Squareeater uses a combination of binaural beats and psychostrobic flicker effects to attempt to induce brainwave entrainment in the viewer.
Binaural beats are achieved by putting a tone in one ear of the listener and a slightly different tone in the other. For example, if the left ear is hearing a sine wave tone of 397hz (cycles per second) and the right is hearing 403hz, the brain perceives a pulse of 6hz, the difference in the frequencies.
Under ideal conditions, frequency following response occurs in brainwave functions, meaning the brain starts to function at the same frequency as the binaural stimulus. Different frequencies of stimulus correspond to different brainwave states, for example 4-7hz correspond to theta waves, a brain state associated with deep meditation or early stages of sleep.
Additionally, other forms of stimulus can achieve some of the same effects. Indigenous cultures have used rhythmic drumming in rituals for neurophysiological effects and research backs up these assertions. Also the stimulus does not have to be auditory, but psychostrobic visuals can also induce similar effects (ie. the dream machine). The strobing used on squareeater is intended to reinforce the audio.
We are often asked "aren't the effects just placebo?". While there certainly have been users whose response is largely imagined, there have been a number of studies (see research below) published in legitimate scientific journals drawing a correlation between binaural beats and brainwave functions. While the research is insufficient at this point to fully understand how the brain reacts with entrainment, a variety of responses have been well documented.
Because of the nature of brainwave entrainment and binaural audio, there is a range of information out there from high quality academic writing to badly written new age texts.
For more information on psychostrobic effects (what flickering does to your brain), we highly recommend the short, very readable but out-of-print Chapel of Extreme Experience: A Short History of Stroboscopic Light and the Dream Machine
If interested in the relation between sound/music and various ecstatic states such as trancing, try Deep Listeners: Music, Emotion, and Trancing by Judith Becker.
For a simple introduction to the basic nature of consciousness, try A Universe Of Consciousness How Matter Becomes Imagination by Gerald Edelman and Giulio Tononi.
For further reading see:
"Binaural-Beat Induced Theta EEG Activity and Hypnotic Susceptibility"
Brady, Brian & Larry Stevens, American Journal of Clinical Hypnosis, 43:1, July 2000
document available
Abstract:
Six participants varying in degree of hypnotizability (2 lows, 2 mediums, and 2 highs) were exposed to 3 20-minute sessions of a binaural-beat sound stimulation protocol designed to enhance theta brainwave activity. The Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) was used for pre- and post-stimulus measures of hypnotic susceptibility. A time-series analysis was utilized to evaluate anterior theta activity in response to binaural-beat sound stimulation over baseline and stimulus sessions. The protocol designed to increase anterior theta activity resulted in a significant increase in percent theta for 5 of 6 participants. Hypnotic susceptibility levels remained stable in the high-susceptible group and increased significantly in the low and medium-susceptible groups.
"Binaural Auditory Beats Affect Vigilance Performance and Mood"
Lane. James D. et al, Physiology & Behavior, Vol. 63, No. 2, pp. 249–252, 1998
document available
Abstract:
When two tones of slightly different frequency are presented separately to the left and right ears the listener perceives a single tone that varies in amplitude at a frequency equal to the frequency difference between the two tones, a perceptual phenomenon known as the binaural auditory beat. Anecdotal reports suggest that binaural auditory beats within the electroencephalograph frequency range can entrain EEG activity and may affect states of consciousness, although few scientific studies have been published. This study compared the effects of binaural auditory beats in the EEG beta and EEG theta/delta frequency ranges on mood and on performance of a vigilance task to investigate their effects on subjective and objective measures of arousal. Participants (n 29) performed a 30-min visual vigilance task on three different days while listening to pink noise containing simple tones or binaural beats either in the beta range (16 and 24 Hz) or the theta/delta range (1.5 and 4 Hz). However, participants were kept blind to the presence of binaural beats to control expectation effects. Presentation of beta-frequency binaural beats yielded more correct target detections and fewer false alarms than presentation of theta/delta frequency binaural beats. In addition, the beta-frequency beats were associated with less negative mood. Results suggest that the presentation of binaural auditory beats can affect psychomotor performance and mood. This technology may have applications for the control of attention and arousal and the enhancement of h
human performance.
"A prospective, randomised, controlled study examining binaural beat audio and pre-operative anxiety in patients undergoing general anaesthesia for day case surgery"
Padmanabhan, R., et al,. Anaesthesia, Volume 60, Issue 9, pages 874–877, September 2005
document available
Abstract:
Pre-operative anxiety is common and often significant. Ambulatory surgery challenges our pre-operative goal of an anxiety-free patient by requiring people to be 'street ready' within a brief period of time after surgery. Recently, it has been demonstrated that music can be used successfully to relieve patient anxiety before operations, and that audio embedded with tones that create binaural beats within the brain of the listener decreases subjective levels of anxiety in patients with chronic anxiety states. We measured anxiety with the State-Trait Anxiety Inventory questionnaire and compared binaural beat audio (Binaural Group) with an identical soundtrack but without these added tones (Audio Group) and with a third group who received no specific intervention (No Intervention Group). Mean [95% confidence intervals] decreases in anxiety scores were 26.3%[19–33%] in the Binaural Group (p = 0.001 vs. Audio Group, p < 0.0001 vs. No Intervention Group), 11.1%[6–16%] in the Audio Group (p = 0.15 vs. No Intervention Group) and 3.8%[0–7%] in the No Intervention Group. Binaural beat audio has the potential to decrease acute pre-operative anxiety significantly.
