Disconnected Connections: Extending Peripersonal Space with a Virtual Hand

Abstract

Peripersonal (reachable) and extrapersonal (beyond reach) space is linked to hand perception. Using a tool to reach farther than normal recalibrates previously unreachable space as peripersonal, evidenced by Intraparietal Sulcus (IPS) activity related to hand perception and lateral biases during line bisection. The current study looked at the role of a visual connection between the hand and body in the ability to manipulate objects within the extended area of reach. In an immersive virtual environment, participants bisected lines using a connected hand (via arm), a disconnected hand, or a floating dot. A rightward shift in bisection was seen only for the dot condition for far lines, indicating that it was the only "tool" incapable of extending peripersonal space.