A comprehensive review of the Psychological Effects of Brainwave Entrainment
Review published: 2008.
Bibliographic details: Huang T L, Charyton C. A comprehensive review of the psychological effects of brainwave entrainment. Alternative Therapies in Health and Medicine 2008; 14(5): 38-50. [PubMed]
The authors concluded that preliminary evidence suggested that brainwave entrapment was an effective therapeutic tool, but further research was required. The evidence presented appeared to justify the recommendation for further research. In view of the lack of controlled evidence and problems with methodology and reporting in the review, the authors? conclusions regarding efficacy did not appear reliable. Full critical summary
OBJECTIVE: Brainwave entrainment (BWE), which uses rhythmic stimuli to alter brainwave frequency and thus brain states, has been investigated and used since the late 1800s, yet many clinicians and scientists are unaware of its existence. We aim to raise awareness and discuss its potential by presenting a systematic review of the literature from peer-reviewed journals on the psychological effects of BWE.
DATA SOURCES: Terms used to describe BWE and psychological outcomes were used to search English language studies from OVID Medline (1950-2007), PsychInfo (1806-2007), and Scopus.
STUDY SELECTION: Twenty studies selected satisfied the following criterion: studies needed to use rhythmic stimuli with the aim ofaffecting psychological outcomes. Peer-reviewed experimental and quasi-experimental studies were accepted. Case studies and review articles were excluded. Psychological outcomes were measured using standard assessment methods or as deemed appropriate by peer review.
DATA EXTRACTION: Other clinical measurements, including electroencephalogram response, galvanic skin response, and neurotransmitter levels were not included.
DATA SYNTHESIS: Psychological outcomes addressed cognition, stress and anxiety, pain relief, headaches or migraines, mood, behavior, and premenstrual syndrome (PMS). Protocols included the use of single, alternating, ascending, or descending frequencies or were determined by the subject, using auditory and/or photic stimulation. Studies examined single session effects and/or longer-term multiple session effects.
CONCLUSIONS: Findings to date suggest that BWE is an effective therapeutic tool. People suffering from cognitive functioning deficits, stress, pain, headache/migraines, PMS, and behavioral problems benefited from BWE. However, more controlled trials are needed to test additional protocols with outcomes.