Gamma waves have been shown to disappear during deep sleep induced by anesthesia, but return with the transition back to a wakeful state.
A recent Scientific American article discussed gamma waves in conjunction with long-term Buddhist meditation practitioners. It was found that the experienced meditators demonstrated self-induced, high-amplitude gamma oscillations during meditation. Researchers also noted that their gamma activity differed significantly from those in a control group, both during the meditation and before they even began. Interestingly enough, a similarly strong presence of gamma waves throughout the cortex has been observed in musicians listening to music, compared against a control group of non-musicians.
One current theory even suggests that gamma brain waves may play a role in creating the unity of conscious perception. Research into this theory is still ongoing, and the question is a difficult one to answer with certainty at this time. Though a further investigation is yet to be completed, the theory points to a very interesting possibility that gamma waves are involved in self-awareness.
The studies highlighted in the infographic above were cited in Dr. Tina Huang's landmark overview of brainwave stimulation, "A Comprehensive Review of the Psychological Effects of Brainwave Entrainment."
To be included in that review, articles had to be original, full-length journal articles in peer-reviewed journals, and the studies had to be of an experimental design, with outcomes measured using reliable and appropriate test procedures, and with statistical outcomes revealed.
That highly selective criteria means that these studies represent only a portion of all of the work conducted in this field, but are some of the most significant. Keep reading to learn more about the incredible results of this research.
Before and after the 6 weeks of treatment, each participant was tested using the Wechsler Intelligence Scale for Children, Third Edition (WISC-III).
Analysis of the test scores from before and after the gamma sessions showed that the 30 participants demonstrated significant progress in a wide variety of tests measuring cognitive abilities.
Researchers found a statistically significant gain in the participant's speed of information processing and visual motor coordination on the Symbol Search subtest (pre-test mean: 6.9, post-test mean: 10.6). There was also a statistically significant gain in the participant's visual short-term memory and sequencing ability, as measured by the Coding subtest (pre-test mean: 6.0, post-test mean: 8.2).
The Arithmetic subtest also revealed significant improvements (pre-test mean: 6.2, post-test mean: 8.3), demonstrating a significant gain in the students number ability and short-term memory. Freedom from Distractibility, which is a measurement of ability to focus and pay attention, increased significantly (pre-test mean: 13.2, post-test mean: 17.5) as did Processing Speed (pre-test mean: 12.9, post-test mean: 18.8).
The authors noted that the relatively low number of AVS sessions needed to improve cognitive abilities served as a further demonstration its efficacy.
Olmstead R. Use of auditory and visual stimulation to improve cognitive abilities in learning-disabled children. J Neurother. 2005;9(2):49-61
A study was conducted by David Noton, Ph.D. and published in 2000, with the goal of further validating the use of brain wave stimulation using light as an aid for migraine sufferers.
Dr. Noton mentioned in his study that the treatment of migraine with light-based stimulation originated in the late 1980s with the work of Dr. Duncan Anderson, a neurologist at the Royal Postgraduate Medical School at Hammersmith Hospital in London. He found that when a patient was presented with red light flickering at 30 cycles per second for 15 minutes, the patient experienced a significant reduction in the frequency of migraine attacks, and occasionally would experience nearly complete remission of their migraines. The same treatment, applied for up to 30 minutes after the start of a headache, sometimes terminated the attack.
Accordingly, subjects in Dr. Noton's study were asked to use photic gamma stimulation for 15 minutes per day, and for at least 30 days.
After 30 days of daily use, all of the participants were given a survey. Out of the total of 55 regular migraine sufferers, 44% reported that the frequency of their migraine attacks after the treatment was either 'Somewhat Less' or 'Much Less' (under a conservative interpretation of these categories). Within the group of 28 migraine sufferers who stated that their migraine attacks were normally preceded by warning signs, 53% reported that the frequency of their migraine attacks was 'Somewhat Less' or 'Much Less.'
The study concluded that "in view of the limited efficacy and undesirable side-effects of the available migraine preventive drugs, photic stimulation (flickering light therapy) must be considered a possible preventive treatment for migraine."
Noton D. Migraine and photic stimulation: report on a survey of migraineurs using flickering light therapy. Complement Ther Nurs Midwifery. 2000;6(3):138-142.