Development of perceptual correlates of reading performance.

Performance on perceptual tasks requiring the discrimination of brief, temporally proximate or temporally varying sensory stimuli (temporal processing tasks) is impaired in some individuals with developmental language disorder and/or dyslexia. Little is known about how these temporal processes in perception develop and how they relate to language and reading performance in the normal population. The present study examined performance on 8 temporal processing tasks and 5 language/reading tasks in 120 unselected readers who varied in age over a range in which reading and phonological awareness were developing. Performance on all temporal processing tasks except coherent motion detection improved over ages 7 years to adulthood (p<0.01), especially between ages 7 and 13 years. Independent of these age effects, performance on all 8 temporal processing tasks predicted phonological awareness and reading performance (p<0.05), and three auditory temporal processing tasks predicted receptive language function (p<0.05). Furthermore, all temporal processing measures except within-channel gap detection and coherent motion detection predicted unique variance in phonological scores within subjects, whereas only within-channel gap detection performance explained unique variance in orthographic reading performance. These findings partially support the (Farmer, M.E., Klein, R.M., 1995. The evidence for a temporal processing deficit linked to dyslexia: A review. Psychon. Bull. Rev. 2, 460-493) notion of there being separable auditory and visual perceptual contributions to phonological and orthographic reading development. The data also are compatible with the view that the umbrella term "temporal processing" encompasses fundamentally different sensory or cognitive processes that may contribute differentially to language and reading performance, which may have different developmental trajectories and be differentially susceptible to pathology.