The Interactive Account of ventral occipitotemporal contributions to reading
Authors: Cathy J. Price, Joseph T. Devlin
Journal: Trends in Cognitive Sciences (2011)

The ventral occipitotemporal cortex (vOT) is involved in the perception of visually presented objects and written words. The Interactive Account of vOT function is based on the premise that perception involves the synthesis of bottom-up sensory input with top-down predictions that are generated automatically from prior experience. We propose that vOT integrates visuospatial features abstracted from sensory inputs with higher level associations such as speech sounds, actions and meanings. In this context, specialization for orthography emerges from regional interactions without assuming that vOT is selectively tuned to orthographic features. We discuss how the Interactive Account explains left vOT responses during normal reading and developmental dyslexia; and how it accounts for the behavioural consequences of left vOT damage. The ventral occipitotemporal cortex (vOT) is involved in the perception of visually presented objects and written words. The Interactive Account of vOT function is based on the premise that perception involves the synthesis of bottom-up sensory input with top-down predictions that are generated automatically from prior experience. We propose that vOT integrates visuospatial features abstracted from sensory inputs with higher level associations such as speech sounds, actions and meanings. In this context, specialization for orthography emerges from regional interactions without assuming that vOT is selectively tuned to orthographic features. We discuss how the Interactive Account explains left vOT responses during normal reading and developmental dyslexia; and how it accounts for the behavioural consequences of left vOT damage. There has been considerable interest in the role of the ventral occipitotemporal cortex (vOT) during reading. Learning to read increases left vOT activation in response to written words [1Xue G. et al.Language experience shapes fusiform activation when processing a logographic artificial language: an fMRI training study.Neuroimage. 2006; 31: 1315-1326Crossref PubMed Scopus (131) Google Scholar, 2Ben-Shachar M. et al.The development of cortical sensitivity to visual word forms..J. Cogn. Neurosci. 2011; : 21615https://doi.org/10.1162/jocn.2011Crossref Google Scholar] and damage to left vOT impairs the ability to read [3Cohen L. et al.The pathophysiology of letter-by-letter reading.Neuropsychologia. 2004; 42: 1768-1780Crossref PubMed Scopus (134) Google Scholar, 4Leff A.P. et al.Structural anatomy of pure and hemianopic alexia.J. Neurol. Neurosurg. Psychiatry. 2006; 77: 1004-1007Crossref PubMed Scopus (113) Google Scholar, 5Pflugshaupt T. et al.About the role of visual field defects in pure alexia.Brain. 2009; 132: 1907-1917Crossref PubMed Scopus (22) Google Scholar, 6Starrfelt R. et al.Too little, too late: reduced visual span and speed characterize pure alexia.Cereb. Cortex. 2009; 19: 2880-2890Crossref PubMed Scopus (86) Google Scholar]. These and other findings have led to claims that the response properties of vOT change during reading acquisition, leading to neuronal populations that are selectively tuned to orthographic inputs [7Dehaene S. Cohen L. Cultural recycling of cortical maps.Neuron. 2007; 56: 384-398Abstract Full Text Full Text PDF PubMed Scopus (828) Google Scholar, 8Dehaene S. et al.The neural code for written words: a proposal.Trends Cogn. Sci. 2005; 9: 335-341Abstract Full Text Full Text PDF PubMed Scopus (784) Google Scholar]. However, a significant number of studies have reported that, even after learning to read, vOT is highly responsive to non-orthographic stimuli, with a selectivity that depends on the nature of the task and the stimulus [9Song Y. et al.The role of top-down task context in learning to perceive objects.J. Neurosci. 2010; 30: 9869-9876Crossref PubMed Scopus (34) Google Scholar, 10Starrfelt R. Gerlach C. The visual what for area: words and pictures in the left fusiform gyrus.Neuroimage. 