Science: The Musical Brain

We all have music on the brain, literally...

Although we may only rarely consider it, music is a part of human behaviour and is as universal as it is inexplicable. Music making has been recorded throughout history and across virtually every different culture. But why? And if music is so much a part of being human, what purpose does it fulfil?

As a typically obsessive professional musician (I began the violin at eight and formed and led an international classical ensemble, The Medici String Quartet, for nearly 40 years), I have had every reason to ponder these questions across my life. About 35 years ago, when I was in my early 20s, I became convinced that the then burgeoning brain sciences could and would provide many answers to these ageless questions. When we began, consultant neuro-psychiatrist Professor Peter Fenwick and I found that, at that time, there was hardly any relevant research. Less than a handful of experiments had been undertaken during brain surgery using implanted electrodes (with the patient conscious), and most other theories had been based on the often-tragic deficits associated with brain lesions and wounds.

About 14 years ago when I came to make a television series about this subject, things were changing and, whilst the overwhelming thrust of research was on speech, vision and movement, a number of scientists were occasionally considering musical function in their work. At least one, Professor Robert Zatorre at McGill University in Montreal, was already focusing almost entirely upon the musical brain. Since then, a whole plethora of wonderful non-intrusive brain mapping technologies have moved the topic richly forward, and now around 200 researchers worldwide are making significant contributions to the area with centres in Leipzig, Germany, at the Max Plank Institute, and at Goldsmith’s College, London, amongst others.

Whilst my insistent enquiries into this arena made me an uncomfortable companion amongst some fellow musicians (most of whom tend to have a profound reticence about discovering a rational source for their own inspiration), I found that I couldn’t stop asking those apparently simple but awkward questions which, when pursued into adulthood, make someone a tiresome eccentric or inspirational irritant – or both!

HEARING AND LISTENING

The physical properties of sound as a molecular energy and the beautiful mechanism of the ear to respond to and calibrate this auditory information (the cochlea, ossides, basilar membrane, etc.) have long been appreciated. But modern research is now uncovering the sophisticated brain structures and processing that enables this energy to be converted into electrochemical signals from the brain. Unlike our eyes, we cannot shut our ears. As a result, we remain continually responsive (but mostly unconsciously so) to all the sounds which fill our personal space – including the rich and often rhythmic sonorous orchestra that fills our internal bodies such as blood flow, pulse and breathing. But thanks to the brain, we are able to only ‘hear’ those sounds that we need to hear.

This omnipresent biological and environmental sound world, together with the brain systems required to render the sensory bombardment of sound bearable and intelligible, give us an important clue as to the true power of music. Only a small part of our musical experience is cognitively construed by us as a cultural experience. The larger part of our musical response takes place at deeper and more primitive levels of the brain where it directly alters our levels of arousal as subjective changes of emotions and moods. These musical ‘affects’ can now not only be tracked within the brain but also measured as alterations of blood pressure, breathing and hormones such as cortisol, adrenalin, serotonin and oxytocin.

And, remarkably, because as a species we are so precocious in our musicality (it’s now well established that from 26 weeks in utero the unborn baby responds to musical stimuli), such innate musicality is functioning long before we use language.

I can illustrate this from my own personal experiences. Last year, I was in a deep coma for six weeks. During this time, my family played me music, and the medical staff measured significant changes to my vital signs as I unconsciously responded and entrained, becoming neuro-physiologically empathetic to the musical rhythms. Similar benefit can also be found with many patients suffering advanced dementia who can often somehow ‘recover’ themselves when played music or engaged in singing.

CURRENT BRAIN MAPPING TECHNIQUES

Over the last 20 years, new brain mapping technologies such as PET, FMRI, EEG and MEG have each developed sophisticated methodologies that allow researchers to discover both where and when events are happening within the brain.

This is particularly important in studying music, which is, after all, essentially a temporal art form. Simply measuring events in isolation – a pitched note, a sonority, a chord – may be interesting and valuable, but music is much more than a succession of events, and it’s only now that scientists are really beginning to tackle musical phenomena as the complex, dynamic integrated system that it is.

Just as musical performance is more than the successful execution of a series of notes, even apparently simple musical response involves a complex mixture of listening, empathy, emotion, movement and cognition, as well as the brain activity needed to process all this information.

MOVEMENT AND EMOTION

Scientists now have a good knowledge of the main brain centres involved in responding and recognising musical rhythm, and are able to trace the profoundly beautiful relationships between musical sound and our muscular responses and sense of movement. To illustrate (courtesy of Professor Nigel Osborne):

"An unexpected loud noise may be converted into neural impulses travelling along the spiral ganglion and superior olivary nucleus (behind the ear), travel via the inferior collicus directly into the spinal motor systems and make us jump as a startle response."

Simultaneously, other neural pathways lead to the amygdala stimulating feelings of fear and stress. All this quite independently of any ‘cognitive’ aesthetic judgements we might otherwise choose to make.

