Individual differences in decoding skill, print exposure, and cortical structure in young adults

Abstract

This exploratory study investigated relations between individual differences in cortical grey matter structure and young adult readers’ cognitive profiles. Whole-brain analyses revealed neuroanatomical correlations with word and nonword reading ability (decoding), and experience with printed matter. Decoding was positively correlated with grey matter volume (GMV) in left superior temporal sulcus, and thickness (GMT) in right superior temporal gyrus. Print exposure was negatively correlated with GMT in left inferior frontal gyrus (pars opercularis) and left fusiform gyrus (including the visual word form area). Both measures also correlated with supramarginal gyrus (SMG), but in spatially distinct subregions: decoding was positively associated with GMV in left anterior SMG, and print exposure was negatively associated with GMT in left posterior SMG. Our comprehensive approach to assessment both confirms and refines our understanding of the novel relation between the structure of pSMG and proficient reading, and unifies previous research relating cortical structure and reading skill.

The relationship between brain structure and proficiency in reading and mathematics in children, adolescents, and emerging adults

“…Also in adults, He et al (2013) reported positive correlations between gray matter volume in the left SMG and precuneus with phonological decoding in Chinese speakers with English as a second language performing English reading tests (n = 416). A relationship between reading ability and gray matter volume in left STS, SMG, and MTG, as well as diffuse bilateral frontal and parietal regions, have been reported by Johns et al (2017) (n = 35), whereas a relationship with gray matter volume in left FG has been reported by Torre and Eden (2019) , both studies conducted in adult readers of English. Taken together, it seems that relationships between gray matter volume and reading ability are more evident in adults than children.…”

“…In contrast, a third, also in English speakers (n = 60), found a positive relationship between cortical thickness of the left IPS, bilateral AG, and bilateral STG with performance on a task of irregular word reading, as well as a negative relationship between cortical thickness of the left central sulcus and FG, bilateral IFG and right lingual and supramarginal gyri with irregular word reading ( Blackmon et al, 2010 ). The fourth study, also in English speakers (n = 35), found a positive relationship between cortical thickness of the right STG, precentral, lateral occipital cortices with single word reading ( Johns et al, 2017 ). One of these studies measured surface area in addition to cortical thickness and reported a negative relationship between surface area and single real word reading in the left FG ( Frye et al, 2010 ).…”

“…Prior studies of brain anatomy, reviewed above, are too few and varied in their results to entirely inform our predictions, so in combination with results from functional brain imaging studies ( Prado et al, 2011 ; Evans et al, 2016 ), we hypothesized that we would observe positive brain-behavior correlations for both reading and math in left frontal, temporo-parietal, and occipito-temporal regions (i.e., that brain regions will show greater cortical thickness, but perhaps not surface area, with better reading and math ability). Since gray matter volume studies looking at anatomical relationships with reading ability in adults ( Pernet et al, 2009 ; Johns et al, 2017 ; Torre and Eden, 2019 ) have revealed more consistent brain-behavioral findings than those in children ( Jednoróg et al, 2015 ; Torre and Eden, 2019 ), we further hypothesized to find correlations in adults, but not necessarily children. Prior fMRI studies on reading ( Turkeltaub et al, 2003 ; Martin et al, 2015 ) and math ( Ansari et al, 2005 ; Rivera et al, 2005 ; Ansari, 2008 ; Kaufmann et al, 2010; Houde et al, 2010; for review, see: Peters and DeSmedt, 2018) have reported age-related differences, reflecting increased age and experience.…”

Investigating Gray and White Matter Structural Substrates of Sex Differences in the Narrative Abilities of Healthy Adults

“…However, for cortical thickness analyses, no covariates were used, as suggested by previous researchers (e.g., Westman et al, 2013). Monte Carlo simulations were used to correct all vertex-wise results at an individual vertex level of p < 0.05 (Hagler et al, 2006; see also Johns et al, 2018…”

Individual Differences in Subphonemic Sensitivity and Phonological Skills

“…Second, we employ a community-based sample with 285 greater variability in linguistic and cognitive abilities, as well as demographics, than typical 286 psycholinguistic samples, potentially providing a more representative picture of reading-related 287 ability in the population and enhancing statistical power for investigating individual differences 288 (cf. Braze et al, , 2007Johns et al, 2018;Johns, Matsuki, & Van Dyke, 2015;Kukona et 289 al., 2016;Van Dyke, Johns, & Kukona, 2014). By comparing individuals' online speech 290 processing to outcome measures of phonological skills more typically used in reading research, 291 we aim to probe the relationship between phonological representations and phonological skills 292 (see Ramus et al, 2013 decoding and reading comprehension).…”