Affiliations: Department of Rehabilitation, Sapporo Medical
University, School of Medicine, Sapporo, Japan
Note: [] Address for correspondence: Sumio Ishiai, MD, Department of
Rehabilitation, Sapporo Medical University School of Medicine, S1W16, Chuo-ku,
Sapporo, 060-8543, Japan. Tel.: +81 11 611 2111; Fax: +81 11 618 5220; E-mail:
ishiai@sapmed.ac.jp
Abstract: Purpose: Eye-fixation patterns, which include ocular searching and
fixation, may change with tasks, stimuli, and instructions. This article
reviews our studies over 18 years on eye-fixation patterns of neglect patients
and aims to elucidate the visuospatial processing of unilateral spatial
neglect. Methods: We recorded eye-fixation patterns when patients with
neglect bisected a line in various conditions. Results: Patients with neglect rarely searched to the left side when
bisecting a line of the ordinary length (e.g., 200 mm). They persisted in
fixating a right-side point, at which they later marked the subjective
midpoint. They made no effective comparison between the leftward and rightward
extents not only for a whole line but also for its explored right segment.
Where they 'favored' to fixate as the subjective midpoint depended strongly
upon the location of the right endpoint in space. Their representational image
of a line was also estimated with modified line bisection tasks performed on a
touch-panel display. Conclusions: For patients with neglect, the representational image
of a line may be formed on the basis of the attended segment between the right
endpoint and the favored point of fixation. The line bisection task, if
combined with recording of eye-fixation, would further contribute to
elucidation of the mechanisms underlying neglect.
