De do do do, de da da da?*

For a long time I thought of it as quite a peculiar phenomenon: grown-ups who, the moment they spot a baby, start talking in a curious dialect. A dialect that has unclear semantics, little or no grammar, and is full of exaggerated rhythmic and melodic diversions.

Nevertheless, babies seem to love it. They react —cooing with pleasure—to melodies that are not unlike pop songs as ‘De do do do, de da da da’ of The Police or ‘La la la’ by Kylie Minoque.

This babbling or, more formally, infant-direct speech (IDS) differs from normal adult speech by its high pitch, exaggerated melodic contours, slower tempo, and more rhythmic variation. A kind of ‘musilanguage’ indeed. It is a widespread phenomenon that is —as far as we know— present in all cultures and has more similarities than differences -- even when some characteristics of IDS conflict with the rules of the adult language (e.g. Chinese). So it seems quite unlikely that IDS is ‘just’ a preparation for language, until recently the most common interpretation.

Laurel Trainor, and her team at McMaster University (Ontario, Canada), suggests that IDS is essentially a tool to communicate emotion. The decoding of the speech patterns into their emotional meaning is something infants can do easily, and long before they learn about language. In that sense, it seems likely that language makes use of faculties special to music instead of it being a side effect of language (as as suggested once by a well-known cognitive psychologist).

Henkjan Honing (2008). De vergeten luisteraar [The Forgotten Listener] Boekman (77), 42-47

* Repeated from June 6th, 2008.

Do you have perfect pitch?

Glenn Schellenberg of the University of Toronto just started an online internet experiment on Absolute Pitch (AP). If you have, or suspect you have, absolute pitch do the online test here. It takes about 15 minutes and you get your score in the end.

Art meets science?

Below a video impression of an evening that was organized this week by the Studium Generale of the University of Groningen. The idea of the lecture/concert was to explore tempo and timing, swing and groove from the perspective of both the performer and the listener (an idea that turned out not always to be a success ;-) See for a longer fragment here.

How well would you do as an expert?

In the Netherlands (and I’m sure there are versions of it in the UK and the US as well) there is a weekly radio show containing a returning item in which music experts are asked to compare and judge two or three CD recordings of the same piece, without knowing who the musicians are. They have to guess the performers and describe why they do (or don’t) like that particular performance.

How well would you do in such a test? The common hypothesis is that experts do this much better, e.g. under the assumption that they are more sensitive in their listening skills. But do experts indeed hear more detali and more nuances when compared to a 'common listener'? Or do they just have more terminology available to verbalize these differences?

Two years ago our group did a large-scale online listening experiment with a similar task. Participants were asked to compare several pairs of recordings of well-known musicians. One of the recordings was taken directly from a CD, but the other was originally performed at another tempo (faster or slower) and then scaled to be similar in tempo to the former recording. The task was to judge which recording was real and which one was manipulated, by focusing on the timing used by the performer.

To give you an idea of the difficulty of the task, below an example.

A
B
(See answer at the bottom.)

The results were recently published in the Journal of Experimental Psychology, with a surprising outcome: the judgments seem to be largely influenced by exposure to music (listening a lot to one’s favorite music) and not (at all) by the level of expertise (amount of formal musical training). One seems to learn a lot by simply listening.

Honing, H., & Ladinig, O. (2009). Exposure influences expressive timing judgments in music. Journal of Experimental Psychology: Human Perception and Performance, 35 (1), 281-288 DOI: 10.1037/a0012732

* The first recording is the original. It is Glenn Gould performing English Suite No. 4 by J.S. Bach. The second recording is Sviatoslav Richter performing the same piece. However, this recording was sped up from 70 to 87 bpm making his use of tempo rubato 'unnatural'.

What makes a theory compelling?*

Karl Popper was a philosopher of science that was very much interested in this question. He tried to distinguish 'science' from 'pseudoscience', but got more and more dissatisfied with the idea that the empirical method (supporting a theory with observations and experiments) could effectively mark this distinction. He sometimes used the example of astrology “with its stupendous mass of empirical evidence based on observation”, but also nuanced it by stating that “science often errs, and that pseudoscience may happen to stumble on the truth.”

Next to his well-known work on falsification, Popper started to develop alternatives to determine the scientific status or quality of a theory. He wrote the complex yet intriguing sentence “confirmations [of a theory] should count only if they are the result of risky predictions; that is to say, if, unenlightened by the theory in question, we should have expected an event which was incompatible with the theory — an event which would have refuted the theory.” (Popper, 1963).

Popper was especially thrilled with the result of Eddington’s eclipse observations, which in 1919 brought the first important confirmation of Einstein's theory of gravitation. It was the surprising consequence of this theory that light should bend in the presence of large, heavy objects (Einstein was apparently willing to drop his theory if this would not be the case). Independent of whether such a prediction turns out to be true or not, Popper considered it an important quality of ‘real science’ to make such ‘risky predictions’. Interesting thought, not?

