Causal Action: A Fundamental Constraint on Perception of Bodily Movements ​

This page contains demos of the study “Causal Action: A Fundamental Constraint on Perception of Bodily Movements”.

Cite：

Peng Y, Thurman S, Lu H. Causal Action: A Fundamental Constraint on Perception and Inference About Body Movements. Psychol Sci. 2017 Jun;28(6):798-807. doi: 10.1177/0956797617697739. Epub 2017 May 8. PMID: 28481714.

Experiment 1

Supplemental video 1

(Supplemental_Video1_Exp1_matched.mp4)

An example action video used in Experiment 1, in which body position changes were synchronized with limb movements. Participants were asked to rate the naturalness of the observed actions in the video.

Supplemental video 2

(Supplemental_Video2_Exp1_ahead.mp4): ​

An example action video used in Experiment 1 for the ahead condition, 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.

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: a processed video from a motion tracking system, which records a person’s posture change over time and keeps the figure always at the center, and the location of the person reported from a GPS system. Our experiment simulates similar situations in which you observe a person walking on an uneven terrain”. They were then asked to judge “whether the GPS signal matches the person tracked by the camera”.

Supplemental video 3

(Supplemental_Video3_Exp2_matched.mp4):

​ An example action video in Experiment 2, in which motion of GPS dot movements was synchronized with limb movements.

Supplemental video 4

(Supplemental_Video4_Exp2_ahead.mp4):

An example action video used in Experiment 2 for the ahead condition, in which GPS dot motion was shifted forward in time relative to limb movements by 1 second (hence effect movements preceded).