Wednesday, January 8, 2014

Music and Wellbeing an introduction to the Musical Brain

by Paul Robertson

Music is a universal experience, and for centuries human beings have engaged with it and wondered at its power. We can now begin to appreciate how musical forms and structures are related to the underlying neurological forms and physiological structures that create them. 

There is a new and burgeoning interest in establishing a biological basis for musical experience. Whilst such pure scientific exploration is facilitated by the remarkable recent development of noninvasive brain mapping, it is driven by a powerful urge to understand the mysteries of music. By mapping the structures of the brain that support music we may gain insight into the roots of personal identity and social relationship as well as into the nature of musicality itself.

Thirty years ago, when I first became fascinated in the relationship of music and brain, any conceptual framework could only be theoretical as there was then virtually no significant research to call upon. However, some understanding of the topic did exist, from the observation of deficits in those who had unfortunately suffered brain lesions, and there was one excellent book edited by Critchley (Music and Brain, 1977) which gave the scientific views current at that time.

There was also a vast resource of Philosophy, Psychology and Musical and Aesthetic theory and, as I discovered when I came to make a television series on Music and Science (‘Music and the Mind’ Channel 4, 1996), although mostly unaware of each other, brilliant people were researching different music-related domains. Since then, there has been a rapid growth in understanding of how our brains perceive and produce music, aided greatly by new methods for non-invasively finding our what goes on inside the human skull..

Whilst these technological advances in brain mapping have undoubtedly moved this topic significantly forward, so has our new culture of inter/intra-disciplinary collaboration and exploration and perhaps the one has driven the other.

Mapping Music
In order to understand contemporary research it is helpful to have a sense of what the current technologies make possible and what are their strengths and limitations.

Basic neuro-anatomy and current brain mapping techniques
The human cerebrum has two broadly symmetrical hemispheres, which in some areas have different but complementary functions. It used to be thought that spoken language and words were solely the province of the left hemisphere whilst music and emotion were located and processed only in the right side of the brain. However, contemporary non-invasive brain mapping techniques reveal a far more complex, interconnected and distributed network of brain areas, which include the evolutionarily older brain areas of the cerebellum and brain stem, which come into play in order to comprehend and discriminate musical sounds.

Mapping Blood Flow Response to Brain Activity
PET (Positron Emission Tomography) scans use injected radioactive isotopes to measure how blood flow varies within the brain. This technique is silent and can be used to map activity to an accuracy of about 5 mm during a 2 minute period. Because of the possible risks of over-exposure only 12 such scans are recommended in a person’s lifetime.

fMRI (Functional Magnetic Resonance Imaging) measures subtle effects on water protons which mark blood oxygenation changes associated with neuronal activity. This technique is very accurate spatially, to about 2 millimeters, and measures reactions over a few seconds, but unfortunately the scanners make loud noises, which presents obvious, though not insuperable, problems in the musical domain.

Both PET and fMRI require a good deal of data analysis because the main interest is in the relatively small differences in brain activity relating to specific stimuli.

Electro-physiological measures
EEG (Electroencephalography) and MEG (Magnetoencephalography) both directly detect electrical brain activity in real time but require massive computation because data analysis and comparison are complex. Neither technique is particularly good at locating where brain activity is taking place, but they are both able to measure precisely when it occurred, and to discriminate responses lasting only a few milliseconds. Because of these technical issues studies usually report averages of data from a number of subjects rather than individual snapshots. (illustrate)

A great deal of fascinating information is generated from studying the exact timings of electrical activity which can also show positive (P) or negative (N) surges. These signals generally occur between 100 milli-seconds (ms) to 600 ms and different types of processing have characteristic profiles. 

Much of our best current information comes from the result of combining information from different technical approaches. Irrespective of which approach they favour, the common dedication and passion of all our contributors is to better understand what music is, and why and how we experience it. It is also true to say that everyone working in this field has been touched by music and moved by its mysterious power.

The Science of Music
The relationship between music and mathematics is as long-standing as that of music as language. As Leibniz brilliantly observed, ‘Music is the human mind using mathematics whilst unconscious that it is calculating’.

For me this exploration (and our whole current musical science) is based upon this strange human urge to comprehend events and phenomena, including the most subjective human experience, as mathematical form. As we know, the curious intermingling of music and mathematics, and the scores and symbolic notational systems we use in Western music, are no more than alternative algorithmic ciphers. Music is after all entirely constructed from pitches and rhythms which can be mathematically expressed as variations in sound vibrations over time.

If we accept the truth of this, then for many of us it is irresistible to seek to discover not only the algebra of the musical construct but of the creative imagination, emotion and ‘ineffable’ beauty of musical inspiration as well. While this might be considered heady stuff, I suspect this impulse underlies many of these scientists painstaking research.

Is there a ‘science’ of meaning or of the emotions? Are these sorties into the musical hinterland the beginning of such a new science? Could such ‘objective’ explorations demystify music? Or, as many musicians seem to fear, explain away the ‘magic’ of music? I don’t believe that many (if any) of our contributors think this either desirable or possible--any more than learning to play scales ‘explains away’ the beauty of inspired music, itself constructed of scale combinations.

The great Russion neuropsychiatrist Luria spoke of his belief in the evolution of a new ‘Poetic Science’. Perhaps we are seeing this emerging in music and brain studies As a species, we have been practicing and refining our musical impulses or ‘instinct’ for thousands of years (at least 30,000 years judging from early bone flutes). Ancient civilizations, including the Chinese, Indian and Greeks, studied the physics of sound, analyzed the mathematics of the harmonic series in order to construct scales and integrated these theories into their aesthetics and (often) religious world views.

Since music plays so fundamental a part of our personal, social and cultural condition I find myself asking whether our musical constructs are actually also such ‘maps’ - if we could just decode them. If this is true then the insights of music-makers would have as great a contribution to the science of mind and consciousness as can the brain scientists.

In this context, Mendelssohn’s profound remark that, ‘Music is too precise to express in Words’ raises a number of questions. Is music a language? Is it the foundation of all language? Is music the auditory distillation of the gestures and pre-linguistic signals of communication and therefore a proto – or universal language? Does music carry meaning or do we create a sense of meaning from it because it is essentially ‘semantic’? or is it somehow a ‘language’ of the emotions? Might we be better understand our musical experience as a combination of embodied ‘feelings’, cognition and affect? If so, how are they joined? How can we experience some or all of these at any one time in music? Is music especially mysterious and potentially ‘meaningful’ because of its temporal structuring? and so on...