DISTINCT PROCESSES IN-LINE BISECTION ACCORDING TO SEVERITY OF LEFT UNILATERAL SPATIAL NEGLECT

We investigated the line bisection performances in 24 patients with le ft unilateral spatial neglect. They bisected lines of two lengths in t hree positions relative to the sagittal midplane of the body. The resu lts showed that in the mild or moderate neglect patients, length and s patial locations of the lines affected the placement of the subjective midpoint. In the severe neglect patients, however, length had little effect on their performances, and location of the right endpoint in th e egocentric space mainly determined the subjective midpoint. The line bisection process of the severe neglect patients was not only quantit atively but also qualitatively different from that of the mild or mode rate cases. (C) 1997 Academic Press.