Music and Emotions: the Intricate Bond between

Many parts of the brain work together to process each emotion an individual experiences, such as stress and anxiety. By studying how these brain regions are affected by music, researchers have discovered how parts like the amygdala and the hippocampus interact with stimuli and individuals’ emotions.

The Role of Amygdala and Hippocampus in Emotion Processing

According to Kolb, Whishaw, & Teskey (2016), the amygdala is a part of the limbic system of the brain that “influences our conscious awareness of the positive and negative consequences of events and objects through its connections to the prefrontal cortex.

” (p. 423). The amygdala also plays a large role in reacting to emotional situations as it works to encode and consolidate the event to store in an individual’s memory (Buchanan, 2007). Another region involved in this is the hippocampus, which is responsible for “species-specific behaviors, memory, and spatial navigation and is vulnerable to the effects of stress.” (p. 416). According to Koelsch, Fritz, Cramon, Müller, and Friederici (2005), it is hypothesized that the Rolandic opercular areas “reflect the activation of mirror-function mechanisms during the perception of the pleasant tunes,” and, therefore, individuals may experience more positive emotions when listening to pleasant music and the urge to sing along (p. 239). Although all of these brain regions’ sole purpose is not emotion processing, they each contribute pieces and work together to make up this vital process in the human body. Because of this, many factors can influence this and alter how an individual feels, so one alternative treatment being researched is the use of music as therapy. By studying how music interacts with these brain regions, such as the amygdala, hippocampus, Rolandic operculum, and prefrontal cortex in both mice and humans, researchers believe that music can be an effective treatment to increase neurological activity and help to control feelings of stress and anxiety.

Music as a Treatment: Experiments in Animal Models

Through studying animal models, researchers have been able to conduct experiments to find how music affects behaviors related to anxiety and the neurological activity that accompanies them. In a study by Li et al., researchers found that brain-derived neurotrophic factor (BDNF) plays an important role in reducing anxiety through music treatment (2010). Mice with two BDNF alleles, known as BDNFMet/Met mice, showed an increase in BDNF mRNA and protein levels in the hippocampus and amygdala. Messenger RNA, or mRNA, is responsible for the transportation of protein code out of the nucleus. The other mice used in the study, BDNF+/- mice, only had one BDNF allele and were found to be significantly less affected by the music treatment when studying brain regions related to anxiety, such as the hippocampus and amygdala (Li et al., 2010). Another study by Yang, Lin, and Hensch (2012) found that WT mice also reacted similarly, as music treatment increased their BDNF levels in the hippocampus and amygdala. Researchers additionally investigated if there was a critical period in the mice’s development that music therapy had a greater effect on and found that mice exposed to music prenatally or at birth had higher BDNF levels than the mice only exposed to music during adulthood. Because of this outcome with the mice, researchers believe music treatment may be more effective for reducing anxiety in humans while an individual is young and developing rather than during adulthood (Yang et al., 2012). This further proved to the researchers how greatly BDNF contributes to regulating emotions like anxiety and how music can directly affect these levels in the brain and, therefore, an individual’s emotions and feelings of anxiety. Researchers believe that music may be an effective treatment for reducing anxiety in humans as music had a significant anxiolytic effect on these mice, and “BDNF is one of the key regulators in the development and function of the mammalian nervous system.” (as cited in Li et al., 2010, p. 75). Because the nervous system is responsible for transmitting signals from the environment to the brain through the body’s neurons, it also plays an important role in regulating emotions such as anxiety and fear between what an individual is experiencing and how they feel and react physically and mentally.

