title: Reading the wrong way with the right hemisphere.
abstract: Reading is a complex process, drawing on a variety of brain functions in order to link symbols to words and concepts. The three major brain areas linked to reading and phonological analysis include the left temporoparietal region, the left occipitotemporal region and the inferior frontal gyrus. Decreased activation of the left posterior language system in dyslexia is well documented but there is relatively limited attention given to the role of the right hemisphere. The current study investigated differences in right and left hemisphere activation between individuals with dyslexia and non-impaired readers in lexical decision tasks (regular words, irregular words, pseudowords) during functional Magnetic Resonance Imaging (fMRI). Results revealed the expected hypo-activation in the left posterior areas in those with dyslexia but also areas of overactivation in the right hemisphere. During pseudoword decisions, for example, adults with dyslexia showed more right inferior occipital gyrus activation than controls. In general the increased activation of left-hemisphere language areas found in response to both regular and pseudowords was absent in dyslexics. Laterality indices showed that while controls showed left lateralised activation of the temporal lobe during lexical decision making, dyslexic readers showed right activation. Findings will inform theories of reading and will have implications for the design of reading interventions.
authors: School of Psychology, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. k.waldie@auckland.ac.nz.
authors: Karen E
authors: KE
authors: Waldie
authors: School of Psychology, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. char.haigh@gmail.com.
authors: Charlotte E
authors: CE
authors: Haigh
authors: School of Psychology, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. g.badzakova@auckland.ac.nz.
authors: Gjurgjica
authors: G
authors: Badzakova-Trajkov
authors: School of Psychology, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. j.buckley@auckland.ac.nz.
authors: Jude
authors: J
authors: Buckley
authors: School of Psychology, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. i.kirk@auckland.ac.nz.
authors: Ian J
authors: IJ
authors: Kirk