Article

The role of the occipital face area in the cortical face perception network

Institute of Cognitive Neuroscience, University College London, Alexandra House, London, WC1N 3AR, UK.
Experimental Brain Research (Impact Factor: 2.04). 02/2011; 209(4):481-93. DOI: 10.1007/s00221-011-2579-1
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ABSTRACT

Functional magnetic resonance imaging (fMRI) studies have identified spatially distinct face-selective regions in human cortex. These regions have been linked together to form the components of a cortical network specialized for face perception but the cognitive operations performed in each region are not well understood. In this paper, we review the evidence concerning one of these face-selective regions, the occipital face area (OFA), to better understand what cognitive operations it performs in the face perception network. Neuropsychological evidence and transcranial magnetic stimulation (TMS) studies demonstrate the OFA is necessary for accurate face perception. fMRI and TMS studies investigating the functional role of the OFA suggest that it preferentially represents the parts of a face, including the eyes, nose, and mouth and that it does so at an early stage of visual perception. These studies are consistent with the hypothesis that the OFA is the first stage in a hierarchical face perception network in which the OFA represents facial components prior to subsequent processing of increasingly complex facial features in higher face-selective cortical regions.

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    • "In order to make the proposed two-stage model more explicit, we will describe in detail how such a system could be implemented in the visual modality when faces are presented as stimuli (see Fig. 3). Research in face perception commonly suggests the occipital faces area (OFA;as the entry-level of the face-processing network and proposes that it relays sensory information to the FFA (Calder & Young, 2005;Haxby, Hoffman, & Gobbini, 2000;Ishai, 2008;Pitcher, Walsh, & Duchaine, 2011). Further, it was shown that the LOC is strongly interconnected with both the fusiform and the occipital face areas, despite its more broadly tuned response profile (Nagy, Greenlee, & Kovács, 2012). "
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    ABSTRACT: While in earlier work various local or bottom-up neural mechanisms were proposed to give rise to repetition suppression (RS), current theories suggest that top-down processes play a role in determining the repetition related reduction of the neural responses. In the current review we summarise those results, which support the role of these top-down processes, concentrating on the Bayesian models of predictive coding (PC). Such models assume that RS is related to the statistical probabilities of prior stimulus occurrences and to the future predictability of these stimuli. Here we review the current results that support or argue against this explanation. We point out that the heterogeneity of experimental manipulations that are thought to reflect predictive processes are likely to measure different processing steps, making their direct comparison difficult. In addition we emphasize the importance of identifying these sub-processes and clarifying their role in explaining RS. Finally, we propose a two-stage model for explaining the relationships of repetition and expectation phenomena in the human cortex.
    No preview · Article · Jan 2016 · Cortex
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    • "This conjecture was based on the observation that category-selective visual cortical regions generally come in anterior–posterior pairs (Taylor & Downing, 2011; Schwarzlose, Swisher, Dang, & Kanwisher, 2008), such as the fusiform face area (FFA; Kanwisher, McDermott, & Chun, 1997) and the occipital face area (OFA; Gauthier et al., 2000), both of which are frequently implicated in fMRI studies of face recognition. One view is that the OFA generates an initial representation of face features or parts that are subsequently integrated with respect to spatial configuration in the FFA (Pitcher, Walsh, & Duchaine, 2011; Liu, Harris, & Kanwisher, 2010; Pitcher, Walsh, Yovel, & Duchaine, 2007). We therefore hypothesized the existence of a secondary VWFA—a more posterior occipital word form area (OWFA) in the left hemisphere—that works together with the VWFA to represent hemifield-split letter strings as whole words. "
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    ABSTRACT: Reading requires the neural integration of visual word form information that is split between our retinal hemifields. We examined multiple visual cortical areas involved in this process by measuring fMRI responses while observers viewed words that changed or repeated in one or both hemifields. We were specifically interested in identifying brain areas that exhibit decreased fMRI responses as a result of repeated versus changing visual word form information in each visual hemifield. Our method yielded highly significant effects of word repetition in a previously reported visual word form area (VWFA) in occipitotemporal cortex, which represents hemifield-split words as whole units. We also identified a more posterior occipital word form area (OWFA), which represents word form information in the right and left hemifields independently and is thus both functionally and anatomically distinct from the VWFA. Both the VWFA and the OWFA were left-lateralized in our study and strikingly symmetric in anatomical location relative to known face-selective visual cortical areas in the right hemisphere. Our findings are consistent with the observation that category-selective visual areas come in pairs and support the view that neural mechanisms in left visual cortex-especially those that evolved to support the visual processing of faces-are developmentally malleable and become incorporated into a left-lateralized visual word form network that supports rapid word recognition and reading.
    Full-text · Article · Nov 2015 · Journal of Cognitive Neuroscience
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    • "Taken together these findings suggest no difference in the representations of upright and inverted faces in the OFA. Based on the finding that upright but not inverted faces are processed holistically (Farah et al., 1998), these findings may further suggest that the holistic representation of upright faces is not generated at early stages of face processing in the lateral occipital lobe (Pitcher et al., 2011c) but only in mid-level stages in the mid-temporal cortex. Direct evidence for this suggestion is reported in studies that employed tasks that directly assessed holistic face processing, as will be discussed next. "
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    ABSTRACT: Faces elicit robust and selective neural responses in the primate brain. These neural responses have been investigated with functional MRI and EEG in numerous studies, which have reported face-selective activations in the occipital-temporal cortex and an electrophysiological face-selective response that peaks 170ms after stimulus onset at occipital-temporal sites. Evidence for face-selective processes has also been consistently reported in cognitive studies, which investigated the face inversion effect, the composite face effect and the left visual field (LVF) superiority. These cognitive effects indicate that the perceptual representation that we generate for faces differs from the representation that is generated for inverted faces or non-face objects. In this review, I will show that the fMRI and ERP face-selective responses are strongly associated with these three well-established behavioral face-selective measures. I will further review studies that examined the relationship between fMRI and EEG face-selective measures suggesting that they are strongly linked. Taken together these studies imply that a holistic representation of a face is generated at 170ms after stimulus onset over the right hemisphere. These findings, which reveal a strong link between the various and complementary cognitive and neural measures of face processing, allow to characterize where, when and how faces are represented during the first 200ms of face processing.
    Preview · Article · Sep 2015 · Neuropsychologia
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