Northeast Regional Biofeedback Society Fall Conference
by Siegfried Othmer | November 24th, 2008
The program of the Northeast Regional Biofeedback Society Fall Conference, convening on the grounds of the former Women’s adjunct college of Rutgers University in New Brunswick, NJ, quite possibly pointed the way to our near-term future, namely the mutual accommodation of the biofeedback and neurofeedback perspectives. The one-day conference was preceded by an all-day seminar on Heart Rate Variability (HRV) training, conducted by Paul Lehrer, Bronya and Evgeny Vaschillo, and Maria Karavidas.
Ever since I first heard of the renaissance of HRV training on the basis of the pioneering Russian work in that area, I have been starting off the discussion of neurofeedback in our training courses with an introduction to HRV training. It illustrates a number of concepts that carry over into our work. It was a relief to hear that the essential concepts have only become even more firmly established over recent years.
First of all, in HRV training it becomes readily apparent that the effects are greatest when the training is conducted at the resonance frequency of the blood-pressure and heart-rate regulatory systems. Under the forcing function of the breath, heart rate follows the breath waveform, and the blood pressure responds in turn to the heart rate, with some delay. At some specific breathing rate, the blood pressure will be out of phase with the heart rate, putting the regulatory mechanisms under maximum duress—but doing so under the most benign conditions of the trainee doing nothing more than paying attention to the breath. It is under these conditions that the heart rate and the blood pressure swing most widely, under their mutual interaction. This regulatory system has oscillatory characteristics. It is, in other words, a resonant system. With paced breathing, the whole resonance curve of the system can be quickly mapped out, and from that point on the paced breathing is set to match the person’s resonance frequency.
The above resonance frequency falls in the vicinity of 0.1 Hz, or nominally six breaths per minute, and covers a range of 4.5 to 6.5 breaths per minute. This is in consequence of a response time constant of about 5 seconds in the baroreflex (blood pressure regulation) system. A second resonance frequency has been identified, involving in this case the even slower response of the vascular tone regulation mechanism. This resonance frequency falls in the range of 0.03 Hz, and is also useful for self-regulation training. This frequency is in consequence of the nominally 15-second time constant of the vasodilation/vasoconstriction mechanism.
The commonalities between this approach to self-regulation and ours in neurofeedback is quite remarkable. We are also constrained to find the single resonance frequency at which our work can be most effectively conducted with a particular client. We are now also probing the domain below 0.1 Hz with many of our clients. And we are having to come to terms in feedback with slowly changing signals.
Paul Lehrer moves beyond the reliance on paced breathing after a while, and asks the trainee simply to track his own heart rate with the breath. That keeps the breath and heart rate in synchrony, and in practice takes the trainee close to the resonance frequency that has already been identified. So the client is training on a fairly slow waveform, while simply wishing for its amplitude to increase. Essentially the same thing happens with the trainees that have low resonance frequencies in neurofeedback.
There is an even greater commonality between the two approaches, namely that the training is neither diagnosis-dependent nor symptom-specific. “We use this for everything,” says Paul Lehrer, who is not given to casual commentary. Similarly, our kind of resonance frequency training is almost entirely independent of the symptoms coming in the door. Even in areas where certain correlations are apparent (i.e. all autistics train at very low frequencies), the specifics remain unpredictable.
The logical chain of argument is as follows: Dysregulation in human regulatory systems is likely to be reflected in autonomic dysregulation. Training autonomic regulation in turn has beneficial fallout for regulation more generally, even beyond the autonomic nervous system (ANS). In fact, there does not even have to be a deficit in ANS regulation for the system to benefit from exercising the ANS regulatory loop. All this carries over nicely to neurofeedback.
There is an even further analogy to our kind of neurofeedback, namely that no one looks to long-term changes in HRV during normal life events to document that useful change has in fact taken place. That effort was given up long ago. We don’t go around in life breathing at six breaths per minute, or at our resonance frequency. Training is being conducted under rather artificial circumstances, and what we measure there does not carry over directly. So it is with neurofeedback. Unless the EEG is manifestly deviant at the outset, it is unlikely to show much change with training except possibly during the session itself.
