This is the first scientific study to show that transcranial stimulation is likely to cause a change in conscious awareness. And we all know that understanding the nature of consciousness is perhaps the biggest challenge of neuroscience, philosophy and psychology.
Research focused on lucid dreaming
The new research gives us information which is undoubtedly important to the process of unraveling the mystery of consciousness. A group of German scientists, with the participation of Allan Hobson of the Harvard University, a researcher who has dedicated his life and work in the research of dreams and sleep, led by neuroscientist Ursula Voss of the Goethe University in Frankfurt, examined the brains of volunteers during lucid or conscious dreams.
Lucid dreams are those during which the person is aware of the fact that he is dreaming while they are in progress. Such dreams are also connected with various other conditions, such as the ability to control them, seeing them from the perspective of a third party, or recalling memories while having them.
The role of brain waves
According to scientists, the brains of people who experience a lucid dream exhibit the phenomenon known as “phase synchronization“. The above means that the neurons in the brain are synchronized with each other, producing waves in a specific common frequency.
Brain waves are divided into five main groups, depending on their frequency and the state of the brain when they appear: alpha waves, beta waves, gamma waves, delta waves and theta waves. Each group represents a different state. For example, a state of relaxed wakefulness is associated with the alpha waves of 8-13 Hz.
During the lucid dreams, the increased frequencies of gamma waves, which correspond approximately to 40 Hz, are observed. In particular, this increase is observed in the frontal and temporal lobes of the brain. This is an observation that till now is not fully understood and has aroused the interest of the scientific community.
Do gamma waves wake the consciousness?
For many years, scientists have been studying whether these synchronized brainwaves are the reason or a consequence of self-awareness during lucid dreaming. The study, published in the journal Nature, has tried to answer this question.
The participants were subjected to stimulation with alternating current through two electrodes placed on a surface of their scalp, after having spent at least 2 minutes in the fifth stage of sleep, known as REM.
30 second after that, the volunteers were woken up and asked questions about their dreams. Amazingly, when the brain was stimulated with a current frequency of 25 or 40 Hz, similar to that of gamma waves, the volunteers reported an increase in lucidity compared to other stimulation frequencies.
The above fact suggests that the consciousness of a higher level is associated with synchronized brain waves of around 25 and 40 Hz. Furthermore, it could mean that gamma waves are not just a feature of higher cognitive functions, but may actually be their cause.