Article Figures & Data
Figures
- Figure 1.
A, Experimental setup (not to scale) of the tactile target condition. B, Layout of the aiming console and stimulus positions (not to scale). Participants were seated facing the aiming apparatus in a dark room. Across all target modalities (visual, somatosensory, tactile), a robotic device delivered target perturbations. Participants performed reaching movements from the home position on their right to the target position near their left. C, A representation of the left-hand placement during the somatosensory and tactile conditions. In the visual condition, the left hand was placed beside the aiming console.
- Figure 2.
Extrapolation method for determining correction latency. Demonstrated here is the extrapolation data for one participant's movement corrections to a target perturbed away from the body compared with unperturbed trials, across (A) visual, (B) somatosensory, and (C) tactile conditions. Presented on each figure is the average acceleration profile of unperturbed trials (solid gray lines) and perturbation trials (dashed gray lines), along with the difference in acceleration between them (solid blue line). The dashed black line represents the onset of the perturbation. Correction latencies were calculated by drawing an extrapolation line between the 75 and 25% points of the maximum difference in the accel difference profile (extrapolation points) and extending this line to the initial zero crossing. Correction latency is defined as the time from the perturbation onset to this zero crossing.
- Figure 3.
A, Correction latency. Participants demonstrated earlier corrections to somatosensory target perturbations compared with tactile and visual target perturbations. B, Correction magnitude. Participants demonstrated larger correction magnitudes to somatosensory target perturbations compared with tactile and visual target perturbations that occurred after the movement onset. C, Direction variable error. Participants demonstrated no differences in direction variable error across sensory conditions. D, Direction RMSE. Participants demonstrated smaller direction RMSE in their movement corrections to visual than somatosensory and tactile target perturbations that occurred after the movement onset. E, Amplitude variable error. Participants demonstrated smaller amplitude variable errors when moving to visual target perturbations compared with somatosensory and tactile target perturbations. F, Amplitude RMSE. Participants demonstrated smaller amplitude RMSE when moving to visual compared with somatosensory and tactile target perturbations. Each plot displays the data distribution with a patch representing the symmetric kernel density estimate. Within each patch is a box plot, with the white line in the box plot representing the data median and the gray box representing the interquartile range (25th to 75th percentiles).
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