Observations in Human Studies

Not only have these decreases in anxiety been observed in mice, but it has also been supported by many studies of humans. In a study by Koelsch et al., researchers analyzed fMRI scans of participants listening to unpleasant music and found that there were significant activations in the left hippocampus, left parahippocampal gyrus, the right temporal poles. The hippocampus works with the amygdala in processing emotions as it is activated by audiogenic stressors and facilitates defensive behaviors and anxiety, which support the findings of activation during unpleasant music. (Koelsch et al.)In another study by Blood & Zatorre (2001), participants experienced chills when listening to their favorite piece of music, and PET measurements showed a decrease in regional cerebral blood flow (rCBF) or a decrease in the amount of blood flow to a certain area, in the left hippocampus. These findings support their hypothesis that the hippocampus plays a role in the brain’s reward and emotion processing centers, as the rCBF decreased when participants experienced chills (Blood & Zatorre, 2001). Regardless of whether the music was pleasant or unpleasant, researchers found that the hippocampus was activated and is important in regulating emotions and processing the music the individual is listening to.

The Function of Dopamine in Music Perception

In addition to the hippocampus participating in the brain’s reward center, dopamine also plays a role as it is released when an individual uses predictive coding to analyze music, which contributes to their pleasurable emotions. Predictive coding is the “conceptual framework of how the brain forecasts,” and because music is predictable, neuroscientist Peter Vuust explains that “‘is what makes it so interesting to science’ … because it helps to investigate the brain’s predictive timing mechanisms” (Weigmann, 2017). As the brain correctly predicts the patterns in the music, dopamine is released to reward the brain for the correct prediction. This is similar to the effect of methylphenidate, as this psychostimulant “primarily inhibits the reuptake of dopamine by pre-synaptic neurons, thus leaving more dopamine in the synapse and available for interacting with the receptors of the postsynaptic neuron.” (Smith & Farah, 2011, p. 3). Therefore, if music can have the same effect as a psychostimulant on dopamine and the brain’s reward system, it is a much better alternative treatment for increasing dopamine where psychostimulants may be otherwise used.

Amygdala's Role in Emotion Processing

Additionally, Koelsch et al. found that the left amygdala was activated in the second block, or the second half, of the unpleasant piece of music. The amygdala is responsible for processing emotions, including fear, so the activation of the amygdala during unpleasant stimuli is in line with what was predicted, as the unpleasant stimuli are associated with negative emotional valence. They also observed significant activation in regions during the pleasant music, including in Heschl’s gyrus, the left inferior frontal gyrus, and the amygdala. In the other study by Blood & Zatorre (2001), researchers found a decrease in rCBF in the right and amygdala, showing that the amygdala is also extremely involved in the participants’ brain reactions and emotions while listening to pleasant music. Bratticom, Bogert, and Jacobsen (2013) describe that the amygdala is one of the first brain regions to react when the body receives a stimulus, as it is responsible for early emotional actions after the initial analysis and integration by the brainstem and sensory cortices and before cognitive processing by the prefrontal cortex and non-primary sensory cortices. Because the amygdala is extremely important for reacting to pleasant and unpleasant stimuli, Koelsch et al. conclude that “the amygdala plays a role in the processing of complex, meaningful auditory information with both negative and positive emotional valence.” (Koelsch et al.). These findings supported their hypothesis that the amygdala plays a role in the brain’s reward and emotion processing centers, as the rCBF decreased when they experienced chills. Another study cited in Blood and Zatorre (2001) found similar outcomes, as their participants had decreased rCBF to the amygdala when experiencing euphoria from cocaine. However, other studies, such as the ones by Breiter et al. (1997), observed that rCBF decreases in the amygdala were related to feelings of “craving” rather than a “rush” related to pleasure from cocaine. Because they have observed several different associations between pleasure and decreased rCBF in the amygdala, researchers conclude that the amygdala is a very complex part of the brain that plays a role in processing many different feelings and experiences, such as extreme pleasure through experiencing chills, euphoria, and even a craving for cocaine (Blood & Zatorre, 2001).

Role of Rolandic Operculum in Emotion Processing

The Rolandic operculum, which plays a role in “the activation of mirror-function mechanisms,” has also been observed to contribute to emotion processing when listening to music. ROLANDIC: The second block of the music also showed increased activation in the Rolandic operculum and the inferior portion of the right frontal operculum. Another region of the brain that showed significant activation was the Rolandic operculum, which has been found in other studies to be responsible for overt and covert singing. Therefore, researchers believe that this area was activated during the pleasant stimuli because the participants “coded vocal sound production (without actual movement)” (Koelsch et al., 2005, p. 247).

