ACP - Birdsong Variation Enables Learning 12 20 07

Above: Normal adult Bengalese finch song segments recorded at three different times of day. Without experimental intervention, the finches sing highly stereotyped songs.
Below: Finch song can be pushed toward higher pitches by playing white noise, which interferes with certain pitches in the song. In the animated graph below, a single syllable of the finch song increases in pitch as the experimenters incrementally increase the pitch interfered with by the white noise. To change such a highly stable adult behaviour researchers must make only small adjustments and work within the finch’s natural range of variability.


				Birdsong Variation Enables Learning December 20, 2007 Why is it that even the best athletes and musicians do not always perform highly practiced movements as well as they could? One suggestion is that this is all part of a natural variation. But a paper in the December 20, 2007 Nature indicates that subtle variability is a means of achieving a trial-and-error improvement in performance. Evren Tumer and Michael Brainard investigated changes in the song of adult Bengalese finches (Lonchura striata). Birdsong is a complex learned skill requiring precise and rapid vocal control. The team showed that the birds were continuously monitoring the consequences of minute variations in their song and were using the information to optimize their output. The researchers suggest that these tiny variations reflect experimentation by the nervous system to optimize performance. Abstract © 2007, Nature “Performance variability enables adaptive plasticity of ‘crystallized’ adult birdsong,” Evren C. Tumer, Michael S. Brainard, December 20, 2007. Nature (Full text was available free on the Nature site as of 12 23 07) Evren Tumer, University of California, San Francisco UCSF Press Release Back to Research 2007



				Above: Normal adult Bengalese finch song segments recorded at three different times of day. Without experimental intervention, the finches sing highly stereotyped songs. Below: Finch song can be pushed toward higher pitches by playing white noise, which interferes with certain pitches in the song. In the animated graph below, a single syllable of the finch song increases in pitch as the experimenters incrementally increase the pitch interfered with by the white noise. To change such a highly stable adult behaviour researchers must make only small adjustments and work within the finch’s natural range of variability. Audio recording and movie © 2007 Evren Tumer

	A Bengalese finch (Lonchura striata) alongside spectrograms representing example songs that span the natural range of variability in pitch for one syllable of Bengalese finch song. Photo figure © 2007 Evren Tumer
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