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EEG Biofeedback: A Generalized Approach to Neuroregulation, Othmer S. Kaiser, DA, Othmer SF
To appear in "APPLIED NEUROPHYSIOLOGY
& BRAIN BIOFEEDBACK"
Edited by Rob Kall, Joe Kamiya, and Gary Schwartz
Page 1 of 13
Overview
Many clinicians who have adopted EEG biofeedback are struck by the
wide variety of clinical indications for which efficacy has been
either observed directly, or claimed by others. This chapter presents
a comprehensive overview of the current state of EEG biofeedback
from the clinical perspective, but with an orientation toward model
building. Specifically, the review covers the higher frequency training
conventionally referred to as "SMR/beta" (nominally 12
to 19 Hz). Discussion of the lower frequency domain of "alpha/theta"
(4 to 12 Hz), though of great interest as well, is left to others.
INTRODUCTION
First, a conceptual model is proposed and discussed. Second, the
research history of the field is drawn upon to illustrate the evolution
of protocols and explain elements of the emerging model. Third,
an overview of our clinical results is given that depicts the use
of the proposed "generalized approach" for a number of
mental disorders. These results were obtained with a relatively
limited set of clinical protocols that evolved out of our extrapolation
of new methods from the original research. From these results emerges
a need to explain how such broad efficacy can be achieved. It is
postulated that the EEG feedback technique not only promotes particular
functional states of the brain, but more generally exercises neural
mechanisms by which the fundamental functions of arousal, attention
and affect are managed by the central nervous system (CNS). Rhythmicity
in the EEG is seen as a key variable in the coordination of cortical
activity, and clinical improvement is traceable to improved neuroregulation
in those basic functions by appeal to their underlying rhythmic
mechanisms. Current models of brain function are used to explain
both the frequency and the spatial specificity of the EEG biofeedback
process.
It will be demonstrated in the following that EEG biofeedback cuts
across the bestiary of clinical diagnostic categories that has been
devised over the last thirty years, demonstrating an ability to
remediate a multiplicity of diagnoses with a limited set of protocols.
It acts directly on underlying physiological mechanisms, and presupposes
a considerable functional plasticity of the brain, a concept that
has only recently become a significant subject of inquiry within
the research community. Such plasticity appears as "noise"
in the search for the genetic basis of behavior, and as such has
asserted itself primarily in its negative implications for such
work. It will be argued that EEG biofeedback affects brain function
at the network level, and a preoccupation with processes at the
molecular, membrane, or even cellular level is not particularly
illuminating for brain function at the higher levels. The implicit
assumption of the bottom-up approach of the neurosciences seems
to be that a viable conceptual model of the network cannot be constructed
until we know the detailed workings of all the parts. Yet EEG biofeedback
has proven to be a valuable clinical tool (as the data cited will
show), and has stimulated the creation of a conceptual model based
on such a top-down, systems approach. .
EEG biofeedback can be best understood, and its relevant mechanisms
discerned, by viewing the brain through the action of its web of
inhibitory and excitatory feedback networks. Such networks require
explicit mechanisms to manage them, integrate them, and assure their
functional integrity. These networks must meet global stability
criteria irrespective of what neurochemical implementation nature
has, by evolutionary happenstance, devised. No doubt the technique
impacts very specific neuromodulatory mechanisms, which remain undefined
at this time. The clinical work can nevertheless proceed fruitfully
on an empirical basis. Thus, EEG biofeedback is deemed to address
itself to the core issue of control, with specificity at the network
level, and yet with considerable generality in terms of clinical
implications.
Click foEEG Biofeedback: A Generalized Approach to Neuroregulation
By Siegfried Othmer, Susan F. Othmer, and David A. Kaiser
To appear in "APPLIED NEUROPHYSIOLOGY
& BRAIN BIOFEEDBACK"
Edited by Rob Kall, Joe Kamiya, and Gary Schwartz
Page 2 of 13
A Comprehensive Conceptual Model
In order for the field of EEG biofeedback to move forward and fulfill
the promise that it has shown thus far, it is necessary to create
a conceptual model that will explain the clinical results that have
already been achieved in a way that will answer questions raised
by skeptics, as well as facilitate a greater level of understanding
and efficacy on the part of practitioners. The conceptual model
presented here describes the characteristics of human neurophysiology
upon which EEG biofeedback is based, how the process works, and
why such wide-ranging efficacy can be gained by means of such a
seemingly simple process.
Structure Versus Function
Before proceeding, it is necessary to clear some semantic underbrush:
Though the process presented here is based on a "functional"
approach, the hard distinction between structure and function survives
in the tenacious tradition of the language of dualism. That is,
structure and function are seen as the realization, if you will,
of brain and mind, respectively. Every brain function, however,
must have its structural underpinnings, so the more tangible distinction,
and the one more accessible to experiment, is one based on the timescale
of change and the ease with which change can be induced. Most of
what we consider in terms of brain function involves typically rapid,
transient changes in the electrical activity in the brain, activity
which may leave little in terms of residual imprint. Most of what
we consider in terms of brain structure is that which remains essentially
unchanged over longer time constants. This is a continuum, and over
much of the range in timescale, one can appropriately describe a
phenomenon either in the vocabulary of structure or that of function.
One analogy that comes to mind is the redefinition by David Bohm
of a noun as a "slow verb".
Another way of looking at the structure/function duality is in the
division between hardware and software in computers. On one hand,
we have the true hardware, the semiconductor devices and ancillary
items needed to service and operate them. On the other hand, we
have the operating system software. Though this can be changed,
it is generally modified only rarely and deliberately. At the next
level is the applications software. A number of different modules
may be drawn upon (brought to consciousness?) at a given moment,
and there is in fact considerable "interaction" with the
outside world which may make "functional" changes in the
application software; and there may even be some adaptation to what
the user typically wants. At the top level is the phenomenology
of what is created with the applications software, which has typically
a very transient quality (e.g., imagery). One could argue that at
each level we are dealing with physical electrons moving around
from site to site (structure), but that would be cumbersome, and
not really to the point. Similarly, one could talk about software
failures in terms of "electron deficiencies" in certain
memory locations. This is both true and absurd as a model for software
failures. Every level has its appropriate terminology, referring
progressively to structure, function, and objects (gestalts).
The categories distinguished here can find their analogues within
the brain. However, the boundaries are not as discernible and the
distinctions between structure and function even less definitive.
Nevertheless, let us push the analogy forward a little further:
A similarity can be drawn between our brain's neuromodulator systems
and the operating system software of a computer. There is persistence
in the workings of our neuromodulator systems that puts them on
a different timescale than the applications software (which might
involve the processing of a visual image, for example). Yet it would
not be correct to regard the characteristics of a person's neuromodulator
systems as immutable (even absent any drug intervention). Over time,
it is clear that environmental influences, for example, can effect
changes in neuromodulator function. A person may become more or
less hypervigilant over time; he may become more depressed or anxious.
He could also, however, achieve "spontaneous" recoveries
from depression, which can be simply interpreted as autonomous normalization
of neuromodulator functioning.
The distinction, therefore, between categories of structure and
function is not based so much on issues of transience versus immutability,
per se, but rather on a multiplicity of factors: the timescale of
change; how matters have been historically viewed; and the level
of abstraction which is appropriate to the discussion. This whole
issue is currently very much in flux, and somewhat confused. We
have, for example, the following from Michael S. Gazzaniga, director
of the Center for Neuroscience at the University of California in
Davis: "When someone remembers something, is there a structural-or
discrete anatomical-change in neuronal synapses? Or is it functional
change, which would simply reflect reprogramming of the pattern
of neuronal discharges in the nervous system?" (Gazzaniga,
1995).
Here the posited "structural" change could equivalently
be talked about in terms of function, and the posited "functional"
change (which clearly must be sufficiently robust to persist long-term
if it is to represent a memory) can be talked about in terms of
structure (altered synaptic coupling strengths).
Click for Next Page
EEG Biofeedback: A Generalized Approach to Neuroregulation
By Siegfried Othmer, Susan F. Othmer, and David A. Kaiser
To appear in "APPLIED NEUROPHYSIOLOGY & BRAIN BIOFEEDBACK"
Edited by Rob Kall, Joe Kamiya, and Gary Schwartz
Page 3 of 13
Brain Plasticity
If we are intent on maintaining the structure/function dichotomy,
we are ineluctably in a semantic swamp. This is at least in part
because the neurosciences are in the process of coming to terms
with mounting evidence for what is collectively called "brain
plasticity", and the old dualist terminology no longer serves
us well. In its most general formulation, EEG biofeedback can be
seen as the deliberate exploitation of 'functional brain plasticity'.
