| Abstract: | We report data on the visual localisation ability of a patient with Balint's syndrome, GK. We show that, with relatively long exposures of displays, GK is better able to judge the spatial relations between separate objects (a “between-object judgement”) than the spatial relations between a part and a whole object (a “within-object judgement”) (Experiments 1–3). This dissociation occurred even when the same stimulus was used for both judgements, and the task instructions biased GK to parse the stimulus as either a single or as two separate objects (Experiments 2 and 6). However, when he could use a stored representation to make a within-object judgement, then performance was better than on a comparable spatial judgement of the relations between two separate objects (Experiments 4–7). The data demonstrate that stored representations of objects can support the spatial coding of parts to perceptual wholes. In the absence of stored representations, part-whole relations must be explicitly coded by attention, a process that is impaired in this patient. |
