Research slated for publication Friday in the journal Science identified the particular area that becomes active when people hear a song for the very first time. Measuring activity in that area _ known as the Nucleus Accumbens _ allows scientists to accurately assess the degree to which people are enjoying the sounds they're hearing.
"This is the part of the brain that's responsible for forming expectations over time," lead researcher Valorie Salimpoor said in a telephone interview. "This plays a big role in music because, as music is unfolding, we're forming a lot of expectations."
Salimpoor and her colleagues at the McGill University's Montreal Neurological Institute and Hospital conducted their research by creating a mock music store resembling iTunes.
Study participants browsed through 60 songs they had never heard before and were encouraged to use their own money to acquire the ones they wanted. Participants underwent MRI scans as they perused the music selection and specified how much they were willing to spend on each song. Music was available for free, 99 cents, $1.29 or $2.
Salimpoor said the amount of neural activity originating in the nucleus accumbens was a very accurate predictor of how much the subjects were enjoying each individual song and what price they were willing to pay to obtain it.
The pleasure people took from the new material was different from the anticipation of hearing a familiar song, she said, adding reactions to much-loved sounds originate in a related but different part of the brain.
Salimpoor said the study also reinforced exactly how subjective the enjoyment of music truly is.
Researchers noted a direct interplay between the nucleus accumbens and the superior temporal cortex, the part of the brain that's been shaped by all the sounds people have been exposed to throughout their lives, she said.
People develop different notions of how music ought to sound based on the music they've listened to over time, she said, adding everyone's superior temporal cortex evolves differently based on their exposure to different styles.
"The fact that the nucleus accumbens is working so coherently with this area suggests that the predictions we're making while we're listening to new music are really stemming from the sounds we have heard in the past and these rules that we've internalized based on our culture, based on the music we listen to and the genres we prefer," Salimpoor said.
Salimpoor said the research was a further extension of a previous study that suggested the enjoyment of music had connections to some of the basic building blocks of human genetics.
That research found that humans release dopamine in the brain when listening to music and experiencing powerful emotions, a process that strongly resembles what takes place during eating or sex. Such brain activity puts music nearly on par with activity that's biologically necessary for human survival, she said.