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Prosopagnosic patients suffer an inability to recognize familiar people by visual inspection of their faces. Despite the absence of overt recognition, though, some prosopagnosic patients continue to process the identities of familiar faces covertly. A longstanding controversy concerns whether the recognition deficit in prosopagnosia is specific for faces,(More)
This study extended our recently reported evidence of a left hemisphere (LH) contribution to spatial processing on standard visuospatial tasks. The present investigation compared performance on these standard tasks with that on 'purer' experimental tasks. Two tasks of line orientation, two of shape rotation and a shape matching task were administered to 50(More)
Experiments were designed to examine the imagery abilities of an agnosic patient, M.S., who has consistently shown more severe deficits in recognizing visually, and in retrieving knowledge of living as compared with non-living items. Judgements of visual similarity were required for named objects and for object-pictures, as well as for the factual(More)
A simple quantitative test is described for measuring the duration of post-traumatic amnesia. It was used in a study of 336 patients with closed head injury; and the results matched closely the independent estimates of experienced neurosurgeons. A systematic procedure of this kind is clinically useful in its sensitivity to fluctuations or deterioration in(More)
A double dissociation of visual and spatial performance is reported in two men with chronic focal missile injuries of the right cerebral hemisphere. The clinical, neuropsychological and post-mortem anatomical data are considered in relation to evidence from physiological research of two major cortico-cortical pathways for object-recognition and spatial(More)
Since sustaining a severe closed head injury P.H. has been completely unable to recognise familiar faces, but remains able to identify written names. Despite his inability to recognise faces overtly, P.H. nevertheless shows a normal pattern of interference from simultaneously presented distractor faces in a politician vs nonpolitician name classification(More)
(1991). Can we l o s e memories for faces? Content speciicity and awareness in a prosopag-nosic. (1991). Classifying faces by race and sex using an autoassociative memory trained for recognition. (1993). A low-dimensional representation of faces in the higher dimensions of the space. (1995). A perceptual learning theory of the information in faces. In T.(More)
We assessed the ability of an achromatopsic patient to detect and discriminate colour and form concealed in a static or dynamic checkerboard display where the luminance differences among adjacent squares were randomly assigned. There were no conditions under which he could discriminate two very different saturated colours from each other. Nevertheless, he(More)
This study addresses the possibility that cognitive sequelae--albeit of a transient or minor character--can be associated with mild head injury. Twenty men (aged 16-30 years of age), whose post-traumatic amnesia did not exceed eight hours, were examined within 48 hours of their accident and again one month later. This unselected sample had no previous(More)