Mommie dearest: reaching to self-, mother- and experimenter-referenced shapes

We analysed movement parameters of reach and return actions to cards with rectangle orientations referenced to the self or with either a close (mother) or distant (experimenter) other. Movement duration was faster overall for reaches to self- than other-referenced rectangles, and velocity was slowed for mother- than experimenter-referenced rectangles. Curvature of the trajectory of the reach movement was reduced for self- compared with mother-referenced rectangles, while the angle of the trajectory was smaller for self- compared with other-referenced rectangles. No changes were seen in the return movement parameters. These differences in timing and spatial parameters are consistent with dissociations in self and other processing evident in perception and recognition memory paradigms, and consistent with a bias towards forming associations for information referenced to the self vs. significant others, even when the information is virtual and arbitrary.