Crossmodal temporal processing acuity impairment aggravates with age in developmental dyslexia

: Virsu V, Lahti-Nuuttila P, Laasonen M

Publisher: ELSEVIER SCI IRELAND LTD

: 2003

Neuroscience Letters

: NEUROSCIENCE LETTERS

: NEUROSCI LETT

: 336

: 3

: 151

: 154

: 4

: 0304-3940

DOI: https://doi.org/10.1016/s0304-3940(02)01253-3

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. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.