Breathe In, Breathe Out

Sensory Mismatch

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 experiement 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.

Technorati Tags: brain, feldenkrais, learning, plasticity

Plasticity and Uncle Albert

Quick. What do Elvis and Einstein have in common? Well, their estates are both making oodles of money from them, long after their deaths. Elvis inclusion on the profitable dead celebs list makes sense, but how did good old Albert find himself along side the king of rock and roll?

Turns out that Einstein's image is plastered all over a best-selling line of interactive videos for babies and toddlers, Baby Einstein. And if you're going to use the image and name of the king of relativity, you gotta pay for the privilege.

Thankfully, Albert's not around to see the current controversy released with a study suggesting watching the Baby Einstein video isn't without a downside.

Now brain plasticity pioneer Michael Merzenich weighs in on the controversy from a plasticity perspective. As I read it, he takes the University of Washington researchers to task mainly for findings that seem little more than a blinding flash of the obvious - at least from a plasticity perspective.

Brain plasticity is driven by whatever it is that we do. And when we spend a lot of time doing one thing, we sacrifice time for doing something else that might also have a plasticity effect. "Fire together, wire together," as they say.

It does make sense that a baby or toddler spending a lot of time with interactive visual and movement material might develop in a certain way and not others:

I suspect that they could also EASILY scientifically demonstrate that Baby Einstein graduates are particularly fond of visual media and are even more avid-than-usual video game players on the statistical average than are non-exposed kids. And I suspect that those later years of time spent away from language and social interactions at passive viewing and active video game playing shall exaggerate and widen the limitations in language and social development initially arising through video exposure in infants and toddlers.

But Merzenich adds a refreshing dose of common sense to all this by concluding with that the videos are both good and bad for kids. It just depends on what the parent wants for the kid.

YOU decide, for your kid, if the expected consequences of such heavy infant exposure are contributing to biasing them in what YOU regard as a positive or negative direction. On the whole, for my own children, thinking forward to the consequences of biasing the infant toward being in love with passive viewing and electronic media in later life, I would vote ‘no’. For YOUR kid, that could be the wrong answer.

It's all relative, I suppose.

Technorati Tags: brain, feldenkrais, learning, memory, plasticity

Video of Forward/Backward Treadmill

Thoughts on Learning Movement Skills described a very non-traditional treadmill that produced some interesting effects on research subjects who walked on it. Pretty thought-provoking stuff, but not the easiest thing to visualize in action.  Fret no more. Here's a video that shows how it works.

Thoughts on Learning Movement Skills

There’s this really wacky treadmill in Maryland that might be changing how we understand the brain’s control of walking. Needless to say, this is pretty exciting for offering therapy for brain injured people who’ve had trouble walking. But, at least to my way of thinking, the implications might also extend to athletic and performance instruction.

What makes the treadmill wacky is that it can go forward and backward — at the same time! Instead of one belt turning under a walker, this thing uses two, one for each leg. The belts can turn in different directions and at different speeds. Sounds like patting you head and rubbing your stomach at the same time, but volunteers participating in a study at the Kenney Krieger Institue quickly adapted to it.

In fact, they adapted so well that they couldn’t stop the odd walking pattern the treadmill had required of them, even when they got off of it. It took about 15 minutes for their brains to adapt and resume their regular walking gait.

The odd pattern of the treadmill had disrupted their brain’s walking pattern and put the new one in it’s place. And they weren’t able to consciously override it.

Researchers who conducted the treadmill study concluded that there are different and separate brain systems that control each leg during walking, and each direction, forward or backward. I understand this is contrary to the current theory of walking control.

There are some pretty exciting implications for therapy here. According to the lead author:

"The notion that we can leverage the brain's adaptive capacity and effectively ,dial in, the patterns of movement that we want patients to learn is incredibly exciting," said Dr. Amy Bastian, senior study author and Director of the Motion Analysis Laboratory at the Kennedy Krieger Institute. "These findings significantly enhance our understanding of motor skills, effective therapeutic approaches and the true adaptive nature of the brain."

But I wonder if these findings might also apply to learning or refining movement-based skills, like those in athletics or performance arts. After all, the treadmill effectively completely disrupted habitual walking patterns and put new ones in their place, at least temporarily.

And here’s the key thing — this “learning” happened without conscious thinking from the treadmill walkers. No figuring out how to do a certain step, like you might do in dance class. The new pattern just happened, then went away.

How could this sort of thing be used in skills instruction? By disrupting a habitual way of performing a skill, old ways of interfering with learning new patterns would be removed automatically. Seems to me that this “new state” would be more conductive to learning a different motor pattern.

And though this new state might be temporary, it would still allow a way to actually feel what it’s like to make a certain movement without habitual ways of interfering with it. The key here would be in developing and using enough awareness during the temporary period.

This would go well beyond just getting feedback while learning. And, for sure, it would be a whole lot better than the traditional “demonstrate and imitate” method used by many instructors.

Technorati Tags: brain, feldenkrais, learning