Abstract
In many different developmental disorders, global motion sensitivity is impaired relative to global form. These complementary measures of extrastriate function reflect processing in the dorsal and ventral streams respectively, suggesting a general 'dorsal stream vulnerability' (Braddick et al, Neuropsychologia 2003) associated with deficits on visuo-motor, spatial, and attentional tasks. These associations have not previously been investigated in typically developing children. As part of the large scale PLING study (Pediatric Longitudinal Imaging, Neurocognition and Genetics), we measured global motion and form thresholds in 120 typically developing children (ages 6 -12 years) and examined their relation to a range of cognitive abilities, and to quantitative MRI measures of regional brain development. Correlations were calculated after adjustment for age effects. Children's global motion thresholds showed highly significant correlations (p<0.0001) with visuo-motor integration (VMI test, shape copying), rapid object naming (CTOPP test), and nonword reading (Woodcock-Johnson Word Attack) and at p<0 .002 with mathematical achievement (Woodcock-Johnson Calculation) and phonological segmentation (CTOPP elision test). Global form thresholds were not significantly correlated with these but were correlated with working memory scores (p<0.005). Both thresholds, but motion more strongly, correlated with NIH Cognition Toolbox tests of reading, vocabulary, and executive function. We computed association maps of cortical surface area at each vertex with age- and gender-adjusted coherence thresholds. Higher form and motion coherence sensitivities were both associated with regional expansion of temporal, parietal and premotor cortex relative to the cuneus region. Within this relatively expanded area, form and motion coherence are associated with distinct patterns of regional differences. These variations may reflect differential trajectories of cortical development, or age independent individual differences in regionalization. Overall, in line with its vulnerability in disorders, dorsal stream function, as tapped by global motion sensitivity, is closely associated with many cognitive abilities, particularly in the visuospatial, mathematical, and phonological domains.
Meeting abstract presented at VSS 2014