Tuesday, October 29, 2013

Music and the Capacity for Love

“If music be the food of love, play on.”- William Shakespeare
                Evolution is a highly efficient process. Every aspect of our physiology, and often our behaviour, has an advantage for survival. Even the appendix, thought to be a vestigial accessory of the intestine, has involvement in probiotic maintenance1. With that in mind, gaining the ability to not only hear, but to cognitively process music requires a phenomenal biological investment, as outlined in multiple chapters of Robert Jourdain’s “Music, the Brain, and Ecstasy.” Jourdain elaborates (pg 307-308) on the theory that music developed for social interaction, and in order to solidify social bonds or mediate conflict. This argument is logical; however, language developed for mostly the same reasons, and is equally, if not more efficient in allowing social interaction and settling conflict. Evolution is a never-ending balancing act between the benefit of a new capability against the energy cost of producing it, and a secondary method of social bonding, or happenstance effect from language processing, seems by far too weak a motive to maintain a cognitive system that is specific and elaborate enough to experience music. There has to be a better reason, and in this essay I will argue that music increases the human capacity to experience and express love. For these purposes, the term love will encompass affection for offspring, partners, and towards community members.  I will begin by outlining why love is a biological necessity that is important enough to drive the evolution of music appreciation, and then briefly describe from a neural plasticity standpoint, how activating the circuitry involved in music may enhance the experience of love.  
                There is no doubt that a loving environment fosters the healthy psychological development of children, but recently there has been a linked made between this benefit and BDNF (brain derived neurotrophic factor)2. BDNF is a protein that is broadly expressed in the central nervous system3, and serves to enhance the survival of neurons and promote neurogenesis4. In children that have wanted for cuddling and love, this gene will be permenantly down-regulated, and in women it will also affect the BDNF expression of their offspring2,4. Clinically, down-regulated BDNF causes susceptibility to major depression, bipolar-disorder, and schizoprenia2, while normal expression supports learning, memory, and stress managment4. Clearly, love is of vital importance in early brain development, and if music can help facilitate the expression of love in a community or towards offspring, this would offer a strong advantage. Later in life, love and the ability to express and experience deep connections with others, become crucial for success within a group, and for finding a mate to raise children with. Emotions in general influence motivation (pg 311) and decision making (pg 309), but love is unique in that the expression and experience thereof can directly impact one’s ability to mate and the viability of those offspring.  In support of the evolutionary intention of music appreciation, consider Jourdain’s description of the cognitive complexities of melodic anticipation (chapter 3), and sense of meter (chapter 5). The ability to distinguish animal calls and hear is of clear advantage (pg 2-3), but melodic and rhythmic appreciation have no evident impact on human survival; yet, these abilities have been conserved to varying degrees in almost every member of the human race (pg 286), and illicit an emotional response unlike that of any visual stimulus (pg 328). Jourdain mentions (pg 308) explicitly that music somehow, undeniably embodies emotion, and if love is so critical to our survival, a system designed to enhance our experience of it would be worth the biological investment.
                The old adage, “practice makes perfect,” comes to mind when Jourdain explains how music practice reinforces the neural pathways required for performance, while neglect degrades them (pg 225). This is an example of synaptic plasticity, which is the activity-based change in synapse-mediated connectivity between neurons5. Essentially, the more you use a synaptic pathway, the stronger it becomes. If the experiences of music or love overlap in neural circuitry, exposure to one could theoretically strengthen the response and plasticity of the other.  In support of this theory, Jourdain mentions that music pleasure is associated with endorphin release (pg 327), which is also implicated in feelings of love6; although this does not prove identical neuronal circuitry, it suggests similarity based on release of the same neurotransmitters. In addition, music, much like love (it is better to have loved and lost than to never have loved at all), has the ability to make sad experiences seem dignified or “worth it” (pg322). This emotional phenomenon is highly unique to both love and music, and may imply similar neurological pathways.
                Much like the theory of muscular representation (pg 325), the conclusion that music might increase the capacity to experience and express love is highly speculative. However, there is currently no satisfying rationale as to why human beings evolved the ability to appreciate music, and given the significance of love in our development and survival, this would be a strong evolutionary incentive. In addition, there are anecdotal and hormonal indications that the experiences of love and music share similar neurological pathways.  Oscar Wilde felt that music could propel an individual to emotional intensities beyond their life experiences; while Jourdain writes that the meaning evoked in music is only what one personally brings to it (pg 322). I argue that the truth is somewhere in between, and that if the experience of love and music are not neurologically similar, it is uncanny how comparable they are in creating a unique sense of ecstasy.
(Word count: 919, excluding references)
1.       Bollinger, R.R. et al 2007 Journal of Theoretical Biology 249(4): 826-831
2.       Roth, T.L. et al 2009 Biological Psychiatry 65(9): 760-769
3.       Conner, J.M. et al 1997 Journal of Neuroscience 17(7):2295-2313
4.       Sullivan, R. and Lasley, E.N. 2010 Cerebrum 17:1-13
5.        Ho, V.M. et al 2011 Science 334:623-628.
6.       Hawkes, C.H. 1992 Journal of Neurology, Neurosurgery, and Neuropsychiatry 55:247-250


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