I cut my teeth as a science writer at the Saskatchewan Science Centre, where I wrote most of the copy for the original exhibits (and continue to write most of the copy for new exhibits, on a freelance basis).
The goal of the Science Centre has always been to make science fun, the idea being that while kids (and adults) are playing, they may just learn a little bit about science–without even trying.
Well, it turns out that learning without trying too hard is a very sound approach. At least, that’s one interpretation of a new, just published in the scientific journal Cerebral Cortex and summarized in the science magazine Nature.
Researchers at the University of Cambridge, led by psychiatrist Paul Fletcher, have used brain imaging to prove that if you really want to learn something, thinking about it too much may actually be counter-productive.
The researchers’ goal was to investigate how explicit memories and implicit memories influence each other. Explicit memories are those that can be brought to consciousness–your recollection of a particular Christmas when you were a child, for example–while implicit memories cannot–your ability to ride a bike, for instance.
Dr. Fletcher’s team gave test subjects a simple task to learn that could be stored in either implicit or explicit memory (or both), to see if the subjects behaved differently when learning using the two different forms of memory. Functional magnetic resonance imaging, which monitors blood flow in the brain, was used to see how brain activity differed when learning implicitly and explicitly.
Subjects were shown a screen on which any one of four different boxes could be highlighted. Each box had a button corresponding to it, and as the boxes were highlighted in an apparently random sequence over a period of six minutes, the subjects were asked to press the corresponding buttons as quickly as possible.
In total, each person pushed a button roughly 300 times–but unknown to one set of volunteers, hidden with a long, random string of highlighted positions was a 10-item sequence that repeated 18 times.
Then, a different set of subjects were asked to complete the same task–but were told ahead of time about the repeating sequence and asked to try to learn it.
In the first instance, any learning of the repeating sequence had to be implicit. In the second, it was explicit.
What the scientists found was that when people just concentrated on pushing the buttons and weren’t thinking about a possible sequence, they got faster–their minds were unconsciously aware of the sequence and taking advantage of it, even though they strongly denied noticing the sequence consciously.
But when the people were told to actively look for a sequence, they did not get faster–even though they were able to identify small segments of the sequence. In other words, the effort to explicitly learn the sequence obliterated the implicit learning of the sequence that otherwise would have taken place.
By the end of the test, those who weren’t looking for a pattern had a reaction time 40 milliseconds faster than those who were looking.
The fMRIs showed that there was a significant boost in brain activity in the right frontal lobe of the volunteers who were trying to learn the sequence. The frontal lobes, important to concentration, explicit memory and problem solving, communicate with the thalamus, an egg-shaped region of the brain that filters sensory information, directing it to where it’s needed–it’s kind of a brain switchboard. The interaction between the frontal lobes, the thalamus and the rest of the brain also changed depending on which kind of learning was underway.
This isn’t the first study that has shown that trying too hard to learn can cause trouble. Way back in 1976, college students were asked to memorize strings of letters in a similar study. Those who were told there was a regular pattern to the letters actually found it harder to tell whether a particular string of letters had the pattern or didn’t have it than those who weren’t told about the pattern to begin with.
Dr. Fletcher concluded, “This study shows that our frontal lobes, although thought to be the seat of higher human psychological function, may, under certain circumstances, be more of a hindrance than a help. That is, as many sportspeople have already discovered for themselves, there are certain circumstances under which we should stop deliberating and just act.”
Or maybe play…and learn something in spite of ourselves.
