title: Crossmodal temporal processing acuity impairment aggravates with age in developmental dyslexia.
abstract: Temporal processing has been found to be impaired in developmental dyslexia. We investigated how aging affects crossmodal temporal processing impairment with 39 dyslexic and 40 fluent 20-59-year-old readers. Cognitive temporal acuity was measured at millisecond levels in six tasks. They consisted of order judgments of two brief non-speech stimulus pulses, the stimuli being audiotactile, visuotactile and audiovisual, and of simultaneity/nonsimultaneity detection of the pulses in two parallel three-pulse trains. Temporal acuity declined with age in both reading groups and its impairment was observed in developmental dyslexia. A new finding was that the crossmodal temporal impairment, directly relevant to reading, increased with age. The age-related exacerbation suggests a developmental neuronal deficit, possibly related to magnocells, which exists before dyslexia and is its ontogenetic cause.
authors.affiliation: Department of Psychology, P O Box 9, FIN-00014 University of Helsinki, Helsinki, Finland. veijo.virsu@helsinki.fi
authors.forename: Veijo
authors.initials: V
authors.lastname: Virsu
authors.forename: Pekka
authors.initials: P
authors.lastname: Lahti-Nuuttila
authors.forename: Marja
authors.initials: M
authors.lastname: Laasonen
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000375:Aging; D001307:Auditory Perception; D001308:Auditory Perceptual Disorders / Q000503:physiopathology* / Q000523:psychology; D016022:Case-Control Studies; D004410:Dyslexia / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D011932:Reading; D013998:Time Perception; D014110:Touch; D014796:Visual Perception