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The illusion of absolute categories

July 23, 2013

Here is a recent fascinating paper (original study and a nice comment). Briefly, the study shows that absolute pitch — the ability to identify a note when played on its own — is not really that absolute. In one of the experiments, subjects with absolute pitch listened to a piece of music that was slightly detuned. For listeners with absolute pitch this detuned music established a new reference point. After listening, their internal map of pitches shifted, and they identified notes in accord with the detuned reference they had just heard.

John Lienhard pointed me to his related radio episode. He points out that even people without absolute pitch will sing a familiar song in the original key. However, the experiment above points to how flexible our minds can be. Our memories, and the internal categories we establish are not absolute. They can be shifted to adjust to the environment – and this will happen without us being aware of these internal changes.

Perhaps this is even more impressive than muscle memory. We do many things mechanically and unconsciously. But our unconscious brain is not dumb robot. It is flexible, and self-correcting. We are under the illusion that our ever changing mind is stable.


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  1. I only skimmed it, but they don’t seem to address the difference between music and pitch. Music is a language this relies primarily on intervals or pitch relations. Individual pitches by themselves are probably processed in a very different context by the brain where the various properties are given much more attention (including absolute volume, overtones, etc.). The brain more naturally associates single pitches with identification of the source (is there danger?, what made that sound?, etc.). So there are probably different contextual processing mechanisms in the nervous system for sound. It’s also interesting that music is most likely remembered primarily as pitch relations as well. Musicians primarily remember the intervals between notes and not the notes themselves. I have not looked for research on this, but it seems obvious that nobody remembers the pitches and then has a neural algorithm for transposing to a different key. Certainly people often memorize a pitch for certain note such as the first note or a particular note that stands out in the song. But there they are probably switching contexts for just that note which then becomes a reference point.

    • josic permalink

      Chris – you are absolutely correct. But there is a very big difference between relative pitch and absolute pitch. There is a physical reason why the octave and the fifth are the basis for most of the music in the world, regardless of culture. However, there is no reason that we chose middle A at 440Hz and not at, say, 445Hz. This is why most people can learn relative pitch, but few have absolute pitch.

      Here is a very nice video about this – probably nothing new to you, but a good reference (

  2. Thanks for the video link. I’m an amateur musician, but I never learned about the Pythagorean ratios. I couldn’t reconcile the 1/2, 1/3, 1/4, … series with what I find on Pythagorean intervals though. Whatever the case, seems this study is another example of multifunctional behavior in the nervous system where one processing “algorithm” wins out over another. I have not read much about this but there’s a new paper that discusses functional suppression of different brain regions and how brain mapping studies have long been using a flawed technique known as “cognitive subtraction”. It has nothing to do with audio processing, but it’s a large-scale example of the inner battle of selectional attention. The paper (Kubit and Jack 2013) is here: There’s a laymen’s description here:

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