Have you ever wondered if that amazing feeling you get while listening to your favorite song is anything like what others experience when they listen to their favorite music? There is a pleasure associated with those songs that we do not get by listening to random sounds put together. Researchers found that when we are indulging ourselves with some sweet melody, the auditory cortex is not the only part of the brain activated: emotion-associated regions and reward circuits are also stimulated.
The study took place at the Montreal Neurological Institute and Hospital and the results were published last week in Science. The study unravels the mechanisms that are activated when listening to music using functional resonance imaging (fMRI).
The fMRI is used to measure brain activity by detecting change in blood flow. The participants of the study had to listen to music while scientists recorded the active areas of the brain.
The music for the study was specifically chosen: 60 previously unheard music excerpts. They were selected using a music recommendation software, similar to Pandora, to pick songs that would appeal to the listener. The participants were then given the option to purchase music with their own money: this was done so that the researchers were able to assess the reward value objectively. The prices of the songs were similar to those on iTunes.
While listening to the samples, the participants also provided a bid of how much they would be willing to spend for each item: $0, $0.99, $1.29, or $2. When recording the brain activity, many regions were active. To determine which was associated with the reward aspect, researchers focused on people who bid $2 multiple times, and were able to find that the nucleus accumbens was a key region for the rewarding aspect.
More precisely, the nucleus accumbens is associated with an expectation for how rewarding a certain activity is going to be. We anticipate the every next sound, whether the music will continue to swell, accelerate, slow down, or even drop the bass.
If activity is present in the nucleus accumbens, expectations have at least been met, and even surpassed. This was pictured in the study by the correlation between activity in the nucleus accumbens and the willingness to purchase the song.
The nucleus accumbens interacts a lot with the auditory cortex, which is responsible for processing and storing the music and sounds we have heard before. As the reward of the stimulus increased, the cross talk between those two regions increased as well. The information stored in the auditory cortex throughout our life is what will determine the expectations we have.
The nucleus accumbens also interacts with other parts of the brain that are involved in the emotional aspects of processing, decision making and reward circuitry.
Reward circuitry, using the neurotransmitter dopamine, is what makes pleasurable activities such as eating and sex desirable: behaviors that are essential for the survival of species. For music, this reward pathway uses some of the most evolved brain areas including the prefrontal cortex, that carries advanced cognitive processes and is associated with personality.
Regardless of the type of music we enjoy, from rap to classical, the same areas of the brain are activated, allowing us to feel a wide range of emotions as a result of the dopamine release.
