It has now been established that music affects both hemispheres. The right hemisphere (emotions) perceives timbre and melody, whilst the left hemisphere (speech and logic) perceives rhythms.

The range of musical rhythms lies close to the frequencies of breathing and the heartbeat. Sounds affect us not only emotionally, but also physically. Thanks to the resonance of certain rhythms, mood and productivity are boosted; with others, calmness and relaxation set in, and blood pressure drops.

However, new research is constantly bringing new insights into these processes. In 1993, Frances Rane (USA) wrote an article in the prestigious scientific journal ‘Nature’ stating that listening to Mozart’s music affects test results — a phenomenon known as the Mozart effect. What is it: an influence on emotions or an influence on physiology? Admittedly, there are now quite a few studies that dismiss this effect as a myth. Many more discoveries await us in our understanding of how the brain works.

Music is a universal art form inherent in the culture of every nation. It is closely linked to other creative forms of human expression, such as dancing and singing. Although the influence of music on people’s state of mind has long been noticed, it remained unclear which areas of the brain and which substances are responsible for the perception of music.

Only recently, following the development of functional magnetic resonance imaging, has it become possible to study changes in the activity of neurons — cells of the nervous system — whilst listening to music. The magnitude of the magnetic resonance signal depends on the degree to which haemoglobin is saturated with oxygen. And the magnitude of blood flow (that is, the oxygen level) in a specific area of the brain is determined by its activity (functional activity). Therefore, a researcher can record the degree of blood oxygen saturation, which reflects the activation of a particular area of the brain — the result of cortical excitation in response to various types of stimulation (alternating phases of the patient’s motor, cognitive or other activity and rest).

This method allows the study of the activity of various parts of the brain and the creation of maps of these areas, including maps of the motor and sensory cortex, as well as speech and auditory areas. A comparison of activation maps and standard tomograms (at rest) of the region under investigation allows parallels to be drawn between individual functions.

It has been conclusively established that music stimulates areas of the brain associated
with emotional behaviour, such as the insula, hypothalamus, hippocampus, amygdala and prefrontal cortex. It has been found that joyful music increases blood flow in the ventral and dorsal regions of the striatum, the anterior cingulate gyrus, the parahippocampal gyrus and
the auditory perception area.
At the same time, sad music stimulates the hippocampus (amygdala) and the auditory
cortex. In response to exposure to neutral music, activation was observed in the brain’s insula and the auditory cortex.

And what do neurochemists say? In those areas of the brain responsible for the perception of music, the levels of a number of neurotransmitters (substances that transmit nerve impulses) also change. We will discuss three of them, the most important for the perception
of music. These are endorphins, endocannabinoids and dopamine.

Endorphins are chemical compounds that are naturally produced in the brain and have the ability to reduce pain. They affect one’s emotional state: they induce a state of euphoria. They are sometimes called ‘natural drugs’ or ‘happiness hormones’. Endorphins are essential for a sense of well-being, and a lack of them can lead to the development
of drug addiction, including alcohol dependence.
Next in this series are endocannabinoids — the body’s regulatory molecules; they are produced in the lateral part of the hypothalamus, the centre that controls food intake,
and are involved in the transmission of endocannabinoid signals. It has only recently been discovered that endocannabinoids are formed post-synaptically (a synapse is a structure
A three-dimensional tomogram of the brain of a person listening to music. Under its influence, excitation is recorded in different areas (a) and (b) of the brain.
structure that ensures the transmission of the nerve impulse), but act on the presynapse. Usually molecular signals travel from the presynapse to the postsynapse, meaning that for endocannabinoids the direction is reversed. By influencing the production and activity of other neurotransmitters, they regulate the processes that determine appetite, memory and forgetting.

Thus, endocannabinoids may help the brain to erase negative emotions from the past, feelings of anxiety and unpleasant memories. Next comes dopamine — a neurohormone, the ‘pleasure hormone’, a neurotransmitter in the nervous system belonging to the catecholamine group; a biochemical precursor of noradrenaline and adrenaline. The ‘progenitor’ of the hormone, which ‘adrenaline junkies’ so desperately chase after, is produced in the brain under the influence of music.

Disruptions in dopamine metabolism are observed in schizophrenia, Parkinson’s disease and others. It has recently come to light that spousal love and fidelity involes are linked to the release of dopamine by brain cells. It is synthesised in endothelial cells (regulating cerebral blood flow), as well as certain neurons in the brain, facilitating the transmission of
information within the central nervous system. There is now a growing body of evidence pointing to the potential use of music therapy for a range of neurological and mental health
conditions: Alzheimer’s and Parkinson’s disease, schizophrenia, depression, anxiety disorders and autism.

At the same time, for music therapy to be effectively introduced into clinical practice, it is necessary to obtain evidence-based results demonstrating its effectiveness — this requires thorough, so-called blind (free from any subjectivity) trials. Apparently, the effect of
music depends on a person’s initial condition. This can be judged to a certain extent by an electroencephalogram, and it would be very tempting, based on the specific changes in the electroencephalogram of a particular patient, to prescribe a specific type of music therapy
for them. Advances in neurochemistry, neuroelectrophysiology and radiotomographic methods give us hope that in the near future, scientists will be able to demonstrate the effectiveness of such non-standard therapies as music, aromatherapy, colour therapy and
others, which can significantly alter neurochemical processes and blood circulation in the
brain.