Proximal intentional neglect: a case study

Although neglect has been demonstrated in the horizontal, vertical, and radial planes of space and has been attributed to sensory-attentional, motor-intentional, and representational deficits, motor intentional neglect in the radial plane has not been previously described. A patient who had a right parietal infarct was tested with a modified cancellation task that uses a fixed window, thereby controlling attentional demands and allowing one to dissociate between intentional and representational neglect. This patient showed proximal (radial) intentional neglect (a failure to move towards or in proximal space). Unlike controls whose search times decreased with increasing window size, our patient showed no change in search time as a function of window size. This pattern of behaviour suggests that the patient's search strategy does not incorporate factors such as the relation between a fixed target space and a variably sized aperture, but rather was based on the allocation of a certain amount of resources for a fixed period of time after which, regardless of performance, the patient would stop searching.