2007; 35: 334-342Crossref PubMed Scopus (96) Google Scholar, 11Xue G. et al.Facilitating memory for novel characters by reducing neural repetition suppression in the left fusiform cortex.PLoS ONE. 2010; 5: e13204Crossref PubMed Scopus (32) Google Scholar]. The same vOT area also responds to orthographic and non-orthographic tactile stimuli [12Amedi A. et al.Visuo-haptic object-related activation in the ventral visual pathway.Nat. Neurosci. 2001; 4: 324-330Crossref PubMed Scopus (515) Google Scholar, 13Buchel C. et al.A multimodal language region in the ventral visual pathway.Nature. 1998; 394: 274-277Crossref PubMed Scopus (324) Google Scholar, 14Costantini M. et al.Haptic perception and body representation in lateral and medial occipito-temporal cortices.Neuropsychologia. 2011; 49: 821-829Crossref PubMed Scopus (49) Google Scholar, 15Price C.J. Devlin J.T. The myth of the visual word form area.Neuroimage. 2003; 19: 473-481Crossref PubMed Scopus (577) Google Scholar]. These diverse response properties suggest that vOT contributes to many different functions that change as it interacts with different areas [1Xue G. et al.Language experience shapes fusiform activation when processing a logographic artificial language: an fMRI training study.Neuroimage. 2006; 31: 1315-1326Crossref PubMed Scopus (131) Google Scholar, 9Song Y. et al.The role of top-down task context in learning to perceive objects.J. Neurosci. 2010; 30: 9869-9876Crossref PubMed Scopus (34) Google Scholar, 11Xue G. et al.Facilitating memory for novel characters by reducing neural repetition suppression in the left fusiform cortex.PLoS ONE. 2010; 5: e13204Crossref PubMed Scopus (32) Google Scholar, 15Price C.J. Devlin J.T. The myth of the visual word form area.Neuroimage. 2003; 19: 473-481Crossref PubMed Scopus (577) Google Scholar, 16Xue G. Poldrack R.A. The neural substrates of visual perceptual learning of words: implications for the visual word form area hypothesis.J. Cogn. Neurosci. 2007; 19: 1643-1655Crossref PubMed Scopus (89) Google Scholar, 17Devlin J.T. et al.The role of the posterior fusiform gyrus in reading.J. Cogn. Neurosci. 2006; 18: 911-922Crossref PubMed Scopus (210) Google Scholar, 18Price C.J. Friston K.J. Functional ontologies for cognition: the systematic definition of structure and function.Cogn. Neuropsychol. 2005; 22: 262-275Crossref PubMed Scopus (187) Google Scholar, 19Woodhead Z.V. et al.The visual word form system in context.J. Neurosci. 2011; 31: 193-199Crossref PubMed Scopus (20) Google Scholar, 20Reinke K. et al.Functional specificity of the visual word form area: general activation for words and symbols but specific network activation for words.Brain Lang. 2008; 104: 180-189Crossref PubMed Scopus (74) Google Scholar, 21Song Y. et al.Short-term language experience shapes the plasticity of the visual word form area.Brain Res. 2010; 1316: 83-91Crossref PubMed Scopus (25) Google Scholar]. In this context, it is difficult to find a functional label that explains all vOT responses. To explain the heterogeneity of responses in vOT, we formalize the Interactive Account of vOT function during reading by presenting it within a predictive coding (i.e. a generative) framework [22Friston K. The free-energy principle: a unified brain theory?.Nat. Rev. Neurosci. 2010; 11: 127-138Crossref PubMed Scopus (3543) Google Scholar, 23Hinton G.E. Learning multiple layers of representation.Trends Cogn. Sci. 2007; 11: 428-434Abstract Full Text Full Text PDF PubMed Scopus (727) Google Scholar]. This perspective provides a parsimonious explanation of empirical findings and is based on established theoretical and neurobiological principles. Before presenting this framework, we begin with an anatomical description of vOT. vOT is centred on the occipitotemporal sulcus but extends medially onto the lateral crest of the fusiform gyrus and laterally onto the medial crest of the inferior temporal gyrus. In the posterior–anterior direction, vOT is located on the ventral border of the occipital and temporal lobes (Figure 1a) , which lies between y = –50 and y = –60 in standard Montreal Neurological Institute (MNI) space. More posteriorly, activation is highest to visual inputs, but more anteriorly activity increases in response to familiar visual, tactile or auditory stimuli [24Kassuba T. et al.The left fusiform gyrus hosts trisensory representations of manipulable objects.Neuroimage. 2011; 56: 1566-1577Crossref PubMed Scopus (43) Google Scholar], consistent with a basal temporal language area [25Luders H. et al.Basal temporal language area.Brain. 