Within- and between-task dissociations in visuo-spatial neglect: a case study.

We describe a patient, J.B., who suffered an infarction of the right internal capsule and thalamus. There was a pronounced left hemiplegia but no visual field deficit. Investigated at four months and four years post-stroke, there were no signs of left visuo-spatial neglect other than a severe impairment of line bisection. The results on a test of perceptual judgement of the left and right extents of pretransected lines showed mild neglect of the left. The magnitude of this deficit did not predict quantitatively the severity of the patient's rightward deviation on a manual bisection task. Additional data are also reported on perceptual judgements and (manual) bisections of radially-oriented lines.