EEG Biofeedback (Neurofeedback) is effective for patients suffering a wide-range of conditions from the frankly physical (examples: seizures, traumatic brain injury and strokes) to the psychological (anxiety, sleep disorders, mood disorders) and the in-between (Attention Deficit Disorder, Migraine and other Headaches, Fibromyalgia). I won’t review the extensive efficacy literature in this blog post, except to trumpet that the American Academy of Pediatrics last October (2012) report on Evidence-based Child and Adolescent Psychosocial Interventions classified neurofeedback as a “Level 1 Best Support” intervention, the highest level of support for the Attention and Hyperactivity behavioral problems. There is a growing literature on neurofeedback for Autism, ASD and Asperger’s Syndrome. I recently read a fascinating (and persuasive) pilot study showing that neurofeedback improved emotional responsiveness in Asperger’s children*.
*[THE EFFECTS OF HUMOROUS LITERATURE ON EMOTION: A PILOT PROJECT COMPARING CHILDREN WITH ASPERGER’S SYNDROME BEFORE AND AFTER NEUROFEEDBACK TRAINING AND CONTROLS. Drysdale et al; J of Neurother. 16:196-209, 2012]
The concept of giving the brain information about itself to create brain change–while not alien to my psychiatric colleagues–is unfamiliar to most of them, who tend to think of neurofeedback as a form of relaxation training, or high-tech CBT. It’s not. And neurofeedback is not simply a form of Operant Conditioning. No specific paradigm has emerged in consensus. Using various clinical systems we can give the brain information about itself (biofeedback) by showing fluctuations in many aspects of EEG activity. And the person receiving the feedback needn’t be actually conscious of the signal as long as the brain itself is receptive to the signal changes being offered.
In our office we offer neurofeedback on a number of systems–each of which allows patients to remain in a passive-alert state while the computer-brain interface is doing the “work” of treatment. Feedback is information about a variety of “brainwave” (EEG) parameters. LENS gives information about dominant frequency shifts through the scalp over 100 times a second ; Cygnet gives continuous visual information about shifts in infra-low frequency brain waves that may require over an hour for a single cycle; Zengar NeurOptimal signals instability patterns with nearly subliminal interruptions of music; BrainPaint uses shifts in visual fractal patterns and consciously incomprehensible auditory “brain music” to communicate back to the brain. Each of these clinical systems is basically passive learning, effective, is partially explained by both operant and classical conditioning, partially explained by the mysterious “placebo effect”, and largely explained within many other trends we are continually discovering about the brain’s self-regulatory mysteries.
We can demonstrate that the brain responds to EEG neurofeedback–see, for examples, the comprehensive work of Mario Beauregard showing PET scan changes after neurofeedback for depression and ADHD, and the very recent study by Newswald et al* that showed statistically significant changes after even one session of infra-low frequency training –but no one has quite demonstrated how those responses turn into the long-term clinical improvement most practitioners frequently note. Call the effect “brain plasticity” (since the work of JM Schwartz and Norman Doidge, most folks recognise that “brain plasticity” means actual cellular structure change as “the brain changes itself”)–and we still do not know specifically how information going into the brain (“biofeedback”) is transformed into these cellular changes.*Newswald, J., Pongpipat, E., Magana, V., Sarkissians, S., Leniki, C., Barb, D. , & Abara, J.P.(November, 2013). The amplitude of the contingent negative variation following neurofeedback procedure. Society for Neuroscience, 43nd Annual Meeting, San Diego, CA.
Personally, I like Siegfried Othmer’s model of the brain monitoring the world and itself by continually predicting succesive states and then altering function as expectations prove just a little off the mark. Neurofeedback can be explained as such: a signal representing even one fragment of the EEG spectrum is streamed back through the patient’s sensory system as the brain is operating. When the millisecond-to-millisecond changes don’t pattern-match the brain’s expectation, it must alert and recalculate. An analogy within conscious experience is seeing a smudge on your face in the mirror and you deciding to wipe it off.
There are now hints that neurofeedback may also be mediated through non-neurons in the brain, the glial cells. Talk about major paradigm shifts! The conventional wisdom has been that glial cells provide support to neurons, and that is true , but there is now evidence that glial cells process and mediate information at some of the frequencies we use for neurofeedback. You can find David Kaiser’s brief review of this topic online.Note, there was exciting news last week of a new support function for glial cells: by contracting during sleep, channels are opened up to “flush out” cerebrospinal fluid carrying neuronal metabolic waste products. The glial cells studied expanded during wakefullness, closing down those channels and thus allowing the cerebrospinal fluid to pool again around neurons, offering fresh nutrition and soaking up neurons’ waste products.
As neurofeedback research continues, the paradox of uncertainty trails with it, keeping us open to new possibilities and explanations. Thank goodness for the trend of neurofeedback efficacy and the not-quite-known that keeps us intrigued. As I was finishing up this blog post, I noticed that Siegfried Othmer had posted his version of how neurofeedback works. I’ll let him have the final summation.There is nothing going on here but the brain engaging with the signal. Once the brain recognizes its connection with the signal, its engagement with the signal is obligatory to the brain. It predicts where the signal is going, and attempts to bring closure between the prediction and the reality. This response exercises the brain’s control mechanisms, which constitutes the exercise that eventuates in the learning of improved self-regulatory control. There is a built-in bias, however. The process tends to take us to calmer states, by and large. This is where improved self-regulation lies: the brain would like to accomplish its tasks at the lowest level of activation consistent with that objective. The additional information about its own state allows it to move in that direction. Adverse reactions result from the fact that the disregulated brain encounters adverse attractor states in its journey through state space. With the impetus of our training, that journey is accelerated. There is, in addition, the parametric sensitivity of the response to training—particularly for the disregulated brain. The underlying mechanisms–neuronal and glial–are undoubtedly the same for all of Neurofeedback.