Volume 3, Issue 33, August 25, 2005

This week’s newsletter contains several pieces. First of all, Larry Lewis contributed a follow-up piece on the Connectivity Conference. Since Bill Hudspeth’s contribution is relatively new to the field, and because of the complexity of the method, it deserves a more detailed look.

Secondly, we turn to a recent topic on one of the lists: working with the Highly Sensitive Person.

Finally, we finish with a fish story.

Hudspeth’s Method of Coherence Analysis

Author: Larry Lewis

I first encountered Bill Hudspeth’s method of coherence analysis in his presentation at the Connectivity Conference in Armonk NY on July 29-31, 2005; and I am writing this exposition of his method because it seemed to me that his work deserves to be more widely known. Not only is his approach highly innovative, it appears to have yielded unusually good clinical results, particularly in the work of Jon Walker who also presented at Armonk. It is likely that Hudspeth’s method would be better known if it did not involve complex matrix algebra techniques that most people find unfamiliar and difficult to understand. Therefore, I have tried here to be as un-mathematical as possible in discussing it.

In Hudspeth’s method, coherence values derived from 19-electrode QEEG data collection are used to generate a graphical display which consists of a three-dimensional depiction of a cube-like space in which little circles float, something like fish in a fish tank. Upon closer look one sees that there are 19 such circles, each labeled as one of the 19 QEEG electrode sites. In general, the circles tend to cluster fairly close to one another; but at times a particular circle stands out because it floats at a distance from the others. As Hudspeth explained, when a circle stands out from the others, it identifies an electrode site that has a problematic pattern of coherence relationship with the other sites.

This display is far from being the usual kind of QEEG coherence display which highlights paired electrode sites when they have unusually large or small coherence values. Hudspeth’s display highlights individual sites only, doing so on the basis of how well the pattern of obtained coherence values for a site agrees with the global patterning of coherence values of all of the sites taken together. The method identifies a site as problematic when its pattern of values does not fit well with the overall pattern. It identifies problematic locations, not problematic coherence values.

Before describing how Hudspeth generates his coherence display, some key concepts will be developed by discussing intelligence testing work which uses a method that is similar to Hudspeth’s but is simpler, easier to understand and probably somewhat familiar already. The method in question is factor analysis.

In this area of work, it has long been known that how a person scores on different measures of intelligence largely depends on the strengths of his or her performance in two major areas: Verbal ability and Spatial ability. A simple, concrete example of how this has been established would be as follows. Suppose that a group of people is given a battery of four tests: 1.) Vocabulary; 2.) Verbal Analogies; 3.) Embedded Figures; 4.) Object Rotation (1. is a test of word knowledge; 2, of verbal thinking; 3, of facility in visually analyzing a complex design; 4, of facility in internally manipulating a mental image). In a situation such as this (i.e. 1 and 2 particularly involve Verbal ability while 3 and 4 particularly involve Spatial), the inter-correlations of the group’s results on each of the tests would typically show the following pattern. All of the tests would have positive correlations with one another; but at the same time the correlation between the Verbal tests would be stronger than the correlations of those tests with the Spatial tests and similarly for the Spatial tests, the correlation would be stronger with each other than their correlations with the Verbal tests.

Thus, in addition to the overall pattern of positive inter-correlations, two sub-tendencies exist. It is not easy to detect such sub-tendencies in much larger datasets without the help of a tool such as factor analysis. If, say, there were 30 tests, factor analysis would involve putting the inter-correlations among them into a 30 x 30 table and then performing complex computations on this matrix to “extract” a mathematically defined “factor” for each sub-tendency that was present. For present purposes it is not necessary to know anything specific about how that definition is mathematically expressed except that the computations also generates a percentage number that measures the strength of the factor. That number measures how much of the total amount of correlation information in the matrix has been captured by the extracted factor. In technical terms, the factor is said to account for a percentage of the total variance in the matrix. If the total number of extracted factors is relatively small compared to the size of the correlation matrix and if the sum of the percentages of all of the factors is high, say 80% or 90%, this would mean that only 10% or 20% of the matrix information has been left out of account and that the factor analysis had thus achieved an efficient grasp of the major underlying factors in the starting data.

