title: Neural correlates of lexical and sublexical processes in reading.
abstract: The purpose of the present study was to compare the brain regions and systems that subserve lexical and sublexical processes in reading. In order to do so, three types of tasks were used: (i). silent reading of very high frequency regular words (lexical task); (ii). silent reading of nonwords (sublexical task); and, (iii). silent reading of very low frequency regular words (sublexical task). All three conditions were contrasted with a visual/phonological baseline condition. The lexical condition engaged primarily an area at the border of the left angular and supramarginal gyri. Activation found in this region suggests that this area may be involved in mapping orthographic-to-phonological whole word representations. Both sublexical conditions elicited significantly greater activation in the left inferior prefrontal gyrus. This region is thought to be associated with sublexical processes in reading such as grapheme-to-phoneme conversion, phoneme assembly and underlying verbal working memory processes. Activation in the left IFG was also associated with left superior and middle temporal activation. These areas are thought to be functionally correlated with the left IFG and to contribute to a phonologically based form of reading. The results as a whole demonstrate that lexical and sublexical processes in reading activate different regions within a complex network of brain structures.
authors.affiliation: Centre de Recherche, Institut universitaire de gériatrie de Montréal, Canada. sven.joubert@medecine.univ-mrs.fr
authors.forename: Sven
authors.initials: S
authors.lastname: Joubert
authors.forename: Mario
authors.initials: M
authors.lastname: Beauregard
authors.forename: Nathalie
authors.initials: N
authors.lastname: Walter
authors.forename: Pierre
authors.initials: P
authors.lastname: Bourgouin
authors.forename: Gilles
authors.initials: G
authors.lastname: Beaudoin
authors.forename: Jean-Maxime
authors.initials: JM
authors.lastname: Leroux
authors.forename: Sherif
authors.initials: S
authors.lastname: Karama
authors.forename: André Roch
authors.initials: AR
authors.lastname: Lecours
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002531:Cerebellum / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010699:Phonation / Q000502:physiology*; D011932:Reading; D012660:Semantics; D014706:Verbal Learning / Q000502:physiology
chemical_list: D010100:Oxygen