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. 2009 Oct;30(10):3299-308.
doi: 10.1002/hbm.20752.

Functional abnormalities in the dyslexic brain: a quantitative meta-analysis of neuroimaging studies

Fabio Richlan  1 , Martin Kronbichler, Heinz Wimmer
Affiliations

Functional abnormalities in the dyslexic brain: a quantitative meta-analysis of neuroimaging studies

Fabio Richlan et al. Hum Brain Mapp. 2009 Oct.

Abstract

This study used foci from 17 original studies on functional abnormalities in the dyslexic brain to identify brain regions with consistent under- or overactivation. Studies were included when reading or reading-related tasks were performed on visually presented stimuli and when results reported coordinates for group differences. Activation likelihood estimation (ALE) was used for quantification. Maxima of underactivation were found in inferior parietal, superior temporal, middle and inferior temporal, and fusiform regions of the left hemisphere. With respect to left frontal abnormalities, we found underactivation in the inferior frontal gyrus to be accompanied by overactivation in the primary motor cortex and the anterior insula. Tentative functional interpretations of the activation abnormalities are provided.

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Figures

Figure 1
Figure 1
(A) Surface rendering of all 128 input foci with underactivation in red and overactivation in green. (B) Overlays of the separate ALE maps for under‐ (red) and overactivation (green), respectively. Regions contained in both maps are shown in yellow. (C) Surface rendering of the difference map (after subtracting the ALE values for underactivation from the ALE values for overactivation). The blurred coloring results from discrepant activations at surface and deeper regions. (D) Composite surface rendering of the two thresholded independent ALE maps for under‐ and overactivation, respectively. (E) Surface rendering of the thresholded difference map. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]
See this image and copyright information in PMC

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