Individual Differences in Music Perception and Sensitivity: A Look at Psychological and Anatomical Factors
Music is a vital component in the lives of many. Whether driving, working out, cleaning, dancing, or singing, listening to music can evoke a myriad of emotions and feelings. In recent years, music has even emerged as a therapeutic instrument and has proven powerful for stress reduction and mood improvement. However, the emotional response that may surface often varies from person to person, including both the classification of emotion released, and its intensity. These observed individual differences bring about the question as to why music taste varies and why others may feel trace amounts of sentiment while others are overcome with intense emotion. Recent studies investigating music reward sensitivity have revealed that these individual differences are not just psychological, but anatomical and physiological.
The psychological contributions to music perception have been widely studied, and researchers have found roots in concepts including the familiarity effect, the tendency to gravitate towards things that are familiar; emotional regulation, efforts to gain control over one’s own emotional state; belongingness, the feeling that one is an integral part of their surrounding systems; and regression, a defense mechanism in which people seem to return to an earlier developmental stage. While much of the psychological foundation of music perception has been uncovered, little is known about how anatomical frameworks play a role.
However, this is beginning to change. Through more recent studies, researchers have taken steps forward in unveiling how differences in biological makeups are substantial in individual music reward sensitivity. A study conducted by psychologist David Greenburg at Cambridge University found correlations between individual thinking styles and musical preferences. On the most basic level, thinking styles, or brain types, can be categorized into Empathizers (Type E), Systemizers (Type S), or Balanced (Type B), the intermediate between Types E and S. At first glance, this discovery may seem psychological, but Type E individuals have been found to have larger hypothalamic regions in the brain compared to their Type S counterparts. This is the area that houses the pituitary gland and is central to the secretion of prolactin, a hormone responsible for many homeostatic functions and is linked to calmness, relaxation, and the experience of empathy. This finding suggests that individuals with larger hypothalamic regions have a stronger affinity for empathy and will often prefer music that is more emotionally reflective. Conversely, Type S individuals have been observed to have larger areas of the brain correlated to analytical thought, including the cingulate and dorsal medial prefrontal areas. Type S individuals are consequently found to gravitate to more energetic and thrilling music.
The anatomical and physiological reasons behind the variation of music sensitivity were further investigated in a piece published in The Journal of Neuroscience. They found that differences in music reward sensitivity are influenced by the connectivity between the nucleus accumbens (NAcc), a key structure of the human reward system, and the right superior temporal gyrus (STG) regions of the brain. The intermediate between these two areas is a white matter microstructure known as the orbitofrontal cortex (OFC) which plays a key role in connectivity levels. This study found that the right axial diffusivity (AD) between the STG and the OFC was inversely correlated with music reward sensitivity. The same relationship was found in the AD between the OFC and NAcc. The higher the AD, the faster the rate at which diffusion occurs between regions, and the shorter amount of time that the signals spend in certain brain regions, reducing their effect.
Variation in BMRQ scores have also been associated with peripheral and central physiological factors. The BMRQ, or Barcelona Music Reward Questionnaire, is a survey which uses subscales of music-seeking, mood regulation, emotion evocation, sensory-motor behavior, and social reward to identify differences in music reward sensitivity. In the STG-OFC connectivity, there was found to be a relationship between white matter microstructure and BMRQ scores only in the right hemisphere, supporting the hemispheric lateralization hypothesis — the idea that the left and right sides of the brain are specialized to deal with different categories of information — and assigning a predominant role of right auditory cortices in many aspects of tonal and musical processing. Analysis of the second portion of structural connectivity, between the NAcc and OFC, identifies its importance in music listening and designation of reward values to music. A stronger connectivity between these areas indicates greater sensitivity to music, while a diminished connection may result in musical anhedonia, an inability to experience pleasure with music.
It is evident that the reasons behind individual differences in music perception is not a result of binary contributors, but rather, a myriad of psychological processes, anatomical characteristics, and physiological functions in combination. While there is still much to be studied on these systems, the research has come a long way and is likely to prove useful in further applications of music in therapeutics as well as in the advancement of research in music reward sensitivity.
References
1. Empirical Musicology Review | How, Rather than What Type of, Music Increases Empathy by Tal-Chen Rabinowitch
2. International Journal of Psychology | Emotional Valence Perception in Music and Subjective Arousal: Experimental Validation of Stimuli by Lena M. Hofbauer and Francisca S. Rodriguez
3. Information Processing & Management | An Emotion-Based Personalized Music Recommendation Framework for Emotion Improvement by Zhiyuan Liy, Wei Xu, Wenping Zhang, and Qiqi Jiang
4. The Journal of Neuroscience | White Matter Microstructure Reflects Individual Differences in Music Reward Sensitivity by Noelia Martines-Molina, Ernest Mas-Herrero, Antoni Rodrigues-Fornells, Robert J. Zatorre, and Josep Marco-Palleres
5. Ludwid Van Toronto | Why We Like Certain Music: The Brain and Musical Preference by Anya Wassenberg
6. Sage Journals | Individual Differences in Music Reward Sensitivity Influence the Perception of Emotions Represented by Music by Nieves Fuentes-Sanches, M. Carmen Pastor, Tuomas Eerola, and Paul Pastor
