Lack of impairments on leftward and rightward line extension tasks in neglect patients.

We asked 16 right-brain damaged patients with left unilateral neglect, 9 right-brain damaged patients without neglect and 11 healthy control subjects to bisect horizontal lines or to extend them rightward or leftward. Although in the line bisection task patients with neglect showed the typical rightward deviation of the subjective line midpoint, they did not show any significant difference when compared to the other two experimental groups in both rightward and leftward line extension tasks. These results suggest that neglect for the left side of space is usually observed in tasks requiring an automatic lateral orienting of attention, but not in tasks in which this lateral orienting is submitted to a continuous intentional control.