Neurofeedback is evolving
Numerous studies show the efficacy of neurofeedback in the treatment of traumatic brain injury, sleep issues, migraine headaches, seizure disorders, fibromyalgia, chronic fatigue syndrome, autistic spectrum disorder and more. Despite this the field is still evolving.
Despite the evidence, some in the scientific community still have difficulty accepting a modality that does not lend itself to the (supposed) gold standard of a double-blind study. This is the same issue as rehabilitation faces in general - we usually can’t design an study in which the experimental subjects and the persons administering neurofeedback don't spot a sham treatment.
I think there are lots of parallels with physical rehabilitation. Neurofeedback has been viewed as "carefully applied brain fitness" by exploiting brain plasticity. Just as body fitness is desirable in maintaining overall health and can be used to recover from physical and health challenges, neurofeedback can similarly improve functionality in both a psychological and physical sense.
Just as in every other field, there is more than approach to neurofeedback and the approaches are still evolving. Neurofeedback’s application history really has followed two branches.
In the USA clinicians and scientists have focused on amplitude based reinforcement of the what we might think of as “traditional” frequency bands between 1 and 30 Hz. This was partly due to the limitations of the early generations of EEG amplifiers which cut off anything below 0.5 Hz. Large amplitude fluctuations in the lowest frequencies would have swamped everything else and these lowest frequencies were regarded as artefacts anyway and not thought to represent useful information.
Meanwhile in Europe and Germany in particular scientists were following that second branch of application and studying the low frequency changes in particular and with great promise. By using EEG amplifiers (such as the NeXus 4, NeXus 10 or NeXus 32) that could work with the lower frequency spectrum they focused on the slow baseline shifts (known as Slow Cortical Potentials) that reflect episodes of cortical activation and deactivation through positive and negative changes in the surface potential.
In the early days, both branches of neurofeedback development mainly recorded EEG signals in the central strip (Cz, C3 and C4) in the international 10-20 system.
Over the years there has been consideration of whether it is necessary to have a customised approach to each individual client or whether a “one-size fits all” approach could be adopted. The individualised approach works best or the skilled practitioner because it was found that the training effects could be achieved more quickly and in a more specific fashion. A “one-size fits all” approach would be favoured for research in particular because of the constraints on the training parameters and the reduced need for a high degree of skill in the practitioner.
The question is how best to adapt the training to the individual needs of the client?
Can the plan of action be derived from interpreting QEEG data with respect to a database of norms like Neuroguide or Loreta? Or should the change of the client’s symptoms guide one to the correct training strategy?
Experienced clinicians find that both methods can work but they caution that brains behave in an idiosyncratic fashion and an individuals reaction to training is not always readily predictable from the EEG.
Discovery of effective training methods has pursued a path toward lower and lower frequencies - referred to as Infra Low Frequencies or ILF which is training conducted with attention to frequencies below 0.1 Hz. We will discuss this in future articles - it takes neurofeedback away from a process which we recognise as operant (reward driven feedback) conditioning to an approach which is closer to continuous control.
Despite its efficacy biofeedback and neurofeedback are not “silver bullets” but do deserve to be part of the tool kit of any medical practice taking an integrative approach to health. Many persons who could benefit from neurofeedback could also have a need for attention to diet and nutrition, sleep patterns, physical activities and so on.
We know that a lack of basic vitamins, minerals and other nutrients will adversely affect brain function. Likewise a lack of physical activity is not great for the brain. It’s one of the best evidenced ways of maintaining brain health in older adults. Treatment of anxiety and depression with exercise and yoga have been found to be as effective as cognitive behavioural therapy or medication.
We are also learning more and more about the consequences of poor sleep. Chronic lack of sleep has been linked to many health and mental health issues.
Neurofeedback or EEG biofeedback is not an easy field to enter. It challenges the clinician or scientist to develop knowledge across multiple domains and yet the rewards are becoming increasingly apparent for those who invest the time.