More specifically, it depends upon plasticity in our neuromodulator
systems. However, this concept is at best ambiguous, and a moving
target. Simply put, brain plasticity refers to long- term alteration
in brain systems that were historically thought to be static. Hence,
the word tends to have a historical contextual reference, much like
the word 'alternative health': once an intervention becomes mainstream,
it is no longer "alternative". Similarly, once plasticity
becomes accepted as an attribute of a particular brain system, the
term tends to be discarded and future references may simply be to
brain function. Hence the term brain plasticity tends to have only
a transient utility, and to serve only where the case for plasticity
is still being made. However, making the case for EEG biofeedback
on a model of brain plasticity may be the most accessible Ansatz.
To make the term maximally useful for our purposes, a review is
in order. A remarkably prescient view of the model of brain plasticity
is to be found in Brodal (1981, p. 259):
"Although our knowledge about the 'plasticity' of the nervous
system is still in its beginnings, there is reason to believe that
this plasticity is a general property of the central nervous system,
and that it is a prerequisite for the capacity to learn (in general,
be it motor patterns or pure intellectual capacities). Restitution
after damage to the central nervous system may therefore in essence
be likened to a learning process. Practical experience is in agreement
with this."
A more modern view is summarized by Oliver Sacks in the popular
book, An Anthropologist on Mars. (The views of neuroscientists are
often more boldly expressed in their popular writings as opposed
to their scientific ones, where they are compelled to be more reserved
and circumspect.)
"Work in the last decade has shown how plastic the cerebral
cortex is, and how the cerebral 'mapping' of body image, for example,
may be drastically reorganized and revised, not only following injuries
or immobilizations, but in consequence of the special use or disuse
of individual parts. We know, for instance, that the constant use
of one finger in Braille leads to a huge hypertrophy of that finger's
representation in the cortex." (Sacks,1995, p.41)
Here the focus is on the long-term dendritic re-programming and/or
regrowth, which has been shown to occur. However, there has still
been little recognition of the obvious ability of the brain to accomplish
significant reorganization on time scales much shorter than that
of dendritic regrowth, which requires simply changes of state, and
of regulatory function, that is, of functional rather than structural
reorganization. This is now changing:
"Reorganization of somatic sensory receptive fields can appear
within the dorsal column nuclei, the thalamus, and the cortex, within
seconds of a peripheral manipulation. Similarly, motor cortical
maps show dramatic shifts within hours of a peripheral nerve lesion
or [within] minutes of a shift in arm configuration." (Donoghue,
1995)
When considering the reassignment of cortical neuronal resources
within a time constant of seconds, one wonders if "plasticity"
is the appropriate descriptor for the phenomenon. This is another
case in point of the use of the term to describe as mutable something
thought to be more permanently stable. If cortical resources can
be so readily reassigned, then the mechanisms involved in stabilization
must lie principally in the functional rather than structural realm.
That is, there is less hard wiring than was thought! Thus we are
likely to see the language of structure replaced over time by the
language of function, and eventually we will see the disappearance
of the term "plasticity" altogether in this connection.
With this in mind the term functional plasticity may be used to
refer to all those processes by which brain functions thought to
be relatively stable can be altered on a timescale short compared
to that of dendritic regrowth, or the formation of new synaptic
boutons. Functional plasticity is undoubtedly mediated, inter alia,
via alteration of synaptic coupling strengths through the generation
or attrition of receptor sites, and the alteration of neurotransmitter
chemistry through changes in neuronal gene expression. The present
interest will focus specifically on the neuromodulator systems and
their regulation. Here the observed "functional plasticity"
can have time constants short compared even to the above-postulated
processes. For example, when we are frightened, we are capable of
changing our state of arousal within fractions of a second. The
functional plasticity of neuromodulator systems clearly exists on
all behaviorally relevant timescales. The claim of EEG biofeedback
is that the dynamic range of neuromodulator system plasticity (flexibility)
can be increased where it is deficient, and stabilized when it is
unstable, by operant conditioning techniques.
Functional Plasticity: Implications of Recent Research
A number of developments over the past several years have prepared
the ground for the claims we are now making for EEG biofeedback.
First of all, the findings from functional magnetic resonance imaging
(fMRI) are refocusing attention on collective neuronal activity;
its time course, temporal interrelationships, and change as learning
and habituation take place. Inevitably, these findings will raise
questions about how such neuronal populations are organized and
managed by the brain. Secondly, there is the ongoing research into
the thalamocortical generation of rhythmic activity in the EEG by
Mircea Steriade, David McCormick, and others. (Steriade, 1984; McCormick,
1990) Thirdly, there is the emerging interest in the binding problem,
the mechanism for how the brain retains as a coherent phenomenon
something that is parallel-processed at multiple neuronal sites
(a visual image, for example, or a phoneme.) (von der Malsburg,
1995). We shall return to this critical theme below.
At another level, it may be said that much of psychopharmacology
implicitly makes the case for the kind of functional plasticity
required to explain the presumptive efficacy of EEG biofeedback.
Quick-acting medications like stimulants can only operate by shifting
the functional state of neuromodulator systems; there is no time
for significant structural adaptation. The short-term effects of
EEG biofeedback can be explained by similar shifts. The longer-
acting medications such as anti-depressants and anti- psychotics
work on the same timescale as the cumulative effects shown in many
of the recoveries claimed for EEG biofeedback. The effect of Prozac
administration, for example, can be discerned in the cerebrospinal
fluid within hours, just as with stimulants, and yet its anti-depressant
effects may take days or weeks to manifest. Such medications may
work by means of longer-term adaptations that involve both functional
and structural change. But it is not a large leap to argue that
such changes can be induced over time by the challenge to the nervous
system imposed by operant conditioning of the EEG. Both EEG biofeedback
and pharmacological intervention can even be seen as a disequilibration
of nervous system functioning to which the brain responds by long-term
adaptation. In this view, their mode of action is seen to be uncannily
similar. Regardless of whether or not this concept can survive further
scrutiny, it is clear that the claims of EEG biofeedback are consistent
with, and certainly not antithetical to, the implications of pharmacology.
Efficacy of pharmacology for a variety of psychiatric disorders
is often taken to imply that such chemical intervention is absolutely
required for remediation, by analogy to the provision of insulin
in the case of Type I diabetes. That this is not the case is demonstrated
by the efficacy of electro-convulsive shock therapy for depression.
Here the remediation may be long-term even absent any long- term
pharmacological support. Additionally, spontaneous recovery from
episodes of both mania and deep depression is the rule, not the
exception, in even mature cases of bipolar disorder. Clearly, these
brains have quite functional states within their inventory. The
question of efficacy of EEG biofeedback (for the vast majority of
applications) is then reduced to the relatively minor issue of whether
a change in functional state can be induced, or at least promoted,
by operant conditioning of the EEG, and the second issue of whether
such a training can have lasting effects.
In the case of pharmacology, the challenge to the nervous system
is provided by neurochemicals or their metabolic precursors, or
other metabolic agents, or factors which modulate receptor site
sensitivity or ion channel permeability. In the case of EEG biofeedback,
the challenge is to the means by which brain function is organized
and maintained in the time domain, which is reflected in the EEG.
It will be argued in the following that neuromodulator systems function
to organize both general organismic arousal and more localized activation
of collective neuronal activity by modulation of rhythmicity. The
EEG is preferentially sensitive to such collective, periodic, activity.
Click for Next Page
EEG Biofeedback: A Generalized Approach to Neuroregulation By Siegfried
Othmer, Susan F. Othmer, and David A. Kaiser To appear in "APPLIED
NEUROPHYSIOLOGY & BRAIN BIOFEEDBACK"Edited by Rob Kall,
Joe Kamiya, and Gary Schwartz Page 4 of 13 The Bio-electrical Domain:
The Role of Periodicity and the EEGWe must pause in the chain of
argument to admit to a degree of circularity: The normal EEG in
an activated state has the appearance of a noisy signal devoid of
any dominant frequency. Hence, it is not obviously rhythmic (periodic).
Nevertheless, the frequency decomposition of this signal manifests
the bursts of rhythmicity referred to. However, one could decompose
any such noisy signal (the noise from a waterfall, for example)
and obtain band-limited (frequency-decomposition) data looking much
like the EEG, with similar bursts of rhythmicity. Hence, the physical
reality that is ascribed to these rhythms must be based on more
than the EEG signal itself. That is, looking through green sunglasses
(band- limiting visual data) does not allow us to proclaim the world
to be green. In the present context, the most persuasive argument
for the physical reality of these rhythmic bursts comes from the
fact that they appear to respond in a frequency-specific manner
to EEG biofeedback training! However, we should not assume the answer
in order to help us prove it. Historically, the EEG was first studied
with a focus on its most obvious feature, the alpha rhythm. We now
associate a prominent alpha rhythm in occipital cortex with idleness
of the visual system. Similarly, the sensorimotor rhythm (14 Hz
[Hertz]) so prominent in the cat (or in Stage 2 sleep in humans)
is associated with stillness of the motor system (Chase 1971). Inactivation
is associated with increased rhythmicity (increased amplitude),
as neuronal populations coalesce to collective firing under their
mutual influence in the absence of independent sensory stimuli or
other inputs. When activation levels are increased, due to stimulation
or processing, these neuronal populations desynchronize, to a point
at which rhythmicity may no longer be readily observable in the
raw signal. Hence, the normal activated EEG is seen as the relatively
desynchronized extrapolation of manifest rhythmic activity, which
has a defined physiological function: maintaining a state of inactivity,
or perhaps of readiness. A noisy (desynchronized) EEG arises then
from the superposition of many rhythmic generators of different
frequencies, each undergoing its own rapid ebbing and flowing from
rhythmicity to desynchronization. When any one of these generators
reaches the extreme of low activation, it may begin to dominate
the EEG record. "Although our knowledge about the 'plasticity'
of the nervous system is still in its beginnings, there is reason
to believe that this plasticity is a general property of the central
nervous system, and that it is a prerequisite for the capacity to
learn (in general, be it motor patterns or pure intellectual capacities).
