When we touch something with a tool, do we feel the touch at the tip of the tool or at the hand that holds the tool? Our brain seems to feel it at the tip of the stick. A research group in Neuroscience Research Institute has recently obtained the first objective evidence for this.

They have shown that the judgment of the temporal order of two successive stimuli, delivered to the tips of sticks held in each hand, was dramatically altered by crossing the sticks without changing the positions of the hands, where the actual mechanoreceptors are located. This would never occur if the stimuli are perceived at the hands, because the position of the hands was not altered at all. The results indicate that tactile signals evoked at a hand are referred to the tip of a tool in the hand. These findings would contribute not only to the field of neuroscience but also to the development of robots that manipulate objects with tools.

*The results are published in the October issue of Nature Neuroscience.
Yamamoto S & Kitazawa S (2001) Nat Neurosci 4:979-980.