Part‐based representations of the body in early childhood: evidence from perceived distortions of tactile space across limb boundaries
Published online on June 19, 2016
Abstract
Studies show that touch in adults is referenced to a representation of the body that is structured topologically according to body parts; the perceived distance between two stimuli crossing over a body part boundary is elongated relative to the perceived distance between two stimuli presented within one body part category. Here we investigate this influence of body parts on tactile space perception in children of 5, 6 and 7 years of age. We presented children with pairs of tactile stimuli on the left hand/arm, either within the hand, within the forearm, or over the wrist. With their eyes closed children were asked to adjust the distance between the thumb and forefinger of their right hand to represent the felt distance between the two tactile stimuli. Like adults, the children perceived the distance between two stimuli that cross the body part boundary to be further apart than those that were presented within the hand or arm. They also perceive tactile distance to be greater on the hand than the arm which is the first observation of Weber's illusion in young children. We propose that a topological mode of body representation is particularly advantageous during early life given that body part categories remain constant while the metric proportions of the body change substantially as the child grows.
Here we show that in childhood, as in adulthood, the way we represent our body in terms of its constituent parts and their boundaries, modulates the way that we perceive touch on the skin's surface. Two tactile stimuli presented on one body part are perceived as more similar, and therefore closer together, than two equally spaced tactile stimuli that cross over a body part boundary.