Category: Scientific

Understanding Bipolar Placement

In the following I hope to demystify some of the aspects of neurofeedback training with bipolar placements, or at least provide substantiation for some of the statements I have been making about it. We are concerned with reward-based training with narrow-band filters that select a particular training frequency. The bipolar montage feeds a differential amplifier that senses the difference in voltage waveforms appearing at the two sites. The signal that is common to the two sites cancels out in the amplifier circuit. This helps us with respect to cancellation of electronic interference that is common to both electrodes, but the same considerations apply to the signal itself. We only get to see the differential signal between the two sites.

For reasons that will ultimately become clear, I am particularly interested in the phase dependence of the signal, mostly because this has been missing from the discussion to date. How can we best illustrate this? One would like to have the same waveform, for example a sinusoidal waveform at the center frequency of the filter, appearing at both electrodes, and to see what happens as we shift the phase between the two signals. The resulting signal would be time-dependent, which cannot be easily shown in a static graphic in a newsletter. So we will do the next-best thing: We will simulate two slightly different frequencies at the two sites. They will therefore progressively move out of phase and then back into phase in yet another sinusoidal pattern, namely at the beat frequency or the difference frequency. This can be shown as a frozen image, as we have done in Figure 1. Continue reading “Understanding Bipolar Placement”

A Simple Proposition

One issue in particular has been weighing on a number of people with regard to our work. It is the question of why a single protocol should be so effective for such a variety of conditions, and why a particular virtue seems to attach to the use of bipolar training, a tactic that has been abandoned by many in the field who have made the transition to QEEG-based training. This issue has come up again recently, so this is not a bad time to discuss it. A secondary issue is why inter-hemispheric training should hold such special virtues for us, but that issue can await its own individual treatment.

First of all, it needs to be recalled that all of the early work of Barry Sterman and Joel Lubar was done with bipolar placement, which is characterized by the fact that both active leads are placed on the scalp over cortex, as distinguished from referential placement in which one active lead is placed on a “quasi-neutral” site such as the ear. Continue reading “A Simple Proposition”

Misbranding

The Food and Drug Administration uses the term “misbranding” to finger any piece of medical equipment for which specific claims are being made that have not been validated in research. When we now survey the field of neurofeedback and consider the various “claims” that we believe to be reasonable to make for neurofeedback, it is seems much closer to the truth that it is the disorders that have been misbranded, not the neurofeedback claims.

Any condition for which neurofeedback is highly effective is probably not what practitioners say it is. We can start this argument with Attention Deficit Disorder. This “disorder” keeps metamorphosing from one description to another, yet whatever model is currently in vogue is represented as sacrosanct. Apparent throughout this evolution in thinking is that ADHD is not a unitary condition; it is not stable over time within a subject; it is situationally dependent; the boundary between the well and the impaired is not unambiguous; and it is not independent of other defined disorders. To give the impression that this disorder is something discrete on which various professionals actually agree is visiting a kind of fraud upon the public. Continue reading “Misbranding”

A Critique of NIMH’s Major Study of Anti-Depressant Effectiveness

On March 23rd the Washington Post reported in a front-page article on the findings just released from NIMH’s 35-million dollar “Sequenced Treatment Alternatives to Relieve Depression” study. The study results were met with mixed reviews. The url:
http://www.washingtonpost.com/wp-dyn/content/article/2006/03/22/AR2006032202450.html
The results from this study were published in three articles and discussed in an editorial in the New England Journal of Medicine (NEJM):

  1. The 1st article appeared in the January 2006 American Journal of Psychiatry (AJP) and focused on the initial response to citalopram (an SSRI) by 2,876 patients presenting with major depression in either a psychiatric clinic or primary care setting.
  2. The 2nd article appeared in last week’s NEJM and focused on the effectiveness of bupropion, sertraline, or venlaffaxine for patients who failed to respond to citalopram.
  3. The 3rd article appeared in last week’s NEJM and focused on medication “augmentation” by adding either bupropion or buspirone to citalopram for those patients who failed to respond to citalopram alone.

Continue reading “A Critique of NIMH’s Major Study of Anti-Depressant Effectiveness”

Scientific Absolutism

The other day it was 87 degrees in our neighborhood in Los Angeles. Unusual? Yes, but the previous record was 86 degrees, and that was twenty years ago. One can’t base much of a case on such isolated extrema in weather, but viscerally they do give one pause. I have yet to close the sunroof in my car this winter, or to put away my short-sleeved shirts. The heater has hardly gone on in our house at all. Last year was the warmest year on record around the world, the continuation of a consistent trend over the past few years. So far this winter is turning out to be the warmest as well, the winter storm in the East notwithstanding.

To get a better handle on global warming, one should look at those phenomena that have built-in smoothing functions–like arctic ice. Greenland ice sheets have been thinning at accelerating rates, measurably larger every year than the one before, and glaciers are going into accelerating retreat. Evidence is starting to accumulate on the slow-down of the Atlantic Conveyor, with grave prospects for European farmers north of the Alps as climate goes unstable and temperatures plunge in Northern Europe. Continue reading “Scientific Absolutism”

A Tribute to Richard O. Lawrence

Over the years we have been following the technique of using music-based auditory challenges to help with auditory processing deficits, the work that arose out of Tomatis’ original research in France. It is apparently still a much smaller field than our own, and it has had its own growth pains along the way. The field is still small enough that when a key figure dies, it affects nearly everyone in the field because it is likely that he was be known by them all. Richard Lawrence was most recently the Music Director at Advanced Brain Technologies, which authors The Listening Program that we use in our work.

We never met Richard Lawrence, but he has left quite a vacuum among his colleagues. He succumbed to a recurring cancer after more than a year of treatment. Members of his family will continue the work he was involved in with Alexander Doman and Advanced Brain Technologies. Continue reading “A Tribute to Richard O. Lawrence”