Parallel, multi-stage processing of colors, faces and shapes in macaque inferior temporal cortex

Abstract

Visual-object processing culminates in inferior temporal (IT) cortex. To assess the organization of IT, we measured fMRI responses in alert monkey to achromatic images (faces, fruit, bodies, places) and colored gratings. IT contained multiple color-biased regions, which were typically ventral to face patches and, remarkably, yoked to them, spaced regularly at four locations predicted by known anatomy. Color and face selectivity increased for more anterior regions, indicative of a broad hierarchical arrangement. Responses to non-face shapes were found across IT, but were stronger outside color-biased regions and face patches, consistent with multiple parallel streams. IT also contained multiple coarse eccentricity maps: face patches overlapped central representations; color-biased regions spanned mid-peripheral representations; and place-biased regions overlapped peripheral representations. These results suggest that IT comprises parallel, multi-stage processing networks subject to one organizing principle.

Color naming across languages reflects color use

“…Color processing depends upon an extensive network of brain regions that process retinal signals (40), culminating in the highest levels of processing, in frontal cortex (41). The present report leverages color language as perhaps the best readout of this machinery as it pertains to behavior to uncover the forces behind the most fundamental color categorization, warm versus cool.…”

Which visual functions depend on intermediate visual regions? Insights from a case of developmental visual form agnosia

“…And indeed, color information processing begins at the retinal level (cone receptors, parvocellular and bistratified ganglion cells) and remains somewhat segregated through LGN (parvocellular and koniocellular layers), early visual cortex (V1's color blobs and V2's thin stripes; Wong-Riley, 1979;DeYoe and Van Essen, 1988;Lu and Roe 2008), and even within downstream regions in the ventral pathway (V4 and PIT globs; Conway et al, 2007;Conway and Tsao, 2009), where color "columns" resembling the perceptual color space are organized within color-sensitive cortical regions (Conway and Tsao, 2009). These color-sensitive regions have relatively weak shape-selectivity, whereas nearby shape-sensitive regions have relatively weak color-selectivity (Conway et al, 2007;Lu andRoe, 2008, LaferSousa andConway, 2013), suggesting that color and shape are predominantly processed in parallel within the ventral stream. Since the abnormality in LG's visual cortex was revealed with fMRI and EEG (Gilaie-Dotan et al, 2009), both methods averaging across extensive neural populations, and since the network supporting color processing constitutes a minor portion of the visual cortex (Lu and Roe, 2008;Lafer-Sousa and Conway, 2013) which in V1 and V2 is rather uniformly distributed (Lu and Roe, 2008), LG's color system, even if normally functioning, might have gone undetected under these circumstances.…”

“…These color-sensitive regions have relatively weak shape-selectivity, whereas nearby shape-sensitive regions have relatively weak color-selectivity (Conway et al, 2007;Lu andRoe, 2008, LaferSousa andConway, 2013), suggesting that color and shape are predominantly processed in parallel within the ventral stream. Since the abnormality in LG's visual cortex was revealed with fMRI and EEG (Gilaie-Dotan et al, 2009), both methods averaging across extensive neural populations, and since the network supporting color processing constitutes a minor portion of the visual cortex (Lu and Roe, 2008;Lafer-Sousa and Conway, 2013) which in V1 and V2 is rather uniformly distributed (Lu and Roe, 2008), LG's color system, even if normally functioning, might have gone undetected under these circumstances. And lastly, direct subcortical projections (e.g.…”

A Channel for 3D Environmental Shape in Anterior Inferotemporal Cortex

“…As with face and color information (Tsao et al 2003; Lafer-Sousa and Conway, 2013), environmental shape information remains at least partially segregated at these advanced processing stages. (Our anatomical sampling range largely spared regions where face and color modules have been identified.)…”