At this point in the process, all operations have been mathematical. The factors have been identified mathematically but have not been given verbally expressed meaning. To accomplish that, the “loadings” for each of the tests in the dataset on each of the factors are computed. These numbers measure how strongly each test is involved with each of the factors. In the present example, the Vocabulary test would thus have a high loading on the Verbal factor and a low loading on the Spatial factor. By studying the nature of the tests that load highly on a given factor, one is finally able to verbally define what the factor is about and thus apply labels such as “Verbal” or “Spatial” to them.

That a dominant Verbal-Spatial pattern is typically found in factor analyses of intelligence tests should be no surprise given that there appears to be no larger form of differentiation of function in the human brain than that between the left and right hemispheres. Verbal functioning is well known to be primarily left hemisphere and spatial functioning, right. These two major factors do not come out of the blue; instead they exist in the test data because of a fundamental way that the brains of the people who generated the test data are organized. This important point deserves re-statement: Whenever it is possible to capture with relatively few factors most of the information in a matrix of measures of co-relationship, it is reasonable to conclude that one has captured in simpler mathematical form something about the fundamental organization of the actual data source.

In essentially the same way that factor analysis has just been described, Hudspeth uses a somewhat different matrix algebra technique called principal component analysis to extract not “factors, but rather “principal components from a 19 x 19 matrix of QEEG coherence values. Note that both correlation coefficients and coherence values are measures of co-relationship. In practice, he finds that extraction of just four principal components usually yields results that closely approach the ideal previously described of accounting for most of the information in the matrix. This means that he thus gets a mathematical handle on the major functional patterns of connectivity in the person’s brain. These four components measure the dominant, major patterns in the ways that the 19 electrode sites simultaneously relate to one another.

His method then uses the “loadings” (described earlier) that are computed for each electrode site on each of the four components to plot displays. Because we live in a three- dimensional world, one display is devoted to one of the sets of component loadings while loadings on the other three components are used for the three dimensional display described earlier. This main display is plotted in much the same way that Compressed Spectral Arrays are generated using measures of time, frequency and amplitude along the three axes of the display. Here the axes of the cubical display are based on the sets of loadings for three of the components.

The distribution of electrode sites in the main display does not depict the strength of their coherence relationships with one another. When sites cluster closely together in the display this does not mean that the sites have high coherence values with one another. Indeed, the coherence values that each site might have with the other sites in a cluster might variously be small, large or medium. Instead the clustering exists because the sites that belong to it are those that work well together to produce the global patterning of connectivity that the principal component analysis has grasped. Similarly, an electrode site that stands apart from the clustering is one that shows a dysfunctional relationship with the overall organization of connectivity.

This organization exists in any person except when extreme pathology is present. In most cases, the problems addressed by any form of therapy exist within the otherwise, more-or-less-healthy organized functioning of the person. Moreover, part of that healthy functioning consists of those self-healing processes without which the therapy is impotent. The clustering of electrode sites in Hudspeth’s display represents the integrated organization of connectivity in the individual’s brain. Without the context of that organization, it would not be possible to identify sites that are not well related to it. In an analogous way, the factor analytic identification of specific types of intelligence depends upon the existence of an overall pattern of positive inter-correlation among all types of tests.

In the conventional QEEG analysis of coherence values, the detection of a problematic paired-site value says little about its source location. Is it at one of the electrodes sites, or the other, or both? Moreover, the actual value obtained is not simply a reflection of the functional relationship of only the two sites in question. Rather, the way each site functions individually is influenced by its relationship with many other sites and these multiple influences will affect in unknown ways the strength of any of the single, paired-site coherences that are measured. The conventional approach looks at paired sites in a piecemeal fashion and ignores much of the information that exists about those multiple influences in the full set of coherence values. While eyeballing the separate problematic coherences in a conventional Q display will sometimes indicate that a particular single site needs attention, Hudspeth’s results often differ from such conclusions, sometimes even identifying sites that the usual approach finds no problem with at all.

