A Channel for 3D Environmental Shape in Anterior Inferotemporal Cortex

Abstract

SUMMARY Inferotemporal cortex (IT) has long been studied as a single pathway dedicated to object vision, but connectivity analysis reveals anatomically distinct channels, through ventral superior temporal sulcus (STSv) and dorsal/ventral inferotemporal gyrus (TEd, TEv). Here, we report a major functional distinction between channels. We studied individual IT neurons in monkeys viewing stereoscopic 3D images projected on a large screen. We used adaptive stimuli to explore neural tuning for 3D abstract shapes ranging in scale and topology from small, closed, bounded objects to large, open, unbounded environments (landscape-like surfaces and cave-like interiors). In STSv, most neurons were more responsive to objects, as expected. In TEd, surprisingly, most neurons were more responsive to 3D environmental shape. Previous studies have localized environmental information to posterior cortical modules. Our results show it is also channeled through anterior IT, where extensive cross-connections between STSv and TEd could integrate object and environmental shape information.

Representation of Gravity-Aligned Scene Structure in Ventral Pathway Visual Cortex

“…Sampling was constrained to be evenly distributed across the small object, large object, and environment ranges. As recently reported [2], a substantial fraction of AIT neurons are more responsive to scene stimuli than to object stimuli. Here, we analyzed the shape information carried by neurons with significantly stronger responses (Wilcoxon Rank-Sum Test, p < 0.05, two-tailed) to scenes (58/141).…”

“…These peaks cannot be due simply to a bias in receptive field positions toward the bottom and top of the visual field, since scene-selective AIT neurons respond only to 3D environmental shape and are unresponsive to 2D stimuli at equivalent locations [2]. Planar orientation peaks were peculiar to the scene-selective population; the object-selective population had no visible bias for planar tilt (Figure 3F).…”

“…Here, we show the ventral pathway also represents scene structure aligned with the gravitational reference frame in which objects move and interact. We analyzed shape tuning of recently described macaque monkey ventral pathway neurons that prefer scene-like stimuli to objects [2]. Individual neurons did not respond to a single shape class but to a variety of scene elements that are typically aligned with gravity: large planes in the orientation range of ground surfaces under natural viewing conditions, planes in the orientation range of ceilings, extended convex and concave edges in the orientation range of wall/floor/ceiling junctions.…”

Dynamics of scene representations in the human brain revealed by magnetoencephalography and deep neural networks

“…Perceiving the geometry of space is a core ability shared by all animals, with brain structures for spatial layout perception and navigation preserved across rodents, monkeys and humans (Epstein andKanwisher, 1998, 1998;Doeller et al, 2008Doeller et al, , 2010Moser et al, 2008;Epstein, 2011;Jacobs et al, 2013;Kornblith et al, 2013;Vaziri et al, 2014). Spatial layout perception, the demarcation of the boundaries and size of real-world visual space, plays a crucial mediating role in spatial cognition (Bird et al, 2010;Epstein, 2011;Kravitz et al, 2011a;Wolbers et al, 2011;Park et al, 2015) between image-specific processing of…”

Eight open questions in the computational modeling of higher sensory cortex

“…It is also now known that specialized face, place, body, and color-preferring regions at the multiple-millimeter scale are found in each of these IT areas (33)(34)(35)(36). Are these the only regions?…”