1991; 114: 743-754Crossref PubMed Scopus (271) Google Scholar]. Given its position between visual and language areas, it is not surprising that vOT responds to a range of visual stimuli as well as the language demands of the task [1Xue G. et al.Language experience shapes fusiform activation when processing a logographic artificial language: an fMRI training study.Neuroimage. 2006; 31: 1315-1326Crossref PubMed Scopus (131) Google Scholar, 9Song Y. et al.The role of top-down task context in learning to perceive objects.J. Neurosci. 2010; 30: 9869-9876Crossref PubMed Scopus (34) Google Scholar, 11Xue G. et al.Facilitating memory for novel characters by reducing neural repetition suppression in the left fusiform cortex.PLoS ONE. 2010; 5: e13204Crossref PubMed Scopus (32) Google Scholar, 15Price C.J. Devlin J.T. The myth of the visual word form area.Neuroimage. 2003; 19: 473-481Crossref PubMed Scopus (577) Google Scholar, 16Xue G. Poldrack R.A. The neural substrates of visual perceptual learning of words: implications for the visual word form area hypothesis.J. Cogn. Neurosci. 2007; 19: 1643-1655Crossref PubMed Scopus (89) Google Scholar, 17Devlin J.T. et al.The role of the posterior fusiform gyrus in reading.J. Cogn. Neurosci. 2006; 18: 911-922Crossref PubMed Scopus (210) Google Scholar, 18Price C.J. Friston K.J. Functional ontologies for cognition: the systematic definition of structure and function.Cogn. Neuropsychol. 2005; 22: 262-275Crossref PubMed Scopus (187) Google Scholar, 19Woodhead Z.V. et al.The visual word form system in context.J. Neurosci. 2011; 31: 193-199Crossref PubMed Scopus (20) Google Scholar, 20Reinke K. et al.Functional specificity of the visual word form area: general activation for words and symbols but specific network activation for words.Brain Lang. 2008; 104: 180-189Crossref PubMed Scopus (74) Google Scholar, 21Song Y. et al.Short-term language experience shapes the plasticity of the visual word form area.Brain Res. 2010; 1316: 83-91Crossref PubMed Scopus (25) Google Scholar]. The association between vOT and language processing is further supported by observations that lateralization (left versus right hemisphere dominance) in vOT correlates with language lateralization in frontal language areas [26Cai Q. et al.The left ventral occipito-temporal response to words depends on language lateralization but not on visual familiarity.Cereb. Cortex. 2010; 20: 1153-1163Crossref PubMed Scopus (84) Google Scholar]. The Interactive Account is based on the premise that perception involves recurrent or reciprocal interactions between sensory cortices and higher order processing regions via a hierarchy of forward and backward connections (Figure 2) [22Friston K. The free-energy principle: a unified brain theory?.Nat. Rev. Neurosci. 2010; 11: 127-138Crossref PubMed Scopus (3543) Google Scholar]. Within the hierarchy, the function of a region depends on its synthesis of bottom-up sensory inputs conveyed by forward connections and top-down predictions mediated by backward connections. These predictions are based on prior experience and are needed to resolve uncertainty and ambiguity about the causes of the sensory inputs on which predictions are based. The hierarchical nature of neocortical organization is reflected in the abundance of backward relative to forward connections [27Friston K. et al.A free energy principle for the brain.J. Physiol. Paris. 2006; 100: 70-87Crossref PubMed Scopus (740) Google Scholar]. Because functional magnetic resonance imaging (fMRI) does not distinguish between synaptic activity induced by forward connections and that induced by backward connections, it reports their combined contribution (Figure 2), which includes prediction error. For reading, the sensory inputs are written words (or Braille in the tactile modality) and the predictions are based on prior association of visual or tactile inputs with phonology and semantics. In cognitive terms, vOT is therefore an interface between bottom-up sensory inputs and top-down predictions that call on non-visual stimulus attributes. Without prior knowledge the relationship between orthography and phonology, vOT activation to words will be low because phonological areas do not