Month: April 2012

Mental Fitness – How to Improve your Mind through Bodily Exercise
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

Infants choose their teachers

By Hardeep Singh from Vancouver, Canada (Mohkam Mopping) [CC-BY-2.0 (], via Wikimedia Commons
My father has seen his four children grow up and is still fascinated with the things that children do NOT know. He likens them to a new computer whose hard drive is still void of information and needs to be filled by a user, i.e. by their parents or other care takers. The computer metaphor is a very widely used one in the cognitive sciences. It turns out that for infant learning it is a misleading one. Rather than being like an empty disc which accumulates knowledge, infants act like explorers who use every bit of information they have in order to make sense of the unknown, to evaluate new inputs and ultimately to decide for themselves what to learn.
Zmyj and colleagues have an article in press in the journal Infant and Child Development which illustrates this nicely. 14 month old infants were presented with a new object: a lamp. Ordinarily lamps are switched on with hands (you knew that, right?) but infants were shown videos in which another person switches the lamp on using the head. Will children imitate them and, thus, show evidence for learning in terms of how to use a new object? They will, but it depends on how old the person in the video is. Most infants imitated an adult, less infants imitated a child aged three and a half, even less imitated another infant. This pattern of results makes intuitive sense. Instead of imitating any person blindly, infants trust people more who tend to be more knowledgeable given that they are older.
Previously, Seehagen and Herbert (2011) had found similar results for infants asked to imitate a person building a rattle. However, Zmyj and colleages went further and showed that a different pattern emerges when children see a person use toys in a rather intuitive way. Now, the infant peer was imitated most and the older child or the adult less. Infants appear to imitate people differently depending on whether they want to acquire knowledge (adults have more knowledge than infants) or whether they want to have fun (infants know better how to have fun than adults). Even before their second birthday, children decide for themselves who they turn to for learning.
Infants deciding what to learn? At 14 months they can hardly speak. They just started walking. Toilet training is still an issue. And they should decide for themselves? The aforementioned studies could perhaps be reinterpreted in a less extreme way. Perhaps appearances drive the effect. By 14 months the child could find an adult more like parents and, thus, trust an adult more for learning novel things. It is imaginable that the child identified better with fellow infants when there is nothing to learn and, thus, imitates them more. This argument is not only a bit constructed, it is also contradicted by a bunch of publications contrasting two adults rather than an adult and an infant.
Chow and colleagues presented infants with either an adult who is reliable or an adult who is not. The unreliable adult would express great happiness when looking into a container even though the container is empty. Children may find such an adult a bit odd. His actions do not really match expectations. Chow and colleagues (2008) found infants to be more hesitant in exploring a container which an unreliable informant claimed contained a nice object. They followed a reliable adult’s information faster. The same or a similar manipulation of an adult’s reliability also changes other infant behaviours:
– their looks behind a barrier to see what the adult is going on about (Chow et al., 2008)
– their surprise at seeing the adult look in the wrong direction in order to find an object (Poulin-Dubois and Chow, 2009)
– their imitation of the head movement to switch on the aforementioned new lamp (Poulin-Dubois et al., 2011; Zmyj et al., 2010).
Infants are not like a container which you can fill with knowledge. The computer metaphor of an empty hard drive simply does not hold. Every new bit of information is evaluated in terms of where it comes from. This evaluation itself is driven by what the infant already knows. It is as if children try to coat themselves against unreliable information. Before toddlers have seen their second birthday cake they show a higher level of self-guided learning than parents realise. You better don’t act unreliable in front of them!
Chow, V., Poulin-Dubois, D., & Lewis, J. (2008). To see or not to see: infants prefer to follow the gaze of a reliable looker. Developmental Science, 11, 761-770. doi: 10.1111/j.1467-7687.2008.00726.x
Poulin-Dubois, D., & Chow, V. (2009). The Effect of a Looker’s Past Reliability on Infants’ Reasoning About Beliefs. Developmental Psychology, 45, 1576-1582. doi: 10.1037/a0016715
Poulin-Dubois, D., Brooker, I., & Polonia, A. (2011). Infants prefer to imitate a reliable person. Infant Behavior and Development, 34, 303-309. doi:10.1016/j.infbeh.2011.01.006
Seehagen, S., & Herbert, J.S. (2011). Infant Imitation From Televised Peer and AdultModels. Infancy, 16, 113-136. doi: 10.1111/j.1532-7078.2010.00045.x
Zmyj, N., Buttelmann, D., Carpenter, M., & Daum, M.M. (2010). The reliability of a model influences 14-moth-olds’ imitation. Journal of Experimental Child Psychology, 106, 208-220. doi:10.1016/j.jecp.2010.03.002
Zmyj, N., Daum, M.M., Prinz, W., Nielsen, M., & Aschersleben, G. (in press). Fourteen-month-olds’ imitation of differently aged models. Infant and Child Development. doi: 10.1002/icd.750