Recovery and regression in visuo-spatial neglect: a case study of learning in line bisection.

We report a case study of (partial) recovery from left visuo-spatial neglect, followed by progressive deterioration. The patient, A.L., suffered a right-hemisphere stroke with left hemiplegia; over the 6 months post-stroke, the overall course of his neglect was monitored with the Behavioural Inattention Test at approximately monthly intervals. An experimental investigation of multitrial line bisection was also repeated six times and analysed both between and within sessions. The results confirm previous reports of a linear relationship between transection displacements and line length, and also of anomalous crossover with 'right neglect' at 'shorter' length. Both effects are reliable over time in this patient. The most striking finding, however, was 'recovery' within a session of the extended line bisection task. We discuss the theoretical and practical significance of this phenomenon in the context of attentional theories of neglect.