When action capability biases perception of space amongst adults

Previous researches suggest that the way one perceives spatial distances in the external world relies partly on the effort that one makes when performing actions. The purpose of the present research is to investigate such potential relationship by using a specific robotic device called REAplan in order to shed light on neural processes involved in it. The present experiment has been conducted on young adults. Space perception capabilities were measured using three tasks investigating perception in peri- and extra-personal spaces as well as in left and right sides of space on a horizontal plane. The first task was a reachability judgment task in which participants were asked to judge whether or not they thought that they could reach targets appearing at several positions on a screen. The second task was a distance estimation task and consisted in evaluating the distance in centimeters between themselves and these targets. The third task was a visual detection task, in which participants were asked to press a robotic handle every time they detected a target. As a manipulation, they performed a pointing task by using the robotic handle and moved it towards targets. In some trials, additional force was induced in the stick, making the action more difficult in order to manipulate action effort before space perception measures. All participants went through all experimental conditions. Most results were non-significant but though an effect of the manipulation was found in the distance estimations. They suggest an overestimation of distances in the peripersonal space following a physical effort with the arm. Such findings might help science to further improve treatments and rehabilitation for neurological disorders impacting motricity and visuo-spatial functions.