Somatosensory Space Abridged: Rapid Change in Tactile Localization Using a Motion Stimulus
Figure 4
A) Mean localization responses to targets A, B, C, D and E for each run in each session. Error bars represent 95% CIs for within-subject designs [19]. Targets are indicated on the scaled illustration of the forearm. The grey box across both panels represents the location of the occluder, which was removed from the arm during each Baseline run (Base 1 and Base 2, green symbols). Lines connect responses to the same target location at different moments in time. Order of runs along the x axis is the same as their order of presentation in the experiment. Note a large pointing bias towards the middle of the forearm during the Short (black symbols) and Long (red symbols) runs in the Double condition (left panel). B) Distance between mean responses to the external targets (A and E) and internal targets (B and D) expressed as a deviation from Baseline 1. Positive values indicate compressive mislocalization. Note compressive mislocalization is present in the Double condition (diamonds) but not Single (squares) for BD (left panel), and is much greater in the Double than Single condition for AE (right panel). C) Left panel of the figure illustrates two directions of brush approach (Bridging and Non-bridging) for targets B and D. Right panel shows the distance between responses to targets B and D in the combined Long runs (Long 1,2) as a function of direction of brush approach. Distances are expressed relative to Baseline 1 (as above). Note that both brush approaches in the Double condition result in compressive mislocalization, but that it is greater with the Bridging (blue) than the Non-bridging (green) approach; the Single condition shows no bias for either direction.