The development of form and motion perception from school-age to adulthood:comparing sensitivity to luminance- and texture-defined stimuli.

Abstract

Visual development has for the most part been assessed within the context of ventral- vs dorsal-stream functioning, underlying form and motion processing, respectively (Braddick et al., 2003; Atkinson, 2017). Few studies have assessed stream-specific visual development at different levels of processing within each stream during typical development (Bertone et al, 2009; Armstrong et al.,2009). The present study aimed to characterize visual development from school-age through adulthood by measuring the sensitivity to static and dynamic gratings defined by both luminance- and texture-defined attributes, presented before a dynamic noise background. One-hundred and fifty-eight (n=158) typically developing participants (Weschler IQ>80) were included in one of 5 age groups; 6–9 years (n=23), 10–13 years (n=34), 14–18 years (n=25), 19–22 years (n=30), and 23–30 years (n=46). Using a single interval, two-alternative, forced-choice paradigm, participants were asked to identify the orientation (vertical-horizontal) or direction (left–right) of a static (0 Hz) or moving (left to right at 2 Hz for 720 ms) grating defined by either luminance- or texture-contrast (1 cpd). An adaptive staircase procedure was used to measure sensitivity to stimuli in all four conditions. Age predicted sensitivity for luminance-defined stimuli (static and dynamic conditions; R²=[0.25–0.38], p< .001) to a significantly greater extent than for texture-defined information(R²=[0.21–0.30], p< .001). Furthermore, sensitivity for both luminance-defined conditions, and the texture-defined, static condition was equal to that of the oldest group by 19 years of age; sensitivity of the texture-defined, dynamic condition reached that of the oldest group at 14 years. Findings demonstrate that visual development within each stream continues through adolescence, but is differentiated by the type of information, luminance- vs texture-defined, processed. We are assessing whether cognitive capacities (i.e. IQ and attention) mediate these findings, which are the first to compare static and dynamic information processing using luminance- and texture-defined stimuli from school-age through to adulthood.