Spatio-temporal selectivity of loss of colour and luminance contrast sensitivity with mutiple sclerosis and optic neuritis
Data(s) |
01/01/2005
|
---|---|
Resumo |
Colour and luminance-contrast thresholds were measured in the presence of dynamic Random Luminance-contrast Masking (RLM) in individuals who had had past diagnoses of optic neuritis (ON) some of whom have progressed to a diagnosis of multiple sclerosis (MS). To explore the spatio-temporal selectivity of chromatic and luminance losses in MS/ON, thresholds were measured using three different sizes and modulation rates of the RLM displays: small checks modulating slowly, medium-sized checks with moderate modulation and large checks modulating rapidly. The colour of the chromatic stimuli used were specified in a cone-excitation space to measure relative impairments in red–green and blue–yellow chromatic channels. These observers showed chromatic thresholds along the L/(L + M) axis that were higher than those along the S-cone axis for all display sizes/modulation rates and both red-green and blue-yellow colour thresholds were higher than luminance-contrast thresholds. The principal change in thresholds with spatio-temporal changes in the display was a reduction in thresholds for L/(L + M) and S-cones with increasing check size and modulation rate. However, luminance contrast thresholds did not change with display size/rate. These results are consistent with MS/ON selectively affecting processing in colour pathways rather than in the magnocellular pathway, and that within the colour pathways neurones with opposed L- and M-cone inputs are more damaged than colour-opponent neurons with input from S-cones.<br /> |
Identificador | |
Idioma(s) |
eng |
Publicador |
Pergamon Press |
Relação |
http://dro.deakin.edu.au/eserv/DU:30003094/n20050680.pdf http://dx.doi.org/10.1111/j.1475-1313.2004.00252.x |
Direitos |
2005, The College of Optometrists |
Palavras-Chave | #Colour vision #Luminance vision #Multiple sclerosis #Optic neuritis |
Tipo |
Journal Article |