| |
Abstract:
Abstract: Tactile-visual links in spatial attention were
examined by presenting spatially nonpredictive tactile cues to
either hand, shortly prior to visual targets in either hemifield.
To examine the spatial coordinates of any crossmodal links, the
hands were either uncrossed, or crossed so that the left hand lay
in the right visual field and vice-versa. Visual judgments were
better on the side where the stimulated hand lay, though this
effect was smaller with crossed hands. Event-related brain
potentials (ERPs) showed a similar pattern. Larger amplitude
occipital N1 components were obtained for visual events on the same
side as the preceding tactile cue. Likewise negativities in the Nd2
interval at midline and lateral central sites, and in the Nd1
interval at electrode Pz, were also enhanced on the cued side. As
in the behavioral results, ERP cuing effects during the crossed
posture were determined by the side of space in which the
stimulated hand lay, not by the anatomical side of the tactile cue.
These results demonstrate that crossmodal links in spatial
attention influence sensory brain responses, and that these links
operate in a spatial frame-of-reference which can remap between the
modalities across changes in posture.
|
