| |
Abstract:
The purpose of this study was to investigate proposed
mechanisms underlying unilateral neglect by studying normal adults.
One classic finding in the neglect literature is that patients with
neglect are slower to react to targets presented to the
contralesional hemifield following cues presented to the
ipsilesional hemifield. In this study, normal adults were asked to
perform a choice reaction time version of the covert orienting task
developed by Posner. Although participants' heads were aligned with
the center of the display throughout the experiment, their trunks
were rotated 0*, 15* to the right, or 15* to the left on different
blocks of trials. Trunk rotation in either direction was associated
with an increase in reaction time to targets presented on the side
of the display opposite the direction in which the trunk was
rotated. This increase was most pronounced for invalidly cued
targets, suggesting that trunk orientation affects the ability to
shift attention within the visual field. These findings are
consistent with the theory that neglect symptoms are related to a
systematic misalignment of a trunk-centered coordinate system for
the representation of space (e.g. Karnath, 1997).
|