Restitution after damage to the central nervous system may therefore
in essence be likened to a learning process. Practical experience
is in agreement with this."Next, it is necessary to make the
case that whatever role the specific EEG frequencies play in cortical
regulation, that role is invariant over cortex. One of the notable
features of the neocortex is that it is morphologically and histologically
fairly homogeneous. Moreover, the same set of neuromodulators, by
and large, subserve a variety of functional subsystems, and are
not unique to any one of them. Similarly, the natural parsimony
which prevails in nature makes it likely that the general role of
rhythmicity in activation and time binding'whatever that role may
be in detail'is probably uniform across cortical regions, varying
only quantitatively over cortex, not qualitatively. Hence, operant
conditioning of the EEG rhythmic activity can be seen as a general
appeal to brain regulatory function, as it is manifested in the
cortical EEG. Depending on scalp location, one may expect some influence
on the specific thalamocortical projections to that region, and
to the specific functions subserved by that cortical region. Also,
one expects some influence on the nonspecific thalamocortical projections,
for a general effect on activation and physiological arousal. Whether
the effect is more localized or more generalized has to be answered
by a review of the data. It is already clear, however, that the
EEG training cannot be specific to one neuromodulator system, as
might be the case for some medications. Recent findings with fluoxetine
(Prozac) make it apparent that even medications which impinge directly
upon one neuromodulator system (serotonin), are behaviorally non-specific
in their effects! (Kramer, 1993) We therefore have every reason
to suppose that EEG training affects and hopefully promotes fundamental
brain regulatory integrity, and that behavioral or other improvements
are simply evidence of the heightening of such self-regulatory performance.
The Specific Role of Rhythmicity in Neuroregulation It has been
argued above that in the extreme cases of EEG synchronization and
desynchronization, an obvious correlation with low and high activation
and arousal, respectively, exists. It is also well known that arousal
correlates with dominant frequency in the EEG. It falls readily
to hand to argue that the degree of rhythmicity, together with changes
in the EEG frequency spectrum, manages the entire range of activation
and arousal in the bio-electrical domain. The EEG, then, reflects
a parameter that the brain tightly constrains in the ordinary course
of events. An appeal to dominant frequency or to the amplitude at
a given frequency by operant conditioning could therefore be expected
to serve as a powerful external forcing function on the brain's
management of arousal. The whole matter of the role of frequency,
however, bears further discussion. One role advocated for rhythmic
activity is that of time binding, the need for harnessing brain
electrical activity which is spatially distributed while maintaining
it as a single entity. The need for this kind of function is apparent
when it is recognized that visual processing, for example, must
occur by parallel processing over large areas of cortical real estate.
The integrity and stability of the image must be maintained over
time. Simultaneity of firing of the various neurons participating
in the mapping of an image may be the relevant criterion of "belonging".
The transient organization of such distributed, correlated neuronal
activity may be the role of the thalamocortical rhythmic generators.
At the lower frequency regimes, say less than 30 Hz, this organization
ranges broadly over the cortex, and manages activation and arousal
with relatively long persistence. At higher frequency regimes, above
30 Hz, and peaking in the 40-60 Hz regimes, the brain manages specific
cognitive processes that are of a more transient nature, and more
spatially localized. A recent study beautifully exhibits both of
these roles of rhythmic activity (Munk, 1996). In this study, a
visual image was moved across the visual cortex under two conditions:
normal, and under electrical stimulation of the mesencephalon (brain
stem region in which the nuclei reside which source the neuromodulator
substances that control attention and arousal.) With stimulation,
a global coherence became prominent in which the firing rates of
neurons in different regions became more coincident. This coherence
was observed over the region of visual cortex that was involved
in mapping the moving image. If the moving image was then changed
into two images, moving in opposite directions, the coherence was
still present, but was restricted to the neurons belonging to each
moving target. This beautiful experiment illustrates the influence
of global activating mechanisms directed from the brainstem. However,
this mechanism was not sufficient to guarantee time binding. That
requires augmentation by information derived from the image itself,
and processed 'locally' in cortex, in order to define the specific
cohort to which each participating neuron belonged. This is a process
of which the brainstem remains ignorant. Hence, time binding requires
both brainstem and cortical governance, and both may be mediated
by thalamo- cortical networks, and may also be modulated by direct
cortical-cortical interaction. It must be kept in mind that most
of the signal processing we do in the brain involves very transient
events taking place on small time scales. The analogy to dynamic
RAMs or to the refresh on your computer screen (every 17 milliseconds)
comes to mind. Further, it is apparent that the real information
content in neural signals (action potentials) relates in first order
(and trivially) to the presence or absence of a particular signal,
and, more significantly, to the actual timing of the signal. The
magnitude of an action potential is not a function of the size of
the stimulus that gives rise to it. Only the timing matters. And
even the timing gains significance only in the context of other
events. All "mental activity" must ultimately have its
basis in particular neuronal firing patterns that become discernible
from the ambient noise background by virtue of timing coincidences
or at least correlations. It is this timing which appears to be
managed by thalamocortical circuitry. Rhythmicity may be one of
the key ways in which such timing is organized. Recent research
by Pfurtscheller (1990) and Sterman (1996), show that the brain's
ability to locally desynchronize in a timely manner defines its
capacity to process the next stage of an ongoing task. The ability
to resynchronize quickly allows it to reenter a state of readiness
for the next task. The process breaks down when synchronization
or desynchronization of specific frequencies persists or is disregulated,
decoupled from the demands of the moment. EEG biofeedback is then
to be seen as a challenge to the mechanisms that underlie the management
of this rhythmic activity, and in application to neuromodulation
of arousal and activation its natural domain is the frequency range
less than thirty Hz. Training is similar to stimulation, and constitutes
a push that invokes the brain's capacity for restoring homeostasis.
Over the longer term, this results in a long-term increase in stability.
Training at a specific frequency is then a push in a very specific
direction, which can be chosen in light of specific arousal disregulation
or attentional deficits found in each case. Click for Next Page
EEG Biofeedback: A Generalized Approach to Neuroregulation By Siegfried
Othmer, Susan F. Othmer, and David A. Kaiser To appear in "APPLIED
NEUROPHYSIOLOGY & BRAIN BIOFEEDBACK"Edited by Rob Kall,
Joe Kamiya, and Gary Schwartz Page 5 of 13 The Placebo ArgumentDoes
EEG biofeedback, with all its instruments, bells and whistles, include
a huge "placebo" component (for which we are not entitled
to claim credit)? The placebo argument sometimes serves as a talisman
which the scientist, comfortable in his paradigm, may use to ward
off disagreeable new claims. However, the placebo effect is no more
than the body's means of mobilizing self-recovery. The placebo effect
is not a cause. It is not itself a mechanism of recovery, but it
does imply a mechanism'though one which may seem featureless and
devoid of testable properties when looked at through the prevailing
structuralist paradigm. Hence, it can provide no help to our understanding.
But EEG biofeedback is by its very nature self-remediation. The
part we are entitled to take credit for cannot be experimentally
distinguished from "other" aspects of the self-healing
process. For researchers attempting to prove the efficacy of medication,
self-recovery represents the counter-hypothesis, which is wrapped
up in the concept of "placebo effect" and need not be
further discussed. It is not of interest to the designer of drugs.
When the discussion is about self-induced recovery (such as EEG
biofeedback) and the mechanisms thereof, then we must openly address
the placebo effect and ask whether its self-healing properties are
any different from what we are claiming. It is a moot point. The
existence of the placebo effect proves the existence of self-remediation.
Self- remediation cannot then be disproved by invocation of the
placebo effect. The existence of a robust placebo effect in medical
and mental health disciplines supports the claims of EEG biofeedback.
It does not undermine them. Still, if one cannot in the individual
case determine what part of recovery is due to the specific effects
of EEG biofeedback training and what part is attributable to non-
specific effects, can one be sure that the effects aren't all in
the latter category? The normal resolution to this question is by
means of statistics. In the case of EEG biofeedback, however, we
are not constrained to rely exclusively on statistics (although
the statistical argument is favorable as well), as there are other
proofs of its efficacy. The placebo effect, seen here as stalking
horse for nonspecific effects of the EEG biofeedback process, is
not the explanation for the efficacy claimed for the following reasons:
1. The effects of the training are highly specific to electrode
placement and to training frequency band. 2. Training protocols
exist which can commonly elicit effects opposite to those desired.
