Walking Perception by Walking Observers.

Abstract

People frequently analyze the actions of other people for the purpose of action coordination. To understand whether such self-relative action perception differs from other-relative action perception, the authors had observers either compare their own walking speed with that of a point-light walker or compare the walking speeds of 2 point-light walkers. In Experiment 1, observers walked, bicycled, or stood while performing a gait-speed discrimination task. Walking observers demonstrated the poorest sensitivity to walking speed, suggesting that perception and performance of the same action alters visual-motion processes. Experiments 2-6 demonstrated that the processes used during self-relative and other-relative action perception differ significantly in their dependence on observers' previous motor experience, current motor effort, and potential for action coordination. These results suggest that the visual analysis of human motion during traditional laboratory studies can differ substantially from the visual analysis of human movement under more realistic conditions.

Unconscious Effects of Action on Perception

“…Motion deviations of this independent stimulus were detected faster when their direction became incongruent with the executed hand movement. Similar effects have been reported for visual discrimination of hand movements [55], judging weights [56], or judging gait speed [57]. Zwickel and colleagues interpreted these results based on the common coding theory, and argued that people are more sensitive to perceive stimuli that deviate from the anticipated effects of their actions [54].…”

“…The predicted sensory state, based on the motor plan, can influence or alter the perceived sensory information, resulting in a relative insensitivity for congruent stimuli [54,55,56,57,59]. However, sensory information that is incongruent with the predicted state is processed rapidly [58] as it is most likely to carry information important to modify our motor plans.…”

Action-specific influences on distance perception: A role for motor simulation.

“…As discussed above, physically rotating one’s own hand influences handedness judgments of depicted hands, which rely on a motor simulation of hand rotation (Wohlschlaeger & Wohlschlaeger, 1998; Wexler, Kosslyn, & Berthoz, 1998). Similarly, walking interferes with perception of point-light walkers (Jacobs & Shiffrar, 2005). Participants’ judgments of the speed of the point-light walkers were impaired when participants had to walk on a treadmill while making their judgments compared with when they just stood still.…”

From movement kinematics to social cognition: the case of autism

“…For example, inducing a motor load through performance of a concurrent task has been shown to modulate perceptual judgements about the weight of an object being lifted by an actor [86] or speed of a walker [87]. Similarly, perceptual judgements can be impaired through application of disruptive transcranial magnetic stimulation to motor regions [88].…”