Thursday, February 14, 2013

What do Birdsongs Have to Say About Human Brain Function?


New research by scientists at the University of California used birdsongs to develop a mathematical explanation on why some things are harder to learn than others. 

Using Bengalese finches as a model, the team headed by biologist Samuel Sober researched how the brain learns to correct vocal mistakes. Birds learn to vocalize when they are very young, listening and imitating the sounds of the adults. At first, their attempts sound garbled. With a little practice, however, the baby birds are able to listen to themselves and fix mistakes until they can sing just like the adult birds.

In order to find out more about the learning functions of human brains, scientists put this principle to the test. After outfitting the adult finches with miniature headphones and a microphone, researchers used sound-processing equipment to convince the birds that they were making vocal mistakes. They would then observe how well the birds would be able to correct their “errors”. The birds, as it turns out, learned very quickly when the errors were small. Curiously, as the scientists began to increase each shift of pitch, the birds’ learning trend declined until they ultimately stopped learning.

But what does that say about human learning? In order to explain the theory, one must examine the period when both birds and human beings learn best: their youth. After birds or humans are hatched or born, they immediately begin to learn more about the world. They are bound to make mistakes and are even hardwired to accept and learn from them. However, as individuals in each species gets older, mistakes become less frequent. 

The theory that was supported by this experiment was that adult brains tend to screen out large mistakes but pay specific attention to smaller ones. This explains both why the young are able to learn faster and why adults are more opposed to change. In the context of the bird songs, their brains relied on their senses to communicate the information. Still, brains know that senses can be tricked and don't entirely trust them. If a mistake is too big to believe, the brains will distrust the senses and ignore the error completely. 

The data in this experiment helped develop a statistical model on the learning rate of songbirds. The researchers hope that this could help aid the development of human behavioral therapies and add to society’s growing knowledge of the human brain.

Photo Credit: George Gentry/U.S. Fish and Wildlife Service

NOS Themes:
  1. Science is collaborative: This article specifically mentioned two scientists - a physiologist and a biologist - by name, and also implied the presence of other researchers.
  2. Science is based on evidence: This article explained how the experiment was conducted and gave the evidence before providing a conclusion that was derived from the original data.
  3. Science is subject to debate and tentative: The scientists involved expressed their hopes that they would be able to develop more tests so that they may refine their data and results.

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1 comment:

  1. This article was very fascinating. It is interesting to think that birds can fix their pitch that they are singing when they think that they are making a vocal mistake. It is also interesting that the birds learned quickly from their small errors but enventually stopped improving. This article really shows how little improvements can be easy to fix, but bigger mixed are less likely to be changed.

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