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

“…for written words than spoken words (Booth et al., 2002a, 2002b; Cohen et al., 2002), written words than chequerboards or consonants (Cohen et al., 2002); and to be invariant to the spatial location of the stimuli (Cohen et al., 2002) or the case and font of the letters (Dehaene et al., 2002).”

“Ϫ42 Ϫ57 Ϫ15; Dehaene et al., 2002).”

“However, one of them, which is the focus of this review, appears uniquely concerned with written as opposed to spoken word recognition (Dehaene et al., 2002).”

“This location is in good agreement with a number of previous activation studies (for reviews see Cohen et al., 2000; Dehaene et al., 2001; Dehaene et al., 2002).”

“To demonstrate functional specialization in the VWFA, one should exhibit a pattern of activation that cannot be reduced to generic visual processes, but necessarily reflects regularities of the writing system.”

“…irrespective of typographical case (Dehaene et al., 2001; see also Polk and Farah, 2002) and that it does not respond to same– different matching of auditory words or pseudowords (Dehaene et al., 2002), the authors have labeled this left midfusiform region the " visual word form area " (VWFA).”

“…been called the ‘visual word form area’ (VWFA) to reflect the localized and reproducible response to written words and pseudowords at this site 26,27 , although it should be noted that even after reading acquisition, this region continues to respond, to a lesser extent, to visual stimuli besides…”

“…of lines of investigation indicates that a portion of the posterior reading systems, the occipitotemporal area, is critical for the development of skilled reading and functions as an automatic, instant word recognition system, the visual word form area (Cohen et al 2000, 2002; Dehaene et al 2002).”

“…automatic, rapidly responding system is localized within the occipitotemporal area, functioning as a visual word form area (Cohen et al 2000, 2002; Dehaene et al 2001, 2002; Moore and Price 1999), that appears to respond preferentially to rapidly presented stimuli (Price and Giraud 1998) and is…”

“…have addressed the issue of the functional cortical organization of the semantic system (Chao et al., 1999; Epstein et al., 1999; Haxby et al., 1999; Price, 2000; Dehaene et al., 2002; Hasson et al., 2002; McCandliss et al., 2003; Amedi et al., 2004; Cohen and Dehaene, 2004; Vihla et al., 2006).”

“In one study (Dehaene et al., 2002), they demonstrated that regions in the right occipital cortex are sensitive to low-level visual features (repetition effects were found only for physically identical stimuli), whereas left occipital–temporal areas revealed sensitivity to more abstract features (repetition was found…”

“Some authors (81, 94) claim that visual information resulting from lowlevel sensory analysis enters the “visual word form area” (VWFA) that they argue lies in the middle portion of the left fusiform gyrus, this being also one of the major lesion sites associated with severe alexia (31, 81; see also Ref.”

“The VWFA is activated by visual but not auditory words (Dehaene et al., 2002), irrespective of their position in the visual field (Cohen and Dehaene, 2000).”

“For example, length of stimulus alone does not affect the region of processing [34], nor does readability: non-words (groups of letters) are processed in ‘word regions’ rather than in ‘letter regions’ [17,18,6].”

“been shown to be more activated for words or pseudowords than for false fonts 132 or consonant strings [7-10].”

“13 prelexical, as demonstrated by its identical response to words and to pronounceable pseusowords (Dehaene et al., 2002).”

“The VWFA was originally proposed to host prelexical visual orthographic representations based on orthographic regularities that constrain letter combinations in a given orthography [Cohen and Dehaene, 2004; Dehaene and Cohen, 2011; Dehaene et al., 2002, 2005; Vinckier et al., 2007].”

“McCandliss et al. (2003) justify this hypothesis by findings showing similar VWFA activation by frequently encountered visual words and never-seen pseudowords (e.g., Dehaene et al., 2002) and by high-frequency words and low-frequency words (e.g., Fiebach et al., 2002).”

“Form invariant, abstract representations of highly overlearned visual objects such as words and faces have been found to originate in the fusiform gyrus (Haxby et al., 1994; Chao et al., 1999; Cohen et al., 2000; Dehaene et al., 2002).”

“How do these three hypotheses relate to one another? The ‘neuronal recycling’ hypothesis was prompted by the discovery of a cortical visual area in the human occipito-temporal region (the visual word form area, VWFA, see [96]) specifically activated by early perceptual stages of the reading process.”

