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SUMMARY A patient is described whose most striking visual disorder was a grossly impaired ability to discriminate between different colours (hues) that were matched for brightness. In contrast his ability to discriminate between different neutral greys presented in the same fashion was much less abnormal, even though the greys were perceptually difficult. Although visual acuity was reduced and visual fields were constricted, and the patient's memory was moderately impaired, these associated symptoms could not themselves be the cause of his unusual colour vision. The patient had the symptoms of cerebral achromatopsia, and the relative preservation of his form vision (when his reduced acuity is taken into account) and his achromatic vision supports the view that the many different visual cortical areas recently demonstrated in the brains of monkeys, and presumed to exist in man, have a perceptual specialisation that matches their physiological differences.Cerebral achromatopsia is a severe disturbance of the perception of colour caused by cerebral cortical damage. The patient has great difficulty in discriminating between hues and commonly complains that the world looks drained of colour. Although the term achromatopsia implies that vision has become colourless, colours may still be perceived, albeit faintly (that is, they are desaturated). The condition contrasts sharply with other acquired disorders of colour vision where the primary fault is a disconnexion syndrome or a semantic disorder involving the use of colour words (see reference I for review) or an impaired ability to remember perceived colours for more than a few seconds.2 There are several reports which suggest that cerebral achromatopsia can appear without accompanying deficits in the perception of depth, form, acuity, movement or any other psychophysical dimension.34 However, the disturbances are often accompanied by apperceptive visual agnosia' and the cortical damage invariably involves

Normative data on the Purdue Pegboard are presented, based on the performance of 206, right-handed male and female children between the ages of 2 years, 6 months and 5 years, 11 months. Results demonstrate developmental trends in the increased efficiency of peg placement for the right hand, left hand, and bimanual conditions. Scores increase monotonically with age; performances are stable, with high test-retest reliability. Continuity is evidenced between these data and those available for older children. Evidence for the dissociation of hand preference and peg placement efficiency in the younger groups is discussed.

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