May 27, 2009

Gonna (Evolve To) Sing You My Love Song

ResearchBlogging.orgWhy do we like to sing soppy love songs to our loved one? What is it about them that evokes a mood of affinity and bonding? Why do tears spring to our eyes when we hear a lyric that reminds us of a friendship, relationship or other close bond?

The composition and interpretation of music through song, dance, and playing a musical instrument, are complex and high-level tasks of the creative brain. Indeed, the 'creative' aspects of personality are thought to constitute a particular division of intelligence in itself. Although it is possible to gain a certain level of proficiency in playing the works of Beethoven and Mozart through social and/or environmental factors (parental support, music school), the phenomenon of the child prodigy does in fact suggest an innate genetic basis for talent. Creativity itself is a complex process that draws largely from areas of the right hemisphere, not activating the frontal lobes or cortices very much. And since we are talking mainly of cognitive processes,we can expect hormones such as arginine vasopressin (AVP), which helps to control higher functions such as memory and learning, to take a lead role. Given that this hormone is mediated by the AVP receptor 1A (AVPR1A) gene, that affects many behavioural, social and emotional traits such as male aggression, pair bonding, altruism, parenting, sibling relationships, love etc., it stands to reason that this key gene is the one to watch.

A team of researchers at Helsinki University, headed by Liisa Ukkola, carried out a study purporting to investigate the neurobiological basis of music in human evolution by analysing the role of the AVPR1A gene and five others and their effects on general creativity and musical aptitude by testing 343 multigenerational participants from 19 Finnish families, professional and amateur musicians alike. Ages varied from 9 to 93 (mean age 43) and DNA was obtained by 298 (86.9%) of those over age 15. Three measures were administered: an extensive online questionnaire to assess creativity in those who composed, improvised or arranged music; Carl Seashore's pitch and time discrimination subtests (SP and ST respectively); and a Karma Music Test (KMT) designed by one of the research team. The results showed that high scores on the music tests associated well with high levels of creativity, and also higher in creative individuals than non-creative individuals. Genetic testing confirmed that creativity was a heritable trait.

Wait a minute - what does all this have to do with the brain?

This study showed how auditory structuring ability (gleaned from the KMT test) were associated with the AVPR1A gene, with the strongest effect found in the RS1+RS3 haplotype. The ST and SP tests also suggested this association, and this was further confirmed when the associations were replicated with combined music test score (COMB). The kicker is that the AVPR1A gene is instrumental in modulating social and cognitive behaviours, and music is certainly a medium that initiates, enhances and accelerates certain behaviours! We all know about the peculiar social customs of singing songs of romantic content in order to attract the opposite sex, music played to enhance group cohesion and initiate vigorous hip-spinning activity, and mothers singing soothing lullabies to their offspring in order to induce a state of quietness.

But aside from all of that, the genetic studies provided interesting tidbits of information relating to the homologies of the AVPR1A gene as various alleles were recognised to associate with either composing, arranging and performing music. Higher spatial scores were found among musicians than non-musicians, a possible explanation being that musicians tend to need to read and memorise notes and/or sheet music. Research into the recently discovered TPH2 gene may uncover the details behind the numerical sense necessary to perceive rhythm. The A1 allele associated with the dopamine receptor D2 (DRD2) gene is suggested to be linked to courtship.

The releases related to this story hyped up the evolutionary implications in a big way but I can find very little basis for that in this paper. As usual, evolutionary extrapolations are mainly speculative but interesting nevertheless. The text specifically mentions that evolutionary contributions are speculated on the basis of PET imaging that show partial overlapping between music and language-related areas of the brain. As improvising music usually consists of collaboration with other musicians or between a performer and their audience it makes sense that the role of these brain areas and the genes associated with musical talent be highlighted as it has. As the paper itself says:

"Creativity is a multifactorial genetic trait involving a complex network made up of a number of genes."
And it is because of that and the connections to social/cognitive areas of the brain that there is justification for the idea that music enables and enhances social communication in a way that increases attachments. This can explain why people automatically feel closer when they find they share the same types of music.

Ukkola, L., Onkamo, P., Raijas, P., Karma, K., & Järvelä, I. (2009). Musical Aptitude Is Associated with AVPR1A-Haplotypes PLoS ONE, 4 (5) DOI: 10.1371/journal.pone.0005534

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