3. The effects of training with one protocol can be reversed with
another. 4. The effect of the training is cumulative, rather than
fading with time, as is common with placebos. If EEG biofeedback
were to be explained in terms of placebo phenomena, it would be
the first time that placebos are dose- dependent (i.e., cumulative).
5. Training effects are in line with research from neuropsychology
regarding localization of function.6. Populations can be moved to
levels of performance which exceed those of nave populations
7. The effects of the training often lie outside the range of expectations
for spontaneous recovery or placebo effects, not only with respect
to the magnitude of the changes elicited but also with respect to
the consistency with which they are produced, and the timescale
over which they occur. (Curiously, the more striking and unusual
the claims for EEG biofeedback, the more strenuously is the placebo
hypothesis invoked by critics!)8. EEG biofeedback was discovered
in connection with animal research. It may be assumed that the test
animals were not subject to the placebo effect. Moreover, the researcher
was blind, since the discovery was by way of serendipitous connection
to an unrelated experiment (Sterman, 1976). The spatial and frequency
specificity of the EEG training, as well as its reversibility, allow
every subject to be their own control in the training. This is not
to say that conventional controlled studies are entirely superfluous.
We are just at the beginning of the scientific inquiry into this
technique, much of which will require controlled paradigms. Rather,
we are asserting that the epistemological assumptions operative
in the clinical setting are already sufficient to demonstrate efficacy
in the case of EEG biofeedback because of the above-enumerated features
of the training. In view of the above, then, the recoveries, remediations,
and performance enhancements claimed for EEG biofeedback may be
regarded on their own merits, and cannot be gainsaid either by placebo
factors or by the argument that they are not individually supported
by blinded controlled studies. Another prevailing perception must
be examined before proceeding with review of the protocols and the
clinical data. It is often asserted that the EEG biofeedback "trainee"
is actually training his own behavior, and that the changed EEG
is simply a manifestation of that altered behavior. Behavioral state
and the EEG are clearly coupled, and a conscious redirection of
one's physiological state can obviously be helpful in achieving
the objectives of the training in the moment. This is the dominant
theme in conventional biofeedback, which is dependent upon a great
deal of deliberate engagement in the process by the subject. This
is not a necessary condition for EEG biofeedback training to succeed,
and in this sense it departs fundamentally from conventional, peripheral
biofeedback. The successful training of cats, of very young children,
and even of people in mild vegetative states, demonstrates that
the training can proceed without the subject being particularly
aware of their behavioral state, or intent upon altering it, or
indeed very conscious about what is going on at all. The training
in this case consists in operant conditioning of the EEG, neither
more nor less. For example, in the use of EEG biofeedback for the
remediation of epilepsy and stroke, it is not "behavior"
in any conventional sense that is being trained. In fact, we have
observed that people can respond quite counter to their own desires,
expectations, and motivations; with the expected effects (and even
some that weren't expected by either the client or the therapist)
arising out of the particular protocol selected. The resulting behavioral
state may be concordant with the protocol selected, and quite at
odds with the participant's conscious goals. Finally, there is the
compelling observation that sleep EEG is changed subsequent to EEG
training in the waking state. (Sterman, 1970) All these observations
are evidence for the proposition that it is 'brain behavior"
that is being trained directly. And brain behavior may be non-specific
with respect to overt organismic behavior. Research History: Implications
for Mechanisms of EEG BiofeedbackIf EEG biofeedback training is
indeed capable of promoting self-healing, its role is that of facilitating
a process of change the capacity for which already exists in the
human brain. But how is it that such an apparently simple tool is
capable of such wide-ranging effects? What is it about the brain
that allows it to be led to more functional states? And how can
the operant conditioning process embodied in EEG biofeedback be
applied systematically and predictably, to good effect? The implications
of our clinical findings are that the EEG training is not narrowly
specific in its clinical effects, but that it impacts very basic
regulatory mechanisms, the disregulation of which is responsible
for causing or at least maintaining the disorders discussed. In
the following, the case will be further made for such a simple underlying
model. A connection will be made to current models of brain function,
and the central role of rhythmic brain activity will be discussed
in explaining the remarkable breadth of efficacy of this emerging
modality. The early model of efficacy proposed by Sterman is that
the EEG training at sensorimotor cortex lowers the setpoint of the
gamma motor system reactivity (Howe, 1972). As a result, cortical
hyperexcitability is reduced. This manifests in higher threshold
of onset of seizures, most particularly in the case of motor seizures
(Sterman, 1984). Lubar initially worked only with those hyperactive
children who were Ritalin- responsive, on the assumption that these
were the ones whose hyperactivity was grounded in underarousal (Shouse
& Lubar, 1979). So the early work already presaged our current
perspective, that the principal mechanism of action of EEG biofeedback
is to normalize autonomous management of arousal and to enhance
overall nervous system stability. The intimate relationship between
seizure susceptibility and arousal makes it plausible that efficacy
for seizures is also at least partly attributable to normalization
of arousal regulation. On the basis of the early work, it was close
to hand to consider all the conditions being treated in terms of
their arousal dimension, and in terms of the stability/instability
continuum. Table 1 shows a classification of conditions with respect
to the arousal axis, and with respect to the instability axis. In
preparation of Table 1 it became obvious that this system of categorization
represents an oversimplification, although it does provide a useful
perspective. It is, for example, an oversimplification to talk about
depression and anxiety as separate and distinct entities. It is
a further oversimplification to appear to reduce these to merely
arousal disorders. It is perhaps better to identify these as correlations
or covariations. Then again, arousal itself is not a unitary concept.
Moreover, the arousal dimension is very important in the conditions
we have listed as instabilities (as already mentioned for seizures).
It is hoped that the Table will prove useful in illustrating the
connection between various conditions at the process level, and
indeed the mechanisms by which EEG biofeedback can impact them.
Table 1. Classification of Common Disorders in Terms of Arousal
and InstabilityUnderarousal
Endogenous Unipolar or Reactive Depression Attention Deficit Disorder:
Inattentive Subtype Chronic Pain (Low Pain Threshold) Insomnia (Frequent
Waking)
Overarousal
Anxiety DisordersSleep Onset Problems/Nightmares Hypervigilance
Attention Deficit Disorder: Impulsive SubtypeAnger/Aggression Agitated
Depression Chronic Nerve Pain Spasticity
Underarousal/Overarousal
Anxiety and Depression Attention Deficit Hyperactivity Disorder:
Combined Type
Instabilities
Endogenous Vulnerability
Tics Obsessive-Compulsive Disorder Aggressive Behavior Episodic
Rage DisorderBruxism Panic AttacksHot Flashes Bipolar Disorder Migraine
Headaches NarcolepsyEpilepsy Sleep Apnea Vertigo TinnitusAnorexia/Bulimia
Suicidal ideation and behavior PMSMultiple Chemical Sensitivities
Dysglycemia; Diabetes (Type II); Hypoglycemia Explosive Behavior
Exogenous Vulnerability
Just as depression has its arousal dimension, it also has its attentional
dimension, and its affective dimension. Similarly for the other
conditions listed. For present purposes, it is sufficient to argue
that these are coupled systems. One of the most obvious implications
of the biofeedback work is that it is not possible to intervene
unilaterally with the brain. Impinging upon the arousal axis has
implications for attention and affect, and vice versa. Moreover,
challenging the brain with biofeedback tends to move the brain toward
stability. The observation was made decades ago by Elmer Green that
biofeedback in general moves the organism toward homeostasis and
toward stability. This has been abundantly confirmed in the present
work. Having said this, it is also possible to drive the brain toward
any instability that may exist, with a powerful technique such as
this. Skillful clinical application is still required. Instabilities
can be characterized by the degree to which they arise autonomously
within the CNS or require an external trigger for initiation. An
internal vulnerability is referred to as endogenous, and an externally
triggered vulnerability is referred to as exogenous. The relevant
instabilities are distributed along a continuum in this regard,
and a case can be made that there is a natural progression for different
instabilities from the exogenous domain to the endogenous over the
course of a lifetime. This is known as the kindling model, and it
is particularly applicable to seizures, Tourette's syndrome, OCD,
depression, anxiety and panic, bipolar disorder, and migraines.
A crude attempt has been made at an ordering along the exogenous/
endogenous axis in Table 1.
