Does tool use extend peripersonal space? A review and re-analysis

The fascinating idea that tools become extensions of our body appears in artistic, literary, philosophical, and scientific works alike. In the last fifteen years, this idea has been re-framed into several related hypotheses, one of which states that tool use extends the neural representation of the multisensory space immediately surrounding the hands (variously termed peripersonal space, peri-hand space, peri-cutaneous space, action space, or near space). This and related hypotheses have been tested extensively in the cognitive neurosciences, with evidence from molecular, neurophysiological, neuroimaging, neuropsychological, and behavioural fields. Here, I briefly review the evidence for and against the hypothesis that tool use extends a neural representation of the space surrounding the hand, concentrating on neurophysiological, neuropsychological, and behavioural evidence. I then provide a re-analysis of data from six published and one unpublished experiments using the crossmodal congruency task to test this hypothesis. While the re-analysis broadly confirms the previously-reported finding that tool use does not literally extend peripersonal space, the overall effect-sizes are small and statistical power is low. I conclude by questioning whether the crossmodal congruency task can indeed be used to test the hypothesis that tool use modifies peripersonal space.

Review of The Search for a Common Language: Environmental Writing and Education Edited by Melody Graulich and Paul Crumbley

This edited collection grew out of a symposium held at Utah State University in Logan in 2002. According to the editors, the symposium's purpose was to "publicly explore the particular ways environmental writing educates the public through a fusion of science and literary expression." The Search for a Common Language achieves that purpose by including short prose pieces-ranging from memoirs, essays on specific locations, and scientific papers - as well as poetry on natural themes. The range of topics and genres and the inclusion of poetry provide a variety of ways to talk about the environment and reach out to different audiences to educate them about the natural world.