiner et al 2018;Margalit et al 2020), that are typically shown to produce the strongest contrast in response between categories. Further, the difference between contralateral and ipsilateral visual fields is typically the strongest retinotopic effect observed (Silson et al 2015).…”

Psychotherapy in pain management: New viewpoints and treatment targets based on a brain theory

“…Recent high-resolution fMRI with humans has shown columnar-like structures in V1 [42] , [43] , V2 and V3 [44] , V3a [45] , hMT [46] , and ventral temporal cortex showing differential representations of categories and domains [47] . Of particular relevance is the recent study by Schneider et al [48] in which high resolution fMRI provided proof that in the human middle temporal visual complex, columnar clusters meet the criteria of content-specific neural correlates of consciousness (NCC).…”