Theory and Development
Neurofeedback
is effective due to the brain’s neuroplasticity. Neuroplasticity is defined as the reorganization of and changes in
connections between linked neurons in the brain1.
Like all forms of learning, it is a process that is initiated by a challenge. With repeated challenges, the brain will change,
grow, and develop and reorganize synapses2.
Neurofeedback appears to accelerate neuroplasticity by influencing the
strengthening of neural networks3 because of the near-instantaneous nature of the feedback loop and the extremely
high number of trials that can be completed in a very short period of time (e.g., 900 in a half-hour feedback session). This
means that by using neurofeedback, one can complete 18,000 successful trials in only 10 hours of training.
The London taxi driver study conducted at University College London and published in the Proceedings of the National Academy of Sciences provides
a useful example of what is meant by neuroplasticity. Maguire and colleagues4 used structural magnetic resonance
imaging (MRI) to compare the brains of London taxi cab drivers with non–taxi drivers.
London taxi drivers must apprentice for up to three years
before being licensed, a period colloquially termed “being on the knowledge.” Drivers learn to find the most arcane
locations and describe the history and scenery on the way there. The drivers’ visual-spatial memory and navigational
skills are constantly challenged in order to accommodate their passengers’ requests.
Brain scans of the taxi drivers pre- and post-apprenticeship and
over longer terms of duty revealed that part of their hippocampi nearly doubled in size compared
to others who had not undergone training5. The extraordinary challenge faced by the taxi drivers during their apprenticeships
is proposed to have initiated the increased development of posterior sections of their hippocampi, with greater growth in
proportion to the time spent on the job. The brain’s ability to grow and change in response to new learning defines
neuroplasticity.
Operant Conditioning
Over 100 years of research has been conducted on how to best facilitate learning in organisms. Edward Thorndike, a pioneer
in conditioning research, studied the learning of cats by putting them in puzzle boxes. The cats had to learn how to escape
by figuring out which device to pull. As the trials proceeded, the cats were able to escape more quickly, indicating that
they had learned. Thorndike observed that this learning was gradual and orderly. He concluded that the cats didn’t use
reason but instead learned through trial and error, or what he called the “Law of Effect.” Responses that resulted
in satisfaction gradually turned into habits. Responses that resulted in annoyance were eliminated.
Thorndike also described the “Law of Exercise,” according
to which the stimulus-response connections that are repeated are strengthened, and those stimulus-response connections not
used are weakened. This is what we call today the “use it or lose it” dictum. This is a connectionist theory that
we describe in terms of new dendritic branches and stronger neuronal connections. Thorndike believed that through experience,
neural connections are formed between perceived stimuli and emitted responses.
B. F. Skinner and others helped us to learn the reinforcement schedules that are optimal for learning.
These are the principles that guide the neurofeedback clinician on a daily basis in the clinic. The behavior being trained
is the electro-encephalography (EEG) program, the operator is the patient, and the reinforcement is visual and auditory stimuli
that indicate success at the task. The felt experience of focused attention or motoric calm is paired with the visual and
auditory display, so the subject gets near-immediate feedback (250 msecs) about the state of his or her brain and attention.
Neurofeedback, then, is simply operant conditioning using encephalography.
1 Nasrallah
& Tolbert, 1997; Pallagrosi, 1993; Shaw, Lanius, & van den Doel, 1994; Swann, Pierson, Smith, & Lee, 1999
2
Machado et al., 2008; Self & Choi, 2004; Shashoua, 1985;
Sunderland & Tuke, 2005
3 Cannon, Congedo,
Lubar, & Hutchens, 2009
4 Maguire,
Frackowiak, & Frith, 1997; Maguire, Woollett, & Spiers, 2006
5 Maguire, Frackowiak, & Frith, 1997; Maguire, Woollett, & Spiers, 2006