EEG Biofeedback: A Generalized Approach to Neuroregulation By Siegfried
Othmer, Susan F. Othmer, and David A. Kaiser To appear in "APPLIED
NEUROPHYSIOLOGY& BRAIN BIOFEEDBACK"Edited by Rob Kall,
Joe Kamiya, and Gary Schwartz Page 6 of 13 Arousal, Attention, and
AffectThe conceptualization of brain function in terms of coupled
systems was broached by W.R.Hess (1954). Experiments with electrical
stimulation of regions of the diencephalon (thalamus and hypothalamus)
in some instances led to very specific behavioral responses, and
in other instances led to broad overall changes in behavior: arousal,
quiescence, somnolence, torpor, and sleep. Hess subsumed these global
changes in sympathetic and parasympathetic arousal in the terms
ergotropia and trophotropia. The 'ergotropic shift' is characterized
by a tendency toward higher sensory acuity, external focus, sympathetic
arousal, high motor setpoint, etc. The 'trophotropic shift' is characterized,
in contrast, by a tendency toward a more inward focus, less alertness,
reduced sensory acuity, a shift toward vegetative functions, and
a reduced motor system readiness. It is clear from our work that
invoking either of these two shifts is possible with EEG biofeedback.
What we refer to as "beta" training (15 to 18 Hz) is to
be identified with a global ergotropic shift in organismic function,
and that of "SMR" training (12 to 15 Hz) is to be identified
with a trophotropic shift. The response of an individual to even
a single session of EEG biofeedback training can make this quite
obvious, an assertion which is independent of any claims for long-term
efficacy of training. Long-term EEG training has the effect of exercising
and expanding the brain's ability to move freely along the continuum
of ergotropic or trophotropic dominance, with all its implications
for arousal, attentional state, and affect regulation. This brain
exercise moves the individual into regions where he or she may not
heretofore have been able to reside comfortably or stably. This
is made possible not only by increased flexibility of state, but
by an increased ability to maintain overall nervous system stability.
The reason that two primary training regimens (higher and lower
frequency) are sufficient is attributable to the fact that the ergotropic
shift and the trophotropic shift are mutually inhibitory. To enhance
the one is to suppress the other, as was already apparent to Hess.
Gellhorn (1967) originally referred to the dynamic balancing of
the ergotropic and trophotropic domains in terms of 'tuning' of
the nervous system. The EEG biofeedback, by explicit appeal to rhythmic
mechanisms, may be seen as a particularly efficacious agency of
'nervous system tuning.' The brain's intrinsic bias toward homeostasis
dictates that any training which evokes a brain response away from
its then- prevailing equilibrium state will set in train forces
to restore the original state. Thus, promoting an ergotropic shift
will in first order tend to produce such a shift, and on the other,
set in train compensatory mechanisms by which the brain restores
the state it had intended for itself. Hence, even dis-equilibration
can bring about improved equilibrium maintenance as a long-term
consequence. Hemispheric Specificity of Training: Spatial Dependence
of Protocols The clinical data reviewed below are supportive of
the view that the training exercises the two hemispheres specifically,
and differentially. Cumulative clinical evidence in our offices
has also reinforced the view that referential training near C3 and/or
C4 is generally the most effective. Small displacements from these
sites laterally from the midline along the coronal plane seem to
have a minor effect on the training. Small displacements in the
horizontal plane, on the other hand, change the quality of the training
more significantly in our experience. Hence the training sites have
been determined by a process of local optimization (i.e., small
spatial displacments), rather than of global optimization. For some
applications (principally to the instabilities), T3 and T4 have
been found preferable to C3 and C4, respectively. With a large amount
of clinical data at our disposal (several thousand cases), a picture
has emerged that the EEG training addresses the specific failure
modes of each hemisphere. If a particular disorder could be associated
more directly with one hemisphere than the other, it might give
us a clue as to what part of the brain might require redress. Such
a connection would then imply a unique, differential protocol. We
found this to be true, and a number of disorders began to yield
to assignment to one hemisphere or the other. Then, using a process
of "local optimization" both in terms of spatial location
and selection of the reward frequency band, a training strategy
emerged which has gained considerable 'stability' from the effort
at continual refinement, and what may have started out as mere clinical
impressions have gradually been reinforced to the point at which
they now constitute a defensible training strategy. The principal
hallmarks of the strategy are as follows: 1. There appears to be
a certain simplicity and directness attached to training along the
sensorimotor strip. 2. Training away from the midline appears to
yield stronger and more hemisphere-specific training effects, than
training at Cz. 3. There is a distinct predominance of the need
for up- regulation of the left hemisphere, using beta training (nominally
15-18 Hz), and a corresponding predominance of the need for down-regulation
of the right hemisphere using SMR- training (nominally 12-15 Hz).
Frequently, the need for both exist within the same individual.
(This frequency dependence is addresses further below.)The apparent
advantage of training at the sensorimotor strip for most of the
conditions discussed is consistent with the early Sterman hypothesis,
since amply validated, that what is being trained is the degree
of rhythmicity of the thalamocortical regulatory circuitry. And
whereas the rhythmic EEG activity observable anywhere on cortex
is traceable to these thalamically-mediated regulatory functions,
the primary sensory areas of cortex are perhaps the most direct
access we have to them. Specifically, the highest cortico-thalamic
fibre-density is to be found in the primary sensory areas of cortex
(and also in projections to the frontal lobe). Historically, most
of the EEG biofeedback training that has been done has focused on
the primary sensory regions. Our continuing observation over a large
clinical population of the need for up-regulation of the left hemisphere
and down- regulation of the right can be explained in terms of the
specific way in which the two hemispheres fail, or disregulate.
The work of Malone, Kershner, and Swanson, et al, (1994), provides
us with a detailed neurophysiological model which explains this
hemispheric laterality in training effect. In this model, it is
proposed that the left hemisphere (in collaboration with the frontal
lobe) manages tonic activation for the conduct of intellectual and
motor tasks, and for the maintenance of vigilance over time. This
activity is preferentially under the management of the neuromodulators
dopamine and to a certain extent acetylcholine. The right hemisphere,
by contrast, manages phasic arousal for maintenance of sensory system
readiness to receive and process new inputs from any source. This
system is predominantly under the management of norepinephrine and
to a certain extent serotonin.The model, as applied to ADD, which
will be discussed further in the coverage of our clinical outcomes,
reveals ADD to be a problem of underactivation of the left hemisphere,
principally involving dopamine, and of overarousal of the right
hemisphere, principally involving norepinephrine. Hence, neither
the sequential processing of intellectual or motor tasks, nor the
deployment of resources responding to new incoming stimuli are well
managed. The efficacy of Ritalin is attributed to a dual influence,
the up-regulation of the dopamine system and the down-regulation
of the norepinephrine system. In a kind of parallel or equivalent
model, ADD of the inattentive subtype is addressed with higher frequency
left hemisphere training (central and possibly frontal) and ADD
of the impulsive subtype is addressed with lower frequency training
of the right hemisphere (central and possibly the parietal region
as well). A mutual consistency thus emerges between the claims of
EEG biofeedback and psychopharmacology for ADD. The Tucker and Williamson
(1984) model lays a credible foundation for the general claim that
the two hemispheres need to be specifically and differentially addressed
in the training, just as they are pharmacologically. Recent clinical
work has led to further refinements of the principal protocols so
that they now incorporate frontal and parietal training with bipolar
placements that combine left central with prefrontal sites (e.g.,
C3-Fpz), and right central and parietal sites (e.g., C4-Pz).These
latter refinements specifically challenge communication loops between
the selected sites. When a bipolar montage is used, then the reinforcement
promotes an anti-phase relationship between the two sites. This
may be counter- intuitive. It has been shown (Rappelsberger, 1994)
that when distant cortical locations communicate with one another,
they come into greater synchronization in the process. Why then
would one wish to train these sites to reduce the prevailing degree
of synchrony? The only justification that really counts is that
this has been found effective empirically. The theoretical justification
is to be found in the 'regulatory challenge' model of EEG biofeedback.
The biofeedback reinforcement takes the brain momentarily out of
its prevailing equilibrium, to which it then wishes to return. It
may not matter in first order whether the disequilibration occurs
in one direction or the other. Improved regulatory function may
eventuate in either case. It may now be possible to generalize the
Malone model to other conditions. Just as there are left hemisphere
and right hemisphere aspects of ADD, the same may hold for affective
disorders of depression and anxiety (Goodwin,1990). The left hemisphere
aspects of depression and anxiety may have to do with anticipatory
activity, planning, ruminating, perseverating, worrying. The right
hemisphere, by contrast, may harbor the non-rational, more catastrophic
aspects of depression and anxiety, namely fear, panic, agitated
depression, and suicidality (Heller, 1997). With a spatially localizable
technique at our disposal, hemispheric specificities have been confirmed
with EEG training not only for ADD, cognitive function, anxiety,
and depression, but also for pain syndromes, sleep disorders, eating
disorders, endocrine and immune system disorders. Laterality turns
out to be one of the key organizing principles for the evolution
of protocols. The Protocols' Frequency DependenceProtocols used
for EEG biofeedback training of the 12-19 Hz band, are essentially
derived from Sterman's seminal work with seizures. The 12-19 Hz
region was originally identified as being prominent in the bursts
of sensorimotor rhythm of the cat (Sterman, 1969). Subsequently,
operant conditioning of the cat EEG was restricted to the peak frequency
range of this distribution, 12-15 Hz (Sterman, 1970). As additional work was undertaken with human subjects, the 15-18Hz band was also
investigated in one study (Sterman, 1978). In the following, we
will refer to training with the lower frequency (12-15 Hz) and higher
frequency (15-18 Hz) bands. The lower frequency training has also
been colloquially referred to as "SMR" training, for historical
reasons, and the higher frequency as "beta" training.
