Crossmodal temporal order and processing acuity in developmentally dyslexic young adults

: Laasonen M, Service E, Virsu V

Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE

: 2002

Brain and Language

: BRAIN AND LANGUAGE

: BRAIN LANG

: 80

: 3

: 340

: 354

: 15

: 0093-934X

DOI: https://doi.org/10.1006/brln.2001.2593

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. (C) 2002 Elsevier Science (USA).