Learning

Why does music training increase intelligence?

We know that music training causes intelligence to increase, but why? In this post I 1) propose a new theory, and 2) falsify it immediately. Given that this particular combination of activities is unpublishable in any academic journal, I invite you to read the whole story here (in under 500 words).

1) Proposing the ISAML

Incredible but true, music lessons improve the one thing that determines why people who are good on one task tend to be better on another task as well: IQ (Schellenberg, 2004; Kaviani et al., 2013; see coverage in previous blog post). Curiously, I have never seen an explanation for why music training would benefit intelligence.

I propose the Improved Sustained Attention through Music Lessons hypothesis (ISAML). The ISAML hypothesis claims that all tasks related to intelligence are dependent to some degree on people attending to them continuously. This ability is called sustained attention. A lapse of attention, caused by insufficient sustained attention, leads to suboptimal answers on IQ tests. Given that music is related to the structuring of attention (Boltz & Jones, 1989) and removes attentional ‘gaps’ (Olivers & Nieuwenhuis, 2005; see coverage in previous blog post), music training might help in attentional control and, thus, in increasing sustained attention. This in turn might have a positive impact on intelligence, see boxes and arrows in Figure 1.

music_training_IQ_link

Figure 1. The Improved Sustained Attention through Music Lessons hypothesis (ISAML) in a nutshell. Arrows represent positive associations.

The ISAML does not predict that intelligence is the same as sustained attention. Instead, it predicts that:

a) music training increases sustained attention

b) sustained attention is associated with intelligence

c) music training increases intelligence

2) Evaluating the ISAML

Prediction c is already supported, see above. Does anyone know something about prediction b? Here, I shall evaluate prediction a: does music training increase sustained attention? So far, the evidence looks inconclusive (Carey et al., 2015). Therefore, I will turn to a data set of my own which I gathered in a project together with Suzanne R. Jongman (Kunert & Jongman, in press).

We used a standard test of sustained attention: the digit discrimination test (Jongman et al., 2015). Participants had the mind-boggingly boring task of clicking a button every time they saw a zero while watching one single digit after another on the screen for ten minutes. A low sustained attention ability is thought to be reflected by worse performance (higher reaction time to the digit zero) at the end of the testing session compared to the beginning, or by overall high reaction times.

Unfortunately for the ISAML, it turns out that there is absolutely no relation between musical training and sustained attention. As you can see in Figure 2A, the reaction time (logged) decrement between the first and last half of reactions to zeroes is not related to musical training years [Pearson r = .03, N = 362, p = .61, 95% CI = [-.076; .129], JZS BF01 with default prior = 7.59; Spearman rho = .05]. Same for mean reaction time (logged), see Figure 2B [Pearson r = .02, N = 362, p = .74, 95% CI = [-0.861; 0.120], JZS BF01 = 8.181; Spearman rho = 0.03].

fig-2

Figure 2. The correlation between two different measures of sustained attention (vertical axes) and musical training (horizontal axes) in a sample of 362 participants. High values on vertical axes represent low sustained attention, i.e. the ISAML predicts a negative correlation coefficient. Neither correlation is statistically significant. Light grey robust regression lines show an iterated least squares regression which reduces the influence of unusual data points.

3) Conclusion

Why on earth is musical training related to IQ increases? I have no idea. The ISAML is not a good account for the intelligence boost provided by music lessons.

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Carey, D., Rosen, S., Krishnan, S., Pearce, M., Shepherd, A., Aydelott, J., & Dick, F. (2015). Generality and specificity in the effects of musical expertise on perception and cognition Cognition, 137, 81-105 DOI: 10.1016/j.cognition.2014.12.005

Jongman, S., Meyer, A., & Roelofs, A. (2015). The Role of Sustained Attention in the Production of Conjoined Noun Phrases: An Individual Differences Study PLOS ONE, 10 (9) DOI: 10.1371/journal.pone.0137557

Jones, M., & Boltz, M. (1989). Dynamic attending and responses to time. Psychological Review, 96 (3), 459-491 DOI: 10.1037//0033-295X.96.3.459

Kaviani, H., Mirbaha, H., Pournaseh, M., & Sagan, O. (2013). Can music lessons increase the performance of preschool children in IQ tests? Cognitive Processing, 15 (1), 77-84 DOI: 10.1007/s10339-013-0574-0

Kunert R, & Jongman SR (2017). Entrainment to an auditory signal: Is attention involved? Journal of experimental psychology. General, 146 (1), 77-88 PMID: 28054814

Olivers, C., & Nieuwenhuis, S. (2005). The Beneficial Effect of Concurrent Task-Irrelevant Mental Activity on Temporal Attention Psychological Science, 16 (4), 265-269 DOI: 10.1111/j.0956-7976.2005.01526.x

Glenn Schellenberg, E. (2004). Music Lessons Enhance IQ Psychological Science, 15 (8), 511-514 DOI: 10.1111/j.0956-7976.2004.00711.x

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The curious effect of a musical rhythm on us

Do you know the feeling of a musical piece moving you? What is this feeling? One common answer by psychological researchers is that what you feel is your attention moving in sync with the music. In a new paper I show that this explanation is mistaken.

