Discrimination Training Alters Object Representations in Human Extrastriate Cortex

Beeck, Hans Op de; Baker, Chris I.; DiCarlo, James J.; Kanwisher, Nancy

doi:10.1523/jneurosci.2481-06.2006

Cited by 233 publications

(277 citation statements)

References 55 publications

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“…In a recent study (49), we found that 10 h of training on a novel object category produces a nearly 2-fold response to trained compared with untrained categories in some voxels in the ventral visual pathway, which was not present before training. Similarly, neurophysiological studies in nonhuman primates have found that training on discrimination and recognition of visual objects can lead to changes in the selectivity of neural responses in the inferior temporal cortex, a region critical for object recognition (50,51).…”

Section: Discussionmentioning

confidence: 67%

Visual word processing and experiential origins of functional selectivity in human extrastriate cortex

Baker

Liu

Wald

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

347

302

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How do category-selective regions arise in human extrastriate cortex? Visually presented words provide an ideal test of the role of experience: Although individuals have extensive experience with visual words, our species has only been reading for a few thousand years, a period not thought to be long enough for natural selection to produce a genetically specified mechanism dedicated to visual word recognition per se. Using relatively high-resolution functional magnetic resonance imaging (1.4 ؋ 1.4 ؋ 2-mm voxels), we identified a small region of extrastriate cortex in most participants that responds selectively to both visually presented words and consonant strings, compared with line drawings, digit strings, and Chinese characters. Critically, we show that this pattern of selectivity is dependent on experience with specific orthographies: The same region responds more strongly to Hebrew words in Hebrew readers than in nonreaders of Hebrew. These results indicate that extensive experience with a given visual category can produce strong selectivity for that category in discrete cortical regions.learning ͉ vision ͉ fMRI ͉ experience ͉ ventral visual pathway

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Section: Discussionmentioning

confidence: 67%

Visual word processing and experiential origins of functional selectivity in human extrastriate cortex

Baker

Liu

Wald

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

347

302

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“…First, could high-level visual areas simply be selective for shape characteristics? In support of this view, unfamiliar artificial-object categories and relatively simple patterns elicit selective responses in the object-and face-selective cortex in humans 94,95 (FIG. 4).…”

Section: Basic Properties In the Ventral Visual Cortexmentioning

confidence: 85%

“…The pattern of selectivity is distributed and weak in individual voxels, at least for the unfamiliar-object classes that have been tested. For example, in a recent study with high spatial resolution, in the scattered regions that showed the most selectivity the strength of the regions' response to their least-preferred novel objects was approximately two thirds of the response to a preferred novel object 95 . By contrast, the maximum selectivity for some familiar objects is far stronger, even at lower spatial resolution: the FFA, the PPA and the EBA all respond at least two to three times more strongly to their preferred object class (faces, houses and bodies, respectively) than to a wide range of nonpreferred object classes 21 .…”

Section: Basic Properties In the Ventral Visual Cortexmentioning

confidence: 95%

“…In addition, supervised category learning can change the perception and visual processing of objects 118 , leading to a biased processing of relevant dimensions [122][123][124][125][126] . Furthermore, learning to discriminate objects within categories changes the pattern of selectivity across the object-vision pathway 95 . Thus, learning about categories and their members might be responsible for some of the functional organization that exists with regards to object category.…”

Section: Object Category As a Basic Propertymentioning

confidence: 99%

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Interpreting fMRI data: maps, modules and dimensions

2008

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Neuroimaging research over the past decade has revealed a detailed picture of the functional organization of the human brain. Here we focus on two fundamental questions that are raised by the detailed mapping of sensory and cognitive functions and illustrate these questions with findings from the object-vision pathway. First, are functionally specific regions that are located close together best understood as distinct cortical modules or as parts of a larger-scale cortical map? Second, what functional properties define each cortical map or module? We propose a model in which overlapping continuous maps of simple features give rise to discrete modules that are selective for complex stimuli.Advances in brain imaging technology (especially functional MRI (fMRI)) have radically improved our understanding of the functional organization of the human brain (BOX 1). In this Review we describe the organization of the ventral visual pathway, which is characterized by strong selectivity for particular object categories (for example, faces and bodies) at the level of both individual neurons and larger cortical regions. We then consider two central questions: whether this organization reflects maps or modules, and what properties are mapped. In each case we derive clues from the literature on the primary sensory cortex, in which cortical maps have been studied extensively using electrophysiology in animals. We find that apparently modular cortical regions, such as orientation columns and face-selective regions, might be parts of larger maps, and show that it is a substantial challenge to determine the basic properties and dimensions that describe functional organization most parsimoniously. We then propose a new framework that reconciles the existence of graded cortical maps and distinct functional modules. In this framework, the strong category selectivity that exists for faces and other objects might arise from the nonlinear combination of multiple correlated maps for simpler stimulus properties. The ventral visual pathwayThe ventral visual pathway comprises a large cortical region that occupies the ventral and lateral surfaces of the occipital and temporal lobes (FIG. 1). A substantial proportion of fMRI voxels in this pathway are 'object-selective' -that is, they respond more strongly when people view images of objects than when people view scrambled versions of these objects or texture patterns. This object-selective region is often referred to as the lateral occipital complex (LOC) 1 . The LOC has little selectivity for particular stimulus categories 2-4 , but several regions of NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript cortex near the LOC are selective for particular object categories: they respond at least twice as strongly to their 'preferred' stimuli than to other stimuli. For example, in essentially all humans cortical regions can be found that respond selectively to faces (the fusiform face area (FFA) 5,6 and, in many individuals, the occipital face area (OFA)) 7,8 , to pl...

