Jon22: The Website of Jonathan Dobres

There’s an interesting post over at Dave Munger’s Cognitive Daily that reports on recent work that implants small magnets in a person’s fingertips. The user is then able to sense the presence of magnetic fields and electrical currents. Munger then asks whether this constitutes a genuine “sixth sense.” As a perception-obsessed nerd, I couldn’t resist answering, but my answer got a little long for a comment.

I think that first you have to throw out the idea of there being five senses in the first place. For instance, fluid in the inner ear maintains one’s “sense” of balance, and the ability to reliably wake up just before my alarm clock rings attests to an inborn “sense” of the passage of time. I’ve always disliked the ingrained (and incorrect) notion that we have five senses. You have five major sensory modalities that can work from the surface of your head, but sensation and perception is so much more than that.

The magnets enhance one’s normal tactile senses and are incorporated into what James Gibson would have called a “perceptual system.” To get an idea of what this means, the next time you’re at restaurant, grip a spoon tightly in your hand and use it to feel the shape of your wine (or beer) glass. Your skin never makes contact with the glass, yet you can easily “feel” the shape and probably even the texture of the glass. In this case, it’s really the muscles that move your arm and hand that do most of the sensing, and so they are part of the perceptual system for touch.

So, do the implanted magnets grant the user a new sense? I’d have to say yes, since they enable the user to perceive a new aspect of his environment in a very intuitive manner. The magnetic sense, since it is so tightly integrated into the body, can also be integrated into the larger perceptual systems (unlike, say, looking at infrared video).