Extended auditory peripersonal space in blind cane users

In the present work, we investigated whether an auditory peripersonal space exists around hand and whether such a space might be extended following a brief tool-use experience or by long term experience of using a tool in everyday life. To this aim, audio-tactile integration was studied in the space around the hand and in far space in blind subjects regularly using a cane to navigate and in sighted subjects, before and after a short training with the cane. In sighted subjects, before tool-use, auditory peripersonal space was limited around the hand, then it expanded after tool-use and contracted backwards after a resting period. On the contrary, in blind subjects, peri-hand space was immediately expanded when holding the cane but limited around the hand when holding a short handle. This suggests that long term experience with the cane induces a durably extension of the peri-personal space.