Other people’s personal space as noticeable as your own

Peripersonal space (PPS) is an area created by the brain immediately around one’s own body parts that is used when interacting with people and objects. Recently, researchers have shown that some neurons in the primate brain respond to an infringement of another person’s PPS as if their own space was being encroached upon. To determine how this “PPS remapping” phenomenon affects human behavior, Kumamoto University researcher, Dr. Wataru Teramoto, evaluated people’s reactions to visual or tactical stimuli while alone or with a partner. He found that participants responded to stimuli in a partner’s PPS as quickly as they would their own.

The experimental setup used three types of stimuli, tactile only (T-only), visual only, (V-only), and visuotactile (VT) for multiple kinds of experiments. Participants were instructed to press a button with their right hand as quickly as possible in response to any of the three stimuli: a vibration in their left index finger, a change in color of a moving disk (white to green) projected onto the table in front of them, or a combination of the two. Experiments were performed alone, with a partner, or with a fake (rubber) arm. The visual stimuli appeared either inside or outside of the participant’s PPS, with the latter space corresponding to the partner’s PPS.

Source: Sharing spaces: Your brain considers other people’s personal space as your own