Remarkably, then, we find ourselves in much greater kinship with current opinion in biofeedback than with some of the models being forced down our throat in neurofeedback. The difference, no doubt, is attributable to the fact that biofeedback people have been beaten up by nature for some four decades now, and finally a kind of resignation has taken hold in the presence of all these compelling data: Robust clinical results were often not matched by comparable change in the measures. Not only that, but it turns out that we had been doing HRV entirely backwards for many years. With the central precept of homeostasis as our guidestar, we had been avidly training HRV down toward more stable levels.
On a visit to St. Petersburg many years ago, Paul Lehrer found out to his chagrin that the Russians were training to increase HRV rather than decrease it, and they appeared quite confident that they knew what they were doing. They were training cosmonauts and top athletes. Clearly their patients were not succumbing to such malpractice. Eventually, their methods were brought to the States, and HRV began to flourish again. Now the question arises, when we were training HRV down originally (at Menninger, for example), were we killing our patients? The answer is again no. There were no casualties. We were just challenging the system, and it self-corrects even for our errors in judgment.
Paul Lehrer pointed out another example along the same lines. Relaxation training does not particularly help asthma in the short term. It might even make things worse by triggering a parasympathetic instability, i.e. an asthma attack. But if one persists with relaxation training, it can indeed help asthma susceptibility in the longer term.
This points out yet another element of commonality with neurofeedback. We do not need to work against a manifest deficit. It is only necessary to exercise the system, and to do it in the most efficient way possible. In both HRV and EEG feedback, that consists of Resonance Frequency Training.
Somewhat newer on the block, many neurofeedback enthusiasts are still in the mode of trying to impose their kind of Platonic order on the data. EEG anomalies must be looked for as targets of training, and the anomalies must resolve with training before we are allowed to believe our own clinical results. These guys are gnawing on rubber. The biofeedback literature is littered with papers where such dependences were looked for in vain. Now with HRV every vestige of such expectation has been abandoned. Our success must be found in better self-regulatory performance, nothing more. If more is found, then that’s nice, but our work does not stand or fall on the basis of such evidence. One does not have to qualify by virtue of certain thresholds of dysfunction, and there is no direct criterion of completion in either HRV or EEG that would indicate that the person has arrived at the goal. We have no alternative but to rely on functional assessments. No matter how much data accrue in support of the traceability of outcomes to the training variable, the contrary hypothesis is not thereby dislodged.
On the Reunification of Biofeedback and Neurofeedback
The above somewhat selective treatment of Paul Lehrer’s workshop is a good entry into the larger theme of the reconciliation, if not reunification, of peripheral biofeedback and EEG neurofeedback. On the conference day itself there were a number of presentations that fit the theme. Jeff Carmen talked about his work with passive infrared thermal imaging of the forehead, which at least partially reflects pre-frontal cortical activity. Whereas his primary use is in application to migraine, Jeff is covering a number of other bases with the same approach. The technique occupies the ambiguous boundary between neural activity and supportive metabolic mechanisms. Significantly, Jeff seems to be moving away from discrete objectives in the training and more toward an exercise model.
Steve and Robin Larsen presented on the LENS method, the rules for which derive strictly from the instantaneous EEG and have nothing to do with the underlying diagnosis. Subsequently I presented on the Disregulation Model and of EEG feedback as a generic Self-Regulation Remedy. Then we went into a panel discussion to draw all of the threads together.
There is a common message here of a variety of simple techniques that serve to provoke the re-regulation of the system. None of the techniques have definitive objectives relative to the measured parameters. The objective lies outside of the compass of the immediate measurement, for example in greater resilience of a regulatory system, in better maintenance of its appropriate operating points, and in greater overall stability. It was brought up that NeuroCarePro very much fits into this schema as well, and that Val Brown has been advocating the same theme for some years now.
Readers may wish to pursue this further in the following article:
http://www.eeginfo.com/research/researchpapers/Neuromodulation_Technologies.pdf