These terms have become commonplace through clinical usage, even
though we are dealing with only a subset of the entire beta band,
which extends from 12 or 13 Hz to 35 Hz. As we entered the field
in 1985, we were aware only of the work of Barry Sterman, Joel Lubar
et al., Michael Tansey, and Margaret Ayers with respect to the beta/SMR
training. Joel Lubar et al. utilized both bands in the treatment
of ADD (Lubar, 1984). Michael Tansey restricted himself to rewarding
the frequency region centered on 14 Hz (Tansey, 1990), and Margaret
Ayers used almost exclusively beta training (Ayers, 1993). In terms
of electrode placement, Lubar et al. were typically using left-side
training with bipolar placement near the sensorimotor strip, not
deviating far from what Sterman had originally employed (C3-T3).
Tansey exclusively used an electrode placement on the supplementary
motor area, with a large-area contact that covered the space between
Cz forward toward Fz, and also extending partially toward Pz. Margaret
Ayers used C3-T3 placement almost exclusively, except when either
symptomatology or EEG phenomenology indicated a need for right-side
training at C4-T4. All of the above protocols were accompanied by
inhibition of low frequency activity, typically 4-7 Hz (called "theta"
in the following). In the case of Michael Tansey, the information
regarding excessive theta amplitudes was verbally communicated to
the client. Additionally, Sterman and Lubar provided for inhibition
of high-frequency activity in the region above 20 Hz. Out of the
work of these four pioneers, our protocols evolved in several stages.
First, placement was changed from bipolar to referential to the
ipsilateral ear, in line with a general trend within the field toward
referential montage. Secondly, Cz placement was evaluated for the
low frequency training on the basis of Tansey's work. For more than
a year, most of the training was conducted at either C3 with the
higher frequency band ('beta'), or at Cz with the lower frequency
band (SMR), using an A1 reference. Excursions to C4 were, if needed,
based on our early understanding of issues of laterality or in cases
of localization of deficits to the right side (as in seizure disorders,
head injury, and stroke). Over time, as we became more experienced
and our understanding of the hemispheric specificity of certain
aspects of cortical disregulation became clearer, it was observed
that the C4 training was typically most effective with the lower
frequency training, and that often stronger, more specific results
were obtained than at Cz. Eventually, the predominant protocols
became C3-beta and C4-SMR. Some frontal and parietal training was
used as well to address specific issues.Though early protocol selection
was based upon the prior research work, it soon became necessary
to devise methods of assessment (to be discussed later in this piece)
that would assist us in teasing out which of these protocols were
most appropriate for the client. But if the judgment turned out
to be mistaken, then there was always the option to make an early
change in protocol. If the choice was appropriate, then a different
protocol might be used later to address residual issues.It was observed
also that if one persisted with the use of a single protocol, then
eventually certain adverse symptoms could develop which called for
compensatory training. Thus, with left-side training, ultimately
client reports might indicate the need for right-side training,
and vice-versa. Subsequently, more refined clinical skills led to
an earlier integration of the secondary protocol into the training
for optimization. This compensatory training led to the appreciation
that in addition to addressing the specific failure modes of each
hemisphere we really had to also achieve, or maintain, hemispheric
balance. Symptoms could often be attributed to the inappropriate
inhibition of one hemisphere by the other, or inappropriate disinhibition.
This was most directly demonstrated when a left-side seizure focus
was also favorably influenced by training the contralateral placement.
But the principle has proved to be valid broadly. At the present
stage of evolution of protocols, there has effectively been an integration
of the C3-beta and C4-SMR protocols, which are both used with the
majority of clients, generally within the same session, and the
balance between them is titrated on the basis of symptom response.
Assessment is then a matter of determining the client's physiological
response characteristics, and the particular vulnerabilities expressed
in their symptoms. In this appraisal, established clinical categories
(from the DSM-IV) are only approximate guideposts. Whether diagnostic
criteria are met in one respect or another is therefore irrelevant
to the clinical burden. At least 80% of clients have been treated
with this combination of protocols and this combination alone. The
data reported in the following were obtained over the past eight
years with the above protocols or derivations therefrom.
Back to Intro EEG Biofeedback: A Generalized Approach to Neuroregulation
By Siegfried Othmer, Susan F. Othmer, and David A. Kaiser To appear
in "APPLIED NEUROPHYSIOLOGY & BRAIN BIOFEEDBACK"Edited
by Rob Kall, Joe Kamiya, and Gary Schwartz Page 7 of 13 Clinical
Evidence: Validating the ModelClinical application is both the source
and the destination of the theories and models proposed above. Without
the surprises and inventiveness inherent in daily clinical practice,
progress toward a comprehensive model for EEG biofeedback training
would have been much slower, and the scope much narrower. By its
very nature a research orientation must make certain choices and
assumptions, and hold certain procedures invariant throughout the
project. This does not allow for such a variety of approaches to
be tried in such a short time. Yet, due to the volume of clients
we were able to see since 1988, we have achieved significant depth
of experience in a number of areas. It is now our goal to share
this experience widely in order to allow it to be integrated with
other approaches and perspectives, and subjected to more rigorous
scientific evaluation and critique. The list of conditions for which
clinical efficacy of EEG biofeedback has been observed is given
in Table 2, along with the nature of the qualifying evidence (controlled
studies; published outcome studies; single case studies and conference
presentations). Key references are indicated separately at the end
of the chapter. The number of subjects that fall into each category
are estimated as well. No systematic inquiry was under taken to
flesh out this table, so we don't claim that it is complete. All
entries relate only to data of which we have become aware through
various means, and are therefore a lower limit in each case. In
our own work, and that of our affiliates, we have acquired confirming
evidence for all of the conditions listed, with the exception of
Lyme disease. Table 2. EEG Biofeedback StudiesADHD
Control Linden, Habib, & Radojevic (1996)Rossiter & LaVaque
(1995)Nash & Shakelford (1995)Cartozzo, Jacobs, & Gervirtz
(1995)
Outcome Kaiser (1998) Kaiser & Othmer (1997) Thompson &
Thompson (1997) Lubar, Swartwood, Swartwood, & O'Donnell (1995)
Scheinbaum, Newton, Zecker, & Rosenfeld (1995) Fenger (1995)
Toomin, Ibric, & Othmer (1994)Samples (1994) Tansey (1991) Lubar
(1985)Lubar & Lubar (1984) Shouse & Lubar (1979)
Case History Kotwal, Burns, & Montgomery (1996) Tansey &
Bruner (1983)
LEARNING DISABILITIES
Control Linden, Habib, & Radojevic (1996)
Outcome Tansey, Tansey, & Tachiki (1994) Tansey (1991)Tansey
(1990) Tansey (1985) Tansey (1984) Cunningham, & Murphy (1981)
Case History Kade (1995) Tansey (1993)
DEVELOPMENTAL DELAY
Control
Outcome
Case History Fleischman (1997)
AUTISM
Control
Outcome
Case History Sichel, Fehmi, & Goldstein (1995) Cowan (1994)
TOURETTE'S SYNDROME
Control
Outcome
Case History Tansey (1986)
EPILEPSY
Control Lantz & Sterman (1988) Lubar, Shabsin et al (1981)Sterman
& MacDonald (1978) Lubar & Bahler (1976) Seifert, &
Lubar (1975)
Outcome Hansen, Trudeau, & Grace (1996)Andrews, & Schonfeld
(1992)Tozzo, Elfner, & May (1988) Tansey (1986)Cott A, Pavloski
RP, Black AH (1979)Quy & Hutt (1979)Kuhlman (1978)Sterman (1977)Kuhlman
(1977)Wyler, Lockard, Ward, & Finch (1976)Sterman, MacDonald,
& Stone (1974) Sterman & Friar (1972)
Case History Walker (1995)Tansey (1985) Finley (1977)Finley (1977)Ellertsen
& Klove (1976)Finley, Smith, & Etherton (1975)
MILD TRAUMATIC BRAIN INJURY
Control Ayers (1993)
Outcome HWalker (1998)Salerno (1997)Walker (1995)
Case History Byers (1995) Tansey (1994)Weiler, Schumann, &
Brill(1994)
STROKE
Control Ayers (1994)
Outcome
Case History Rozelle, & Budzynski(1995)
MULTIPLE SCLEROSIS
Control
Outcome
Case History Walker (1995)
CHRONIC FATIGUE SYNDROME (CFS)
Control Lowe (1994)
Outcome Tansey (1994) Tansey (1993)
Case History James, & Folen (1996)
CHRONIC PAIN, MIGRAINES
Control
Outcome Othmer & Othmer (1994) Tansey (1991) Fehmi (1987)
Case History
IMMUNE DISORDERS
Control
Outcome Schummer (1995)
Case History
LYME DISEASE
Control
Outcome
Case History Brown (1995)Kirk (1994)
PRE-MENSTRUAL SYNDROME (PMS)
Control
Outcome Othmer & Othmer (1994)
Case History
POST TRAUMATIC STRESS DISORDER
Control
Outcome Manchester(1995)
Case History
BIPOLAR DISORDER
Control
Outcome
Case History Othmer & Othmer (1995)
Italics - Conference Presentation This list is staggering in the
variety of conditions responding to the training. A comprehensive
treatment of the claims for these conditions cannot be undertaken
here. Instead, a subset of conditions will be reviewed to indicate
the breadth of the remediation accomplished with respect to types
of symptoms, and to demonstrate that the remediation is non-trivial.
