Trajectory forms as a source of information about events

Abstract

The ability to use trajectory forms as visual information about events was tested. A trajectory form is defined as the variation in velocity along a path of motion. In Experiment 1, we tested the ability to detect trajectory form differences between simulations of a freely swinging pendulum and a handmoved pendulum. The trajectory form of the freely swinging pendulum was symmetric around the midpoint, whereas the hand moved was not. In Experiment 2, we isolated trajectory form information by varying the amplitudes of events while holding their periods constant. Straight path versions of the harmonic events from Experiment 1 were tested. In Experiment 3, we tested sensitivity to symmetrical peakening or flattening of trajectory forms. Participants detected small differences in all three experiments. In Experiment 4, we tested the ability to identify specific events based only on differences in trajectory forms. Participants were able to identify four different events. We investigated properties of trajectory forms that might potentially be detected and used as information, and we found that the curvature yielded good results.

Anticipation of tennis-shot direction from whole-body movement: The role of movement amplitude and dynamics

“…Of late, the (topological) structure in phase flows has been used as a conceptual tool for the categorization of (discrete and rhythmic) movements (Huys, Studenka, Rheaume, Zelaznik, & Jirsa, 2008;Jirsa & Kelso, 2005). Phase flow patterns, however, may also underlie the perceptual recognition of distinct motor processes (Perdikis & Jirsa, 2010; see also Muchisky & Bingham, 2002). For the purposes of visual identification of human movement, visual recognition of biological motion may proceed through the extraction of these (macroscopic) dynamical structures (Haken, 1996(Haken, , 2000(Haken, , 2004.…”

Perspective distortion of trajectory forms and perceptual constancy in visual event identification

“…Spectators in the stands will see the pitch from various oblique angles, depending on where they are sitting. Muchisky and Bingham (2002) showed that adults can use trajectory forms to identify simple oscillating events seen from the side, but they did not investigate other perspectives. We now will investigate this issue of perceptual constancy in event identification.…”

“…2 In addition, space is the natural frame of reference in which the trajectory of an event is seen to evolve. Muchisky and Bingham (2002) investigated the sensitivity of adults to the speed component of trajectory forms by systematically manipulating the shape of the speed profile of an oscillator in one of four ways while holding the path and duration constant. The computergenerated event consisted of a circle oscillating back and forth along a straight horizontal path on the computer screen.…”

A review of event perception: The first step for convergence on robotics

“…Muchisky and Bingham [41] investigated the ability of adults to use trajectory forms as visual information about events. They tested whether observers were able to discriminate a freely swinging pendulum and a hand-moved pendulum by detecting trajectory form differences between two events.…”

“…Direct perceptionists claim that biological motion perception is not special because such point-light demonstrations for the other object events (e.g., bouncing balls, free falling, splashing water) are equally effective [39,40,41]. Bingham et al [40] used patch-light displays for 9 events selected to represent rigid-body dynamics (free fall, pendulum, rolling ball, and struck ball), biodynamics (hand-moved spring and hand-moved pendulum), hydrodynamics (stirred water and splash), and aerodynamics (falling leaves).…”