A left attentional bias in chronic neglect: a case study using temporal order judgments.

Previous studies of left visuospatial neglect using temporal order judgments (TOJs) have reported a temporal advantage for a stimulus presented on the right of fixation. The present case study examines an individual who shows a left temporal advantage on TOJ tasks, despite classic left-sided neglect on other tasks and in self-report. Experiment 1 found a continued left advantage on TOJs when employing a novel red/blue TOJ task to reduce potential response bias. Phasic alerting tones presented prior to random trials in Experiment 2 did not improve the abnormal attentional bias, as has been reported in previous studies of neglect. The addition of unilateral trials mixed within bilateral trials in Experiment 3 reduced the observed left advantage, suggesting a flexible attentional focus and implicating a role for strategic endogenous attentional strategies in this individual. Some implications for our understanding of endogenous orienting and relevance to rehabilitation therapy are discussed.