Abstract
To act safely and adequately in the environment, we must accurately perceive the
relationship between environmental properties and our own body properties. Over
time, body properties change due to aging or motor dysfunction. There may also be
changes in the short term due to artificial extensions or experimental manipulations.
Previous studies have reported that people do not always successfully adapt after such
changes as some dissociation between perception and action might have remained in
some cases. It is unclear what conditions cause such dissociations to disappear and
adaptation to occur. The present study attempted to apply a constructive approach to
examine the dissociation between perception and action in stepping over an obstacle by
means of loading on the non-dominant leg to change body properties of healthy young
participants. The loaded positions of the leg (ankle and thigh) were also manipulated
to investigate the different effects on the dissociation. The results demonstrated that
participants tend to underestimate their action abilities in the ankle condition and overestimate
their abilities in the thigh condition. As a result, the different effects between
the loaded positions on the dissociation were found. These findings are discussed in
terms of the complex relation between the loaded positions, exploratory action after
body properties were altered, and the action required as an experimental task.
