Length Perception and Affordances of Gyroscopic Device

AUTHOR: Dipesh Pokharel
FACULTY: TR brooks
DEPARTMENT: Psychology

ABSTRACT

Haptic touch by wielding can help us to predict the mass distribution of rigid objects. Variation in mass lawfully influences human judgments of weight, length, and orientation of the objects has been found by previous researchers. However, many wielded objects are non-rigid, and the forces governing the perception of such objects are less clear. This experiment addressed the role of gyroscopic reactive forces (GRFs) on length judgments. In the experiment, participants wielded three gyroscope devices of different lengths (30cm, 45cm, and 60cm). These devices consisted of a wooden handle, and an aluminum shaft with a 60 g flywheel mounted on the end. The aluminum shaft served as the axis of rotation of the flywheel so that any rotation of the wrist (and the device axis) produces GRFs. This configuration allows for the variation of GRFs produced by the devices under different movements without changing the mass distribution of the objects. For all three devices, spin velocity (and by extension angular momentum and GRFs) were varied across three velocities, -733 rad/s, 0 rad/s, and 733 rad/s. In addition, participants wielded the objects according to two different prescribed wielding modes: 90° in one direction or 45° in both directions). Each participant completed three trials for each length, spin velocity, and wielding mode combination, for a total of 54 conditions. Participants then estimated the length of the device using a pully system, and their response was recorded. We found a significant difference between participants' length judgments across the three-length conditions. Also, found a significant difference in mode and length mode from the data analysis. In general, participants accurately perceived changes in object length and did not experience changes in GRFs as changes in object length.