The Brain as a Percussion Instrument
SNU Medical School Reveals Relationship Between the Brain and Sounds

Koreans have long believed in prenatal education, 'taegyo', like most other cultures over the centuries. Then, this belief was dismissed in the modern age as not being scientific. However, modern scientists are now returning to the early belief that what happens to us during our nine months in the womb does affect the rest of our lives with scientific support. On September 29, 2010, an article was published in the Korea Economic Daily about a scientific discovery that has interesting implications for both pregnant mothers concerned about their babies' taegyo as well as the treatment of retarded or schizophrenic children using music.

The Seoul National University College of Medicine recently discovered a relationship between sounds and the brain, which can serve as scientific evidence for prenatal education and music therapy. The researchers found that music is an electric stimulation far more precise than previously believed, and that various parts of the brain react to each different sound.

The Brain is Like a Piano

The relationship between the brain and an auditory stimulation can be examined by using the Motionless Electromagnetic Generator (MEG). The brain's nerve cells transmit information to one another via synapses, electric or chemical signaling junctions. This signifies that when an electric current flows in the brain a magnetic field forms in a particular direction, as according to the Ampere rule. This neuromagnetic field, however, is as small as 100~100femto (factor of 10−15) tesla (T: SI derived unit of magnetic field B, also known as"magnetic flux density" and"magnetic induction"), one millionth the size of the Earth？s magnetic field. Therefore it can only be measured using a special sensor made with superconductors - this is called the MEG.

The research team, with the sole MEG device in the country, has studied the change in the MEG produced data for each millisecond of an auditory stimulation. Only one hundred or so MEGs exist in the world today. Various high technologies are integrated into this device in order to maintain its superconductor condition. It graphs the neuromagnetic field in an electrocardiographic (ECG) manner.

The research team measured the neuromagnetic field from specific auditory stimulations to the brain through each of the 306 different channels in the MEG device. Then from this data, they deducted a graph of an average of these neuromagnetic fields. By utilizing other devices such as the PET (photoinduced electron transfer) image with this graph, they investigated exactly which auditory stimulations trigger which parts of the brain. To clarify, this means that if a specific sound, such as a millisecond of the 'C' sound of any particular major, was stimulated into the brain, the part of the brain triggered was tracked down.

SEOL Jae-Ho, a researcher in the SNU Cognitive Science Program and the Magnetoencephalography Center of Seoul National University Hospital described this discovery in comparison to the piano."Like the keyboard of the piano, the brain also has different sections responsible for cognition of different sounds", he explained. The paper revealing the complete results of this sound-brain investigation is at present being prepared for publication. 

Application to Prenatal Education and Treatment of Mental Illness

The results of this investigation go against our common notion that music is a culturally perceived stimulation. The research team said it only takes about 30ms for us to identify jarring sounds from pleasant harmonies. Furthermore it only takes 100ms to identify a piano sonata from the white noise of TV. This skill is no rational judgment but an instinctive reaction to electric signals that only takes a few hundred milliseconds.

Neuromagnetic field measurement can be used as a medical tool to verify whether the cause of a mental illness is in the sensory organs such as the ears or eyes, or is in the brain synapses. As a followup of this investigation, the research team is also investigating a clue for diagnosis of schizophrenia or Attention Deficit Hyperactivity Disorder (ADHD) common in children. Because the neuromagnetic field blueprint allows detailed analysis of the brain reacting to the auditory trigger with time, it can identify if there is an attention deficit and provide basic knowledge of where the characteristics of schizophrenia, such as auditory and visual hallucinations and collapsed language, come from. In addition, as mentioned above, the affects of sounds on the brain can also lead to further investigations on music beneficial to fetuses in the womb. Professor CHUNG Chun-Kee of SNU College of Medicine's Department of Neurosurgery said,"The ability to hear is the most intuitive biological reaction", and added,"Research on the brain-hearing relationship surprisingly hasn't been undertaken much but once the relationship is understood, it can be applied to numerous subjects of study."

Written by LEE BoYoung, SNU English Editor
bylee0708@gmail.com