Optic aphasia for colours and colour agnosia: A distinction between visual and visuo-verbal impairments in the processing of colours

Publisher Website
Google Scholar
Abstract
Two patients, both of whom would have been described according to classic criteria as cases of colour agnosia, were studied. Three kinds of colour tasks were administered: Visual, verbal and visuo-verbal tasks. However this was not only done by manipulating the kind of stimulus and the kind of response—one being visual, the other verbal (Experiment 1)—as is standard in most of the studies on colour agnosia, but also by manipulating the intervening processes required to perform the task (Experiment 2), as well as the strategies used by the patients (Experiment 3). The systematic manipulation of these three variables allowed the authors to differentiate two syndromes which are actually very different: Optic aphasia for colours and colour agnosia. The implications of these syndromes for cognitive psychology are discussed.