We naturally emit sound waves from our bones, muscles, and brains in a very narrow spectrum range up to 125 hertz (Hz). There are five types of brain waves, each occupying a unique frequency range and each affecting the brain’s behaviour in different ways.
Gamma waves (40+ Hz) are associated with higher learning functions such as memory and information processing. Beta waves (12-40 Hz) are most active when we are awake and doing conscious tasks such as reading, writing, and socialization. Alpha waves (8-12 Hz) are known for bridging the gap between our conscious and subconscious minds, a transition stage helping us to relax and prepare for other brain wave activity. Theta waves (4-8 Hz) are active while sleeping and dreaming, and are associated with improving our creativity and intuition. Delta waves (0-4 Hz) tend to be responsible for deep healing and restorative sleep. Too much or too little of each of these types of brain waves can negatively affect the brain’s overall performance.
Brain waves are typically measured by EEG (the electroencephalograph) using electrodes placed at different points on the skull. Both the PET scan (positron emission tomography) and CT scan (computed tomography) use Xray technology. The MRI (magnetic resonance imaging scanner) uses electromagnetic projection and provides a clear image of soft tissue. The fMRI scanner functional magnetic resonance imaging machine) measures oxygenated blood flow.
Although the MRI and fMRI machines look very similar, they perform completely different functions. Where the MRI focus is on water and tissue density, the fMRI introduces the dimension of time measuring what is commonly referred to as BOLD contrast (blood oxygen level dependent contrast). As various stimuli are introduced, the fMRI shows where parts of the brain light up suggesting more neural activity in that area. Skeptics of fMRI technology question the assumed correlation between increased oxygen flow and increased cognitive activity, but this concern is diminishing every year.
The EEG and the fMRI are the machines most commonly used in creativity studies. Remember that the EEG measures electrical activity and the fMRI measures oxygenated blood flow. As more testing is done in this field, the correlation between the two is becoming stronger. Both can detect the position in the brain of the activity being monitored.
There are three main sections of the brain: the forebrain, midbrain, and hind brain. It is the cerebrum, or cortex, in the forebrain that is associated with higher brain function. Studies in creativity tend to focus solely on the forebrain, more specifically, in the prefrontal lobe.
Neurologic activity has been connected with many aspects of physical and mental health. Sound is one method of connecting brain activity to improved health and the medical profession is becoming more responsive to recommending sound-based solutions. This type of audio prescription, sometimes referred to as vibroacoustic therapy or audioceuticals, is relatively new in the medical field and it will be interesting to see how it unfolds.
Keith Loach 