Planning and Online Movement Guidance to visual and non-visual target locations


Prior work has explored the spatial and temporal characteristics of adjusting movements to visual tactile and somatosensory target positions. This experiment aimed to explore movement corrections across all three modalities. Twelve participants made reaching movements to an LED (visual target), a brush touching the non-reaching finger (tactile target), or the non-reaching finger (somatosensory target). On some trials the target was displaced either 3-cm away or toward the participant, prior to, or 200 ms following movement onset. Participants were instructed to adjust their trajectories towards the new target location. Overall, participants exhibited a larger magnitude of correction to somatosensory target perturbations, followed by tactile target perturbations. Participants also exhibited shorter correction latencies in the somatosensory than the vision and tactile conditions, with no differences between the vision and tactile conditions. These findings support previous work showing that moving the target hand (i.e., somatosensory target) yields earlier and larger corrections than moving to a visual or tactile target. This work provides evidence that corrections to non-visual targets may be different depending on the sensory modality used to detect changes in target location.