Dreaming improves creative problem solving

In a study just out, researchers at the University of California San Diego tested whether “incubating” a problem allowed a flash of insight, and found it did when people entered a type of sleep known as REM.

When we sleep we pass through different ‘stages’ of sleep that are associated with different types of brain activity. REM sleep is the stage that we know as dreaming. It is detectable by electrical activity in the brain that looks much like the waking state, and by rapid eye movements – hence ‘REM’.

Volunteers who had entered REM or rapid eye movement sleep in this Proceedings of the National Academy of Sciences (PNAS) study were then better able to solve a new problem that required lateral thinking. Lateral thinking involves looking at a problem from unconventional angles in order to solve it, making connections that are not obvious. It involves thinking ‘around’ a problem rather than tackling it head-on.

On the morning of the test day, 77 volunteers were given difficult creative problems to solve. After trying to solve them, they were asked to mull over the problem until the afternoon – either by resting but staying awake, or by taking a nap. The naps were monitored, to check whether or not the participants entered REM sleep.

Compared with quiet rest and non-REM sleep, REM sleep increased the chances of success on the problem-solving task – improving creative problem solving ability by close to 40%.

The results suggest a very special role for dreaming in problem solving. It is not just sleep itself, or the passage of time, that is important for the problem solving, but whether REM sleep has occurred.

The researchers believe that dreaming “creates a richer network of associations for future use”.

Other studies indicate it does more than this: it is actually able to help in unravelling logical connections through unconscious reasoning – an important aspect of fluid intelligence.

Dreaming improves finding logical patterns and seeing ‘the big picture’

A study in 2007 – also published in the PNAS – led by Matthew Walker and colleagues demonstrated that solving fluid intelligence type questions (such as those of the last post), involving abstracting logical relations, and seeing ‘the big picture’ in terms of underlying  patterns, was much improved by sleep.

For instance, if a person learns that A is greater than B and B is greater than C, then she knows those two facts. But embedded within those is a third fact – A is greater than C. This can be deduced by an inference. It is this kind of logical relationship finding that dreaming can also enhance. In other words, dreaming helps with fluid intelligence problem solving.

References

Jeffrey M. Ellenbogen, Peter T. Hu, Jessica D. Payne, Debra Titone, andMatthew P. Walker. (2007). Human relational memory requires time and sleep, PNAS, 104, 7723-7728.

Simply listening to classical music–the so-called ‘Mozart effect’–does not make you smarter. I have presented the grounds for this conclusion in the last post. In this article we take a look at the question: do music lessons make a child smarter? Do music lessons have ‘collateral benefits’ that extend to non-musical areas of intelligence? Do music lessons increase a child’s overall IQ level, making them better at reasoning, math and language comprehension? How this question has been answered is as interesting as what the answer turns out to be.

Why is this question of interest?

Here is one answer. Children have limited free time to invest into extra-curricular activities, and parents have to make choices between activities for their children. If the choice is between, for example, ballet and music lessons, and music is known to increase intelligence but ballet is not, this might be reason enough to choose music over ballet. Ballet may be good for reasons that music may not be–for motor coordination skills, for example–but at least now the parent has a firmer basis on which choose.

How can we cannot answer the question: do music lessons improve IQ?

The question ‘do music lessons make a child smarter?’ isn’t something that can be answered through common sense and the facts of personal experience. It may be tempting to reason from your observation that all the children you know who take music lessons are doing well at school, that these lessons must be helping them develop their intelligence and school success. But this conclusion isn’t justified. Why not? Because it’s just as likely that they are both doing better at school and taking music because they are from a certain socioeconomic class where the average IQ is higher to begin with. Children with high IQs are more likely than other children to take music lessons because better educated and more affluent parents tend to provide music lessons for their children–it’s part of the culture of the more educated and affluent to provide music lessons. Not all educated and affluent parents, but a lot of them. But this doesn’t necessarily mean that music lessons have any impact on the childrens’ developing intelligence. Many educated and affluent parents also buy certain brands of clothes for their children, but the clothes children wear don’t make them more intelligent.

So we cannot go about trying to figure out whether taking music lessons improves IQ like this.

How we can answer the question: do music lessons improve IQ?

To find out the answer to this question we need to do an experiment. We need to set things up like this: take a lot of children from a variety of backgrounds and randomly assign (by the flip of a coin) half of these children to music lessons for a year, and half to some other extracurricular activity for a year–for instance ballet, or football. We test both groups of children on an IQ test before the lessons, and then again after the lessons, and see if there is a difference between the two groups. If there is a difference–if those who took music lessons on average score higher on the IQ test–we know that it’s not due to family background (because family backgrounds are mixed evenly across the two groups). If we find a difference we will also be more confident that the intelligence gain is specific to music and not any extra curricular activity (whether music, drama, ballet, karate or soccer). In essence, by doing this kind of ‘critical experiment’ we make sure that we’ve pinpointed the effect of the music lessons on intelligence.