I still find this an intriguing idea. The notion of ‘risky’ or ‘surprising predictions’ might actually be the beginning of a fruitful alternative to existing model selection techniques, such as goodness-of-fit (which theory predicts the data best) and simplicity (which theory gives the simplest explanation). Also in music cognition measures like goodness-of-fit (r-squared, percentage variance accounted for, and other measures from the experimental psychology toolkit) are often used to confirm a theory. Nevertheless, it is non-trivial to think of theories that make surprising predictions. That is, a theory that predicts a yet unknown phenomenon as a consequence of the intrinsic structure of the theory itself. If you know of any, let me know!

K. R. Popper (1963). Conjectures and Refutations. London: Routledge.

* Repeated blog entry from July 23, 2007 (celebrating finalizing a research proposal with Jan-Willem Romeijn on these issues, hoping to be able to address these issues head-on ;-)

Do newborn infants have a sense of rhythm?

[Report related to PNAS Early Edition]

It might look somewhat disturbing, but the picture that accompanies this entry is a snapshot of a two day old baby that is healthy and sound asleep! She is one of fourteen newborns that participated in a recent listening experiment, a collaboration between the Institute for Psychology of the Hungarian Academy of Sciences and our research group at the University of Amsterdam in the Netherlands. In this project we are interested in how newborn infants perceive the musical world around them and in how far certain musical skills are innate.

We know that newborn infants are sensitive to a variety of sounds. But what do they factually hear? Can they make sense of the musical world around them? Do they have a sense of rhythm, arguably one of the fundaments of music?

To study this, we collaborated with a research group in Budapest, Hungary lead by István Winkler, a specialist in auditory perception and one of the pioneers in measuring brain activity in neonates.

Since the start of this European research project (named EmCAP) we talked a lot about how we could take advantage of existing theories in music cognition to study auditory perception in newborn infants, and how to probe their (potential) sense of rhythm. After many pilot studies, and resolving quite a few methodological issues that come with doing experiments with neonates, in the end we opted to use a simple, regular rock rhythm, consisting of hi-hat, snare, and bass drum (see below). We made several variants of this rock rhythm by omitting strokes on non-significant metrical positions (i.e. non-syncopated rhythms in music theoretical terms). We then inserted, once in a while, a 'deviant' segment: the same rhythm but with a missing ‘downbeat’ (i.e. a syncopated rhythm). The result sounded like this [click on the play button; to stop, click again]:

Since it is quite difficult to observe behavioral reactions in newborns a small number of electrodes were carefully glued to the scalp and face of the newborns to be able to measure their electrical brain signals (see photo). N.B. The baby’s were fed just before the measurements with their mother being present during the whole session that lasted twenty minutes.

What did the experiment reveal? Well, shortly after each ‘deviant’ segment began, the babies' brains produced an electrical response indicating that they had expected to hear the downbeat but had not. As such we could show that newborn infants can detect the beat in music (The results will be published this week in PNAS Early Edition).

What are the potential implications of these findings? For me, one of the most important realizations is that a cognitive skill called beat induction, which most of us think of as trivial (e.g., being able to tap your foot to the beat), is active so early in life. It can be seen as additional support for the idea that, beat perception contributed to the origins of music since it enabling such actions as clapping, making music together and dancing to a rhythm. Next to being music-specific, beat induction is also considered to be uniquely human. Even our closest evolutionary relatives, such as the chimpanzee and bonobo, do not synchronize their behavior to rhythmic sounds. This makes the topic of beat induction a fundamental issue in current music cognition research (see, e.g., Patel, 2008:402).

Furthermore, the results challenge some earlier assumptions that beat induction is learned in the first few months of life, for example by parents rocking the infant. Our study suggests that beat perception must be either innate or learned in the womb (as the auditory system is at least partly functional as of approximately three month before birth).

Finally, it should be noted that the auditory capabilities underlying beat induction are also necessary for bootstrapping communication by sounds, allowing infants to adapt to the rhythm of the caretaker’s speech and to find out when to respond to it or to interject their own vocalization. Therefore, although these results are compatible with the notion of the genetic origin of music in humans, they do not provide the final answer in this longstanding debate.

István Winkler, Gábor P. Háden, Olivia Ladinig, István Sziller, Henkjan Honing (2009). Newborn infants detect the beat in music. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.0809035106

Hoe was het Spinozadebat? [Dutch]

This is a short entry with a video impression of the Spinoza te Paard lecture series on recent developments in science, aimed at a general audience. The full broadcast can be viewed at spinozadebat gemist.

A 2006 recording of Glenn Gould?*

A well-known recording company recently released a new recording of Glenn Gould performing the Goldberg Variations. The recording date was summer 2006. Curious, not? Another pianist with the same name as the legendary Canadian musician?

