Thursday 15 December 2016

Old Familiar Carols: Familiarity and the Mere Exposure Effect

Christine, the lovely parish co-ordinator at our local church, smiles at me across the desk.  I’m there to pay the rental charge for my piano studio, located in the church basement.  But she has something else in mind. 

“Are you around this Christmas?” She raises her eyebrows hopefully.  “Are you available to play at the Christmas Eve service?”

Last year we were away, traveling at Christmas, but in previous years I’ve played my flute at the church on Christmas Eve, adding some shimmer to an otherwise quiet evening for the small congregation.  Two years ago I also roped my children into singing, to the delight of the elderly ladies celebrating their Christmas worship.  This year we don’t have any plans for Christmas Eve, so I willingly agree to perform something.  I know I’ll need to plan music for a prelude, postlude, offertory and a solo during communion, in addition to adding a flute descant to the hymns.

What’s left to decide is the hard part:  what to play.  I’ll wait for the church music committee to tell me what the hymns will be, and then I can pick my incidental music from the remainder of the canon of Christmas tunes. 

I have to confess, I am not thrilled about any of those tunes.  I’ve heard and played them all a million times before. 

As a child, I loved Christmas music.  I started early every year, spending a large chunk of the fall belting out Christmas songs, often in the bathroom where I mistakenly felt no one could hear me.  My very first book of sheet music, given to me before I could read music, and well before I started playing an instrument, was a collection of Christmas carols.  I remember poring over the words, memorizing every verse.  Later, after I started studying piano, the music itself was learned and played endlessly.  The book, now battered and torn, still gets pulled out every year.

But after forty-some Decembers of listening to the same Christmas songs, I admit to being entirely bored by them.  Silent Night?  No thanks.  O Come All Ye Faithful?  Snore….  Even the slightly less common carols seem utterly mundane.  However, I still have to pick at least four to play on Christmas Eve.

There are newer, less familiar carols.  The problem is that no one really wants to hear them on Christmas Eve.  It turns out that it’s a natural human phenomenon to prefer tunes we already know.

Scientists call it the Mere Exposure Effect:  simply being exposed to something (in this case a tune) makes you like it more when you meet it a second time.  The Mere Exposure Effect in music was first shown over one hundred years ago, and holds true for music of all styles.  Research studies that look at this effect generally work like this:  volunteers listen to a series of (usually unfamiliar) melodies.  Then, later, they hear another series of melodies that includes some of the melodies they have heard before, and some new melodies.  In this second listening period, they have to rate each tune on how much they like it.  The results show that hearing a piece of music (even only once!) predisposes you to like it more than other music you have not heard before.

The Mere Exposure Effect tells us something about the different ways in which we remember music.  And that’s because this effect holds true whether you remember having heard the tune before or not.  If people are distracted with another task while hearing the music, they often don’t remember they’ve heard it before, but they will still give it a higher rating than tunes they’ve never heard.  This shows that the mere exposure effect is dependent on our implicit, unconscious memory for music.  In contrast, if we consciously remember having heard the tune before, this uses our explicit memory. So we might not remember having heard an unfamiliar Christmas carol before, but the more we’ve heard it, the more we’ll like it.

Researchers want to understand why this effect works the way it does:  what is it about being exposed to something that makes us enjoy it more?  One theory is the perceptual fluency model, which proposes that when we’ve been exposed to something before, our brains have an easier time processing the information.  The first time we hear a new tune, we don’t know exactly what will come next, and so, whether we’re aware of it or not, our minds are constantly trying to guess what the next note or phrase will be.  That’s a lot of work, and makes us feel as if the tune is difficult.  When we’ve heard the music before, we might not remember exactly how it goes, but our brain does a better job of predicting the next note, and this is less work, making us like the music more.

A second theory is called the two-factor model.  This idea is that our aesthetic rating of a piece of music is based on two things:  our dislike for things that are too new or complex, and our boredom with things that are two simple or familiar.  In other words, we like to be able to predict what will happen next, but if it is completely obvious what will happen next, that’s no fun.  The two-factor model suggests that in addition to the mere exposure effect, there should also be a satiation effect, in which people start to dislike stimuli that they have been exposed to too many times.  (As in... ahem… Christmas carols).


Studies looking for a satiation effect have had mixed results, depending on the stimuli used, but it looks like the more realistic the stimuli are, the more likely they are to generate a satiation effect.  This was found for musical stimuli in a study from the University of Toronto (Szpunar et al., 2004).  When the researchers in this study played computer generated atonal sequences for people, they did not find that the subjects got bored of them, even after 64 exposures.  However, when the same experiment was conducted using excerpts of orchestral recordings, they found that people gave lower ratings to the excerpts they had heard many times.

Where does this leave me in my Christmas Eve music planning?  Well, clearly I want to try to hit that sweet spot in the liking curve, by playing something that people have heard before, but not too many times.  I’ll aim for less-familiar carols, and maybe include something that most people won’t have heard.  They may not appreciate this year, but when they hear that tune again another Christmas, they’ll like it better.


