Music and the Brain?
The perception and processing of music by the brain and, in general, the neural correlations with music represent a research field of great interest and importance in the field of cognitive sciences, as demonstrated by specialized publications dedicated to topic, which came out in the early 21st century. Among the methods of investigation, neuro physiological techniques (EEG, ERPs, Event-Related Potentials) and neuromaging are of particular importance; among the latter, the fundamental role is played by functional magnetic resonance imaging (fMRI): it allows to record the activity of the central nervous system, highlighting its anatomical and functional characteristics related to cognitive processes.
Neural systems engaged in the perception of music. It is known, thanks to the studies carried out with fMRI, that in adults the perception and processing of music occur through complex neural systems, predominantly at the level of the right hemisphere, specialized in functions that allow to decode the tones, the timbre , the melody, harmony, structure and meaning of the music. These specialized neural systems include not only the primary auditory areas, but also the secondary, higher level integrative, temporal, parietal and frontal lobe. The fundamental data emerging from neuro physiological techniques (EEG, ERPs), on the other hand, concern the stages of cortical processing of music and the degree of influence that musical education has on the electrophysiological responses of subjects engaged in musical tasks. In particular, an interesting fact emerged at the presentation of music with imperfect chords, or of music that contains dissonances (according to the concepts of Western musicology): the lower frontal gyrus responds early to these violations of the rules of musical language, in a comparable way. to what happens in the presentation of language syntactic errors. It therefore seems that this region is responsible for the elaboration of syntactic structures that are the basis of both music and language.
A universal musical syntax?
According to some theories, music and language are homologous functions evolved from a common ancestor. There is a model that foresees shared and parallel aspects of language and music that would have evolved before assuming distinct and domain-specific aspects. Among the characteristics shared by the two domains are combinatorial elements that can generate structured sentences, in turn modulated by precise mechanisms. The principles of the syntax of language and music are based on this basis, which also has rules that allow you to combine musical signs with each other to form a system. Over time, music has evolved to generate even deconstructed and dissonant musical forms: however, this must be interpreted as a cultural phenomenon linked to particular historical and social contexts. As with language, a dialectic between nature and culture would also be established for music, in which the first component is based on generative and universal principles. A recent research (2009) conducted by a team from the Max Planck Institute in Leipzig has shown, for example, that populations never exposed to Western music consider its dissonances unpleasant, while they greatly appreciate the consonant; the same judgment is given to their own music presented in consonant or dissonant form. The same behavior is present in children, even infants, and in most people (non-musicians) when they have to judge consonant or dissonant Western music as pleasant or unpleasant.
Studies in the developmental age. The studies in children from a few months up to the early stages of language development mainly concern EEG or ERPS recordings: these researches have highlighted electrical responses of the children’s brains (in those who have the characteristic right hemispheric dominance) when listening to the music; More interestingly, studies have shown changes in electrical responses in children with musical knowledge and skills and a great sensitivity of the brain to dissonance, which manifests itself in profound reductions in the brain’s electrical response. As evidence of this, behavioral studies in newborns have shown negative reactions (from crying to lack of interest) to dissonant music.
Neuro biological predisposition or Cultural Conditioning?
A question of extreme interest for neuroscience is whether there is a neurobiological predisposition, which evolved with the human species, which has allowed the production and understanding of music, or whether all this is the cultural result of exposure to music, as it happens. in the life of individuals, from childhood onwards, up to the high levels of experience that concern musicians. A study (2010) in newborns, carried out by Daniela Perani and collaborators, who used fMRI during the presentation of Western music pieces, set the stage for an answer: this research showed the brain activity of newborns with 24 ÷ 48 hours of life, when the auditory experience to music is still minimal or nothing: the music of Mozart, Schubert, Chopin activates a circuit at the level of the right hemisphere as in adults exposed to music for some time.
This discovery highlights that already at birth there is a neural architecture and a right hemispheric specialization for the processing of musical processes: music requires complex neural systems to be processed in the human brain, and this possibility already exists at birth, as a result of our evolution. Also for language , already at birth there is an anatomo functional specialization at the left hemispheric level for auditory inputs with specific characteristics. The neuro scientific evidence therefore supports the existence of a left and right hemispheric functional asymmetry present from birth and based on biological differences.
It has been suggested that two types of acoustic input resolution are needed for a complete auditory analysis: temporal and spectral. A high temporal resolution is important for language processing, while a good resolution of the spectral frequencies is important for music. The role of these structures of the right hemisphere, specialized for music and already functionally active at birth, must also be fundamental for the elaboration of the musical aspects of language such as prosody, fundamental for the acquisition of language in childhood.
Studies in Musicians:
Neuro physiology studies have shown the existence of a cerebral specialization in musicians: the cerebral electrical responses to the presentation of musical stimuli are wider than those of non-musicians, and this also happens in the case in which musical irregularities (dissonances, alterations , violations of agreements), although complex and difficult to perceive.
In expert musicians, MRI has shown that music processing involves, in addition to the systems of the right hemisphere, also others at the level of the left hemisphere, linked to more extensive capacities. Another interesting aspect concerns the close correlation with the sensorimotor system: the activation of this is always present in the musicians even during the simple listening of musical pieces, as in their baggage of experiences they also contain the motor ones, concerning the mastery of use. of a musical instrument (piano, violin, harp). With structural magnetic resonance studies in expert musicians, plastic changes in the brain have been highlighted, related to exposure to music and the use of instruments. These are represented by increases in the volume of gray matter due to greater connectivity (development of dendrites and synapses) in the auditory and motor areas, as well as changes in the main intra- and inter hemispheric connecting bundles.