Reading normal and degraded words: Contribution of the dorsal and ventral visual pathways

@article{citeulike:2357955, abstract = {Fast, parallel word recognition, in expert readers, relies on sectors of the left ventral occipito-temporal pathway collectively known as the visual word form area. This expertise is thought to arise from perceptual learning mechanisms that extract informative features from the input strings. The perceptual expertise hypothesis leads to two predictions: (1) parallel word recognition, based on the ventral visual system, should be limited to words displayed in a familiar format (foveal horizontal words with normally spaced letters); (2) words displayed in formats outside this field of expertise should be read serially, under supervision of dorsal parietal attention systems. We presented adult readers with words that were progressively degraded in three different ways (word rotation, letter spacing, and displacement to the visual periphery). Behaviorally, we identified degradation thresholds above which reading difficulty increased non-linearly, with the concomitant emergence of a word length effect on reading latencies reflecting serial reading strategies. fMRI activations were correlated with reading difficulty in bilateral occipito-temporal and parietal regions, reflecting the strategies required to identify degraded words. A core region of the intraparietal cortex was engaged in all modes of degradation. Furthermore, in the ventral pathway, word degradation led to an amplification of activation in the posterior visual word form area, at a level thought to encode single letters. We also found an effect of word length restricted to highly degraded words in bilateral occipitoparietal regions. Those results clarify when and how the ventral parallel visual word form system needs to be supplemented by the deployment of dorsal serial reading strategies.}, author = {Cohen, Laurent and Dehaene, Stanislas and Vinckier, Fabien and Jobert, Antoinette and Montavont, Alexandra }, citeulike-article-id = {2357955}, doi = {10.1016/j.neuroimage.2007.11.036}, journal = {NeuroImage}, keywords = {3290, recognition, word}, month = {March}, number = {1}, pages = {353--366}, posted-at = {2008-02-09 15:44:12}, priority = {2}, title = {Reading normal and degraded words: Contribution of the dorsal and ventral visual pathways}, url = {http://dx.doi.org/10.1016/j.neuroimage.2007.11.036}, volume = {40}, year = {2008} }

TY - JOUR ID - citeulike:2357955 L3 - citeulike-article-id:2357955 TI - Reading normal and degraded words: Contribution of the dorsal and ventral visual pathways JF - NeuroImage VL - 40 IS - 1 SP - 353 EP - 366 N2 - Fast, parallel word recognition, in expert readers, relies on sectors of the left ventral occipito-temporal pathway collectively known as the visual word form area. This expertise is thought to arise from perceptual learning mechanisms that extract informative features from the input strings. The perceptual expertise hypothesis leads to two predictions: (1) parallel word recognition, based on the ventral visual system, should be limited to words displayed in a familiar format (foveal horizontal words with normally spaced letters); (2) words displayed in formats outside this field of expertise should be read serially, under supervision of dorsal parietal attention systems. We presented adult readers with words that were progressively degraded in three different ways (word rotation, letter spacing, and displacement to the visual periphery). Behaviorally, we identified degradation thresholds above which reading difficulty increased non-linearly, with the concomitant emergence of a word length effect on reading latencies reflecting serial reading strategies. fMRI activations were correlated with reading difficulty in bilateral occipito-temporal and parietal regions, reflecting the strategies required to identify degraded words. A core region of the intraparietal cortex was engaged in all modes of degradation. Furthermore, in the ventral pathway, word degradation led to an amplification of activation in the posterior visual word form area, at a level thought to encode single letters. We also found an effect of word length restricted to highly degraded words in bilateral occipitoparietal regions. Those results clarify when and how the ventral parallel visual word form system needs to be supplemented by the deployment of dorsal serial reading strategies. KW - 3290 KW - recognition KW - word AU - Cohen, Laurent AU - Dehaene, Stanislas AU - Vinckier, Fabien AU - Jobert, Antoinette AU - Montavont, Alexandra PY - 2008/03/01/ UR - http://dx.doi.org/10.1016/j.neuroimage.2007.11.036 ER -