“The VWFA was repeatedly shown not to be typically activated in a bottom-up fashion by auditory words (e.g., spoken language; Cohen et al., 2004; Dehaene et al., 2002; Tsapkini and Rapp, 2010), giving rise to the hypothesis that its function is limited to vision (Cohen et al.”

“The VWFA is often located in the posterior fusiform gyrus (Baker et al., 2007; Cohen et al., 2000; Dehaene et al., 2002) or on two OTS locations (BenShachar et al.”

“This region was proposed to act as an interface between visual word form and higher order stimulus properties (Devlin, Jamison, Gonnerman, & Matthews, 2006; Price & Devlin, 2003; but see, e.g., Dehaene et al., 2002; McCandliss, Cohen, & Dehaene, 2003).”

“…of activity for words and pseudowords (seemingly plausible nonwords made up of standard letters), but not for illegal letter symbols, suggesting an area that processes visual stimuli that look like words, prior to establishing whether they have a meaning (Dehaene et al., 2002; Posner et al., 1988).”

“Responsiveness of the Visual Word Form Area has been shown to be highly specific to visually presented alphabetic characters, which produce a greater response than either auditory words [Dehaene et al., 2002] or visually presented false font characters that control for low-level visual qualities [Price et al.”

“Activations were present in regions frequently reported in simple calculation and arithmetic procedure tasks, namely the bilateral precuneus (BA 7) observed in both groups and the left angular gyrus (BA 39) only observed in controls [Dehaene et al., 1996; Rickard et al., 2000; Zago et al., 2001].”

“We recently studied the activations to spoken and written words, using a repetition detection task (Dehaene et al., 2002).”

“…activation in pITG in the word condition (Experiment 2) indicated that this region was close to the visual word form area as described by Dehaene et al. (2002). hMT ⁄V5+ hMT ⁄V5+, a known motion-sensitive area, was strongly activated in response to our three types of complex motion…”

“The first divergent relationship was observed for RSFC of the FFG, a region commonly referred to as the visual word form area (Dehaene et al., 2002).”

“This finding contrasts with previous studies demonstrating similar activation for W and PW in the VWFA (Dehaene et al., 2002; Wydell et al., 2003) and adjacent areas (Vinckier et al.”

“The question as to whether the VWFA is used while reading seems largely settled: VWFA circuitry is responsive to visual word forms (Dehaene et al., 2002; Salmelin et al., 1996, 2000; Wandell, 2011; Wandell et al., 2012); damage to the VWFA or nearby white matter produces reading deficits (Epelbaum…”

“…(Cohen et al., 2003; Yeatman et al., 2012) and damage to this tract can result in alexia (Epelbaum et al., 2008), presumably due to its role in connecting low-level visual regions to the visual word form area (a fusiform region involved in processing word/letter strings; Dehaene et al., 2002).”

“The VWFA is located lateral to the middle section of the fusiform gyrus, with remarkable reproducibility across subjects, even across a variety of script types (Cohen et al., 2000; Dehaene et al., 2002; Jobard et al., 2003; Bolger et al., 2005).”

“In addition, VWFA shows font-type invariance (Dehaene et al., 2002).”

“This limited prelexical string processing function was mainly based on a finding by Dehaene et al. (2002), showing that the VWFA exhibited about the same activation to letter strings of familiar words (e.g., street), which allow whole-word recognition, as to letter strings of pseudowords (e.g.,…”

“The regions of the brain that are differentially sensitive to printed words versus nonwords are nothing to do with bringing stimuli to consciousness, because they are activated even by stimuli of which the subject does not become conscious (Dehaene et al., 2001 ).”

“The activation of this region has also been demonstrated to be independent of word meanings (Dehaene et al., 2002) and sensitive to priming even when the appearance of letters was altered using different letter case (Dehaene et al.”

“These group analyses are especially useful in comparing our results with those of prior studies in which data was analyzed in the same manner (e.g., Cohen et al., 2000; Dehaene et al., 2002).”

“The dichotomous view has been challenged by imaging studies on alphabetical words, for example, in French (Cohen et al., 2000, 2002; Dehaene et al., 2001, 2002).”

