Everyday Life

Music and the brain: a biased symphony

Music is a fundamental part of our every-day life. We either listen to it actively while walking, studying, relaxing, attending concerts and operas, or passively, being exposed to background music in bars, restaurants, waiting rooms and many other places. There exists a large amount of literature investigating music and its effects on our emotions and perceptions. The emotional power of music was already clear to ancient populations that used it to scan and mark the most important stages of human existence, such as rites of passage and religious celebrations. The ancient Greek made music a fundamental part of their artistic expression, including it in tragedies which were almost entirely sung and accompanied by musical instruments. Many studies suggest that music is somehow a universal experience, that, despite differences related to cultural and social norms, has a similar impact on all humans. This led many scholars to question how music is processed by the brain. More rigorous analyses about the links between music and neural activity have been carried out just recently and they can shed light on many patterns observable when experiencing music. The aim of this article is to explore first the ways in which the experience of music can be altered by our sensorial and neural system and then how music can, in turn, influence our perception and behavior through alterations of the decision-making process. 

Through its prominent use in dance, opera and cinema, music is regarded as an integral aspect of multimodal artistic experiences. Yet, music by itself is typically considered as an acoustic endeavor and consequently musical analyses usually focus on sound or visual representations of sound, such as a notated score. However, there is a growing realization that the musical experience cannot be fully explained by sound alone. Extra-acoustic information plays a large role in the experience of music listening. 

It is widely recognized that vision affects a broad range of musical evaluations and this is reflected by some normative standards for concert dress and stage performance or by the fact that many orchestras and music contests employ blind auditions in which committees sit behind a screen to avoid extra-acoustic influences on their judgments. Even though some types of visual influence might be reduced or even eliminated based on the goals of the jury or audience, other influences on low-level perception of basic musical properties such as timbre, loudness, and pitch perception are obligatory and beyond conscious control. For example, judgments of the emotional quality of major musical intervals can be strongly affected by visual information. In an experiment, musical intervals were judged as “happier sounding” when paired with the lip movements and facial expression used to produce a major third (nominally “happy”), than when paired with the lip movements and facial expression used to produce a minor third (nominally “sad”). This influence occurred also when participants were asked to ignore visual information and persisted even when their visual attention was split between other concurrent tasks. However, there are many cases in which visual information improves our perception of music instead of altering it, such as when it helps enhance listeners’ comprehension of sung lyrics. 

Sensorimotor interactions play a role as well. Moving to the beat while listening to a metrically ambiguous rhythm can actually change the understanding of its metric structure. Bouncing on every second or third beat affects subsequent evaluations of the actual sound’s meter (e.g. 2/4 or 3/4), indicating that movement can shape the way in which sounds are heard and remembered. This effect appears to be independent of culture-specific training or extensive personal experience. On the other hand, it has also been proved that moving while listening can affect one’s ability to extract a pulse (i.e. find the beat) from rhythmic sequences. Movement can objectively improve rhythmic acuity. For example, listeners demonstrate greater sensitivity to rhythms when tapping along while listening, rather than when listening without moving. These links between movement and rhythm seem to be powerful, innate, and ancient. Motor areas of the brain exhibit activation when passively listening to rhythms, even when these rhythms have not been previously performed by the listener. The understanding of how sensorial extra-acoustic information affects musical experience and processing can certainly be a powerful instrument to improve performances in such a way that they have long(er)-lasting or more impactful effects on the audience. 

But how do listeners remember the emotional impact of music heard in the past? While the evaluation of momentary affect (i.e. any experience of feeling or emotion) happens with little reflection, the retrospective evaluations of past affective experiences require recall and overall assessment that involves integrating many different moments of that experience. There exist two main theories about the way people remember past affective experiences. According to the first one, which is called temporal integration, the overall evaluation of an experience is best predicted by the average of all single moments. The longer the affect is relatively strong, the larger the average becomes over time, and the longer the affect is relatively weak, the smaller the average becomes. The second, contrasting, theory, usually referred to as duration neglect,  suggests that the whole experience is represented in memory fragmentally. This means that the overall evaluation can be predicted using the average of just some particular moments, completely disregarding the duration of the exposure to a certain input. Evidence from other types of affective events, such as pleasure or pain endurance, suggests that these particular moments may coincide with the peak (most emotionally intense passage) and the end of the experience. This is commonly known as the peak-end rule. Scholars performed several regression analyses (using as regressors respectively the overall average and the average of multiple peaks and end, plus other control variables) in order to understand which model could better estimate the retrospective evaluation. However, results were ambiguous and, as of now, the most supported explanation appears to be that people compute the overall average of the affective experience and then adjust it integrating the value obtained by applying the peak-end rule. 

