March 7, 2013
Solving The ‘Cocktail Party Problem': How We Can Focus On 1 Speaker In Noisy Crowds
In the din of a crowded room, paying attention to just one speaker's voice can be challenging. Research in the March 6 issue of the Cell Press journal Neuron demonstrates how the brain hones in on one speaker to solve this "Cocktail Party Problem." Researchers discovered that brain waves are shaped so that the brain can selectively track the sound patterns from the speaker of interest and at the same time exclude competing sounds from other speakers. The findings could have important implications for helping individuals with a range of deficits such as those associated with attention deficit hyperactivity disorder, autism, and aging.
"In hearing, there is no way to 'close your ear,' so all the sounds in the environment are represented in the brain, at least at the sensory level," explains senior author Dr. Charles Schroeder, of Columbia University's Department of Psychiatry. "While confirming this, we also provide the first clear evidence that there may be brain locations in which there is exclusive representation of an attended speech segment, with ignored conversations apparently filtered out." In this way, when concentrating hard on such an "attended" speaker, one is barely, if at all, aware of ignored speakers.
"Most studies use very simplified, unnatural stimuli to study the Cocktail Party Problem–like brief beeps, or even brief phrases–whereas we were able show that with appropriate techniques, we could study this problem using natural speech," says Dr. Schroeder. "This will stimulate future research to continue the study of this and related issues under rich, natural conditions. Just as importantly, the ability to directly analyze widespread brain activity patterns in surgical epilepsy patients provides an unprecedented opportunity to firmly connect the work on the Brain Activity Map at the model systems level in mice, songbirds, and nonhuman primates to the study of capacities like language and music, that may be uniquely human."
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