Examination of common and unique brain regions for atypical reading and math: a meta-analysis

Abstract

The purpose of this study is to identify consistencies across functional neuroimaging studies regarding common and unique brain regions/networks for individuals with reading difficulties (RD) and math difficulties (MD) compared to typically developing (TD) individuals. A systematic search of the literature, utilizing multiple databases, yielded 116 functional magnetic resonance imaging and positron emission tomography studies that met the criteria. Coordinates that directly compared TD with either RD or MD were entered into GingerALE (Brainmap.org). An activation likelihood estimate (ALE) meta-analysis was conducted to examine common and unique brain regions for RD and MD. Overall, more studies examined RD (n = 96) than MD (n = 20). Across studies, overactivation for reading and math occurred in the right insula and inferior frontal gyrus for atypically developing (AD) > TD comparisons, albeit in slightly different areas of these regions; however, inherent threshold variability across imaging studies could diminish overlying regions. For TD > AD comparisons, there were no similar or overlapping brain regions. Results indicate there were domain-specific differences for RD and MD; however, there were some similarities in the ancillary recruitment of executive functioning skills. Theoretical and practical implications for researchers and educators are discussed.

Neurocognitive mechanisms of co‐occurring math difficulties in dyslexia: Differences in executive function and visuospatial processing

“…MD is also often associated with a deficit in numerical processing or number sense (Landerl et al, 2013; however, also see Mammarella et al, 2021). Studies of the neurobiology of MD have frequently pointed to the intraparietal sulcus as a hub of numerical processing, with reduced activation during math tasks in individuals with MD compared to peers without MD (Ashkenazi et al, 2012(Ashkenazi et al, , 2013Martinez-Lincoln et al, 2023;Price et al, 2007).…”

“…Phonological difficulties may impede children's ability to connect speech sounds to print, decode words, and read fluently. Individuals with RD demonstrate differences throughout the reading system, including left inferior frontal, occipitotemporal, and temporoparietal brain regions (Kronbichler & Kronbichler, 2018; Martinez‐Lincoln et al., 2023; Pugh, 2001; Richlan, 2012; van der Mark et al., 2011). RD is also frequently linked to difficulties with rapid automatized naming (RAN) (Norton & Wolf, 2012) and executive functioning (Al Dahhan et al., 2022; Daucourt et al., 2020; Lonergan et al., 2019), as well as perceptual differences (e.g., in visual processing and visuospatial attention; see Kristjánsson & Sigurdardóttir, 2023 for a review).…”

“…However, little is known about co‐occurring math and reading difficulties as they relate to functional or task‐related brain activation. A meta‐analysis of RD and MD revealed mostly distinct neurocognitive correlates of the two disorders (Martinez‐Lincoln et al., 2023); however, nearly all the studies included in this meta‐analysis involved one domain‐specific task (i.e., reading‐related activation for RD samples or math‐related activation for MD samples).…”

Developmental dyscalculia is not associated with atypical brain activation: A univariate fMRI study of arithmetic, magnitude processing, and visuospatial working memory

“…The current, pre‐registered study investigated differences in brain activation elicited by number processing, arithmetic, and VSWM tasks between typically achieving children (TA) and children with developmental dyscalculia (DD). Previous studies have lacked consensus, often reporting both increased and decreased activation for DD children compared to their TA peers across these tasks, with some recent coherence of decreased activity for DD in the right anterior IPS, presented through meta‐analyses (Martinez‐Lincoln et al, 2023; Tablante et al, 2023). One reason for this inconsistency may be that previous studies were challenged by limitations in sample size and inconsistent inclusion criteria for DD.…”

“…Two recent meta‐analyses provide two common findings across this literature. Both Martinez‐Lincoln et al (2023) and Tablante et al (Tablante et al, 2023) report that a region of the right anterior intraparietal sulcus (IPS) is consistently less active for individuals with math difficulties than for their typically achieving (TA) peers and that one region in the right insula is more active for the math difficulty group. However, there is less specificity about what elicits these differences in processing.…”