Hand-centered attentional and motor asymmetries in unilateral neglect
Section snippets
Subjects
From a population of MossRehab inpatients and outpatients with unilateral right-hemisphere stroke, we studied eight consecutive patients with evidence of neglect on neurologic examination and in daily activities who met study criteria (arousal, visual acuity, and hearing sufficient to participate; absence of prior neurologic history). Twelve right-handed healthy age-matched adult subjects (nine females and three males) were also enrolled. All subjects provided informed consent to participate.
Errors
No control subject made any errors in any condition. Patients N1, N2, N3, N4, and N6 similarly made no errors. In the left start condition, N5 made four errors and N7 made one error. In the right start condition, N5 made 18 errors and N8 made one error. Sixteen of N5's errors in the right start condition were failures to respond by deadline. The remaining two errors were responses to distractor (rather than target) location.
Total time, no distractor condition
To assess the hypothesis that patients would be slower to reach to the
General discussion
In this study we investigated the hypothesis that a putative asymmetry in selection of targets and responses in neglect may arise with respect to a hand-centered frame of reference in the context of an action task. We assessed the time required for subjects to reach to a central target from right and left start positions, in the presence or absence of distractors. The hypothesis of a hand-centered asymmetry in neglect predicts that patients' performance will have two characteristics. First, it
References (28)
- et al.
Perception and action in hemispatial neglect
Neuropsychologia
(1998) - et al.
Unilateral neglect of representational space
Cortex
(1978) - et al.
Movement initiation and control: abduction, adduction and locus of limb
Neuropsychologia
(1988) Mechanisms of unilateral neglect
Divided attention: evidence for coactivation with redundant signals
Cognitive Psychology
(1982)- et al.
Neural circuits for spatial attention and unilateral neglect
- et al.
Reorienting attention across the horizontal and vertical meridians: evidence in favor of a premotor theory attention
Neuropsychologia
(1987) Selection for action: some behavioral and neurophysiological considerations of attention and action
Coordinate transformations and motor planning in posterior parietal cortex
- et al.
Visual processing without awareness: evidence from unilateral neglect
Journal of Cognitive Neuroscience
(1992)
Spatio-motor representations in reaching: evidence for subtypes of optic ataxia
Cognitive Neuropsychology
Subtypes of optic ataxia: reframing the disconnection account
Neurocase
Study of selective reaching and grasping in a patient with unilateral parietal lesion: dissociated effects of residual spatial neglect
Brain
Directional hypokinesia and hemispatial inattention in neglect
Brain
Cited by (12)
Action control in visual neglect
2006, NeuropsychologiaCitation Excerpt :However, there is very little evidence regarding the frame of reference used for reaching in neglect patients. One study has argued for a hand-centred reference frame for selection of targets, using evidence from the effects of distractors (Buxbaum & Permaul, 2001), but this does not address the question about the reference frame in which the motor command is issued. Similarly, to the best of our knowledge, no study has examined the integrity of ‘forward models’ of motor control (Desmurget & Grafton, 2000; Wolpert, 1997) in the neglect syndrome (see Buneo & Anderson in this special issue for a full discussion of forward models).
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2012, Expert Review of NeurotherapeuticsAmantadine treatment of hemispatial neglect: A double-blind, placebo-controlled study
2007, American Journal of Physical Medicine and Rehabilitation