send backward predictions to vOT (Figure 2 and Box 1). Once phonological associations are learned, backward connections can deliver top-down predictions to vOT when the stimuli are words or word-like. In this context, top-down processing does not imply a conscious strategy; it is mandated by unconscious (hierarchical) perceptual inference. In other words, it represents the intimate association between visual inputs and higher level linguistic representations that occurs automatically and is modulated by attention and task demands. Interpreting activation in vOT therefore requires consideration of the stimulus, experience-dependent learning and context (i.e. the task requirements and the attentional demands). Likewise, interpreting the effect of damage to vOT depends on how word recognition is affected by disrupting top-down inputs from higher order regions to vOT, and from vOT to lower level visual regions (Box 2).Box 1Learning to read and developmental dyslexiaReading involves linking orthography (i.e. written symbols) to phonology (speech sounds) and semantics (meaning). Learning these associations enhances the ability to predict and perceive the defining visual features of symbols that have been learned. For example, letter combinations will be recognized more efficiently when they are familiar and strongly linked to phonology (e.g. WINE) than when they are less familiar (e.g. WINO) [54Goswami U. Ziegler J.C. A developmental perspective on the neural code for written words.Trends Cogn. Sci. 2006; 10: 142-143Abstract Full Text Full Text PDF PubMed Scopus (45) Google Scholar]. At the neural level, learning involves experience-dependent synaptic plasticity, which changes connection strengths and the efficiency of perceptual inference.According to the Interactive Account of ventral occipitotemporal cortex (vOT) function during reading, top-down predictions are conveyed by backward connections from phonological and semantic areas to vOT (Figure 2). These top-down predictions are engaged during the early stages of learning to name objects, and when learning to read words or learning a new orthography. The predictions produce prediction errors, which drive learning to improve prediction. In pre-literates, vOT activation is low because orthographic inputs do not trigger appropriate representations in phonological or semantic areas and therefore there are no top-down influences (stage 1 in Figure 2b). In the early stages of learning to read, vOT activation is high because top-down predictions are engaged imprecisely and it takes longer for the system to suppress prediction errors and identify the word (stage 2 in Figure 2b). In skilled readers, vOT activation declines because learning improves the predictions, which explain prediction error efficiently (stage 3 in Figure 2b). In developmental dyslexics, abnormally low vOT activation [55Blau V. et al.Deviant processing of letters and speech sounds as proximate cause of reading failure: a functional magnetic resonance imaging study of dyslexic children.Brain. 2010; 133: 868-879Crossref PubMed Scopus (208) Google Scholar, 56Brunswick N. et al.Explicit and implicit processing of words and pseudowords by adult developmental dyslexics: a search for Wernicke's Wortschatz?.Brain. 1999; 122: 1901-1917Crossref PubMed Scopus (475) Google Scholar, 57Richlan F. et al.A common left occipito-temporal dysfunction in developmental dyslexia and acquired letter-by-letter reading?.PLoS ONE. 2010; 5: e12073Crossref PubMed Scopus (77) Google Scholar, 58Shaywitz B.A. et al.Disruption of posterior brain systems for reading in children with developmental dyslexia.Biol. Psychiatry. 2002; 52: 101-110Abstract Full Text Full Text PDF PubMed Scopus (772) Google Scholar, 59van der Mark S. et al.Children with dyslexia lack multiple specializations along the visual word-form (VWF) system.Neuroimage. 2009; 47: 1940-1949Crossref PubMed Scopus (180) Google Scholar, 60Wimmer H. et al.A dual-route perspective on poor reading in a regular orthography: an fMRI study.Cortex. 2010; 46: 1284-1298Abstract Full Text Full Text PDF PubMed Scopus (100) Google Scholar] and reduced functional connectivity between vOT and other language areas [61van der Mark S. et al.The left occipitotemporal system in reading: disruption of focal fMRI connectivity to left inferior frontal and inferior parietal language areas in children with dyslexia.Neuroimage. 