A Lifespan View on Modulation of Peripersonal and Extrapersonal Reach Space via Tool Use

Abstract

This study examined lifespan characteristics associated with tool use in the modulation of peripersonal and extrapersonal space. Three age groups: Children (7-12 years), Young Adults (19-23 years), and Older Adults (65-92 years) were presented with two experiments using an estimation of reach paradigm involving arm and tool conditions and a switch-block of the opposite condition. Experiment 1 tested Arm and Tool (20 cm length) estimation and switch-block conditions (from Arm to Tool and Tool to Arm) and found a significant effect for Age and Condition (ps <.05). Post-hoc analysis for Age indicated that children were significantly less accurate than young and older adults. Analysis for condition revealed significant differences for the Arm Switch-Block condition (Retraction) when compared to Tool and Arm estimations. Experiment 2 was similar to Experiment 1 with the exception of using a 40 cm length tool. Results were analogous to those found in Experiment 1. Considered together, these results hint that: (1) the ability to be as accurate when estimating reach with a tool and arm is present across the lifespan, (2) development and decline of action representation follow distinct paths, and (3) retraction of space seems to be more difficult than extension.