Watch the start of the following video and observe carefully what is happening in the first minute or so (you may stop it after that).

Noticed something? Nearly everyone in the audience moved to the rhythm, clapping, moving the head etc. And you? Did you move? I guess not. You probably looked carefully at what people were doing instead. Your reaction illustrates nicely how musical rhythms affect people according to psychological researchers. One very influential theory claims that your attention moves up and down in sync with the rhythm. It treats the rhythm like you treated it. It simply ignores the fact that most people love moving to the rhythm.

The theory: a rhythm moves your attention

Sometimes we have gaps of attention. Sometimes we manage to concentrate really well for a brief moment. A very influential theory, which has been supported in various experiments, claims that these fluctuations in attention are synced to the rhythm when hearing music. Attention is up at rhythmically salient moments, e.g., the first beat in each bar. And attention is down during rhythmically unimportant moments, e.g., off-beat moments.

This makes intuitive sense. Important tones, e.g., those determining the harmonic key of a music piece, tend to occur at rhythmically salient moments. Looking at language rhythm reveals a similar picture. Stressed syllables are important for understanding language and signal moments of rhythmic salience. It makes sense to attend well during moments which include important information.

The test: faster decisions and better learning?

I, together with Suzanne Jongman, asked whether attention really is up at rhythmically salient moments. If so, people should make decisions faster when a background rhythm has a moment of rhythmic importance. As if people briefly concentrated better at that moment. This is indeed what we found. People are faster at judging whether a few letters on the screen are a real word or not, if the letters are shown near a salient moment of a background rhythm, compared to another moment.

However, we went further. People should also learn new words better if they are shown near a rhythmically salient moment. This turned out not to be the case. Whether people have to memorise a new word at a moment when their attention is allegedly up or down (according to a background rhythm) does not matter. Learning is just as good.

What is more, even those people who react really strongly to the background rhythm in terms of speeding up a decision at a rhythmically salient moment (red square in Figure below), even those people do not learn new words better at the same time as they speed up.

It’s as if the speed-up of decisions is unrelated to the learning of new words. That’s weird because both tasks are known to be affected by attention. This makes us doubt that a rhythm affects attention. What could it affect instead?

fig5e_blog

Figure 1. Every dot is one of 60 participants. How much a background rhythm sped up responses is shown horizontally. How much the same rhythm, at the same time, facilitated pseudoword memorisation is shown on the vertical axis. The red square singles out the people who were most affected by the rhythm in terms of their decision speed. Notice that, at the same time, their learning is unaffected by the rhythm.

The conclusion: a rhythm does not move your attention, it moves your muscles

To our own surprise, a musical rhythm appears not to affect how your attention moves up and down, when your attentional lapses happen, or when you can concentrate well. Instead, it simply appears to affect how fast you can press a button, e.g., when indicating a decision whether a few letters form a word or not.

Thinking back to the video at the start, I guess this just means that people love moving to the rhythm because the urge to do so is a direct consequence of understanding a rhythm. Somewhere in the auditory and motor parts of the brain, rhythm processing happens. However, this has nothing to do with attention. This is why learning a new word shown on the screen – a task without an auditory or motor component – is not affected by a background rhythm.

The paper: the high point of my career

You may read all of this yourself in the paper (here). I will have to admit that in many ways this paper is how I like to see science done and, so, I will shamelessly tell you of its merits. The paper is not too long (7,500 words) but includes no less than 4 experiments with no less than 60 participants each. Each experiment tests the research question individually. However, the experiments build on each other in such a way that their combination makes the overall paper stronger than any experiment individually ever could.

In terms of analyses, we put in everything we could think of. All analyses are Bayesian (subjective Bayes factor) and frequentist (p-values). We report hypothesis testing analyses (Bayes factor, p-values) and parameter estimation analyses (effect sizes, Confidence intervals, Credible intervals). If you can think of yet another analysis, go for it. We publish the raw data and analysis code alongside the article.

The most important reason why this paper represents my favoured approach to science, though, is because it actually tests a theory. A theory I and my co-author truly believed in. A theory with a more than 30-year history. With a varied supporting literature. With a computational model implementation. With more than 800 citations for two key papers. With, in short, everything you could wish to see in a good theory.

And we falsified it! Instead of thinking of the learning task as ‘insensitive’ or as ‘a failed experiment’, we dug deeper and couldn’t help but concluding that the attention theory of rhythm perception is probably wrong. We actually learned something from our data!

PS: no-one is perfect and neither is this paper. I wish we had pre-registered at least one of the experiments. I also wish the paper was open access (see a free copy here). There is room for improvement, as always.

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Kunert R, & Jongman SR (2017). Entrainment to an auditory signal: Is attention involved? Journal of experimental psychology. General, 146 (1), 77-88 PMID: 28054814

Infants choose their teachers

By Hardeep Singh from Vancouver, Canada (Mohkam Mopping) [CC-BY-2.0 (www.creativecommons.org/licenses/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).
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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!
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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