Sparsely-distributed organization of face and limb activations in human ventral temporal cortex

Abstract

Functional magnetic resonance imaging (fMRI) has identified face- and body part-selective regions, as well as distributed activation patterns for object categories across human ventral temporal cortex (VTC), eliciting a debate regarding functional organization in VTC and neural coding of object categories. Using high-resolution fMRI, we illustrate that face- and limb-selective activations alternate in a series of largely nonoverlapping clusters in lateral VTC along the inferior occipital gyrus (IOG), fusiform gyrus (FG), and occipitotemporal sulcus (OTS). Both general linear model (GLM) and multivoxel pattern (MVP) analyses show that face- and limb-selective activations minimally overlap and that this organization is consistent across experiments and days. We provide a reliable method to separate two face-selective clusters on the middle and posterior FG (mFus and pFus), and another on the IOG using their spatial relation to limb-selective activations and retinotopic areas hV4, VO-1/2, and hMT+. Furthermore, these activations show a gradient of increasing face selectivity and decreasing limb selectivity from the IOG to the mFus. Finally, MVP analyses indicate that there is differential information for faces in lateral VTC (containing weakly- and highly-selective voxels) relative to non-selective voxels in medial VTC. These findings suggest a sparsely-distributed organization where sparseness refers to the presence of several face- and limb-selective clusters in VTC, and distributed refers to the presence of different amounts of information in highly-, weakly-, and non-selective voxels. Consequently, theories of object recognition should consider the functional and spatial constraints of neural coding across a series of nonoverlapping category-selective clusters that are themselves distributed.

Normal acquisition of expertise with greebles in two cases of acquired prosopagnosia

“…Substantial evidence suggests faces are processed by mechanisms that are not involved in the recognition of most other objects (19,(30)(31)(32)(33)(34)(35), but whether these mechanisms are Although it has been suggested that the response time comparison in the verification trials is the critical measure of expertise, we have empirical and theoretical concerns about it. In one of the first papers involving greebles (13), of 12 subjects, two met the expertise criterion in the fourth session, two in the third session, one in the second session, and one in the first session.…”

The neural basis of perceiving person interactions

“…Sex categorization times on correct trials did not differ across the three types of dyads [F(2,22) = .24, p = .79]. Rossion et al, 2012;Weiner & Grill-Spector, 2010) and replicate reports according to which face-selective activity is right-lateralized and elicited more consistently in the FFA than the OFA (e.g., Andrews, Davies-Thompson, Kingstone, & Young, 2010;Engell & McCarthy, 2013;. Mean parameter estimates in all five ROIs were extracted from the main experiment for each participant (see Figure 3).…”

“…Such encoding is thought to occur in the so-called core neural network of person perception (Gobbini & Haxby, 2007;Rossion, Hanseeuw, & Dricot, 2012;Weiner & Grill-Spector, 2010), a system that comprises several brain regions, including the occipital face area (OFA), fusiform face area (FFA), posterior superior temporal sulcus (pSTS), extrastriate body area (EBA) and fusiform body area (FBA). All five regions act in concert to extract the structural and dynamic representation of an individual's facial and bodily appearance (Grosbras, Beaton, & Eickhoff, 2012;Gobbini & Haxby, 2007;Pavlova, 2012;Peelen & Downing, 2007;Weiner & Grill-Spector, 2010).…”

“…Such encoding is thought to occur in the so-called core neural network of person perception (Gobbini & Haxby, 2007;Rossion, Hanseeuw, & Dricot, 2012;Weiner & Grill-Spector, 2010), a system that comprises several brain regions, including the occipital face area (OFA), fusiform face area (FFA), posterior superior temporal sulcus (pSTS), extrastriate body area (EBA) and fusiform body area (FBA). All five regions act in concert to extract the structural and dynamic representation of an individual's facial and bodily appearance (Grosbras, Beaton, & Eickhoff, 2012;Gobbini & Haxby, 2007;Pavlova, 2012;Peelen & Downing, 2007;Weiner & Grill-Spector, 2010). When their interplay gets disturbed -through brain damage, repetitive TMS, or intracerebral electrical stimulation -face and body recognition skills decline, indicating the network's necessity for adequate person perception (e.g., Barton, Press, Keenan, & O'Connor, 2002;Jonas et al, 2012;Grossman, Battelli, & Pascual-Leone, 2005;Pitcher, Garrido, Walsh, & Duchaine, 2009;Sorger, Goebel, Schiltz, & Rossion, 2007;Urgesi, Candidi, Ionta, & Aglioti, 2007).…”

Vision, action and language unified through embodiment

“…The results are discussed in terms of motor processes in the left brain hemisphere associated with action nouns. Weiner and Grill-Spector (2012) summarize the results of two recently published studies (Weiner & Grill-Spector, 2010 that investigated the distribution of face and limb selectivity in human visual cortex. They propose a new three-stream model of high-level visual cortex which includes ventral, lateral and dorsal areas where multimodal processing related to vision, action and language might converge.…”