Magnocellular and parvocellular pathway mediated luminance contrast discrimination in amblyopia


Autoria(s): Zele, Andrew J.; Wood, Joanne M.; Girgenti, Cameron
Data(s)

01/05/2010

Resumo

To evaluate whether luminance contrast discrimination losses in amblyopia on putative magnocellular (MC) and parvocellular (PC) pathway tasks reflect deficits at retinogeniculate or cortical sites. Fifteen amblyopes including six anisometropes, seven strabismics, two mixed and 12 age-matched controls were investigated. Contrast discrimination was measured using established psychophysical procedures that differentiate MC and PC processing. Data were described with a model of the contrast response of primate retinal ganglion cells. All amblyopes and controls displayed the same contrast signatures on the MC and PC tasks, with three strabismics having reduced sensitivity. Amblyopic PC contrast gain was similar to electrophysiological estimates from visually normal, non-human primates. Sensitivity losses evident in a subset of the amblyopes reflect cortical summation deficits, with no change in retinogeniculate contrast responses. The data do not support the proposal that amblyopic contrast sensitivity losses on MC and PC tasks reflect retinogeniculate deficits, but rather are due to anomalous post-retinogeniculate cortical processing of retinal signals.

Formato

application/pdf

Identificador

http://eprints.qut.edu.au/38525/

Publicador

Elsevier

Relação

http://eprints.qut.edu.au/38525/1/c38525.pdf

DOI:10.1016/j.visres.2010.03.002

Zele, Andrew J., Wood, Joanne M., & Girgenti, Cameron (2010) Magnocellular and parvocellular pathway mediated luminance contrast discrimination in amblyopia. Vision Research, 50(10), pp. 969-976.

http://purl.org/au-research/grants/ARC/DP1096354

Direitos

Copyright 2010 Elsevier

Fonte

Faculty of Health; Institute of Health and Biomedical Innovation; School of Optometry & Vision Science

Palavras-Chave #111399 Optometry and Ophthalmology not elsewhere classified #Amblyopia #Magnocellular #Parvocellular #Contrast #Retina #Cortex #Strabismus #Anisometropia
Tipo

Journal Article