Actually, the recording was made using measurements of the original, old recordings that were used to remake the performance on a computer-controlled grand piano, a modern pianola. In the recording studio a grand piano was moving its keys without someone behind the piano. Glenn Goulds original performance was re-performed on a modern instrument in a modern studio.

The technology that was used dates from the early nineties, a time when several piano companies (including Yamaha and Bosendorfer) combined MIDI (an industry standard for communicating between computers and electronic keyboard instruments) and modern solenoid technology with the older idea of a pianola. Old paper piano rolls with recordings of Rachmaninoff, Ravel, Stravinsky and others were translated to MIDI and could be reproduced 'live' on modern instruments like the Yamaha Disklavier. Until now, the only left challenge was to be able to do this for recordings of which no piano-rolls exist.

Besides the technicalties of all this, for most people the real surprise -- or perhaps disillusion -- might well be the realization that a piano performance can actually be reduced to the 'when', 'what' and 'how fast' the piano keys are pressed. Three numbers per note can fully capture a piano performance, and together with the pedaling information it allows for replicating any performance on a grand piano(-la). The moment a pianist hits the key with a certain velocity, the hammer releases, and any gesture that is made after that can be considered merely dramatic: it will have no effect on the sound. This realization puts all theories about the magic of piano touché in a different perspective.

Nevertheless, while it is relatively easy to make the translation from audio (say a recording from Glenn Gould from 1955) to the 'what' (which notes), and the 'when' (timing) in a MIDI-like representation, the problem is in the 'reverse engineering' of key velocity. What was the speed of Gould's finger presses on the specific piano he used? The Zenph Studios claim to have solved it for at least a few recordings. Only trust your ears.



* Repeated blog entry from August 18, 2007.

Werner Goebl, Caroline Palmer (2008). Tactile feedback and timing accuracy in piano performance Experimental Brain Research, 186 (3), 471-479 DOI: 10.1007/s00221-007-1252-1

Does rhythm make our bodies move?*

Louis Johnson and Cassandra Phifer-Moore rehearsing “Forces of Rhythm” at Dance Theater of Harlem. Credit Marbeth.

Why do some people dance more rhythmically to music than others? Are these differences genetically or culturally determined? These are some typical questions journalists who are interested in rhythm research like to ask.

The link between musical rhythm and movement has been a fascination for a small yet passionate group of researchers. Early examples, from the 1920s, are the works by Alexander Truslit and Gustav Becking. More recently researchers like Neil Todd (University of Manchester, England) [1] defend a view that makes a direct link between musical rhythm and movement. Direct in the sense that it is argued that rhythm perception can be explained in terms of our physiology and body metrics (from the functioning of our vestibular system to leg length and body size).

While this might be a natural line of thought for most people, the consequences of such theories are peculiar. They predict, for instance, that body length will have an effect on our rhythm perception, longer people preferring slower musical tempi (or rates), shorter people preferring faster ones. Hence, females (since they are on average shorter than men) should have a preference for faster tempi as compared to males.

To me that is too direct and naïve a relation. There are quite a few studies that looked for these direct physiological relations (like heart rate, spontaneous tapping rate, walking speed, etc.) and how these might influence or even determine rhythm perception. However, none of these succeeded in finding a convincing correlation, let alone a causal relation. In addition, they ignore the influence that culture and cognition apparently have on rhythm perception. Nevertheless it should be added that embodied explanations do form a healthy alternative to the often too restricted ‘mentalist’ or cognitive approach.

An intriguing study in that respect was done by Jessica Phillips-Silver and Laurel Trainor (McMaster University, Canada) [2] a few years ago. They did an inventive experiment with seven month old babies, and showed that body movement (i.e. not body size) can influence rhythm perception. They had a group of mothers bounce their infants on a rhythm that could be interpreted as either being in duple or in triple meter. They could show (using a head-turn preference procedure, measuring the time an infant pays attention to a stimulus) that bouncing in three or in four influenced the perception of the infant. While one could be critical on some important details, this is a striking empirical finding, and a small step forward in trying to underpin the relation between rhythm cognition and human movement.

J. Phillips-Silver (2005). Feeling the Beat: Movement Influences Infant Rhythm Perception Science, 308 (5727), 1430-1430 DOI: 10.1126/science.1110922

* Repeated blog entry from July 17, 2007.

Waarom kan muziek zulke sterke herinneringen oproepen? [Dutch]

'Muziek raakt onze allerdiepste emoties en blijkt een spoor te trekken in de hersenen. Muziek is ook een drager van herinneringen. Hoe werkt dat? En waarom houdt de één van Bach en de ander van The Beatles?'

De Ncrv-tv zendt vandaag een aflevering uit over muziek, emotie en herinneringen. Zie de trailer. Voor de volledige aflevering, zie uitzending gemist. Zie tevens gerelateerd artikel in de Volkskrant bijlage van 13.12.2008 (met levendige reacties).