Schellenberg’s critical experiment

In 2004 someone did finally this scientific experiment: Glenn Schellenberg from the Department of Psychology, University of Toronto. The study can be found here. He put an advertisement in a local, community newspaper, offering free, weekly arts lessons for 6 year olds for a year. 144 children were then assigned randomly to one of four different groups, with 36 children in each group. Group 1 was given keyboard lessons, Group 2 was given voice/singing lessons, Group 3 was given drama lessons, and Group 4 had no extra-curricular lessons. The instructors were trained, female professionals. The children in all groups took an intelligence test called the WISC-III both before and after the year of lessons. The WISC-III is the most highly regarded and widely used intelligence test for children. All four groups had the same average IQ level at the start of the experiment. Children in each group differed in their intelligence level of course, but the average intelligence of each group was the same. This is obviously important for us to draw any conclusions about the effects of the different types of lessons.

And what did Schellenberg find? Do music lessons increase IQ?

The first interesting finding was that all four groups of children showed an increase in IQ level after the year was up, even the group that took no lessons whatsoever. What explains this general increase in IQ for all children? An increase of IQ known to be a usual consequence of entering grade school. Since all these children started grade school during the period of the experiment, it is easy to explain this general IQ increase as due to simple attendance at school.

But–and this is the crux–the two music lesson groups had significantly greater gains in IQ than the drama and ‘no-lesson’ groups. We can conclude from this data that taking music lessons, but not drama lessons, caused gains in intelligence in addition to the gains obtained by attending school. The type of music lesson didn’t matter (whether keyboard or voice); both groups had the same average IQ score after a year of lessons. And both music groups had a 3 point higher IQ score compared to the drama and n0-lesson groups who didn’t differ from each other in their IQ score.

This relative superiority of IQ in the music groups was not confined to one particular aspect of intelligence–such as spatial intelligence–but was found in all all but 2 of the 12 subtests of the WISC-III intelligence test, across a broad range of cognitive abilities that require intelligence. It benefited all subtests of what is known as fluid intelligence–the ability to reason and find relationships in a way that does not depend on background knowledge.

The size of the effect: how should we judge it?

3 IQ points doesn’t sound like a big effect, but there is a way of looking at this gain in IQ that help put it in perspective and help us evaluate its importance. Compare it to the gain of first going to grade school. The average IQ gain of going to school was about 4 points. The additional gain of taking music lessons (3 points) was, therefore, nearly as much as the full experience of school itself. This is now looking like quite a big effect.

What is special about music?

We need to be clear about one thing. Schellenberg’s experiment shows that music lessons improve IQ for six year olds. It does not tell us that music lessons improve IQ for older children or for adults unfortunately. Six year olds’ brains are known to be highly ‘plastic’–that is, these young brains can be shaped and reorganised to a large extent by experience. Older children and adults have less brain plasticity and it might be predicted that a year of music lessons in this case would have less of an impact on general intelligence–although we don’t know for sure.

In taking music lessons, knowledge and skill relating to music increases, and this is important in itself. But what Schellenberg’s experiment shows is that in addition to this, general cognitive ability is also trained and improved – indirectly. Taking music lessons is good ‘brain training’ at this age! Music lessons involve long periods of focused attention, daily practice, reading musical notation, memorization of extended musical passages, learning about a variety of musical structures (e.g., scales, chords), and progressive mastery fine-motor skills. It is not known exactly which combination of these skills improves general intelligence, and further studies will have to investigate this question.

Introduction

The idea that classical music – particularly Mozart – makes you smarter has received a lot of press, and is widely believed to be an established fact . Music by Mozart sounds highly intelligent – it is intricate, skillful, precise and sophisticated. It seems natural to think that some sort of ‘brain entraining’  occurs just by sitting and listening to Mozart with full concentration – and that this makes you more intelligent.  We can imagine our brain activity becoming coordinated or synchronized better in response to concentrating on the amazing harmony and complexity of Mozart.  This is an appealing idea, but this article should convince you that it is not true that listening to classical music or Mozart makes you more intelligent.

The scientific evidence for the ‘Mozart effect’

Francis Rauscher and her colleagues published a study in the prestigious scientific journal Nature in 1993 that people have been quoting ever since in support of the ‘Mozart effect’ on IQ. They performed an experiment in which participants were randomly divided into three groups: one group sat in silence for 10 minutes, one group listened to a relaxation tape for 10 minutes, and the last group listened to Mozart for 10 minutes. After the 10 minutes were up, all three groups were given three sets of standard spatial intelligence tasks.  They found that the average IQ of the Mozart group was 8-9 points above the average IQ score of the other two groups. They also found that the IQ effect was only short-lived – for about 10-15 minutes.

