Working in Movement

Ever get “car sick” when reading in the backseat of a moving car? It’s happened to me ever since I was a little kid, and I’ve always wondered why it happens.

Turns out it’s probably the explanation for out-of-body experiences that you sometimes read about. No, I’ve never had one of those. But if I had, it would be for roughly the same reason as the car sickness from reading.

In both cases, the sensations are produced by a mismatch of sensory information reaching the brain.

Motion sickness, says journalist Scott McCredie in his new book Balance: In Search of the Lost Sense usually occurs when what you see and what your vestibular system senses don’t agree. It’s called the sensory conflict theory.

For example, my eyes aren’t following the motion of the car as I’m reading, although the balance organs on my inner ear are on board with the motion. That’s a mismatch and my gurgling stomach sends me a strong indication that something’s wrong.

McCredie gives other examples. In WWII, it wasn’t unusual for airplane navigators to get sick while the pilots didn’t. Both could sense the motion of the airplane, but the navigator couldn’t see the movement out of a window since he was in the windowless interior of the plane.

The out-of-body experiences were produced in two separate but similar virtual reality experiments. But in both cases, the out of body sensation resulted from a mismatch of sensory information. This time it was between seeing and feeling touch.

The method involved having subjects look at visual projections of themselves through a special set of video goggles. Experimenters then simultaneously stroked the subject and the image they were viewing. When this happened, subjects reported sensing they were outside of themselves and instead inhabiting the observed image.

This was kind of a whole body adaptation of the rubber hand experiment that I first heard of in Ramachandran’s Phantoms in the Brain.

To be sure, this sensory mismatch isn’t the only explanation for motion sickness. There are many structural, chemical or biological sources for the misery.

And who knows if sensory mismatch is the only explanation for the out-of-body sensation?

People who participated in the experiments said that they felt a sense of drifting out of their bodies but not a strong sense of floating or rotating, as is common in full-blown out of body experiences, the researchers said.

What is clear is how easily an illusion can crop up from seemingly innocuous circumstances. And sometimes, it’s done on purpose, as in magic shows. For a well-written and fascinating look at how easily attention can be manipulated, see Sleights of Mind.