HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mechelli, A. Articles by Price, C. J. Search for Related Content PubMed PubMed Citation Articles by Mechelli, A. Articles by Price, C. J.

Dissociating Reading Processes on the Basis of Neuronal Interactions

¹ Functional Imaging Laboratory, Wellcome Department of Imaging Neuroscience, Institute of Neurology, London, UK, ² University of Manchester, UK, ³ MRC Cognition and Brain Sciences Unit, Cambridge, UK, ⁴ Center for the Neural Basis of Cognition, Pittsburgh, PA, USA

Reprint requests should be sent to Andrea Mechelli, Wellcome Department of Imaging Neuroscience, 12 Queen Square London, WC1N 3BG, UK, or via e-mail: andream{at}fil.ion.ucl.ac.uk.

Previous studies of patients with phonological and surface alexia have demonstrated a double dissociation between the reading of pseudo words and words with atypical spelling-to-sound relationships. A corresponding double dissociation in the neuronal activation patterns for pseudo words and exception words has not, however, been consistently demonstrated in normal subjects. Motivated by the literature on acquired alexia, the present study contrasted pseudo words to exception words and explored how neuronal interactions within the reading system are influenced by word type. Functional magnetic resonance imaging was used to measure neuronal responses during reading in 22 healthy volunteers. The direct comparison of reading pseudo words and exception words revealed a double dissociation within the left frontal cortex. Pseudo words preferentially increased left dorsal premotor activation, whereas exception words preferentially increased left pars triangularis activation. Critically, these areas correspond to those previously associated with phonological and semantic processing, respectively. Word-type dependent interactions between brain areas were then investigated using dynamic causal modeling. This revealed that increased activation in the dorsal premotor cortex for pseudo words was associated with a selective increase in effective connectivity from the posterior fusiform gyrus. In contrast, increased activation in the pars triangularis for exception words was associated with a selective increase in effective connectivity from the anterior fusiform gyrus. The present investigation is the first to identify distinct neuronal mechanisms for semantic and phonological contributions to reading.

This article has been cited by other articles:

				S. M. Wilson, S. M. Brambati, R. G. Henry, D. A. Handwerker, F. Agosta, B. L. Miller, D. P. Wilkins, J. M. Ogar, and M. L. Gorno-Tempini The neural basis of surface dyslexia in semantic dementia Brain, November 20, 2008; (2008) awn300v1. [Abstract] [Full Text] [PDF]

				J. Fan, P. R. Hof, K. G. Guise, J. A. Fossella, and M. I. Posner The Functional Integration of the Anterior Cingulate Cortex during Conflict Processing Cereb Cortex, April 1, 2008; 18(4): 796 - 805. [Abstract] [Full Text] [PDF]

				K. Nakamura, S. Dehaene, A. Jobert, D. Le Bihan, and S. Kouider Task-specific change of unconscious neural priming in the cerebral language network PNAS, December 4, 2007; 104(49): 19643 - 19648. [Abstract] [Full Text] [PDF]

				J. Kujala, K. Pammer, P. Cornelissen, A. Roebroeck, E. Formisano, and R. Salmelin Phase Coupling in a Cerebro-Cerebellar Network at 8-13 Hz during Reading Cereb Cortex, June 1, 2007; 17(6): 1476 - 1485. [Abstract] [Full Text] [PDF]

				V. Sluming, J. Brooks, M. Howard, J. J. Downes, and N. Roberts Broca's Area Supports Enhanced Visuospatial Cognition in Orchestral Musicians J. Neurosci., April 4, 2007; 27(14): 3799 - 3806. [Abstract] [Full Text] [PDF]

				W. W. Graves, T. J. Grabowski, S. Mehta, and J. K. Gordon A neural signature of phonological access: distinguishing the effects of word frequency from familiarity and length in overt picture naming. J. Cogn. Neurosci., April 1, 2007; 19(4): 617 - 631. [Abstract] [Full Text] [PDF]

				M. Carreiras, A. Mechelli, A. Estevez, and C. J. Price Brain activation for lexical decision and reading aloud: two sides of the same coin? J. Cogn. Neurosci., March 1, 2007; 19(3): 433 - 444. [Abstract] [Full Text] [PDF]

				E. Orfanidou, W. D. Marslen-Wilson, and M. H. Davis Neural response suppression predicts repetition priming of spoken words and pseudowords. J. Cogn. Neurosci., August 1, 2006; 18(8): 1237 - 1252. [Abstract] [Full Text] [PDF]

				J. T. Devlin, H. L. Jamison, L. M. Gonnerman, and P. M. Matthews The role of the posterior fusiform gyrus in reading. J. Cogn. Neurosci., June 1, 2006; 18(6): 911 - 922. [Abstract] [Full Text] [PDF]

				O. Hauk, K. Patterson, A. Woollams, L. Watling, F. Pulvermuller, and T. T. Rogers [Q:] When would you prefer a SOSSAGE to a SAUSAGE? [A:] At about 100 msec. ERP correlates of orthographic typicality and lexicality in written word recognition. J. Cogn. Neurosci., May 1, 2006; 18(5): 818 - 832. [Abstract] [Full Text] [PDF]