The Differential Engagement of Executive Functions In Word and Contextual Reading After Reading Training In Children With Dyslexia: An fMRI Study Introduction Reading disability (RD; or dyslexia) is characterized by slow, inaccurate reading accompanied by difficulties in executive functions (Brosnan et al., 2002). The reading acceleration program is based on executive functions’ principles and is designed to increase reading speed and accuracy (Breznitz, & Nevat, 2004). Contextual reading fluency is based on word-level reading, and both are impaired in individuals with RD (Horowitz-Kraus & Breznitz, 2010). Methods Participants: 18 individuals with dyslexia and 18 skilled readers (8-12 years old), matched for IQ and attention ability. Children with dyslexia scored a standard score of -1.5 and below in words/nonwords and contextual reading from a normative reading tests battery (WJ-III: Woodcock and Johnson, 1989; TOWRE: Torgesen, Wagner & Rashotte, 1999). Reading Acceleration Program: Both groups were trained for 20 sessions with a computer program containing 50 different sentences each. Imaging data was acquired and reading ability was assessed before and after training (within a month). Behavioral data was obtained before and following training. Word reading was assessed using the TOWRE test and contextual reading was measured using the reading speed measures from RAP. Functional Magnetic Resonance Imaging: We examined the change in BOLD signal in a Stroop task (Floden, Vsallesi, & Stuss. 2010) following RAP (Test 2). We contrasted the ‘different’ condition (i.e., words which are colored in a different color than the word) with the colored XXX (see Fig. 1). Imaging data was collected using a 3T Philips imaging system and were analyzed using SPM8 software (Friston et al., 1995). Conclusion RDs engage both the right and left Anterior Cingulate Cortex as well as reading regions to perform an executive functions task as well as for word reading. TRs are using reading regions specifically (i.e., the precuneus). TRs who gained more from RAP training, are using both their right and left frontal regions for contextual reading and executive functions, whereas RDs relied more on the right hemisphere for these abilities. These results can suggest an increase in the efficiency of the executive functions in the prefrontal cortex after completion of RAP (Reading Acceleration Program). The results may provide biological evidence that reading relies on executive functions in both RDs and TRs. RAP may assist RDs using their left hemisphere for word reading, but contextual reading involves the right hemisphere to a greater extent. The results may point at possible compensatory mechanisms in RDs which involve the right hemisphere, such as comprehension and sematic abilities. References Breznitz, Z., and M. Nevat "The reading acceleration program (RAP)." Haifa: The Edmond J. Safra Brain Research Center for the Study of Learning Disabilities, University of Haifa Bronsan, S., Newton-Fisher, N., Van Vugt, M “A Melding of the Minds: When Primatology Meets Personality and Social Psychology” Primate Social Psychology. Web Floden, Vsallesi, and Stuss. (2010): "Task Context and Frontal Lobe Activation in the Stroop Task."Journal of Cognitive Neuroscience n. pag. PubMed. Web. Friston, K.J., Frith, C.D., Frackowiak R. S. J., and Turner, R Characterizing dynamic brain responses with fMRI: A multivariate approach. NeuroImage. Horowitz-Kraus, T., & Breznitz, Z. (2010). Reaction time and accuracy in erroneous vs correct responses among dyslexic and regular readers: from letters to sentences. Dyslexia, 17, Prapti Shah, Nicole D. Cicchino, B.S., Scott K. Holland, Ph.D., and Tzipi Horowitz- Kraus, Ph.D. Pediatric Neuroimaging Research Consortium, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States Figure 1. The Stroop Task Participants were exposed to a series of colored words, where the color of the word did and did not match the word’s meaning. This was contrasted with colored Xs (RED vs. XXX) (Floden, Vsallesi, & Stuss. 2010). In the current study only the words which did not match the color of the word were used. Results Behavioral measures Imaging measures A. Correlation of gain in word reading and fMRI Stroop data after intervention (Test 2) in RDs and TRs (contrast: different>XXX, P<.005, uncorrected). RDs TRs B. Correlation of gain in contextual reading and fMRI Stroop data after intervention (Test 2) in RDs and TRs (contrast: different>XXX, P<.005, uncorrected). RDs TRs Lateralization index (frontal lobe) L L L LR Aim To determine the engagement of neural circuits related to executive functions during word and contextual reading in individuals with dyslexia (RD) and typical readers (TR). R R R Figure 2.a. Figure 2.b. Figure 2a.b. Both TRs and RDs showed greater word reading after training (Figure 1a). Both had a decreased contextual reading speed (Figure 1b). Correlation of Stroop in Test2 with word reading gain Correlation of Stroop in Test2 with contextual reading gain Lateralization index (frontal lobe)