Music hath charms to soothe a savage breast, to soften rocks, or bend a knotted oak. - William Congreve
Please note the correct wording of the above quotation because everybody gets it wrong. But why does music have the power that it does? Certainly music can evoke a wide range of emotions, it can be soothing, stimulating, upsetting, or reassuring depending on the kind of music played and when we hear it. It can even affect us when we least want it to, including the dreaded earworm that can linger for hours without relief.
Music is more than a collection of sounds however. Research looking at the effect that music can have on us goes well beyond the psychological or cultural effects. A new review article published in Psychomusicology provides a comprehensive look at the neurobiology of music and why it has the effect that it does. Written by Assal Habibi and Antonio Damasio of the University of Southern California, the article reviews what we know about the mammalian nervous system and how it responds to external stimuli such as music.
The purpose of the central nervous system (CNS) is to monitor the body's internal and external environments. That means sensing changes inside and outside the body that can affect our well-being. Internal changes, such as pain, thirst, or hunger, signal disturbances in the body's basic balance (also known as homeostasis) while external changes are signalled by our senses such as hearing, vision, touch, taste, and smell.
Certain stimuli can trigger highly specific reactions linked to different regions of the brain. They can also trigger the body's basic fight or flight response depending on the nature of the stimulus and whether it can be viewed as a threat. These responses are known as action programs since they involve maintaining or restraining the body's balance. They can include:
- drives, or physiological responses aimed at satisfying basic physiological needs such as hunger, thirst, sex, pleasure, and attachment
- emotions, such as fear, disgust, anger, sadness, or joy, which are triggered by external stimuli. .
Drives and emotions are involved not only in regulating how the body responds to internal and external stimuli but, more broadly, how we associate with other people. Though different brain areas can regulate different action programs, drives and emotions are still highly interrelated and play a vital role in helping living organisms to survive.
So what does this have to do with music?
Based on research into the psychological effects of music, it has been well-established that music can evoke a broad range of emotional responses and that these responses can lead to changes in physiology. Not only has music been proven to influence heart and respiration rate, galvanic skin response, and temperature, but evoked potential research has shown that listening to music can directly affect different regions of the central nervous system linked to bodily functioning. This includes the brain stem nuclei, cingular cortices, and insular cortices. As a result, music can contribute to individual well-being by triggering memories, emotions, and general feelings that help relieve emotional distress.
Listening to music even seems to cross cultural barriers with people from different parts of the world enjoying music that they find completely unfamiliar. Age doesn't appear to be a factor either since research shows that even infants as young as two months can respond to music. It is probably not surprising that music plays a role in most social occasions including weddings, funerals, coming-of-age ceremonies, graduations, etc. Virtually every nation in the world has an identifiable anthem intended to arouse patriotism and solidarity.
Music may well be linked to our own evolutionary history. Studies of animal communication show that a wide variety of birds and mammals can communicate warnings through vocalizations that vary in pitch and volume. Habibi and Damasio suggest that the rising and falling pitch in music may have begun as a way of communicating emotional messages though this original purpose has become obscured as music grew and evolved over time. Beginning with emotional messages conveyed by singing, drum beatings, and playing a flute to help social groups bond, music became part of the process of survival. But we still respond, physiologically and emotionally, to changes in musical pitch as our distant ancestors once did.
There are certainly specific regions of the brain directly linked to music perception. The primary and secondary auditory cortices and the anterior frontal regions of the brain have long been identified for their role in processing musical stimuli. There also appears to be a strong overlap between areas of the brain associated with language and with musical ability. Along with being associated with language production, Broca's area in the left frontal lobe has been found to be involved in processing musical "syntax", much as it is involved in processing the deep structure of language. Wernicke's area in the superior temporal gyrus is linked to understanding written and spoken language as well as music perception. Different types of amusia, i.e., loss of musical ability, can occur following brain damage to specific brain regions, including the frontal lobe and auditory cortex.
Along with studies of how brain damage can affect musical ability, brain imaging studies have also demonstrated that listening to pleasurable music can activate key pathways in the limbic system. This includes altering the blood flow in parts of the brain as well as the release of dopamine and increased physiological arousal associated with the "chills" that many people report when hearing certain types of music. Interestingly enough, research has also shown that the experience of "chills" when listening to music can be blocked by ingesting naloxone, a known anti-opioid medication that can counter the effects of dopamine.
And then there are the physiological effects of listening to unpleasant music.
Along with the various pleasurable feelings, music can also evoke anger, fear, sadness, or frustration depending on the various tricks used by composers over the centuries. Producing unpleasant feelings in listeners usually involves combining dissonant sounds and an irregular rhythm. The basilar membrane of the cochlea lacks the resolution for people to pick out sounds that are too close together in pitch. As a result, hearing such sounds at the same time creates an irritating sensation. Also, discordant rhythms affecting the firing pattern of auditory neurons help create negative emotions.
Specific brain regions implicated by researchers in processing discordant sounds include the parahippocampal gyrus and the amygdala. Since the amygdala is a key component of the limbic system and is also involved in emotional regulation, it can be directly linked to the positive and negative emotions linked to pleasant and unpleasant music. The ventromedial frontal cortex is another brain region associated with negative emotions in music along with the hippocampus, which also plays a significant role in learning and memory.
The impact of music on emotions, whether positive or negative, is especially strong when combined with visual stimuli to add to the overall effect. Think of the sense of dread conveyed by the music and the images of coming doom in "Jaws" to get an idea of how movie and television directors routinely use images and sound to affect audiences. The shower scene in the Alfred Hitchcock classic, "Psycho", which shows a screaming Janet Leigh about to be stabbed to death also demonstrates how discordant music can add to the buildup of horror.
While much more research needs to be done on the physiological effects of listening to music, there seems little doubt that music can trigger different emotional states, whether pleasurable or not, due to the impact it has on specific brain regions. Though how the physiological effects of music first evolved in humans is still debatable, the universal appeal of music to stir emotions seems rooted in the central nervous system.
So try to be more understanding about the music kids are listening to these days. It's all biological.