Have you ever listened to a piece of music and felt your chest tighten, your emotions swell and “chills” rush over you in response to what you were hearing? According to research that feeling is not just one of joy and a simple appreciation for the music, but a neurological response mediated by the connections in your brain. It makes sense. Humans experience sensory reward in response to food and drug consumption, as well as participation in sexual activity, due to the triggered release of the neurotransmitter dopamine, often called the “pleasure” or “feel-good” hormone. Participation in other activities, such as playing or listening to music, can also trigger the release of dopamine, eliciting those same feelings of pleasure. However, it’s recognized that not everyone experiences pleasure the same way or to the same degree. For example, I might feel that Bohemian Rhapsody by the Queen is one of the greatest songs ever recorded, but you just don’t have the same feeling about it. Is that a difference in taste, or a difference in our brains?
In their study Sachs et al. (2016) wanted to explore the question of why there are such differences in the experience of pleasure between individuals in terms of emotional response to music. They specifically wanted to look at the neurological basis for the difference between those who experienced pleasure or “chills” and those who do not. Based on the previous literature, they theorized that it was the structural connectivity between the auditory region and the reward processing regions of the brain that predicted the degree of emotional response to music. Specifically, they hypothesized that the people who have strong emotional responses to music have a stronger white matter connection between the posterior superior temporal gyrus (pSTG), an auditory region of brain, and the emotion and reward processing regions of the brain, specifically, the anterior insula (aIns) and the medial prefrontal cortex (mPFC).
To explore this, they conducted first hand research. In order to obtain their study sample, they began with an on-line survey that looked at respondent’s demographics, personality measures, music background, preferences and responses to music. From that analysis, 20 people were selected for the study and split into two groups – the ‘chill” group and the ‘non-chill’ group, referring to whether they had reported experiencing chills in response to music. The group was matched in terms of personality traits, IQ, age of start and years of musical training in order to control the effect of those variables. Each participant was asked to identify 3 to 5 pieces of music, ones that induced chills in the chill group and ones that were pleasurable in the non-chill group. Then, while listening to 3 chosen pieces and 3 controls, participants rated their emotional responses. Their heart rates and skin conductance responses were also measured to assess psycho-physiological response to the pieces. Finally, Diffusion Tensor Imaging (DTI) scans were collected for each participant using MRI Magnetic Resonance Imaging (MRI) technology. Moving water in the brain travels more easily along the tracts of axon or nerve-containing white matter. DTI detects that diffusion of water to produce images of the white matter fiber that connects regions of the brain.
Excitingly, analysis of the data and DTI images confirmed Sachs’ et al. (2016) theory: people who experience strong emotional responses or “chills” to music do in fact have greater neural connectivity to the reward structures of the brain. The ‘chill’ group participants – based on behavioural and personality traits, ratings of pleasure, psycho-physiological responses, and brain imagery – have increased white matter volume and greater response to music than those participants in the ‘non-chill’ group. This response difference was not impacted by gender, age, IQ, ethnicity, or years of musical training. The volume of chills experienced was directly related to the volume of white matter connectivity in the tract between the auditory regions of the posterior superior temporal gyrus (pSTG) and the reward processing regions of the anterior insula (aIns) and the medial prefrontal cortex (mPFC).
The results of this study provided the first proof that there is a neural basis for individual differences in sensory access and reward response to music – proof that response to music is more than just a feeling, it’s a matter of brain connectivity.
Source:
Sachs, M. E., Ellis, R. J., Schlaug, G., & Loui, P. (2016). Brain connectivity reflects human aesthetic
responses to music. Social Cognitive and Affective Neuroscience, 11(6), 884-891.
doi:10.1093/scan/nsw009