That is, it may lie quite out of the range of what can be expected
via spontaneous recovery or even, in some cases, with the standard
interventions. Subsequently, an understanding of these findings
will be sought by looking at underlying physiological mechanisms.
Before proceeding, it may be useful to make some more qualitative
distinctions among the claims being made with respect to these varied
conditions. Such an attempt is shown in Table 3. Here conditions
are ranked according to the consistency with which remediation can
be predicted; the completeness of the remediation; the duration
of the training; and the simplicity or complexity of the protocols
to be brought to bear. For entries in this table, the judgments
are entirely our own, and are based on our own clinical experience.
Click for Next Page
EEG Biofeedback: A Generalized Approach to Neuroregulation
By Siegfried Othmer, Susan F. Othmer, and David A. Kaiser
To appear in "APPLIED NEUROPHYSIOLOGY & BRAIN BIOFEEDBACK"
Edited by Rob Kall, Joe Kamiya, and Gary Schwartz
Page 8 of 13
A Review of Clinical Outcomes
In the following section, the categories listed in Table 3 will
be reviewed in cursory fashion in terms of our own clinical experience
(augmented by that of some other practices which have adopted the
same protocols.) It goes without saying that such a cursory overview
of such complex issues can only be unsatisfying to the critical
scientist or the discerning clinician. We offer it only as kind
of intellectual appetizer, in order to achieve a quick overview
of the field that will motivate further engagement and inquiry.
Rating our Effectiveness
CRITERIA:
A) Consistency of Response B) Completeness of Remediation C) Duration
of TrainingD) Ambiguity of Protocol
-Strong, Consistent Results-Full Remediation of Symptoms -Short
Duration of Training -Simple, Standard Protocols -Complex, Variable
and Multiple Protocols-Higher Variability of Outcome -Partial Remediation
of Symptoms -Long Duration of Training
Effectivness cateories. Click the name that interests you.
Depression Hypoglycemia Stroke
Minor Traumatic Brain Injury Sleep Disorders Tourette Syndrome
Premenstrual Syndrome Anxiety Narcolepsy and Sleep Apnea
Headaches Chronic Pain Major Head Injury
Attention Deficit Disorder Oppositional-Defiant Disorder and Conduct
Disorder Chronic Fatigue Syndrome
Attention Deficit Disorder-Combined Type Prenatal Substance Exposure
Autoimmune Dysfunction
Bruxism Epilepsy
Depression
It is noteworthy that depression is among the easiest conditions
to treat with EEG biofeedback. These findings cover not only the
mild depression that is frequently seen in connection with ADD,
such as the dysthymia observed in childhood or the kind of low-grade
pervasive depression for which Prozac has become the palliative
of choice. They also cover episodes of deep depression, including
some which are accompanied by episodes of suicidality, and even
reactive depression.
The early effects of the training may be observed in the first
few sessions. A person may recover from an excursion into suicidality
in just one or two sessions. Full recovery from depression may,
however, require on the order of twenty to forty training sessions.
The recovery is seen as a restoration of a normal range of physiological
arousal. The recovery is not characterized, however, by a numbing
of feelings or constriction in affective state (in the event of
reactive depression), nor does it interfere with a normal grieving
process. The training is usually effective in disrupting patterns
of chronic pain that are often seen in depression, although we are
not dealing here with an anesthesia. Normal pain sensitivity is
retained.
It is noteworthy that with SMR/beta protocols the greatest efficacy
for unipolar depression is achieved with beta training on the left
hemisphere at sensorimotor cortex. Since the left hemisphere is
where language resides, one is aided by the fact that the patient
can usually articulate very well the consequences of each training
session for left hemisphere function and thus help to guide the
process. Matters are different with respect to agitated depression
or suicidality. These are attributed to disregulation primarily
lodged in the right hemisphere, and require the calming and more
stabilizing lower frequency training in the general case. The client
may not be in a position to either properly appraise or to articulate
his or her own state with respect to right hemisphere dysfunction.
These findings are so startling in their import that perhaps they
stretch the credulity of the reader, and are entitled to some further
discussion to make this plausible. First of all, this finding of
efficacy for depression is concordant with the belief among psychiatrists
that depression is rather consistently responsive to electroshock
treatment, as already mentioned in the introduction. In many clinical
circles, ECT is considered the gold standard of treatment for depression.
The severe side effects attendant to that procedure keep it from
being employed except as a last resort, and in severe depression.
However, the belief is firmly entrenched that depression is expected
to respond to shock treatment in the general case. Shock treatment
can be seen as a sudden change in the ambient electrical state of
brain function. Existing reinforcement patterns of pathological
arousal and affect are broken up, and a new homeostasis in terms
of arousal level and affect can be quickly established and apparently
sustained, often without continuing pharmacological support.
On the other therapeutic extreme, that of non-intervention, it
is found that episodes of deep depression quite frequently result
in spontaneous remission. Such remission is so commonplace in children
and young adults, when deep depression is first observed, that anti-depressant
medication has never been shown to be better than placebo (read
spontaneous recovery) in children. (Just recently, a first study
appeared in which statistical significance was achieved (Emslie,
1997). Yet no one would argue that the nervous system of a child
is non-responsive to anti-depressants. The drugs clearly work there
as well. It is simply that spontaneous recovery is so robust and
commonplace that anti-depressants are not obviously superior statistically
in a controlled research setting over a fixed time interval. The
mechanisms are clearly in place for a natural recovery to occur
in most individuals with a first experience with major depression.
Hence, the claim of efficacy of EEG biofeedback for depression
would seem to have the same difficulty vis-a-vis spontaneous recovery
that has confounded the drug studies. Not so. In fact, we assert
that the mechanisms of spontaneous recovery and of EEG biofeedback
are probably identical. The existence of a robust spontaneous recovery
capability supports the claim; it does not undermine it. EEG biofeedback
can simply induce a systematic re-normalization of arousal function
which might also happen randomly all by itself. The difference is
that when EEG biofeedback is employed, the response is prompt, predictable,
relatively consistent, and more likely to be sustained over the
longer term. Moreover, it tracks the specific protocols employed
(in terms of electrode placement and reward frequency band). This
proposition does not need to await statistical proof (although such
proof would be salutary). Simple clinical observation is sufficient
(just as it was for shock therapy).
Minor Traumatic Brain Injury
A second category in which rapid, substantial recovery is observed
is minor traumatic brain injury. The principal symptoms associated
with MTBI are listed in Table 4. Many of these symptoms relate to
disregulation of arousal, and of these the majority is depressive
in character: depression, inattention, irritability, effort fatigue,
chronic pain, and frequent waking. Some relate to overarousal: mania,
impulsivity, anxiety and fear, anger, and sleep onset problems.
Others relate to cognitive function: dyslexia, loss of short-term
memory, articulation problems, word retrieval problems. Other problems
relate more to frontal lobe function: behavioral disinhibition,
obsessive-compulsive disorder, exacerbated motor and vocal tics,
perseveration.
Table 4: Characteristic Symptoms of Minor Traumatic Brain Injury
Headache Anxiety and Depression Aphasia
Chronic Pain Sleep Disturbances Visuospatial impairments
Dizziness-Vertigo Irritability Changes in appetite
Difficulty Concentrating Mood Swings Sensitivity to hot and cold
Difficulty with Attention Personality Changes Seizures
Difficulty Planning Effort Hemiparesis
Fatigue Palsies
Characteristically much of the whole spectrum of MTBI symptoms may
be manifested in any one head injury victim. And characteristically
also, essentially all of these symptoms remediate with the training
at least to some significant degree, although at different rates.
The recovery of energy, the restoration of the ability to sleep
properly, and the stabilization of mood, are the early markers for
EEG training. Subsequently, there is recovery of cognitive function,
diminution of pain syndromes, and ultimately even recovery of memory
function.
