Influence of tool use on peripersonal space in 2-year-olds

• In Event: Effects of movement, tool use, and object exploration on children's perception of space

Abstract

The present study investigated the effect of tool use on young children’s peripersonal space (PPS). PPS has been conceptualised as the space around our bodies, approximately covering a distance of an arm’s length. PPS is the space in which our actions take place and body-related information is integrated with external information, so that we can, e.g., protect ourselves from a fast approaching object. Extant data show that in adults and older children the size of the PPS is dynamic and can be extended by using a tool. Judgements of object reachability have thus been shown to change after tool use to include objects further away from the body than before tool use. The question of the present study was whether a comparable extension of peripersonal space could also be found in 2-year-olds who are just beginning to use tools efficiently. 22 two-year-olds (9 male, 13 female) participated in a task of grasping toys which approached them across a table. Each toy was fixed with velcro onto a small wooden platform that was pushed towards the children in a regular slow motion with short stops every 5 cm. The children were required to take the toy as soon as they felt that they could get hold of it. The point of first reach was taken to indicate children‘s perception of the object’s reachability. In the baseline phase, 10 objects were presented to the children at consecutive trials. The mean reaching distance was taken as a marker of PPS boundary. After the baseline phase, children were randomly assigned to either the tool use group or the control group. Children in the tool use group (n=14) were given a rake to retrieve different objects presented out of their reach across 15 trials. Children in the control group (n=8) interacted with the same toys for the same time duration without using the tool. All children participated in the subsequent test phase that corresponded to the baseline phase. We tested whether the perceived PPS boundary had changed after the tool use training by comparing the mean reaching distances between baseline and test phase between the groups. As expected, an ANOVA on the preliminary data yielded a significant interaction between group (tool use / control) and phase (baseline / test), F(1,20) = 8.76, p = .008. This indicates a change in reaching distance from baseline to test in the tool use goup, with children reaching at a greater distance at test as compared to baseline, but no difference in reaching distance between baseline and test in the control group. The data provide first evidence of a PPS extension after tool use in young children.

Authors

• Bianca Jovanovic, University of Giessen
  Presenting Author

• Luisa Kuhl, University of Giessen

• Lucy Bolte, University of Giessen