Tuesday, 13 March 2018

Over-thinking the simple

For several years at the beginning of this century, I spent every Wednesday evening in a Samba School, starting off shukkasukka-ing a chocalho, then graduating to a repinque. We were collectively pretty good: we practiced for 2 hours a week, when out on parades many weekends and we won a prize in the Dublin St Pat's Parade in 2004 [that's gorgeous me L thoughtfully chocalho-ing] . It was really hard work for intellectual me. If I let my hands do the talking, I could keep my end up but if I ever looked at those hands, they said "oh ho, brain taking over here" and FLUB! they were all ahoo and out of synch. We were asked to do three asynchronous things at once: 1) buddabudda or womba-womba with our percussion instrument 2) walk forward with the rest of the band and 3) sway from side to side in time with the music and our co-sambistas. I could, reliably, do any two of the above. When I got confident in the groove, I'd think try the sway now Bob but my feet would stop and the girl behind would crash into stationary me.  This is relevant to Fred Cummins of UCD and his theories about group singing. Those of us in the unnatural wing of the school would often talk about how we'd learned, without ever having lessons, to walk and eat ice-cream without getting a wet face - how difficult could it be. We talked in the same vein as adults in the Home Education movement, how our kids taught themselves to read and write without the hassel of getting them up for school every day.

This all came back to me while reading, in the current issue of Nature, The mind-reading devices that can free paralysed muscles. This sort of thing is on my List, because of the tribulations, trials and experiments of my friend Mark Pollock, who fell out of a second-storey window a few years ago and broke his back. Because he is made of courage, forged in the heat of adversity he wasn't going to take the rest of his life lying down. Because he's a bit geeky, he signed up as a guinea-pig for a novel out-there experimental therapy to walk again. This involves 1) a prosthetic exo-skeleton which braces up his lower body and has motors to move the articulated parts 2) a can't-be-done and against-all-we-know regime of neuromuscular stimulation to get his muscles to operate again. If they can achieve 2) then they can discard 1).

In 2012, paraplegic Eugene Alford, was wired up with a cap that could pick up specific electrical activity in the motor cortex of his brain and translate that into movement of his exo-skeletal robot. That was 6 years ago and the interface was pretty crude, he had to think his legs into walking forward, and he was making little enough progress. Then he saw a coffee cup on a table the other side of the room and thought "Shaggit, this isn't working, I wish I could have a break and a cup of joe" and suddenly he was off across the room his robotic legs dragging his uncomprehending head behind. That was a, if not The, breakthrough!  When you're learning to walk in your second year outside in the world, you don't say flex those glutes, loose those quadriceps, you leave that to a lower system of actors.

It's a bit like soldiering. A fresh-faced officer will tell the grizzled old sergeant that The Men have to march round to the canteen and the sergeant will make it happen. But the squaddies also do it right because they've be trained to do similar stuff before . . . a lot of times. In Human Physiology, I make a similar point about the motor neurons which are under 'conscious control'; in contrast to the autonomic nervous system which controls peristalsis and heart-beat and peripheral vaso-dilation, which is not under conscious control. If I was really in conscious control of my legs as I strut back and forth in the lecture theatre, then I wouldn't be able to talk at the same time.

The Nature article goes on to talk about getting stroke victims and others to regain ownership of their dead arms. This is where mirror-neurons can be a great help.

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