This page contains demos for the study “Causal Action: A Fundamental Constraint on Perception and Inference of Bodily Movements
” by Yujia Peng, Steven Thurman, & Hongjing Lu

 

Experiment 1

Demo1:

Supplemental video 1: An example action videl used in Experiment 1, in which body position changes were synchornized with limb movements. Participants were asked to rate the naturalness of the observed actions in the video. Move the mouse cursor on the video frame, click twice to start the video, click once to stop the video.

 

Demo2:

Supplemental video 2: An example action videl used in Experiment 1, in which body position changes were shifted forward in time relative to limb movements by 1 second. Participants were asked to rate the naturalness of the observed actions in the video. Move the mouse cursor on the video frame, click twice to start the video, click once to stop the video.

 

Experiment 2

Participants were first given a cover story. “Imagine that you work for a specialized video analysis company and are given two sources of information: (1) A posture-change video from a motion tracking system, which records a person’s posture change over time and keeps the figure always at the center; (2) A dot-motion video from a GPS system, which tracks the location of the person. It turns out that in preparing the combined videos, mistakes are sometimes made. Sometimes the posture-change video is correctly linked to the dot-motion video. However, in other cases the posture-change and dot-motion videos were mixed up so that the two videos shown together do not match”. After viewing two example stimuli, one with matched videos and the other highly unmatched, participants were asked to judge whether the posture-change video and dot-motion video were matchedby pressing one of the two response buttons.

Demo3:

Supplemental video 3: An example action video in Experiment 2, in which dot motion was synchronized with limb movements. Move the mouse cursor on the video frame, click twice to start the video, click once to stop the video.

 

Demo4:

Supplemental video 4: An example action video in Experiment 2 for the lead condition, in which dot motion was shifted forward in time relative to limb movements by 1 second (hence effect movements preceded). Move the mouse cursor on the video frame, click twice to start the video, click once to stop the video.