"Left neglected," but only in far space: spatial biases in healthy participants revealed in a visually guided grasping task
Loading...
Date
2014
Authors
de Bruin Nutley, Natalie
Bryant, Devon C.
Gonzalez, Claudia L. R.
Journal Title
Journal ISSN
Volume Title
Publisher
Frontiers Media
Abstract
Hemispatial neglect is a common outcome of stroke that is characterized by the inability
to orient toward, and attend to stimuli in contralesional space. It is established that
hemispatial neglect has a perceptual component, however, the presence and severity of
motor impairments is controversial. Establishing the nature of space use and spatial biases
during visually guided actions amongst healthy individuals is critical to understanding the
presence of visuomotor deficits in patients with neglect. Accordingly, three experiments
were conducted to investigate the effect of object spatial location on patterns of grasping.
Experiment 1 required right-handed participants to reach and grasp for blocks in order to
construct 3D models.The blocks were scattered on a tabletop divided into equal size quadrants:
left near, left far, right near, and right far. Identical sets of building blockswere available
in each quadrant. Space use was dynamic, with participants initially grasping blocks from
right near space and tending to “neglect” left far space until the final stages of the task.
Experiment 2 repeated the protocol with left-handed participants. Remarkably, left-handed
participants displayed a similar pattern of space use to right-handed participants. In Experiment
3 eye movements were examined to investigate whether “neglect” for grasping in
left far reachable space had its origins in attentional biases. It was found that patterns of
eye movements mirrored patterns of reach-to-grasp movements.We conclude that there
are spatial biases during visually guided grasping, specifically, a tendency to neglect left far
reachable space, and that this “neglect” is attentional in origin.The results raise the possibility
that visuomotor impairments reported among patients with right hemisphere lesions
when working in contralesional space may result in part from this inherent tendency to
“neglect” left far space irrespective of the presence of unilateral visuospatial neglect.
Description
Sherpa Romeo green journal: open access
Keywords
Pseudoneglect , Visuospatial neglect , Attention , Human , Peripersonal space , Reach-to-grasp , Grasping , Handedness , Spatial biases , Visually-guided grasping
Citation
de Bruin, N., Bryant, D. C., & Gonzalez, C. L. R. (2014). "Left neglected," but only in far space: spatial biases in health participants revealed in a visually guided grasping task. Frontiers in Neurology, 5:4. doi:10.3389/fneur.2014.00004