2011; 54: 2426-2436Crossref PubMed Scopus (174) Google Scholar] are consistent with failure to establish hierarchical connections and access top-down predictions, perhaps because of a paucity of phonological knowledge (i.e. failure to progress from stage 1 to stage 2 [Figure 2b]).This perspective explains the learning-related increases in vOT activation that have been demonstrated in non-reading pre-school children learning the sounds of letters [62Brem S. et al.Brain sensitivity to print emerges when children learn letter-speech sound correspondences.Proc. Natl. Acad. Sci. U.S.A. 2010; 107: 7939-7944Crossref PubMed Scopus (306) Google Scholar], adults learning sounds and meanings in an artificial orthography [1Xue G. et al.Language experience shapes fusiform activation when processing a logographic artificial language: an fMRI training study.Neuroimage. 2006; 31: 1315-1326Crossref PubMed Scopus (131) Google Scholar] and children improving their overt word reading speed [2Ben-Shachar M. et al.The development of cortical sensitivity to visual word forms..J. Cogn. Neurosci. 2011; : 21615https://doi.org/10.1162/jocn.2011Crossref Google Scholar]. In addition, vOT activation is reduced following visual form learning [1Xue G. et al.Language experience shapes fusiform activation when processing a logographic artificial language: an fMRI training study.Neuroimage. 2006; 31: 1315-1326Crossref PubMed Scopus (131) Google Scholar], which demonstrates that learning-related effects are task dependent [1Xue G. et al.Language experience shapes fusiform activation when processing a logographic artificial language: an fMRI training study.Neuroimage. 2006; 31: 1315-1326Crossref PubMed Scopus (131) Google Scholar, 63James K.H. Sensori-motor experience leads to changes in visual processing in the developing brain.Dev. Sci. 2010; 13: 279-288Crossref PubMed Scopus (161) Google Scholar]. The Interactive Account explains these effects in terms of experience-dependent plasticity and the resulting increases and decreases in prediction error (Figure 2b). The same learning-related principles apply irrespective of whether the stimuli are letters, words or objects [9Song Y. et al.The role of top-down task context in learning to perceive objects.J. Neurosci. 2010; 30: 9869-9876Crossref PubMed Scopus (34) Google Scholar, 21Song Y. et al.Short-term language experience shapes the plasticity of the visual word form area.Brain Res. 2010; 1316: 83-91Crossref PubMed Scopus (25) Google Scholar, 64Turkeltaub P.E. et al.Development of ventral stream representations for single letters.Ann. N. Y. Acad. Sci. 2008; 1145: 13-29Crossref PubMed Scopus (30) Google Scholar, 65McCrory E.J. et al.More than words: a common neural basis for reading and naming deficits in developmental dyslexia?.Brain. 2005; 128: 261-267Crossref PubMed Scopus (125) Google Scholar].Box 2Damage to the ventral occipitotemporal cortex and pure alexiaReading impairment is the most notable effect of selective damage to the ventral occipitotemporal cortex (vOT) [3Cohen L. et al.The pathophysiology of letter-by-letter reading.Neuropsychologia. 2004; 42: 1768-1780Crossref PubMed Scopus (134) Google Scholar, 4Leff A.P. et al.Structural anatomy of pure and hemianopic alexia.J. Neurol. Neurosurg. Psychiatry. 2006; 77: 1004-1007Crossref PubMed Scopus (113) Google Scholar, 5Pflugshaupt T. et al.About the role of visual field defects in pure alexia.Brain. 2009; 132: 1907-1917Crossref PubMed Scopus (22) Google Scholar, 6Starrfelt R. et al.Too little, too late: reduced visual span and speed characterize pure alexia.Cereb. Cortex. 2009; 19: 2880-2890Crossref PubMed Scopus (86) Google Scholar]. This deficit is typically referred to as 'pure alexia' because speech and language abilities remain intact, as does the ability to write words. Most patients with vOT damage also have difficulty naming objects [66Hillis A.E. et al.Restoring cerebral blood flow reveals neural regions critical for naming.J. Neurosci. 2006; 26: 8069-8073Crossref PubMed Scopus (150) Google Scholar, 67Hillis A.E. et al.The roles of the "visual word form area" in reading.Neuroimage. 