“…the VWFA consistently falls in the depth of the occipito-temporal sulcus, lateral to the fusiform gyrus (Cohen et al., 2000; Cohen et al., 2002; Dehaene et al., 2002; Gauthier et al., 2000; Puce, Allison, Asgari, Gore, & McCarthy, 1996), a region that was clearly spared in patient C.Z.…”

“This particular subregion may be attuned specifically to the visual representations of words, or more precisely, to abstract (shape-independent ) representations of visual letter strings (Cohen, Lehericy, et al., 2002; Dehaene, Le Clec, et al., 2002).”

“In adult readers of English, activity in the right hemisphere fusiform is weaker and more variable than the left hemisphere fusiform region [Dehaene et al., 2002], and sensitive in only some individuals to alphabetic stimuli [Cohen et al., 2002].”

“…orthographic word processing is accomplished in ventral occipito-temporal cortex areas [Booth et al., 2001; Brown et al., 2004; Cohen et al., 2003; Dehaene et al., 2002; Pugh et al., 1996; Schlaggar et al., 2002; Tagamets et al., 2000], referred to as the visual word form system (VWFS) [Vinckier…”

“In 1 of these 3 locations, the left inferior occipital--temporal gyrus, several recent adult studies have provided evidence for specialization in processing visual words (a ‘‘visual word form area’’ [vWFA]) (e.g., Cohen et al. 2002; Dehaene et al. 2002; McCandliss et al. 2003).”

“Similar to our area FG2, the VWFA was first described to be located on the lateral fusiform gyrus (Cohen et al. 2000; Dehaene et al. 2002), but more recent findings show that the large portion of VWFA lies within the fundus of the lateral occipitotemporal sulcus and about 1 cm anterior to FG2…”

“The activation of the VWFA together with inferior frontal areas during passive reading of single words is consistent with earlier findings (e.g. Dehaene et al., 2002; Hauk et al., 2004).”

“…part of the left FFG, at a location coinciding with the ''Visual Word Form Area'' that is responsive to word and word-like orthography (Cohen et al. 2000; Dehaene et al. 2002); 3) STG (x = –53, y = –31, z = 9), in the posterior part of the left STG, which is included in Wernicke's area and…”

“This region, referred to as the visual word form area (VWFA) [Cohen et al., 2000; Dehaene et al., 2002; Dehaene and Cohen, 2011], receives homolateral visual inputs from the occipital pole via the ventral occipitotemporal (vOT) region [Epelbaum et al.”

“functional imaging data suggest that the critical region for processing orthographic stimuli when reading is more ventrally located in the left fusiform gyrus (Dehaene et al. 2002; Leff et al. 2006), and it no longer seems plausible that the function of the left AG is confined to processing written word forms.”

“, the visual forms of letter combinations, morphemes, and whole words) (1, 3, 4).”

“This is consistent with recent evidence that the previously described visual word form area (VWFA: Dehaene et al., 2002) in the left ventral visual cortex (approximate MNI coordinates: −43, −54, −18) is equally responsive to words, pseudo-words and semantic symbols (Reinke et al., 2008; Kronbichler…”

“We excluded the initial 250 ms because previous studies have suggested that this is the time window of visual processes (Dehaene et al., 2002; Tarkiainen et al., 1999) while the majority of higher order processes, which are the main focus of our interest, such as lexical and context effects, occur…”

“Recently, researchers focusing on the recognition of alphabetic scripts (Cohen et al., 2000, 2002, 2003; Dehaene et al., 2002, 2001; McCandliss et al., 2003) proposed that the middle fusiform gyrus of the left hemisphere is responsible for the processing of visual word forms and for the…”

“…visual cortex (low-level perception of the visual stimuli), leftlateralized posterior inferior temporal regions (recognition of visual word forms (Dehaene et al., 2002; McCandliss, Cohen and Dehaene, 2003; Cohen and Dehaene, 2004)), left middle temporal cortex near Wernicke’s area (retrieval of…”

“…forms of words and pictures could either be represented by neuronal populations that are specific to stimulus type in the bottom-up direction (Dehaene et al. 2002) or they could be represented by differences in the distributed pattern of responses across shared neuronal populations in LvOT…”

“…of activity for words and pseudowords (seemingly plausible nonwords made up of standard letters), but not for illegal letter symbols, suggesting an area that processes visual stimuli that look like words, prior to establishing whether they have a meaning (Dehaene et al. 2002; Posner et al. 1988).”