We stood in the middle of the motorway, about to drive onto it in the wrong direction. The windscreen wipers worked madly even though the weather was very dry. One of the passengers screamed, I can’t remember whom.
A German family’s holidays in South Africa can be scary indeed.
What had happened? In psychological jargon, my mother – who drove – was overcome by pre-potent responses which were not inhibited by her executive control system. In other words, her German driving habits – drive down a motorway on the right hand side, indicate using a lever on the left of the steering wheel – were incompatible with the South African traffic system – drive on the left – and the car – the wind screen wipers are activated on the left, the indicator on the right. In order to drive in South Africa my mother needed to hold in mind the correct information about how to drive and at the same time had to stop herself falling back on her usual driving habits. Worse, she had to do so while sitting basically motionless.
A link between immobility and mental performance is suggested by a recent meta-analysis done by Chang and colleagues (just published in Brain Research). They pooled 79 studies with a total of over 2000 participants and overall found a very small positive effect of a small bout of exercise on cognitive performance.
If you would like slightly superior mental abilities, here is some self-help advice:
If you want to show off your slightly improved concentration during exercise:
– Exercise intensity: doesn’t matter too much.
– Cognitive improvements: executive control
Positive effects are only seen for tasks similar to my mother sitting in a foreign car on a foreign road, i.e. situations where you need to concentrate in order to perform differently to what you are used to or to what is usually obvious. Forget about higher intelligence or better memory while sweating it out.
– People: The better your overall fitness level the more positive the effect.
If you want to mentally perform slightly better just after exercising:
– Exercise intensity: light to intermediate
– Cognitive improvements: executive control, attention, intelligence
– People: unfit or very fit (not moderate)
If there is a small pause of at least a minute between physical exercise and cognitive performance:
– Exercise intensity: light or above (not very light)
– Cognitive improvements: executive control, factual knowledge
– People: any level of bodily fitness
How long should the exercises be to see positive effects?
At least 10 minutes.
For how long do the improvements last?
No more than 15 minutes.
How old are people who show cognitive improvements?
Age effects are not strong but generally any age after primary school will show improvements.
Which type of exercise works best?
Aerobic exercise works. Anaerobic and muscular resistance training regimes may have the opposite effect but more research is needed before strong conclusions can be drawn.
At what time of day are the improvements seen?
In the morning. However, often testing time is not reported, so don’t take my word for it.
So much for the self-help. But what does it all mean? Chang and colleagues interpret their results in terms of some unspecified bodily mechanism related to exercise, e.g., heart rate, to increase to some optimal level. Before it declines again to rest level, one has got a limited time window of perhaps 15 minutes in order to show minimally improved cognition. It is a nice illustration of how body and mind are intertwined.
So, had my mother cycled – instead of driven a car – her chances of nearly driving down the wrong side of the motorway would perhaps have been a bit smaller. Also, her chances of riding on a bicycle on any motorway at all would have been smaller, of course. Well, you get my point.
Now think about all the great inventions, all the great ideas, all the great insights that we could have had if only we didn’t spend the 15 minutes after physical exercise with stretching, chatting, and showering. Now go jogging for fifteen minutes and, immediately afterwards, think again.
Chang, Y.K., Labban, J.D., Gapin, J.I., Etnier, J.L. (2012). The effects of acute exercise on cognitive performance: A meta-analysis. Brain Research, 1453, 87-101. doi: 10.1016/j.brainres.2012.02.068