Cerebral achromatopsia: colour blindness despite wavelength processing.

Cortical colour blindness is caused by brain damage to the ventro-medial occipital and temporal lobes. A possible explanation is that the pathway responsible for transmitting information about wavelength and its subsequent elaboration as colour has been destroyed at the cortical level. However, seve...

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Main Authors: Cowey, A, Heywood, C
Format: Journal article
Language:English
Published: 1997
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author Cowey, A
Heywood, C
author_facet Cowey, A
Heywood, C
author_sort Cowey, A
collection OXFORD
description Cortical colour blindness is caused by brain damage to the ventro-medial occipital and temporal lobes. A possible explanation is that the pathway responsible for transmitting information about wavelength and its subsequent elaboration as colour has been destroyed at the cortical level. However, several signs of chromatic processing persist in an achromatopsic subject who, despite his inability to tell colours apart, can still detect chromatic borders, perceive shape from colour, and discriminate the direction in which a striped pattern moves when the determination of direction requires the viewer to 'know' which stripes have a particular colour. Perhaps only the information about wavelength that leads to conscious awareness of colour has been destroyed. It is unclear whether incomplete achromatopsia is merely a less severe form of the disorder or whether it is qualitatively different, perhaps reflecting impaired colour constancy. In monkeys, removing cortical area V4 impairs performance on colour constancy tasks but, invariably, impairs several other aspects of visual perception. If the lesion that causes total achromatopsia in human subjects corresponds to area V4 in monkeys, it is an unsolved puzzle that a totally achromatopsic subject paradoxically demonstrates certain characteristics of colour constancy, unless his residual performance reflects the much underrated retinal contribution to colour constancy.
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spelling oxford-uuid:c85d8513-f632-4acf-9c0d-bf3abbaa2c332022-03-27T06:51:36ZCerebral achromatopsia: colour blindness despite wavelength processing.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:c85d8513-f632-4acf-9c0d-bf3abbaa2c33EnglishSymplectic Elements at Oxford1997Cowey, AHeywood, CCortical colour blindness is caused by brain damage to the ventro-medial occipital and temporal lobes. A possible explanation is that the pathway responsible for transmitting information about wavelength and its subsequent elaboration as colour has been destroyed at the cortical level. However, several signs of chromatic processing persist in an achromatopsic subject who, despite his inability to tell colours apart, can still detect chromatic borders, perceive shape from colour, and discriminate the direction in which a striped pattern moves when the determination of direction requires the viewer to 'know' which stripes have a particular colour. Perhaps only the information about wavelength that leads to conscious awareness of colour has been destroyed. It is unclear whether incomplete achromatopsia is merely a less severe form of the disorder or whether it is qualitatively different, perhaps reflecting impaired colour constancy. In monkeys, removing cortical area V4 impairs performance on colour constancy tasks but, invariably, impairs several other aspects of visual perception. If the lesion that causes total achromatopsia in human subjects corresponds to area V4 in monkeys, it is an unsolved puzzle that a totally achromatopsic subject paradoxically demonstrates certain characteristics of colour constancy, unless his residual performance reflects the much underrated retinal contribution to colour constancy.
spellingShingle Cowey, A
Heywood, C
Cerebral achromatopsia: colour blindness despite wavelength processing.
title Cerebral achromatopsia: colour blindness despite wavelength processing.
title_full Cerebral achromatopsia: colour blindness despite wavelength processing.
title_fullStr Cerebral achromatopsia: colour blindness despite wavelength processing.
title_full_unstemmed Cerebral achromatopsia: colour blindness despite wavelength processing.
title_short Cerebral achromatopsia: colour blindness despite wavelength processing.
title_sort cerebral achromatopsia colour blindness despite wavelength processing
work_keys_str_mv AT coweya cerebralachromatopsiacolourblindnessdespitewavelengthprocessing
AT heywoodc cerebralachromatopsiacolourblindnessdespitewavelengthprocessing