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

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Abstract

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.

Section snippets

Perceptual expertise underlying visual word recognition

Literate 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

Spatial localization

Numerous neuroimaging studies have provided converging evidence in support of a central finding: Perception of visual words and pseudowords reliably activates the left fusiform gyrus to a greater degree than other highly similar control stimuli. Although early neuroimaging efforts produced various estimates for the localization of visual word form activity (for a review, see [7]), more recent experiments demonstrate reliable activation for words, versus stimuli that control for visual

Response properties of the VWFA

Now that this region can be reliably identified and repeatedly probed under different experimental contrasts, it is possible to address questions concerning the nature of the associated cognitive operations by investigating the response properties of this region. Such research has demonstrated several fundamental characteristics of the response properties of the VWFA that are relevant for establishing its operational role in visual word perception.

Origins of the VWFA specialization

Taken together, the response properties of the VWFA are largely consistent with a proposed level of perceptual processing in word recognition that constructs an abstract representation of letters sequenced into word forms [28]. But how did this area of the visual system evolve to have response properties that show specific sensitivity to invariant and abstract properties of a class of stimuli that never existed before the relatively recent invention of alphabetic writing systems? In addressing

Conclusions and future directions

We started this article with a paradox: how can reading – a recent cultural invention – rely on a cerebral substrate that is tuned to the abstract properties of a class of stimuli that did not exist for most of human evolution? The hypothesis of a progressive specialization of the left VWFA over the course of reading acquisition avoids problems inherent to the notion of a ready-made ‘word recognition module’. The similarity between reading and other forms of acquired visual expertise emphasizes

References (55)

  • A.L. Bokde

    Functional interactions of the inferior frontal cortex during the processing of words and word-like stimuli

    Neuron

    (2001)
  • K. Rayner et al.

    The Psychology of Reading

    (1989)
  • T.A. Nazir

    Letter legibility and visual word recognition

    Mem. Cogn.

    (1998)
  • G.M. Reicher

    Perceptual recognition as a function of meaninfulness of stimulus material

    J. Exp. Psychol.

    (1969)
  • E.J. Gibson

    The role of grapheme–phoneme correspondence in the perception of words

    Am. J. Psychol.

    (1962)
  • T.H. Carr

    Orthography and familiarity effects in word processing

    J. Exp. Psychol. Gen.

    (1979)
  • J.A. Fiez et al.

    Neuroimaging studies of word reading

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

    (1998)
  • L. Cohen

    Language-specific tuning of visual cortex? Functional properties of the visual word form area

    Brain

    (2002)
  • L. Cohen

    The visual word form area: spatial and temporal characterization of an initial stage of reading in normal subjects and posterior split-brain patients

    Brain

    (2000)
  • T.A. Polk et al.

    Functional MRI evidence for an abstract, not perceptual, word-form area

    J. Exp. Psychol. Gen.

    (2002)
  • S. Dehaene

    The visual word form area: a prelexical representation of visual words in the fusiform gyrus

    Neuroreport

    (2002)
  • S. Bentin

    ERP manifestations of processing printed words at different psycholinguistic levels: time course and scalp distribution

    J. Cogn. Neurosci.

    (1999)
  • P. Helenius

    Dissociation of normal feature analysis and deficient processing of letter-strings in dyslexic adults

    Cereb. Cortex

    (1999)
  • A. Tarkiainen

    Dynamics of visual feature analysis and object-level processing in face versus letter-string perception

    Brain

    (2002)
  • A.C. Nobre

    Word recognition in the human inferior temporal lobe

    Nature

    (1994)
  • C. Büchel

    A multimodal language region in the ventral visual pathway

    Nature

    (1998)
  • S. Dehaene

    Cerebral mechanisms of word masking and unconscious repetition priming

    Nat. Neurosci.

    (2001)
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