Running on plenty
Moving towards better motor memory:CAN YOU IMPROVE your body’s ability to remember by making it move? That rather odd-seeming question led researchers at the University of Copenhagen to undertake a reverberant new examination of just how the body creates specific muscle memories and what role, if any, exercise plays ( iti.ms/PKG6n3).
They first asked a group of young, healthy right-handed men to master a complicated tracking skill on a computer. Sitting before the screen with their right arm on an armrest and a controller similar to a joystick in their right hand, the men watched a red line squiggle across the screen and had to use the controller to trace the same line with a white cursor. Keeping as close to the red squiggle as possible required input from both the muscles and the mind.
The men repeated the task many times, until the motion necessary to track the red line became ingrained, almost automatic. They were creating a short-term muscle memory.
The term “muscle memory” is something of a misnomer. Muscles don’t make or store memories. They respond to signals from the brain, where the actual memories of any particular movement are formed and filed.
But muscle memory – or “motor memory,” as it is more correctly referred to among scientists – exists and can be quite potent. Learn to ride a bicycle as a youngster, abandon the pastime and, 20 years later, you’ll be able to hop on a bicycle and pedal off.
To date, most studies of the effect of exercise on memory have looked at more intellectual tasks, such as memorising lists of words. In those cases, regular exercise appears to improve the brain’s ability to remember.
But the Copenhagen scientists wanted to see how exercise influences the development and consolidation of physical memories. So before having their volunteers master the squiggle test, they first had a third of the group ride a bicycle at an intense but not exhausting pace for 15 minutes. The other two-thirds of the group rested quietly during this time.
Then, after the computer motor-skill testing, a third of those who’d previously rested completed the same strenuous 15-minute bike ride. The others rested.
All of the volunteers then repeated the squiggle test after an hour, a day and a week, to see how well they’d learned and remembered that skill.
Their scores for speed and accuracy were almost identical at the one-hour point, although the group that had ridden the bicycle after the first computer practise session was a bit less accurate.
After a week, things looked different. The men who had exercised just after first learning the motor skill were noticeably better at remembering the task. The men who’d exercised before learning the new skill were not quite as adept now, although they were better than those who hadn’t exercised at all.
What this suggests, says Marc Roig, a postdoctoral researcher at the University of Copenhagen who led the study with Kasper Skriver, is that physical exercise may help the brain consolidate and store physical or motor memories.
It may be that physical, aerobic exercise performed right after a memory has been formed, intensifies the imprinting, Dr Roig says.
In the short term, though, exercise may leave the brain overstimulated, he says, making it less able to pinpoint and access new memories.