2005; 24: 548-559Crossref PubMed Scopus (133) Google Scholar, 68Marsh E.B. Hillis A.E. Cognitive and neural mechanisms underlying reading and naming: evidence from letter-by-letter reading and optic aphasia.Neurocase. 2005; 11: 325-337Crossref PubMed Scopus (48) Google Scholar], consistent with a generic difficulty linking visual inputs to the language system. Nevertheless, a few patients with vOT damage have been reported with worse reading than naming accuracy [6Starrfelt R. et al.Too little, too late: reduced visual span and speed characterize pure alexia.Cereb. Cortex. 2009; 19: 2880-2890Crossref PubMed Scopus (86) Google Scholar, 69Gaillard R. et al.Direct intracranial FMRI, and lesion evidence for the causal role of left inferotemporal cortex in reading.Neuron. 2006; 50: 191-204Abstract Full Text Full Text PDF PubMed Scopus (302) Google Scholar]. This does not mean that vOT is only necessary for reading, because: (i) accurate object naming following vOT damage has only been reported in patients with mild alexia, which manifests in reading speed rather than reading accuracy; (ii) difficulties with object recognition and naming become apparent when the speed of processing is taken into account [6Starrfelt R. et al.Too little, too late: reduced visual span and speed characterize pure alexia.Cereb. Cortex. 2009; 19: 2880-2890Crossref PubMed Scopus (86) Google Scholar, 70Starrfelt R. et al.Visual processing in pure alexia: a case study.Cortex. 2010; 46: 242-255Abstract Full Text Full Text PDF PubMed Scopus (63) Google Scholar]; and (iii) better object naming after vOT damage may be supported by post hoc learning-related changes in other brain regions that provide alternative connections from vision to the language system, with these connections being more successful for object recognition than word recognition.How does the Interactive Account explain why vOT is more critical for reading than for object recognition? According to the Interactive Account, damage to vOT will disconnect forward and backward connections at all levels of the hierarchy (Figure 2), leading to imprecise perceptual inference. This will have a disproportionate effect on reading because written words comprise the same component parts occurring repeatedly in different, but sometimes highly similar, combinations (e.g. attitude, altitude, aptitude). Object recognition will also be impaired when vOT is disconnected from occipital and higher order language areas, but it will be less impaired than reading when it can proceed on the basis of holistic shape information and a limited number of defining features. Reading involves linking orthography (i.e. written symbols) to phonology (speech sounds) and semantics (meaning). Learning these associations enhances the ability to predict and perceive the defining visual features of symbols that have been learned. For example, letter combinations will be recognized more efficiently when they are familiar and strongly linked to phonology (e.g. WINE) than when they are less familiar (e.g. WINO) [54Goswami U. Ziegler J.C. A developmental perspective on the neural code for written words.Trends Cogn. Sci. 2006; 10: 142-143Abstract Full Text Full Text PDF PubMed Scopus (45) Google Scholar]. At the neural level, learning involves experience-dependent synaptic plasticity, which changes connection strengths and the efficiency of perceptual inference. According to the Interactive Account of ventral occipitotemporal cortex (vOT) function during reading, top-down predictions are conveyed by backward connections from phonological and semantic areas to vOT (Figure 2). These top-down predictions are engaged during the early stages of learning to name objects, and when learning to read words or learning a new orthography. The predictions produce prediction errors, which drive learning to improve prediction. In pre-literates, vOT activation is low because orthographic inputs do not trigger appropriate representations in phonological or semantic areas and therefore there are no top-down influences (stage 1 in Figure 2b). In the early stages of learning to read, vOT activation is high because top-down predictions are engaged imprecisely and it takes longer for the system to suppress prediction errors and identify the word (stage 2 in Figure 2b). In skilled readers, vOT activation declines because learning improves the predictions, which explain prediction error efficiently (stage 3 in Figure 2b). In developmental dyslexics, abnormally low vOT activation [55Blau V. et al.Deviant processing of letters and speech sounds as proximate cause of reading failure: a functional magnetic resonance imaging study of dyslexic children.Brain. 