Significance of paradoxical leftward error of line bisection in left unilateral spatial neglect

We intended to determine if leftward error of line bisection means "right" or "left" neglect in a patient with left unilateral spatial neglect. The patient placed the subjective midpoint to the left of the true center when bisecting lines without cueing. By contrast, when cued to the left endpoint, he showed typical rightward errors that became greater as longer lines were presented. Cueing to the right endpoint increased leftward errors compared with the bisections without cueing. The results suggest that paradoxical leftward error of line bisection is a form of "left" unilateral spatial neglect in that the shortness of the left extent is ignored.