Both the uniqueness and strength of Hudspeth’s approach is that it utilizes in a single analysis much of the information that is present in the 171 coherence values (19 times 18, divided by 2) that QEEG data collection generates. This gives the analysis great power as shown in the Jon Walker’s work with learning disabilities. This is an area in which neurofeedback has not been very successful in the past. When working with a particular disability, Walker first makes a list of the brain locations that might be involved in the person’s problem, basing this list on established neurological knowledge of the brain’s modular functioning. Then, if any one of the locations on the client’s list is also a Hudspeth “stand out”, he trains there and finds that he often gets surprisingly swift, good results. Hudspeth also reported much the same with other case material. This radically new method appears to have enabled a new level of clinical effectiveness. Surely it deserves to be more widely known.

NOTE: In his workshop at the upcoming iSNR conference, Hudspeth will present new slides said that will help understanding of his technique.

Larry Lewis, PhD
155 East 38th Street (corner Third Avenue)
New York NY 10016
212-697-5990
llewis@nyc.rr.com

Ruminations on the Highly Sensitive Person

Some while ago Hershel Toomim observed that some clients are significantly more sensitive than others to a thermal probe used to monitor pain sensitivity. In pursuit of this interesting finding, he came upon the book by Elaine Aron titled “The Highly Sensitive Person.” More recently, Martin Brinker has found the same phenomenon in his practice in Berlin. So who are these highly sensitive people, and what characterizes them?

Our own approach to this question is very much driven by our neurofeedback experience. Some individuals are clearly much more sensitive to the particulars of the training than others. It is from these people that we first learned of the parametric sensitivity on reward frequency. In extreme cases, such sensitivity can be at the quarter-Hertz level, with some clinicians even asking for vernier control at the tenth-Hz level in order to accommodate such sensitive folk. Once this dependency of response on reward frequency is well established for these people, it is looked for in others as well. We find that the dependence is there in general, but with some people it has to be probed for more diligently. They are simply not as sensitive to their own state. An analogy here might be to the tender points in fibromyalgia. Even among those who are not plagued with fibromyalgia, the common tender points may show a lower pain threshold than other points on the body under modest pressure. So what differentiates people is more a matter of overall sensitivity to pain than the peculiar feature of specific tender points.

The people who are most sensitive to the particulars of a neurofeedback protocol are first of all those who are unstable in their physiology, especially those with fibromyalgia or migraines, but also including those with a trauma history. In reading Elaine Aron’s book, however, one does not get the strong sense of a necessary connection between the highly sensitive physiology and psychopathology. In fact, highly sensitive persons may consider themselves quite functional and healthy, and even be correct in that appraisal. So it may be necessary to distinguish a class of those who are “born sensitive” and those who “become sensitized.”

We may not be able to draw a firm connection between “sensitive” and “disregulated.” There is apparently a broad distribution in sensory sensitivity in which we can live without significant compromise of function. Of course each pattern of responding would call for very different accommodations to the challenges of our environment. I can illustrate this from within our own household. I turn the stereo up; Sue turns it down. I turn the intensity to max on the torchiere; Sue prefers subdued lighting. There is for her no such thing as background music, or incidental conversation. Music in the room will always be attended to. Studying in the library, where conversations would always be readily audible, was always out of the question. Sue will not be seen at loud parties. She avoids the contentious ambience of neurofeedback conferences. Sue withdraws from confrontation. In sum, Sue is a highly sensitive person.

We are much more likely to have a clinical concern with respect to folks who have become sensitized through life events---through trauma, toxic exposure, pediatric encephalitis, acquired traumatic brain injury, etc. In these cases, the sensitization can be not only in the sensory modalities but also in interoceptive sensation (our interior sense of the state of the body), in autonomic responding, and in emotional reactivity. And fortunately in these cases the reactivity is responsive to our neurofeedback interventions. Whereas our intrinsic sensory sensitivity may not be altered much by our training, it does appear possible to train our susceptibility to symptom formation even in the highly sensitive constitution.

There are two prominent and specific classes of sensory sensitivity that readily come to mind. The first is Irlen Syndrome, and the second is Auditory Processing Disorder. In Irlen Syndrome we are dealing with a structurally grounded visual processing deficit. This condition alone is sufficient to qualify a person as “highly sensitive.” Further, the resulting disregulation of cortical processing can perturb other regulatory systems. The Syndrome is not directly remediable through neurofeedback, although we can help to minimize the radiating effects on other systems. It is intriguing to observe that the incidence of both Irlen Syndrome and of the “Highly Sensitive Person” is deemed to be about 20% in the population. One suspects a huge overlap.