We all know that not only can music make us literally move (entrain) into dance or through tapping of feet or hands, but it can also move us emotionally. This connection between bodily movement and emotion seems to be more than semantic, and even a brief personal reflection reveals how hard it is to imagine an emotion (or ‘feeling’) disconnected from an associated or defining bodily state (or ‘affect’). Such music, which shapes our subjective experience so insidiously, is not only found in the concert hall but is part of the everyday manipulation of our perceptions by way of film, television and advertising.

MUSIC AND DANCE

The internal transition from hearing rhythmic music to physical rhythmic expression involves a connected group of brain functions including the pre-motor cortex (in which we consider and reflect upon action), the basal ganglia (by which unconscious action occurs), together with the cerebellum and vestibular system (by which the muscles are regulated and balanced posture maintained). Plus, if we are consciously processing rhythmic information, cognitive areas of the brain such as the auditory cortex and right secondary auditory cortex are also recruited.

Without these systems, not only would we lack dance music and ensembles but also conductors, marching bands, cheerleaders and commercial recorded music. But perhaps more importantly, we would also be far less adept as social animals since, as well as providing much cultural value, these are also a prime source of our shared emotional experience and social rituals.

Interestingly, for a long time it was thought that the ability to move rhythmically to music was an exclusively human gift. Other so called ‘dancing’ animals such as elephants, horses, bears are actually trained to respond to visual signals rather than auditory ones. However, this neat theory was recently brought crashing down by a beguiling little film on the internet (see ‘Dancing Cokatoo/Cockatiel’ on YouTube), which clearly shows a cockatiel dancing perfectly in time to the Backstreet Boys!

MUSIC AND LANGUAGE

Like spoken language, music is structured and organised, and some even suggest that music is a kind of universal language. Although this is a very attractive notion, it’s impossible to tell exactly what it is that music tells us. Once again, the most current brain science is opening up some very interesting insights into what has previously been an abstruse philosophical debate.

Although there are some contemporary commentators (most notably Steven Pinker), who believe that music is merely an interesting side effect of other more important evolutionary developments, most music/brain researchers by contrast consider our musical instinct to be a vital precursor to much of our more highly prized human attributes.

Professors Colwyn Trevarthen and Sandra Trehub are among the world leaders in exploring early musicality, particularly between mother and child. Although it’s clearly impossible to sum up such a vast dedication and expertise in a few sentences, we can say that their work proves that in all cultures and societies earliest communication takes place in spontaneous musical ‘motherise’ – a type of primordial pre-verbal prosody in which both mother and baby emote in a kind of songlike stream, ‘goo-goo, agaa, agaa’ and so on. These unconscious and entirely natural outpourings can be notated and even musically scored when a clear periodic phrasing, imitation and general creative ‘play’ becomes immediately evident. The strong suspicion must be that these are the fundamental building blocks of what later becomes the music we enjoy.

Like music, language communication is founded upon sound and, in order to carry meaning, both systems contain syntax and semantic structures. This means that in both we must be able to understand implicit rules of relationship and context between single events (e.g. words and grammar in spoken language, harmonic and melodic events in music). A number of researchers have sought to explore the possible similarities between brain areas implicated in both of these.

Measuring the brain’s response to hearing chord sequences, Koelsch has discovered significant differences in how we respond to regular chord sequences compared to irregular ones. Broadly speaking, it seems that much innate musical response involves brain areas closely related to similar speech processing. Brain areas closely associated with speech recognition have equivalent areas in the right brain dedicated to musical comprehension. In essence, it seems that the early parts of both speech and music processing within the brain may use common areas. Unexpected ‘wrong’ words and ‘wrong’ notes both elicit activity in areas of the brain such as part of the medial temporal gyrus close to the superior temporal sulcus – an area known to be involved in semantic understanding.

CODA

Although we can hardly conceive of a human culture without music, its ubiquity and the organisation of our auditory systems, combined with our contemporary verbal/visual culture, make us easily forget its inherent power and subtle influence.

The Taliban banned the playing of music during their reign in Afghanistan, and other despotic regimes have attempted to curtail its use and style, yet music remains an innate and universal human need. Irrespective of all other social pressures, economic upheavals or conflicts, human beings continue to listen to and participate in music making.

Music plays a vital role in early social and cognitive development, underscoring our individuality from before birth until the point of death (taking up earlier shamanic and traditional practices there are now once again skilled musicians working in some oncology units as ‘thanatologists’ who ease dying patients as they pass from this world). Throughout life, music is present and actively involved in celebrating the rites of passage we make as individuals and societies.

We would do well to attend to the lessons that music offers us, and risk a dreadful impoverishment of the human spirit if we do not. I firmly believe that the current work in the musical brain will furnish us in time with a richer understanding of what it means to be human.