Green, A.C., Bærentsen, K.B., Stødkilde-Jørgensen, H., Roepstorff, A., and Vuust, P. (2012). Listen, learn, like! Dorsolateral prefrontal cortex involved in the mere exposure effect in music. Neurol Res Int 2012, 846270.

Peretz, I., Gaudreau, D., and Bonnel, A.-M. (1998). Exposure effects on music preference and recognition. Memory & Cognition 26, 884–902.

Szpunar, K.K., Schellenberg, E.G., and Pliner, P. (2004). Liking and Memory for Musical Stimuli as a Function of Exposure. Journal of Experimental Psychology: Learning, Memory, and Cognition 30, 370–381.

Wednesday 7 December 2016

Brain Activity: Is Less More?

Areas of the brain that show a decrease in activity upon learning a task (from Chein and Schneider, 2005)

Imagine an experiment where scientists are using fMRI to look at activity in a person’s brain before and after the person learns how to do a particular task. (The task itself doesn’t matter too much right now, but it could be something like tapping a particular sequence of fingers, or reading backwards, or picking out pictures of dogs hidden in a complicated landscape.) The scientists scan the person’s brain while she is doing the task for the very first time. Then they have the person practice doing the task until she's really good at it. Finally, the person gets scanned again, while performing this well-learned task. What do you think the difference will be in the person’s brain activity? Would you expect to see more activity or less activity?

I’ve been slogging through scientific papers that look at changes in brain activity (using either fMRI or PET) when we learn skills, and growing increasingly puzzled. In some cases, when people learn to do something, there is more activity in their brains, and the researchers say: “See, that’s because they’re using more of their brains for this!” But sometimes there is less activity, and the researchers conclude that when we are good at something, our brains are more efficient.

Don’t those two things sound contradictory to you? Which is it? Do we use less brain power or more brain power when we’re good at doing a task? I’ve spent some time looking into this question, and when you get into the details, the answer is… it depends.

But it does make sense, trust me.

The best explanation that I found was in The Cambridge Handbook of Expertise and Expert Performance. There’s a chapter by Nicole Hill and Walter Schneider entitled “Brain Changes in the Development of Expertise: Neuroanatomical and Neurophysiological Evidence about Skill-Based Adaptations”. They suggest that when we learn a skill, there are a number of different patterns of changes in brain activity that are seen.

One of the most common patterns is a decrease in activity in parts of the brain that make up the control network. These are the parts of the brain responsible for working memory, attention, decision-making, and sequencing steps in a task. They’re active when we perform any task that isn’t well-learned, whether it’s a motor task, a perceptual task, or a reasoning task. When we gain experience with a task, we don’t need to devote as much concentration to it. We learn what steps follow which, and what is required to efficiently get the job done. Once we’re experienced at a task, the control network is not required to do as much work, so activity decreases in these areas of the brain.

A second pattern that is commonly seen is an increase in activity in parts of the brain specifically related to performing the task. For a motor task such as a sequence of finger taps, there is an increase in activity in the primary motor cortex of the brain (as shown by Avi Karni and colleagues in 1995). This is believed to be due to the recruitment of more neurons into the representation of the movement and supports the idea that networks of neurons in the primary motor cortex can code for sequences of movements. So when musicians are playing, there is a larger part of the primary motor cortex that is active, causing their hands to move in well-learned sequences.

A third pattern is known as functional reorganization, in which different areas of the brain are seen to be active when comparing novices vs. experts. For instance, in motor learning tasks such as learning a sequence of key-presses, when we initially are trying to learn the sequence, there is a lot of activity in the cerebellum, but once the sequence is well-learned, the cerebellum is much less active. Instead, there is an increase in activity in the striatum, a part of the brain believed to be responsible for (among other things) sequences of movements. Julien Doyon and colleagues, who reported this in 2002, conclude that the cerebellum has an important role in learning a motor task, but much less of a role in performing the task once it is well-learned.

All three patterns can be seen when learning different aspects of music, depending on what the learning task is. And sometimes all three patterns occur at the same time, so that we see a decrease in activity in control regions of the brain, an increase in regions specifically related to a task, and also some transfer of activity to regions that are not initially active. This is part of why it is so difficult to interpret data about activity in the brain. Understanding what each region of the brain does in relation to the task at hand allows us to tease apart the differences we see. And conversely, seeing how the activity changes in a particular area of the brain helps us understand how it contributes to learning and to performance of a skilled task.


Hill, N.M., and Schneider, W. (2006). Brain Changes in the Development of Expertise: Neuroanatomical and Neurophysiological Evidence about Skill-Based Adaptations. In The Cambridge Handbook of Expertise and Expert Performance, ed. Ericsson, K.A., Charness N., Feltovich, P.J., and Hoffman, R. R. (Cambridge University Press).