Prefrontal Cortex: An Interface for Memory and Emotion

The prefrontal cortex is extremely important to executive functioning and “takes part in selecting behaviors appropriate to the particular time and place.” (Kolb, Whishaw, Teskey, 2013, p. 419). Therefore, it extensively interacts with previously mentioned brain regions in taking external stimuli, processing them, and executing an individual’s feelings and behaviors. The study by Li et al. (2010) found that the BDNFMet/Met mice also showed an increase in BDNF mRNA and protein levels in the prefrontal cortex, and the BDNF+/- mice were significantly less affected in the prefrontal cortex when listening to music. When participants experienced chills, PET measurements also showed a decrease in regional cerebral blood flow (rCBF) in the ventral medial prefrontal cortex (Blood & Zatorre, 2001). Another study by Brattico et al. (2013) found that changing the melodies “from one tonality to another” activated the prefrontal cortex. Researchers believed that this was because the PFC connected autobiographical memories with the music they were listening to, as the PFC plays a role in both memory and processing stimuli and causes the listener to feel nostalgic (Brattico et al., 2013). Overall, these studies show how both mice and humans are affected by music in their PFC and how their memory and stimulus processing affect their resulting behaviors and emotions, including reducing anxiety, experiencing extreme pleasure, and feeling nostalgic while interacting with other brain regions simultaneously.

Conclusion: The Potential of Music as an Alternative Treatment

These brain regions, are involved in stimulus input and behavioral and emotional reactions, which music can have a great effect on. Because of the anxiolytic effect, it can have on individuals and animals, music has immense promise for alternative medical treatment, especially with the variety of research studies that have been conducted in different settings. Yang, Lin, and Hench (2012) report that music therapy has been effective not only for cases of generalized anxiety disorder and processing other emotions but also in clinical settings with “perioperative patients, patients with dementia, and mechanically ventilated patients.” (p. 17218).

References

1. Buchanan T. W. (2007). Retrieval of emotional memories. Psychological Bulletin, 133(5), 761-79.
2. Blood, A. J., & Zatorre, R. J. (2001). Intensely pleasurable responses to music correlate with Activity in brain regions implicated in reward and emotion. Proceedings of the National Academy of Sciences, 98(20), 11818-11823.
3. Brattico, E., Bogert, B., & Jacobsen, T. (2013). Toward a neural chronometry for the aesthetic Experience with music. Frontiers in Psychology, 4, 1-21.
4. Breiter, H. C., Gollub, R. L., Weisskoff, R. M., Kennedy, D. N., Makris, N., Berke, J. D., 
5. Hyman, S. E. (1997). Acute effects of cocaine on human brain activity and emotion. Neuron, 19(3), 591-611.
6. Koelsch, S., Fritz, T., Cramon, D. Y., Müller, K., & Friederici, A. D. (2006). Investigating Emotion with music: An fMRI study. Human Brain Mapping, 27(3), 239-250.
7. Kolb, B., Whishaw, I. Q., & Teskey, G. C. (2016). An Introduction to Brain and Behavior (5th Ed.). New York, NY: Worth.
8. Li, W., Yu, H., Yang, J., Gao, J., Jiang, H., Feng, M., Chen, Z. (2010). Anxiolytic effect of Music exposure on BDNFMet/Met transgenic mice. Brain Research, 1347, 71-79.
9. Smith, M. E., & Farah, M. J. (2011). Are prescription stimulants “smart pills”? The Epidemiology and cognitive neuroscience of prescription stimulant use by normal healthy individuals.
10. Psychological Bulletin, 137(5), 717-741. 
11. Weigmann, K. (2017). Feel the beat. EMBO Reports, 18(3), 359-362.
12. Yang, E., Lin, E. W., & Hensch, T. K. (2012). The critical period for acoustic preference in mice.
13. Proceedings of the National Academy of Sciences, 109(Supplement 2), 17213-17220.

Did you like this example?

297

16