Welcome to the pleasuredome: How we evolved to love music

Posted: July 16, 2013 by phaedrap1 in Uncategorized

 

Part of an ancient cave bear femur flute discovered in Slovenia in 1995

Part of an ancient cave bear femur flute discovered in Slovenia in 1995

In 2008 at Hohle Fels, a Stone Age cave in Southern Germany, archaeologists discovered what is thought to be the oldest example of a man-made musical instrument: a vulture bone flute dating back to the period when ancestors of modern humans settled in the area (~40,000 years ago). This discovery suggests that our ancestors were probably grooving to their own beat long before this time – making music, arguably, one of the most ancient human cognitive traits.

This raises an interesting question: In a time before electric duvets and home pizza delivery, how and why did our ancestors find time to indulge in such a non-essential task as the creation of music?

This was a mystery contemplated by the father of evolution Charles Darwin. In The Descent of Man he questions why a skill which appears to provide no survival advantage should have evolved at all, stating “As neither the enjoyment nor the capacity of producing musical notes are faculties of the least direct use to man in reference to his ordinary habits of life, they must be ranked among the most mysterious with which he is endowed”. However, in his autobiography he later suggests a solution to this mystery while reflecting on his own lack of musical appreciation, lamenting “If I had to live my life again, I would have made a rule to read some poetry and listen to some music at least once every week; for perhaps the parts of my brain now atrophied would thus have kept active through use. The loss of these tastes is a loss of happiness, and more probably to the moral character, by enfeebling the emotional part of our nature”. Here Darwin seems to have stumbled upon a fact with which many of us would intuitively agree, the notion that music can enrich our life by generating and enhancing emotions. But can we find a biological basis for this assumption?

Do you hear what I hear? – How our brains process and store sounds and melodies:

Scientists believe that we are unique in the way our brains process sounds. Unlike other animals, the auditory centres of our brains are strongly interlinked with regions important for storing memories; meaning, we are very good at combining sounds experienced at different times. This ability may have been crucial for the evolution of complex verbal communication. For example, consider times when the meaning of a spoken sentence does not become apparent until the last word – we’d have a pretty hard time understanding each other if by the end of a sentence we had already forgotten how it started! This is a skill even our closest relatives appear to lack, and one which is necessary for development of both language and musical appreciation.

We are also really good at forming long term memories for sounds – think about your favourite song, are you able to hear the music in your ‘mind’s ear’? Scientists have found that most people are able to imagine music with a surprising level of accuracy.

It is believed that throughout life, as we listen to our own culturally specific music styles, our brains develop a template of what music should sound like. These templates are specific to each individual, depending on what forms of music they are exposed to. From this we develop the ability to predict how certain music styles should sound and are able to tell when something doesn’t quite fit our expectations. The musical templates we develop throughout life provide us with a standard against which we judge the desirability of new melodies.

How music tickles the brain’s pleasure centres:

Life can be a bit of a maze, and there are times when we need something or someone to give us the thumbs up and let us know that we’re doing things right. Like a parent praising a child, our brains provide us with an internal ‘reward’ signal to let us know we’re on the right track. This system, in the brain’s mesolimbic area, is responsible for the hedonistic sense of pleasure produced by evolutionarily desirable behaviours, such as eating, sex or caring for offspring. Scientists are now able to see this reward system and the behaviours which activate it using positron emission tomography (PET) imaging. Interestingly, along with activation caused by behaviours with an obvious survival advantage, researchers have found that the strong emotional response people experience when listening to music (defined as the feeling of chill you get when listening to a particularly emotionally charged piece)  also activates this reward system.

bassImaging studies reveal that the rewarding aspect of music is also a very personal phenomenon, since mesolimbic activation can be initiated by different melodies in different people. This is due to the way our brains are connected. Auditory and frontal cortex regions, which store our musical preferences, are linked to mesolimbic reward pathways meaning that the sensation of music-induced pleasure is defined by your own personal musical preferences.

It is therefore possible that music could have started life as a way of strengthening social groups, through shared preferences – something which still happens today. Groups linked by a shared emotional experience could form stronger bonds which may ultimately have helped group survival. These findings indicate that our ability to enjoy music may be less mysterious than Darwin originally thought.

Post by: Sarah Fox

The brainbank.scienceblog.com

 

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