title: Crossmodal temporal order and processing acuity in developmentally dyslexic young adults.
abstract: We investigated crossmodal temporal performance in processing rapid sequential nonlinguistic events in developmentally dyslexic young adults (ages 20-36 years) and an age- and IQ-matched control group in audiotactile, visuotactile, and audiovisual combinations. Two methods were used for estimating 84% correct temporal acuity thresholds: temporal order judgment (TOJ) and temporal processing acuity (TPA). TPA requires phase difference detection: the judgment of simultaneity/nonsimultaneity of brief stimuli in two parallel, spatially separate triplets. The dyslexic readers' average temporal performance was somewhat poorer in all six comparisons; in audiovisual comparisons the group differences were not statistically significant, however. A principal component analysis indicated that temporal acuity and phonological awareness are related in dyslexic readers. The impairment of temporal input processing seems to be a general correlative feature of dyslexia in children and adults, but the overlap in performance between dyslexic and normal readers suggests that it is not a sufficient reason for developmental reading difficulties.
authors.affiliation: Department of Psychology, University of Helsinki, Helsinki, Finland. Marja.Laasonen@helsinki.fi
authors.forename: Marja
authors.initials: M
authors.lastname: Laasonen
authors.forename: Elisabet
authors.initials: E
authors.lastname: Service
authors.forename: Veijo
authors.initials: V
authors.lastname: Virsu
mesh_terms: D000328:Adult; D001307:Auditory Perception / Q000502:physiology; D004410:Dyslexia / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D010468:Perceptual Disorders / Q000150:complications* / Q000175:diagnosis; D012684:Sensory Thresholds / Q000502:physiology; D013998:Time Perception / Q000502:physiology*; D014110:Touch / Q000502:physiology; D014796:Visual Perception / Q000502:physiology