2010; 133: 868-879Crossref PubMed Scopus (208) Google Scholar, 56Brunswick N. et al.Explicit and implicit processing of words and pseudowords by adult developmental dyslexics: a search for Wernicke's Wortschatz?.Brain. 1999; 122: 1901-1917Crossref PubMed Scopus (475) Google Scholar, 57Richlan F. et al.A common left occipito-temporal dysfunction in developmental dyslexia and acquired letter-by-letter reading?.PLoS ONE. 2010; 5: e12073Crossref PubMed Scopus (77) Google Scholar, 58Shaywitz B.A. et al.Disruption of posterior brain systems for reading in children with developmental dyslexia.Biol. Psychiatry. 2002; 52: 101-110Abstract Full Text Full Text PDF PubMed Scopus (772) Google Scholar, 59van der Mark S. et al.Children with dyslexia lack multiple specializations along the visual word-form (VWF) system.Neuroimage. 2009; 47: 1940-1949Crossref PubMed Scopus (180) Google Scholar, 60Wimmer H. et al.A dual-route perspective on poor reading in a regular orthography: an fMRI study.Cortex. 2010; 46: 1284-1298Abstract Full Text Full Text PDF PubMed Scopus (100) Google Scholar] and reduced functional connectivity between vOT and other language areas [61van der Mark S. et al.The left occipitotemporal system in reading: disruption of focal fMRI connectivity to left inferior frontal and inferior parietal language areas in children with dyslexia.Neuroimage. 2011; 54: 2426-2436Crossref PubMed Scopus (174) Google Scholar] are consistent with failure to establish hierarchical connections and access top-down predictions, perhaps because of a paucity of phonological knowledge (i.e. failure to progress from stage 1 to stage 2 [Figure 2b]). This perspective explains the learning-related increases in vOT activation that have been demonstrated in non-reading pre-school children learning the sounds of letters [62Brem S. et al.Brain sensitivity to print emerges when children learn letter-speech sound correspondences.Proc. Natl. Acad. Sci. U.S.A. 2010; 107: 7939-7944Crossref PubMed Scopus (306) Google Scholar], adults learning sounds and meanings in an artificial orthography [1Xue G. et al.Language experience shapes fusiform activation when processing a logographic artificial language: an fMRI training study.Neuroimage. 2006; 31: 1315-1326Crossref PubMed Scopus (131) Google Scholar] and children improving their overt word reading speed [2Ben-Shachar M. et al.The development of cortical sensitivity to visual word forms..J. Cogn. Neurosci. 2011; : 21615https://doi.org/10.1162/jocn.2011Crossref Google Scholar]. In addition, vOT activation is reduced following visual form learning [1Xue G. et al.Language experience shapes fusiform activation when processing a logographic artificial language: an fMRI training study.Neuroimage. 2006; 31: 1315-1326Crossref PubMed Scopus (131) Google Scholar], which demonstrates that learning-related effects are task dependent [1Xue G. et al.Language experience shapes fusiform activation when processing a logographic artificial language: an fMRI training study.Neuroimage. 2006; 31: 1315-1326Crossref PubMed Scopus (131) Google Scholar, 63James K.H. Sensori-motor experience leads to changes in visual processing in the developing brain.Dev. Sci. 2010; 13: 279-288Crossref PubMed Scopus (161) Google Scholar]. The Interactive Account explains these effects in terms of experience-dependent plasticity and the resulting increases and decreases in prediction error (Figure 2b). The same learning-related principles apply irrespective of whether the stimuli are letters, words or objects [9Song Y. et al.The role of top-down task context in learning to perceive objects.J. Neurosci. 2010; 30: 9869-9876Crossref PubMed Scopus (34) Google Scholar, 21Song Y. et al.Short-term language experience shapes the plasticity of the visual word form area.Brain Res. 2010; 1316: 83-91Crossref PubMed Scopus (25) Google Scholar, 64Turkeltaub P.E. et al.Development of ventral stream representations for single letters.Ann. N. Y. Acad. Sc