Accessing orthographic representations from speech: the role of left ventral occipitotemporal cortex in spelling.
Bottom Line: Such an orthographic word lexicon is posited by cognitive dual-route theories of reading and spelling.In the scanner, participants performed a spelling task in which they had to indicate if a visually presented letter is present in the written form of an auditorily presented word.Our results suggest that activation of left vOT during spelling can be attributed to the retrieval of orthographic whole-word representations and, thus, support the position that the left vOT potentially represents the neuronal equivalent of the cognitive orthographic word lexicon.
Affiliation: Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.Show MeSH
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Mentions: In addition to the whole-brain analysis, we investigated differences between the spelling conditions in left vOT with a ROI-based analysis. Of main interest was the posterior extent of the increased activation for the word spelling conditions relative to the pseudoword spelling condition identified at y= −55 (orthographic) and y = −58 (orthographic-phonological). More specifically, we were interested in whether these peaks were different from the left vOT peak at y = −64 identified for all spelling conditions relative to the control conditions. For this, we computed a spelling > control contrast (collapsed across word and pseudoword conditions). Figure 4 illustrates the resulting left vOT cluster in relation to the orthographic word > phonological pseudoword spelling cluster. Within this spelling > control cluster, we selected three ROIs varying along the anterior–posterior axis. The middle ROI corresponded to the cluster peak at MNI coordinates [−45 −64 −11]. We further selected a 10 mm more anterior ROI (y = −54) and a 10 mm more posterior ROI (y = −74) to cover the entire anterior-to-posterior extent of the cluster. The x and z coordinates for these ROIs were kept constant. Figure 4 shows the approximate locations of the ROIs. Mean contrast estimates for each condition versus rest were then extracted for spheres (r = 4 mm) centered at the mentioned coordinates.
Affiliation: Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.