Library Open Repository

Spatio-temporal contrast sensitivity, coherent motion, and visible persistence in developmental dyslexia

Downloads

Downloads per month over past year

Slaghuis, WL and Ryan, JF (1999) Spatio-temporal contrast sensitivity, coherent motion, and visible persistence in developmental dyslexia. Vision Research, 39. pp. 651-668.

[img] PDF (Visual processing in dyslexia)
Slaghuis_and_Ryan.pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

Abstract

Three experiments measured spatio-temporal contrast sensitivity, coherent motion, and visible persistence in a single group of children with developmental dyslexia and a matched control group. The findings were consistent with a transient channel disorder in the dyslexic group which showed a reduction in contrast sensitivity at low spatial frequencies, a significant reduction in sensitivity for coherent motion, and a significantly longer duration of visible persistence. The results were also examined by classifying the dyslexic group into dyseidetic, dysphonetic, and mixed (dysphoneidetic) subgroups. There were no differences between the control and dyseidetic groups in contrast sensitivity, in coherent motion and in visible persistence. In comparison to the control group, the mixed (dysphoneidetic) dyslexic subgroup was found to have a significant reduction in contrast sensitivity at low spatial frequencies, a significant reduction in sensitivity for coherent motion, and a significantly longer duration of visible persistence. In comparison to the control group, the dysphonetic group only showed a reduction in contrast sensitivity at low spatial frequencies. Comparisons between the dyseidetic, dysphonetic and mixed dyslexic subgroups showed that there were no substantive differences in contrast sensitivity, coherent motion, and visible persistence. The results support the proposal and findings by Borsting, Ridder, Dudeck, Kelley, Matsui and Motoyama (1996) that a transient channel disorder may only be present in a dysphoneidetic dyslexic subgroup. Psychometric assessment revealed that all the children with dyslexia appear to have a concurrent disorder in phonological coding, temporal order processing, and short-term memory.

Item Type: Article
Journal or Publication Title: Vision Research
Page Range: pp. 651-668
Identification Number - DOI: /10.1016/S0042-6989(98)00151-5
Date Deposited: 06 Nov 2007 22:55
Last Modified: 18 Nov 2014 03:24
URI: http://eprints.utas.edu.au/id/eprint/2395
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page