Coherent Motion

Several recent studies have shown that deficits of visual temporal processing are associated with poor mathematical skills in school-aged children. Here, we replicate and extend this finding in a large sample (n = 958) of university-educated adults. As part of the PERGENIC study, we measured psychophysical sensitivity to coherent motion (CM) and to Gabors of low spatial and high temporal frequency (GS), as well as obtaining self-report measures of ability in mathematics and science (MS) and arts and literature (AL). We found that participants with low MS were significantly less sensitive than those with high MS for both CM (Cohen’s d = 0.58) and GS (d = 0.38). Furthermore, MS was positively correlated with CM (Spearman’s ρ = .20) and GS (ρ = .14) across the full sample. In contrast, participants with low AL were significantly more sensitive than those with high AL for GS (d = 0.34), though the two groups did not differ on CM; and AL was negatively correlated with both CM (ρ = −.10) and GS (ρ = −.11) across the full sample. We discuss our findings in the context of magnocellular and dorsal stream theories of cognitive developmental disorders.

Visual processing by 10-year-old children diagnosed on the basis of standardised tests as having developmental 'clumsiness' syndrome, and by a control group of children without motor difficulties, was tested using three different psychophysical tasks. The tasks comprised a measure of global motion processing using a dynamic random dot kinematogram, a measure of static global pattern processing where the position of the target was randomised, and a measure of static global pattern processing in which the target position was fixed. The most striking finding was that the group of clumsy children, who were diagnosed solely on the basis of their motor difficulties, were significantly less sensitive than the control group on all three tasks of visual sensitivity. Clumsy children may have impaired visual sensitivity in both the dorsal and ventral streams in addition to their obvious problems with motor control. These results support the existence of generalised visual anomalies associated with impairments of cerebellar function.