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“…On the one hand, experience must surely play some instructive role in the development of face areas, given the ample evidence that neurons in the ventral visual pathway are tuned by experience (Baker et al 2002;Op de Beeck et al submitted). Evidence of such experiential tuning of face perception, in particular, is seen in the 'other race effect', in which behavioural performance (Malpass & Kravitz 1969;Meissner & Brigham 2001) and neural responses (Golby et al 2001) are higher for faces of a familiar than an unfamiliar race, even if the relevant experience occurs after age 3 (Sangrigoli et al 2005).…”

Section: Open Questionsmentioning

confidence: 99%

The fusiform face area: a cortical region specialized for the perception of faces

Kanwisher

Yovel

2006

Phil. Trans. R. Soc. B

1,441

989

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Faces are among the most important visual stimuli we perceive, informing us not only about a person's identity, but also about their mood, sex, age and direction of gaze. The ability to extract this information within a fraction of a second of viewing a face is important for normal social interactions and has probably played a critical role in the survival of our primate ancestors. Considerable evidence from behavioural, neuropsychological and neurophysiological investigations supports the hypothesis that humans have specialized cognitive and neural mechanisms dedicated to the perception of faces (the face-specificity hypothesis). Here, we review the literature on a region of the human brain that appears to play a key role in face perception, known as the fusiform face area (FFA).Section 1 outlines the theoretical background for much of this work. The face-specificity hypothesis falls squarely on one side of a longstanding debate in the fields of cognitive science and cognitive neuroscience concerning the extent to which the mind/brain is composed of: (i) special-purpose ('domain-specific') mechanisms, each dedicated to processing a specific kind of information (e.g. faces, according to the face-specificity hypothesis), versus (ii) general-purpose ('domain-general') mechanisms, each capable of operating on any kind of information. Face perception has long served both as one of the prime candidates of a domain-specific process and as a key target for attack by proponents of domain-general theories of brain and mind. Section 2 briefly reviews the prior literature on face perception from behaviour and neurophysiology. This work supports the face-specificity hypothesis and argues against its domain-general alternatives (the individuation hypothesis, the expertise hypothesis and others).Section 3 outlines the more recent evidence on this debate from brain imaging, focusing particularly on the FFA. We review the evidence that the FFA is selectively engaged in face perception, by addressing (and rebutting) five of the most widely discussed alternatives to this hypothesis. In §4, we consider recent findings that are beginning to provide clues into the computations conducted in the FFA and the nature of the representations the FFA extracts from faces. We argue that the FFA is engaged both in detecting faces and in extracting the necessary perceptual information to recognize them, and that the properties of the FFA mirror previously identified behavioural signatures of face-specific processing (e.g. the face-inversion effect).Section 5 asks how the computations and representations in the FFA differ from those occurring in other nearby regions of cortex that respond strongly to faces and objects. The evidence indicates clear functional dissociations between these regions, demonstrating that the FFA shows not only functional specificity but also area specificity. We end by speculating in §6 on some of the broader questions raised by current research on the FFA, including the developmental origins of this region and the ques...

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Discrimination Training Alters Object Representations in Human Extrastriate Cortex

Cited by 233 publications

References 55 publications

Visual word processing and experiential origins of functional selectivity in human extrastriate cortex

Visual word processing and experiential origins of functional selectivity in human extrastriate cortex

Interpreting fMRI data: maps, modules and dimensions

The fusiform face area: a cortical region specialized for the perception of faces

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