Data from Rauscher et al. 1993

The public imagination

Based on this study the idea of the ‘Mozart effect’ (as the Press called it) quickly captivated the public imagination. The Mozart recording used in the study quickly sold out in the Boston area in the US. Governor Zell Miller in Georgia was so enthralled by this study’s findings that he actually called for the legislature to allocate $105,000 to give a free classical music CD or tape to every new mother in the state. Tennessee followed with a similar bill, and day-care centers in Florida are now required to play classical music. Needless to say, commercial opportunities were quickly exploited. Businessman Don Campbell trademarked ‘The Mozart Effect’ and published a book by that title, irritating many people with its pseudoscience and false claims. Amazon.com soon advertised half a dozen CD  titles relating to the ‘Mozart effect’ – one whole series called ‘Music for the Mozart Effect’, with other titles like ‘Better Thinking Through Mozart’ or ‘Mozart for Your Mind’ – and even ‘Ultrasound—Music for the Unborn Child’, featuring (you’ve guessed it) Mozart’s music.

But good science is not based on single studies.  There are many examples of single scientific studies that initially catch he public imagination and get a lot of press coverage, but are subsequently proved to be invalid or relatively insignificant. But while the importance of a paper fizzles out in the scientific community, it may continue to live on in the media and public imagination – because it is appealing. The ‘Mozart effect’ is a case in point – as I hope you will be persuaded after considering the points below.

Unreliability of the ‘Mozart effect’

The ‘Mozart effect’ is not consistent – some researchers have found it, some have not. It is unreliable. One of the hallmarks of good science is that a discovery can be replicated – - repeated by other laboratories at other times. Otherwise it could be argued that the so called ‘effect’ that was discovered was due to chance, or due to unintended effects in one particular laboratory that the scientists were not aware of.  Science needs replications to draw sound conclusions. The ‘Mozart effect’ does not reach this standard. In a 1999 review study by of all the ‘Mozart effect’ studies that had been published up to that point, Christopher Chabris concludes that the effect is not significant.

When an effect of listening to Mozart has been found, it is not a general intelligence effect

In those individual studies where an effect of Mozart on cognitive performance has been found,  it is found only on a very specific type of spatial task, which in no way can be considered to be a test of general intelligence.  A closer look at the original study reveals that participants only showed better performance in one of the three spatial IQ tasks they were given, in which you have to visualise folding and cutting a piece of paper. Does this sound like a good test of intelligence to you? Listening to Mozart has been shown to have no effect whatsoever on one of the most valid spatially based measures of general intelligence – the Raven’s Advanced Progressive Matrices. This contrasts with other training methods that have been shown to improve performance on this spatial intelligence test (details here).  Another fact suggests the ‘Mozart effect’ has nothing to do with general intelligence. Working memory is known to be a cognitive memory system that is closely related to general intelligence. Inidivuals with higher intelligence have more working memory capacity. Listening to Mozart has been shown to have no effect on working memory performance. So we can conclude that while listening to Mozart might improve performance on a very specific type of spatial task – and this is questionable because the effect is not reliable – it has been shown to have no effect on the majority of tests for intelligence, or on the spatial tests that are the most valid for measuring intelligence. It is therefore misleading to understand the Mozart effect (if it exists at all) as a effect on intelligence.

The effect is likely to be due to arousal or mood, not changes in cognition

Differences in mood have been shown to have an effect on performance in some reasoning tasks. Listening to Mozart generally puts people in a positive mood, and  this mood might explain better performance on the paper folding spatial task. In support of this claim, one study showed you get exactly the same effect on spatial task performance when participants listened to a Steven King story if they preferred the story to Mozart. The authors of this study concluded:

…although listening to music composed by Mozart might contribute to an improved performance on subsequently presented spatial-temporal task, our research provide no evidence that the improvement differs from that observed with other engaging stimuli that are equally pleasing to participants. (Nantais and Schellenberg 1999)

The authors’ views on their own study

Frances Rauscher,, the lead author of the original Nature study on the ‘Mozart effect’ has repeatedly denounced the over-reaction in the popular press. “I’m horrified—and very surprised—over what has happened,” she has said in an interview. “It’s a very giant leap to think that if music has a short-term effect on college students that it will produce smarter children. When we published the study results, we didn’ t think anyone would care. The whole thing has really gotten out of hand.”  “One of the things we have to be careful about is jumping to conclusions that we don’t have data on at all…I find that ‘Mozart makes you smarter’ thing is quite a bit of a leap.”

Conclusion: Listening to Mozart does not make you smarter

In conclusion, we have gone over a number of very good reasons to be skeptical about the claim that ‘Mozart makes you smart’.  The effect is not reliable. When it is found it lasts for only 10-15 minutes,  and is confined to a particular type of spatial task and not other tasks that are much better measures of general intelligence. And it is likely that the effect is due to changes in mood – not changes in cognition. The authors of the original study that caused all the excitement themselves are horrified at how their results have been interpreted.  After knowing all this, can’t we confidently conclude that listening to Mozart does not make you smarter’. It might put you in a better mood, and it won’t do you any harm, but it won’t make you more intelligent.