The history of neurofeedback
Neurofeedback is founded on two (not so simple) facts:
- a brain’s state (including any dysfunction or dysregulation) is objectively reflected in parameters of EEG recorded from the scalp,
- a human brain has plasticity to memorise the desired (and thereby, rewarded) state of the brain.
These two paragraphs can be stated with confidence due to many decades of research and empirical observation - and the story is not over - there is much still to learn. In this article we look at the history of neurofeedback.
The early days
The physiology of conditioned reflexes forms an objective background for neurofeedback. The experiments on conditioned reflexes were carried out by Ivan Pavlov (remember Pavlov's dogs) in the Institute of Experimental Medicine in St. Petersburg. In the late 1940s, P. Kupalov, a former student of Pavlov, invented a methodology of situational conditioned reflexes. In the West this method was described as the method of Operant Conditioning with the input of BF Skinner. In this method, animal behavioural reactions but not external stimuli served as unconditioned stimuli. In Pavlov’s time those reactions were usually the motor function responses such as occur when the animal runs into a specific section of an experimental room.
In 1930 an American mathematician Norbert Wiener in collaboration with a Mexican psychologist Arturo Rosenblueth introduced the concept of feedback in relation to biological systems. This concept evolved into a new science coined by Wiener as “Cybernetics” in his book published in 1948.
About the same time, a Russian scientist Petr K. Anokhin, a student of Pavlov and Bechterev, in 1935 developed a theory of functional systems. The key element of this theory was neuronal feedback – an interaction between a so-called “acceptor of actions” and behavioural adjustment of the animal. Following these traditions some clinicians started using the method of biological feedback for treating some neurological and psychiatric diseases.
The idea was simple: to train the brain or muscles (as in the case of cerebral palsy) by using physiological parameters as a feedback. EEG patterns, electric activity of muscles(EMG), and slow metabolic processes were used for biofeedback.
Joe Camiya, an American researcher observed that subjects could learn to voluntarily control their alpha waves (an aspect of the frequency spectrum of the EEG). To achieve this goal, every time, when a subject generated the alpha rhythm, the researcher reported this fact.
Thus, though Norbert Wiener and Petr Anokhin formulated the idea of feedback in 1930–1940s, it took until the 1960’s before it was shown for the first time that EEG parameters can serve as a form of feedback for self-regulating the brain. Furthermore Barry Sterman in his studies with cats introduced a rhythm associated with the sensory-motor system and thereafter named the “sensory-motor rhythm.” or SMR. Using operant conditioning, cats were successfully trained to produce this rhythm for a food reward. It was also discovered that overtraining protected these animals from experimentally induced seizures.
Shortly after that, training of the SMRwas applied to epileptic patients. In these studies EEG biofeedback significantly reduced seizures and normalised the EEG.
In 1969, the method of brain self-regulation by means of EEG and other physiological parameters was officially named biological feedback (biofeedback). EEG biofeedback was implemented for treating neuroses and epilepsy neurofeedback as well as an anti-combat-stress rehabilitation therapy for Vietnam veterans.
In the 1970s, Niels Biermbaum and his colleagues in Germany started using slow brain wave electric activity for biofeedback treatment of epilepsy and schizophrenia.
This was a period of significant enthusiasm when biofeedback seemed to be a possible panacea for all brain diseases. However, in 1974, an article by Linch et al. showed that the subjects who learned to control their own alpha rhythm with eyes open were not able to increase it more than they could do with eyes closed. The article showed limitations of human abilities in EEG biofeedback, but these observed constraints were treated too literally and neurofeedback became subsequently unpopular.
However, a few enthusiasts continued to work with EEG biofeedback. Studies of Joel Lubar from University of Tennessee, USA played an important role in 1970–1980s. He proved that sessions with training beta rhythm UP and simultaneously theta rhythm DOWN significantly reduced hyperactivity and improved attention in attention deficit hyperactivity disorder (ADHD) patients (Lubar et al., 1995; Lubar, 1997). However these years were mostly associated with a trial and error approach without using of any reliable scientific theory of neurofeedback.
At the same time (in early 1970s) a new approach in the field of EEG was developed. It was coined by Roy John from New York University Medical Center as neurometrics (John et al., 1977). The idea behind neurometrics was to quantitatively compare parameters of individual EEG with those computed for a normal group.
It was a revolutionary idea because up to this time only visual inspection of raw EEG signals had been considered as the gold standard in electroencepalography. Visual inspection was a slow and difficult art to learn and certainly a practical barrier to wider embrace of the techniques.
In the mid-1980s, the two approaches, EEG biofeedback and neurometrics, merged forming a new direction that is now often called named neurotherapy.
New views for the genesis of EEG rhythms made it possible to form a theoretical basis for a neurotherapeutic approach. Several companies are now specialised in EEG analysis and in development of individual neurotherapeutic protocols.
See Kropotov, Juri D.. Quantitative EEG, Event-Related Potentials and NeurotherapyElsevier Science. 2009