子どもの音楽知識
http://scienceblogs.com/cognitivedaily/2006/08/what_kids_know_about_music.php#more
Just by listening to music, we can learn a lot about its structures and conventions. For example, even you have no musical training, you can tell that something is wrong with this scale (it's followed by a proper C-major scale):
But we learn a lot more than just standard scales when we listen to music. When you're exposed to a particular type of music for many years, you learn much more. Consider the following sequence of chords:
Anyone who's been raised listening to Western music should recognize this sequence as an appropriate musical phrase (if you don't read music, don't worry -- I'll play it for you in a moment).
But change just one of the chords, and now something seems "off." You might not be able to identify the third chord in this sequence as a Neapolitan, but you'll know that doesn't sound right when you hear it:
Even worse is when the final chord is changed, as in this sequence:
Now listen to this clip where all three sequences in a row are played:
But surely we aren't born with such sophisticated musical knowledge. When, exactly, is it acquired? A team led by Stefan Koelsh had adults listen to dozens chord sequences like these and monitored their electric brain responses. They found a different response when Neapolitan chords were played compared to the expected, in-key chord.
In a new study, they tested 5- and 9-year-olds using the same apparatus. The children were told to press a button when the chords were played by instruments other than a piano (this occurred about 8 percent of the time). The researchers weren't interested in the other instruments; this was just to make sure the kids were listening. They analyzed the rest of the data and found the following results:
This graph shows the electrical response of a 5-year-old while the final chord was played. The dotted line is the response when the chord was in key, and the solid line is the response to a Neapolitan chord. The two arrows show where the response is different, starting at around 200 milliseconds after the onset of the chord. Both 5- and 9-year-olds show responses similar to those of adults. However, if the third chord was changed, as in the second sequence played above, the results were different:
Now there is no difference between the in-key chord and the Neapolitan. This differed from the previous results with adults, who, even with no musical training, showed a similar (though smaller) response to a Neapolitan in the third position. Even 9-year-olds show the same results as 5-year-olds. So though children as young as 5 clearly have a sophisticated cognitive mechanism for understanding music, as late as 9, they still haven't developed a complete adult understanding of music.
Koelsch et al. note that language development follows a similar pattern: up to the age of 9, children can learn languages rapidly and recover quickly from disorders such as aphasia. After 9 years, both processes become more difficult. The team argues that this is evidence for a common system for processing both language and music.
Update: Since we're seeing different accounts about whether people can hear what's "wrong" with the clip, I created a poll to find out what portion of our readers can hear the Neapolitans. The poll refers to the second clip above (the chords, not the scales).
[出典]
Koelsch, S., Grossmann, T., Gunter, T.C., Hahne, A., Schröger, & Friederici, A.D. (2003). Children processing music: Electric brain responses reveal musical competence and gender differences. Journal of Cognitive Neuroscience, 15(5), 683-693.
