Friday, 27 January 2017

A Tale of Two Sight-Readers



Aria is 10 years old, and has been studying piano with me for many years. She’s small for her age, with a shy, soft voice and a wry sense of humour. At her lesson, I test her note-naming and find it, to be perfectly frank, abysmal. We continue on with the lesson, and start work on a new piece, Beethoven’s Ecossaise in G Major. I ask her to sight-read the right hand part, and she peers at the music, figuring out what the first note is. Then she plays through the first line of music fairly well, doing an excellent job considering her terrible performance at note-naming. However, in the second bar, there is an interval of a seventh. She misreads the second note of the interval, ending up playing the end of the phrase a step too low.

Despite not knowing her notes very well, Aria is a half-decent sight-reader because she mostly reads by interval, simply going up or down one note (a step) or two (a skip) as the music indicates. Larger intervals are harder to read, so she sometimes makes mistakes with these, and reading over a line break is much more difficult because it’s hard to see the vertical relationship between the notes when they are on different lines.

Leonard, 9 years old, arrives for his lesson with a cheerful smile. He has been learning The Silent Moon by Nancy Telfer, but when he plays it for me, he quickly runs into trouble, hitting a wrong note in the second phrase. He can hear it too, and restarts the phrase, this time landing on a different wrong note in the same place. I notice that Leonard is not looking at the music; he is watching his fingers. Despite the fact that the music book is open on front of him, he is playing from memory, searching for the notes by ear. I’m concerned about his ability to read the music, so I test his note-naming using stack of flashcards. Leonard names the notes quickly and easily, so I open up his sight-reading book to a simple exercise. Before he plays it, I ask him to look at the music and tell me how many times the melody moves by a skip instead of step. He puzzles through the music and incorrectly tells me there are three skips in the melody. In fact, there is only one.

These two students use entirely different strategies for reading music. Leonard does well at reading by note, while Aria’s strength is reading by interval. Strong sight-readers combine the two strategies. What you might not realize is that the two different strategies use entirely different parts of the brain.

When we read music, the visual information travels from the eyes to the visual cortex at the very back of the brain. The visual cortex receives that information and then passes it on to other regions of the visual cortex that process that information, sorting out contours of the things we see, how they’re oriented in space, if they’re moving, what colour they are, and how bright. The brain needs to do two main things with all this information: It has to answer the question “what am I seeing?” and it has to answer the question “what should I do with what I’m seeing?”

To answer these two questions, visual information is processed through two very different pathways in the brain, known as the ventral stream (vision for perception) and the dorsal stream (vision for action). 

Dorsal stream (red arrow) and ventral stream (blue arrow) of visual processing. Image courtesy of "BodyParts3D, © The Database Center for Life Science licensed under CC Attribution-Share Alike 2.1 Japan."


The ventral stream, which involves the temporal lobe of the brain, has long been known as the “what” stream, since it is the pathway we use to recognize and name the things we are seeing. It is this pathway that we use for note-naming. Imagine we see a note on the first space of the treble staff. In the ventral stream, what we see match up the image of what we see with pictures we have stored in memory, and this is how we know to name that note as a F. This is how we recognize what we see, leading to a conscious perception of what we are looking at, and a conscious understanding of what we see. In music reading, we use the ventral stream for note-naming, recognizing musical symbols and understanding their meaning, for conscious pattern recognition, and for naming chords.

It’s this ventral stream that is a weakness in Aria’s sight-reading. She has a hard time naming individual notes, so finding the correct note to play at the beginning of a line or after a large interval is difficult. Leonard, on the other hand, has a strong ventral stream, but on its own it is not enough to make him a good sight-reader. He also needs to have a strong dorsal stream.

The dorsal stream, which involves the parietal lobe, directly relates what we see to the actions that are required. The parietal lobe plays an important role in spatial perception, and so this pathway processes the spatial aspects of what we’re looking at, and matches it up with our knowledge of what to do with that object. This activates the correct movement. In music reading, we use the dorsal stream to know what movements to make to play straight-forward patterns, to know how far to reach for each interval, to make the correct hand shapes for chords. The dorsal stream automatically converts well-known visual cues into movements.

This is why Aria, who is terrible at note-naming, can sight-read music pretty well. Her dorsal stream does a good job of reading intervals and telling her what finger movements she should make. Leonard, on the other hand, tries to rely on his ventral stream for reading music. He can name the notes well, but he doesn’t easily translate the written notes into how he should move his fingers.

How do I help these two students? It’s not enough to just hand them a sight-reading book and tell them to go practice. Aria needs to practice note-naming specifically:  matching up notes on the staff with their names. In addition, she should practice playing individual notes on the piano. Flashcards are a good tool here. Leonard has different needs:  he should practice reading intervallically. An excellent resource for this is The Sight Reading Drill Book by Barbara Siemens, which systematically introduces intervals and chord patterns, and encourages the student to read by interval and by hand shape rather than by note-naming, strengthening the dorsal stream of visual processing. Siemens describes this approach by saying, “It’s a mind-finger thing. I think sometimes you have to try to bypass that naming thing and just do it intuitively. Which means you have to drill it enough.” As an experienced piano teacher, Siemens saw a need in her own students for intervallic sight-reading practice. “Because you don’t have time to think of notes as you’re going.  The name thing is just attaching a tag to something that should go intuitively.”

Every student has different strengths and weaknesses. This is true even within a single skill such as sight-reading. As a teacher, it’s important that I remember that and use different approaches to bolster students’ abilities and help them achieve their musical goals.

References

Goodale, M.A. (2011). Transforming vision into action. Vision Res. 51, 1567–1587.

Goodale, M.A. (2013). Separate visual systems for perception and action: a framework for understanding cortical visual impairment. Developmental Medicine & Child Neurology 55, 9–12.

Goodale, M.A., and Milner, A.D. (1992). Separate visual pathways for perception and action. Trends in Neurosciences 15, 20–25.

Ungerleider, L.G., and Mishkin, M. (1982). Two Cortical Visual Systems. In Analysis of Visual Behaviour, (Cambridge, Mass.: MIT Press), pp. 549–586.

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.

References

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.