Scientists at MIT have developed a novel way to selectively cool parts of the brain, slowing them down and shedding light on the function of that particular spot. In a study of songbirds, which are often used as an experimental model of human speech, cooling part of the brain known as the HVC slowed the birds' songs. Play the videos below to hear a sample song with and without cooling.

According to a press release from MIT,

The song slowed in proportion to the degree of cooling, with the biggest temperature change (a 10 degrees Celsius reduction) causing the song to stretch out by around 30 percent.

Not only did the overall duration of the song increase, so did each individual syllable, so the overall rhythmic structure was preserved without changing the sounds within the song. The effect can be compared to a music box or piano roll. Rotating the drum more slowly slows the tempo of the music without affecting individual notes.

Following this analogy, HVC corresponds to the mechanism that turns the drum; cooling it is equivalent to reducing the speed of rotation.

Michale Fee and his colleagues created the cooling device using technology similar to that used in portable electronic beverage coolers. They say that it could be used to study other complex behaviors, such as walking or swimming.

"We can also use this cooling technology to discover which brain regions control the timing of different complex behaviors in different animals, something that has been very difficult to assess until now," Fee said in the release. "We know that HVC is related in some ways to [the] human cortex, so it could be showing us a very general mechanism for representing the passage of time within the brain."

The research was published today in the journal Nature.