 |
Kitchen Science ExperimentsThe Naked Scientists: Science Radio & Science Podcasts |
 If you like Kitchen Science then you'll love Crisp Packet Fireworks, our new book of home experiments, complete with illustrations and explanations. Find out more Listen to Experiment Part 1 Part 2  ...or download as MP3 [1] [2] Next Experiment: Grape Plasmas |
 Kitchen Science RSS Feed |
Motor learning
Confuse your brain using a mouse. And Ben tries to throw a ball from a differnt perspective.
What you need
| A mouse |
| A computer |
| A brain, your own will do |
What to Do
Get used to the mouse on your computer
Change the sensitivity of the mouse
Try using it.
Practice for 10 minutes
Now turn the sensitivity back again
How does it feel now?
What may Happen
You should find that when you change the settings it feels all wrong and you keep over or undershooting the icon you are looking for. But as you practice you get better and better at dealing with the new settings until it feels about normal. Then when you change them back you should find that it feels wrong again.
We did something very similar on the show. We got Ben to try throwing a ball at me. To start with and his aim wasn't bad. he then put on a pair of glasses which bent the light coming into his eyes by about 15°. This put his aim right off until he had practiced for 5 minutes when he could hit me again with his right hand. But when he tried the left hand which had't had the practice he was still way off.
|
|
Ben in the fetching goggles | The goggles move the image |
He then took the goggles off when he could throw straight using his left hand, but his right hand now missed in the opposite direction.
What is going on?
When you decide to throw a ball your concious brain sends instructions to your cerebellum - a region at the top of your spinal cord. This then translates the instruction into a series of signals to send individual muscles to move to achieve this task. If this has the desired result then the cerebellum will use the same set of signals next time it is told to throw the ball.
|
A picture of a brain with the cerebellum in purple © NIH |
If however something about the throw goes wrong the cerebellum will try doing something different next time, if this is an improvement it will do it again, if it gets worse it will probably tweak the signals in the other direction.
This means that if you do something odd like changing the sensitivity of your mouse pointer, or start wearing goggles which move your view of the world then your cerebellum will start fiddling with the strength of the nerve signals, to make the throw or movement work again. However the learning only works for movements you have practiced. If you try another limb, or a different movement it will not have been optimised. So if you take the goggles off or return your mouse setting the unpracticed limb will work fine, but the practiced once will now be compensating for something which is no longer there, and will have to learn how to do the movement again.
The contents of this site are © The Naked Scientists® 2000-2009. The Naked Scientists® and Naked Science® are registered trademarks.