Efficacy of the biofeedback for MTBI is probably largely attributable
to three factors: 1) restoration of appropriate regulation of arousal
level; 2) increase in the stability of brain function; and 3) increase
in the flexibility of brain function. Commonly in MTBI the EEG exhibits
paroxysmal activity, or elevated low frequency activity. Typically
also, significant deviations in temporal coherence may be seen between
brain regions. These deviations may be in either direction. Too
low a coherence would indicate insufficient coupling or communication
between brain regions, and too high a coherence would indicate too
tight a coupling. It is easy to explain low coherence in terms of
axonal shearing or other structural injury attributable to the original
trauma. However, that may be too facile.
EEG deviations tend to normalize with the training, as would be
expected. However, that is not always the case. Nor does such normalization
closely track the recovery of function. Hence the EEG is of limited
utility as a measure of recovery of function. Diminishing of paroxysmal
activity is attributed to an increase in cortical stability with
a strengthening of thalamic regulatory control. Elevated low frequency
amplitude could simply be a manifestation of functional disengagement,
of low activation and arousal. It can also result from inappropriate
cortical-cortical coupling, attributed to insufficient subcortical
regulation. The recovery could therefore again be attributed to
the strengthening of thalamo-cortical regulatory mechanisms. Finally
there are the deviations in coherence themselves. The fact that
coherence is likely to recover with training regardless of whether
it is low or high indicates that we are dealing largely with functional
disorganization rather than structural impediments to function.
Again, it is postulated that reassertion of thalamic control of
brain rhythms is sufficient to restore appropriate coherence. However,
direct cortical-cortical communication surely also plays a role
in normalization of coherence.
Recovery from depressive symptoms is attributed to the first factor,
renormalization of arousal control. Restoration of cognitive function
and short-term memory is attributed to an increase in continuity
of brain function, to which the diminution of paroxysmal activity
and delta and theta amplitudes are testimony. Paroxysmal activity
is very likely to disrupt the temporal relationships by which images,
concepts and gestalts are bound together as coherent entities and
retained for processing. The subjective experience of this disruption
is an inability to organize activities, to make plans, to weigh
several competing ideas, to carry mental challenges through to their
resolution, and to reliably retain a memory. Finally, the restoration
of appropriate coherence leads to recovery of the person's original
behavioral flexibility.
MTBI has been listed as responding very quickly and reliably to
EEG biofeedback training. This is indeed the case, in the sense
that there can be significant recoveries of function even in the
first few sessions. A more complete resolution may require as many
as 50-100 training sessions, although 20 ' 30 sessions are adequate
in most cases. A representative sampling of 16 such cases was reported
by Jonathan Walker, of the Neuroscience Centers in Dallas. The results
are summarized in Table 5. The average recovery with respect to
premorbid functioning, by self- report, was 83%, and the median
improvement was 85%. The average number of training sessions was
32, and the median was 30. The EEGs changed in line with the protocol
to a statistically significant degree (decrease in theta amplitudes,
and an increase in beta amplitudes).
Table 5. Recovery by self-report from symptoms of Minor Traumatic
Brain Injury.
Client Baseline Post training Baseline Post-training Percent Improvement
Number of Sessions
av.pwr Beta/Cz av.pwr Beta/Cz av.pwr q/Cz av.pwr q/Cz
K.R. 5.1 8.3 12.1 7.2 100 14
R.M. 6.5 16.9 11.3 10.8 80 12
M.M. 7 9.3 14 11.9 95 18
J.M. 15.1 18.6 10.5 6.5 90 40
C.G. 4.8 5.6 22.6 19.5 80 43
A.D. 14.4 20.4 10.6 7.8 50 46
S.A. 4.4 5.2 13.9 15.7 90 13
T.G. 5.8 12.8 13.1 13 80 35
P.K. 6.1 11.7 24.7 17.8 50 86
M.D. 8.6 12 18.4 15 80 30
E.S. 9 9 17.4 17.1 100 30
C.H. 10.1 8.1 13.1 11.9 90 20
S.S. 7.7 9.5 27.8 23.1 100 42
S.B. 8.2 11 14.6 9.3 75 23
G.C. 4.7 5.1 12 9.4 98 22
S.B. 9.3 13 25.8 16.9 75 30
Data courtesy of Jonathan Walker, MD
There may also be obvious deficits remaining that relate to organic
(morphological, structural) injury. In these cases significant recovery
is possible as well, but the rate- limiting mechanism is presumably
some dendritic regrowth or rearborization. Hence the pace of progress
is only partly conditional on the schedule of training. The trainee
may continue to make gains by returning to the training episodically,
to exploit any new learning opportunity. This phase of training
is similar to the experience of Bernard Brucker (1985) in his EMG
training for spinal chord injury, where it is found that a limb
which did not yield to training on one occasion may readily respond
a year later.
When specific organic injury has occurred, it seems more appropriate
to include this in the category of major head injury. However, the
latter distinction is reserved for those head injuries in which
skull fracture or major organic loss has occurred. This is a less
meaningful distinction, and often uncorrelated with the severity
of deficits incurred. Paradoxically, some head injury that involves
skull fracture can be less severe than minor head trauma. Conceivably,
this could be due to the fact that the skull fracture, by yielding
somewhat on impact, can reduce the g-forces sustained by the brain
and the brainstem. For present purposes, organic injury is lumped
along with major head injury, and as such appears in the last column
of the chart.
The intimate connection of head injury symptomatology with disregulation
of arousal seems to have been under-recognized by clinicians, who
have by and large retained both a structuralist perspective as well
as a focus on the cortex as the locus of injury. When such techniques
as CAT scans and structural MRI scans failed to confirm injury,
the victim was often declared to be a malingerer and his symptoms
discounted. Thus the person became a victim a second time, in this
instance of the clinician's myopia. In fact, most head injury involves
severe jostling of the head upon its spindly neck, resulting in
trauma to the brainstem, from whence arousal is managed. Fortunately,
such injury consists more likely of compressional effects such as
anoxia rather than of actual axonal shearing. As such, the injury
is functional in nature, rather than structural, and turns out to
be eminently remediable with our techniques.
EEG Biofeedback: A Generalized Approach to Neuroregulation By Siegfried
Othmer, Susan F. Othmer, and David A. Kaiser To appear in "APPLIED
NEUROPHYSIOLOGY& BRAIN BIOFEEDBACK"Edited by Rob Kall,
Joe Kamiya, and Gary Schwartz Page 9 of 13 Premenstrual Syndrome
Another indication for which EEG biofeedback is very helpful is
Premenstrual Syndrome (PMS). This condition is not recognized as
a distinct disorder in the DSM-IV, but that is probably at least
partially in recognition of societal sensibilities. In its severe
form, it is known as Premenstrual Dysphoric Disorder, which is conditionally
listed in the Appendix of the DSM-IV (DSM-IV, p. 715). The difficulties
with such a listing are, among others, that the symptoms of PMS
are so diverse, so highly variable, so subject to 'psychosomatic"
influences, so frequently seen simply as an exacerbation of other
existing disorders, and so devoid of discernible organic basis.
One wishes to blame hormonal shifts, but these are not usually out
of line in those suffering PMS symptoms.The weight of evidence is
that PMS is a matter of brain sensitivity to ordinary shifts in
hormonal levels. PMS can even be considered as the defining condition
for the functionally based "brain disregulation model"
of psychopathology. That is, disregulation is the defining characteristic
of PMS, and the remedy offered by EEG training is to return brain
function to homeostasis and to stability, i.e. to a restored capacity
for neuroregulation. Almost no condition remediates as completely
and consistently as does PMS with EEG training, and few conditions
entail such a breadth of symptomatology. Yet PMS in all its clinical
variety is successfully addressed with little more than this straight-
forward training. PMS symptoms which have been identified are shown
in Table 6 (O'Brien, 1987), and the symptoms which have been observed
in our practice, and which have been subject to remediation, are
shown with an asterisk. We have no relevant experience with the
symptoms that are not marked. Physical
*Drowsiness *Blurred Vision Epilepsy *Pelvic Pain
*Fatigue *Breast Swelling Finger Swelling Edema
Thirst *Breast Tenderness *Flushes *Nausea
*Proneness to Accident *Clumsiness Formication *Muscle Pain
Acne *Constipation *Headache, Migraine *Joint Pain
Asthma *Diarrhea Weight Increase (actual) *Vomiting
Bloatedness (actually) Dizziness Increase (feeling of) Vertigo *Hypoglycemia
Behavioral
*Aggression *Hypersomnia *Loss of Self-Control
Anorexia *Impulsive Behavior *Social Isolation
*Decreased Alertness *Increased Libido *Suicidal Tendency
*Decreased Libido *Insomnia Formication
*Food Craving *Lack of Volition *Tension
*Hunger *Lethargy, Listlessness *Violent Behavior
*Bloatedness(feeling) *Loss of Judgment *Weight
Cognitive
*Confusion
*Loss of Concentration
*Proneness to Accident
*Poor Coordination
Emotional
*Agitation *Loss of Confidence
*Anxiety *Malaise
*Contentiousness *Moodiness
*Depression *Pessimism
*Emotional Lability *Sadness
*Hopelessness
*Irritability
The above results are also non-trivial. PMS symptoms can be disabling
in their severity fo
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