This is another important factor that, together with extra-acoustic influence, should be of interest to performers and composers, if they want to arrange pieces of music that leave an intense (overall) emotional impact on memory. Studies on the links between music and our sensorial and neural system have been conducted also the other way around, in order to investigate whether music itself can alter our perceptions, eventually leading to modifications in behavior. 

Very interesting research suggests that music-evoked emotions modulate  probability weighting in risky lottery choices. Probability weighting is a central aspect of cumulative prospect theory (Kahneman and Tversky, 1979) and describes the transformation of probabilities into subjective decision weights that are actually used to determine risk attitudes. The probability weighting function tries to reflect the observed psychophysical characteristic of diminishing marginal sensitivity, i.e. the fact that people show less sensitivity to changes in outcomes and probabilities, the further they are from a certain reference point (e.g. the status quo). This results in an inverse s-shaped form of the probability weighting function, reflecting the common empirical finding that small probabilities are overweighted and large probabilities are underweighted. 

In an experiment people were asked to choose between more or less risky lotteries. Before making the decision, a first group was exposed to a happy piece of music, a second group to a sad one, and, finally, a control group to no music at all. After checking that music actually altered the emotional status of the participants through a self-reported rating, the experimenters asked them to choose the lotteries they wanted to participate in. People in the happy condition chose riskier lotteries more often than people in the control group, while people in the sad condition chose them less often. This difference seems to be related to an alteration of the probability weighting process: the music-evoked happiness and sadness led people to respectively overestimate and underestimate the weight given to probabilities with respect to the reference function of the people exposed to no music. 

This means that being exposed to a certain type of music can, even unconsciously, affect our evaluation of risk, leading to different risk attitudes. It has been repeatedly demonstrated that emotions affect and sometimes impair the decision-making process. However, the combined relationship between music and emotion and between emotion and risk attitude should be taken into particular consideration if we think that we are very likely to be exposed to background music that we rarely even notice, especially when evaluating different available options. 

Another fascinating study focused on the influence of music on crowd behavior in urban open spaces. Researchers analyzed the walking, passing by, and sitting behaviors of crowds in presence or absence of background music and found very interesting result. A first observation was that different types of music or sound led to a different walking speed, showing once more the tight relationship between our perception of rhythm and motor behavior. A second observation was that when choosing their path, people exposed to no music opted for the shortest way, while, in presence of music, people changed their path to pass nearer the sound source. It is interesting to notice that in this study music was not performed live, therefore a visual explanation for this kind of behavior (e.g. people curious to see who is performing) must be excluded. In fact, the source of the sound was a loudspeaker which was hidden. Finally, the experimenters observed that the density of sitting people tends to decrease with increasing distance from the sound source, while, in absence of music, there is not significant difference in the crowd density of those with sitting behavior. There are a number of possible implications for the applied value of such study. Certain soundscapes, such as some music, may lead pedestrians to different paths in urban open spaces: it could be useful in landscape design to further investigate ways to lead walkers to suitable paths. Moreover, in leisure spaces such as parks, music can be used to decrease the speed of users and help them enjoy the landscape more carefully. Furthermore, in rest areas in squares, a public-address system can be used to broadcast music to increase non-movement behavior, which can effectively increase interactions of citizens. 

The studies here reported show that there are many ways in which music and the brain influence each other. The understanding of this relationship, in both directions, could lead to improvements not only in the music industry and artistic experience, but also in many other fields. Music, in addition to being one of the most enjoyable experiences of human life, can also be a clever instrument to alter people’s behavior without any imposition or effortful action. Evidently, as any other instrument, it may end up being used also for ethically ambiguous purposes, such as stimulating risky behaviors, and this is the reason why it is so important to know in which way music can make us biased, so as to allow for more informed decisions. 

To end on a high note (literally), I would like to share with you a curious project that a group of the most famous behavioral scientists undertook during the COVID-19 pandemic. Recognizing the powerful emotional impact of music, they decided to compile an over five-hour long playlist in which the songs are organized in the categories of the B.E.H.A.V.I.O.R. framework (a mnemonic for remembering the different behavior change strategies: Bias, Ego, Habits, Appeal, Visceral, Incentives, Others, Reminders). On top of being an amusing listen, it is a smart method to meet or delve into the fascinating world of the behavioral sciences. You can find the playlist on Spotify as the “Ultimate Behavioral Science Playlist”. 

Schulreich, S., Heussen, Y., Gerhardt, H., Mohr, P., Binkofski, F., Koelsch, S. and Heekeren, H., 2014. Music-evoked incidental happiness modulates probability weighting during risky lottery choices. Frontiers in Psychology, 4.

Schäfer, T., Zimmermann, D. and Sedlmeier, P., 2014. How we remember the emotional intensity of past musical experiences. Frontiers in Psychology, 5.

Rozin, A., Rozin, P. and Goldberg, E., 2004. The Feeling of Music Past: How Listeners Remember Musical Affect. Music Perception, 22(1), pp.15-39.

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