Complex objects are represented in macaque inferotemporal cortex by the combination of feature columns

Tsunoda, Kazushige; Yamane, Yoshihiro; Nishizaki, Makoto; Tanifuji, Manabu

doi:10.1038/90547

Cited by 337 publications

(262 citation statements)

References 28 publications

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“…IT neurons are able to learn new arbitrary shapes (Logothetis et al, 1995), and arbitrary pairings of stimuli (Sakai and Miyashita, 1991), which might be an analogue of learning letters and of linking arbitrarily related upper-and lowercase letters. Likewise, the binding of letters into words might be related to the representation of complex objects in IT cortex through the coactivation of neurons tuned to their elementary parts (Tsunoda et al, 2001). Binding of letters may also be based on more holistic coding, as suggested by the recent demonstration that single IT neurons develop selectivity for learned complex shapes, above and beyond what could be expected from the additive influence of their component parts (Baker et al, 2002).…”

Section: Resultsmentioning

confidence: 99%

Specialization within the ventral stream: the case for the visual word form area

2004

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Is there specialization for visual word recognition within the visual ventral stream of literate human adults? We review the evidence for a specialized ''visual word form area'' and critically examine some of the arguments recently placed against this hypothesis. Three distinct forms of specialization must be distinguished: functional specialization, reproducible localization, and regional selectivity. Examination of the literature with this theoretical division in mind indicates that reading activates a precise subpart of the left ventral occipitotemporal sulcus, and that patients with pure alexia consistently exhibit lesions of this region (reproducible localization). Second, this region implements processes adequate for reading in a specific script, such as invariance across upper-and lower-case letters, and its lesion results in the selective loss of reading-specific processes (functional specialization). Third, the issue of regional selectivity, namely, the existence of putative cortical patches dedicated to letter and word recognition, cannot be resolved by positron emission tomography or lesion data, but requires high-resolution neuroimaging techniques. The available evidence from single-subject fMRI and intracranial recordings suggests that some cortical sites respond preferentially to letter strings than to other categories of visual stimuli such as faces or objects, though the preference is often relative rather than absolute. We conclude that learning to read results in the progressive development of an inferotemporal region increasingly responsive to visual words, which is aptly named the visual word form area (VWFA).

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Section: Resultsmentioning

confidence: 99%

Specialization within the ventral stream: the case for the visual word form area

2004

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“…They also exhibit learning phenomena, even for essentially arbitrary figures [41]. Furthermore, combined optical imaging and single-cell recordings suggest that the IT cortex is composed of a mosaic of neuronal patches that respond to elementary shapes, whose combination can encode arbitrary objects [39,42]. Remarkably, some of those primitive shapes closely resemble printed or handwritten characters, such as T junctions, a figure-of-eight, a star, and so forth [39].…”

Section: V4 V4mentioning

confidence: 99%

The visual word form area: expertise for reading in the fusiform gyrus

McCandliss

Cohen

Dehaene

2003

Trends in Cognitive Sciences

1,301

934

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Brain imaging studies reliably localize a region of visual cortex that is especially responsive to visual words. This brain specialization is essential to rapid reading ability because it enhances perception of words by becoming specifically tuned to recurring properties of a writing system. The origin of this specialization poses a challenge for evolutionary accounts involving innate mechanisms for functional brain organization. We propose an alternative account, based on studies of other forms of visual expertise (i.e. bird and car experts) that lead to functional reorganization. We argue that the interplay between the unique demands of word reading and the structural constraints of the visual system lead to the emergence of the Visual Word Form Area.Years after children first learn to decode letters into words, a form of perceptual expertise emerges in which groups of letters are rapidly and effortlessly conjoined into integrated visual percepts -a process that is crucial to fluent reading ability. This article reviews the current evidence in support of a link between visual word form perception and a functional specialization in a brain region that we propose to call the 'Visual Word Form Area' (VWFA) -a portion of the left fusiform gyrus that is particularly responsive to visual words. Systematic exploration of the response properties of this region reveals sensitivity to specific and abstract qualities of visual word forms that are not easily attributable to more basic stimulus properties, and are also separable from higher-order linguistic properties.Considering the origin of VWFA poses a paradox for evolutionary accounts of functional specialization of extrastriate visual areas, given that the cultural invention of writing upon which this specialization is predicated did not exist until , 5400 years ago, which is insufficient time for selective pressures to engineer a specialized 'module' for visual word recognition. Instead, we suggest a developmental process through which reading experience drives progressive specialization of a pre-existing inferotemporal pathway for visual object recognition. Under this view, the rise of perceptual expertise in word recognition provides a remarkable example of how specialization processes within the visual system can accommodate a novel cultural invention. Perceptual expertise underlying visual word recognitionLiterate adults possess a special form of visual expertise that allows their visual system to process words efficiently. Within less than 250 ms of viewing a written word, the visual system extracts the information needed to identify its linguistic significance, despite wide variations in print, script, font, size and retinal position. Several lines of cognitive evidence indicate that the perceptual mechanisms that support word recognition rest on a critical process that groups the letters of a word together into an integrated perceptual unit (i.e. a 'visual word form'). This process is highly sensitive to the abstract structural properties of the writing syste...

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“…In the low-level visual system, neural selectivity varies depending on the physical properties such as arcs, intersecting lines, and non-Cartesian gratings (Hegde & Van Essen, 2000). In the highly specialized object-perception domain, neurons are tuned to a dictionary of features at different levels of complexity (Tsunoda, Yamane, Nishizaki, & Tanifuji, 2001). After specific neurons repeatedly and selectively respond to given objects, these objects are represented by their similarity to stored views of prototypes created (Palmeri, Wong, & Gauthier, 2004).…”

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confidence: 99%

It's a word: Early electrophysiological response to the character likeness of pictographs

et al. 2010

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Using unfamiliar and meaningless pictographs that varied in their degree of similarity to Chinese characters, the current study tested whether the early electrophysiological response was modulated by character likeness. We measured P100 and N170 while 20 native Chinese speakers were viewing Chinese characters, drawings of objects, and pictographs. Comparisons across the three categories of stimuli showed that pictographs elicited a smaller N170 amplitude than did Chinese characters and a stronger N170 amplitude than did objects, but did not differ in the P100 amplitude from the other two categories. Within the category of pictographs, stimuli with a higher degree of character likeness elicited larger N170 amplitudes and shorter N170 peak latencies, and this effect was again not observed in P100. These results suggest that N170 is sensitive to visual stimuli's character likeness even though they are unfamiliar pictographs with no meanings or sounds.

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Complex objects are represented in macaque inferotemporal cortex by the combination of feature columns

Cited by 337 publications

References 28 publications

Specialization within the ventral stream: the case for the visual word form area

Specialization within the ventral stream: the case for the visual word form area

The visual word form area: expertise for reading in the fusiform gyrus

It's a word: Early electrophysiological response to the character likeness of pictographs

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