The second major category is Auditory Processing Disorder, in which the detection system is over-matched by the complexity of incoming signals. Left unremediated, the sensory processing deficit likewise radiates to impinge upon other regulatory systems. Thus one “highly sensitive system” sensitizes others. In both of the above instances, the behavioral remedy of first resort lies in reducing the challenge to the system by lowering light intensities and overall sound levels, and by reducing the complexity of inputs.

In summary, we view the Highly Sensitive Person largely from the physiological perspective. Such sensitivity, although it is not intrinsically pathological, places the person closer to the threshold of symptoms. Neurofeedback can successfully move people further away from the symptom threshold, but the protocols may need to be tailored to the individual for optimum benefits.

A Fish Story

The local newspaper reports on an 11-year-old phenom, Ianna Gilbert, who has been reeling in world records in fishing. She currently holds seven world records, with an eighth pending. She still collects dolls. How does this happen? Don’t fish bite pretty much on their own? If you throw them bait, will they not feed? Why should getting fish to eat be about as difficult as getting animals in zoos to mate? I am mystified on both counts. Fishermen in our readership will roll their eyes. Obviously I do not have a clue about fishing.

Ok, then, let’s talk about neurofeedback. If you hook kids up to electrodes and show them a video game, will they not train? If it is possible to argue that a fisherman has something to do with success in fishing, is it not even more likely that success in neurofeedback (particularly with oppositional ADD kids) may have something to do with the clinician? And if that is so, how is that accommodated in the research, particularly if such research would be completely invalidated by the finding that a clinician had anything to do with the results?

Tackle companies are lining up to sponsor Ianna’s tours on the fishing circuit. Apparently they would not be satisfied with blind testing of their gear. They could, for example, just tie the gear up to a pier, toss the line out, and objectively count the resulting haul. Nope. They want a real fisherman to bias the results.

If we accept that Ianna’s seven world records are not a statistical fluke, then an intriguing question might be: what makes Ianna special? No doubt she learned fishing early on from her father, but that holds true for many. I wonder if she might not be a “Highly Sensitive Person,” someone who is exquisitely aware of her environment just because it intrudes so much.

Might it not further be the case that highly sensitive persons make good neurofeedback therapists because they are already sensitized to the issues that may agitate their clients, and because they have already walked in their moccasins? Is it not likely that persons who are overly sensitive to the environment might be particularly good at discerning levels of comfort and of discomfort in their clients? Above we drew a distinction between the phenomenon of extraordinary sensory sensitivity and of disregulation. On the other hand, the existence of such sensitivity heightens the impact of any disregulation that may exist. Highly sensitive people may resonate instinctively with a model that makes that connection explicit. In our new pain chapter (reference below) we make the case for a progressive disregulation cascade in chronic pain. The highly sensitive person may be particularly vulnerable here; and the highly sensitive clinician may be particularly effective in remediation.

Our Recent Publications

“Efficacy of Neurofeedback for Pain Management,” Siegfried Othmer and Susan F. Othmer, Chapter 50 in Weiner’s Pain Management, Seventh Edition: A Practical Guide for Clinicians, edited by Mark V. Boswell and B. Eliot Cole; Taylor and Francis, Boca Raton, Florida (2005)

“Effects of an EEG Biofeedback Protocol on a Mixed Substance Abusing Population”, William C. Scott, David Kaiser, Siegfried Othmer, and Stephen I. Sideroff, American Journal of Drug and Alcohol Abuse, 31 (3), 455-469 (2005)

"The Subjective Experience of Neurofeedback," Siegfried Othmer, Vicki Pollock, and Norman Miller; in "Mind-Altering Drugs, The Science of Subjective Experience," Mitch Earleywine, Oxford University Press, London (2005)

“TOVA Results Following Inter-Hemispheric Bipolar EEG Training”, J.A. Putman, S.F. Othmer, S. Othmer, V.E. Pollock, Journal of Neurotherapy, 9(1), 37-52 (2005)