Listen to the full podcast here Jay Gunkelman Podcast
This week we’re joined by QEEG Diplomate (yes, that’s a term!) and founder of Brain Science International Jay Gunkelman, to talk Electroencephalography. After analyzing over a half-million EEG scans, Jay has a pretty robust set of human brain data at his disposal… And he uses that body of knowledge to guide the work of psychiatric and other health professionals who make proscriptive recommendations about patients’ brains.
Consciousness: An Emergent Property Of Mind-Brain Interaction – presented by Jay Gunkelman
A model of consciousness will be illustrated with physiological data from EEG and Event related potentials. Using millisecond level time resolution, a working model of the interaction between the mind and the brain will be constructed.
The Slow Cortical Potentials generated by Glial activity and the faster gamma activity reflecting activity of bound neural networks will be used to illustrate this model. The physiological correlates of concepts like intention, attention, memory, perception, awareness, sensory differentiation and conscious awareness will all be discussed within the framework of this model. Advanced concepts like neural network binding, nested rhythms, cross-spectral correlation, and the bispectrum will be discussed.
The DC potentials cause an instantaneous phase resetting and binding of a neural network, which can initiate synchronous activity within these neural networks. Current work using this model in clinical work on severe disorders of consciousness, including work by the International Brain Research Foundation on recovery of consciousness in coma cases will be reviewed. The simplest expression of the model: when the DC potentials reflecting activity of the mind interact with gamma activity reflecting neural activity in the brain, the emergent property of this interaction is consciousness.
[youtube]http://www.youtube.com/watch?v=Pv-msnzTk7o[/youtube]
Alpha… it’s not a simple idling rhythm… let’s look at alpha generators:
The thalamic involvement in the generation of the alpha rhythm is being under-valued when looking at the LORETA images of alpha current source generators. The alpha power may come from the sources that LORETA identifies, but the thalamus is intimately involved in alpha rhythm generation, and this is not part of the LORETA image of the sources.
The polarization within the thalamus sets the base frequency of the alpha, but the cortical rhythm requires a complex multi-layer feedback loop from the thalamus to the cortex, and back to the thalamus. Without the cortex, there is a total disruption of the normal spatio-temporal distribution of the alpha wave’s spike trains within the thalamus, and cortical damage often disturbs coherence due to this mechanism.
The thalamus distributes the alpha posteriorly via specific sensory relays, which have a simple return circuit. Like the white matter relay from the lateral geniculate of the thalamus to the occipital lobe’s primary visual areas, and directly back. This thalamo-cortical-thalamic loop is relatively faster than the loop seen frontally. The frontal return circuitry is not simple, but the descending routes are complex and somewhat circuitous, taking more time, and thus it is common for the frontal lobe’s alpha to be at the slower end of the individual’s alpha frequency range. The frontal lobe has a return path through the striatum.
The homunculus is a spatial representation of the cortical topography of the
somato-motor strip which is dedicated to either motor or sensory function.
The two have different structural details, since there are sensory inputs
from non-motor areas.
Some people have tried to create 3D creatures which show the spatial
distortions, with the enlarged surface proportionate to the motor expression or sensory sensitivity, with varied results.
See if you can identify the differences between the sensory and motor
version, and also critique the accuracy of the artist’s rendition of these
various versions.
Have fun with the exercise!
Jay
Life offers us many teachers, and we generally only learn a small sliver of what they have to offer from the breadth and depth of their experience.
One such teacher was E. Roy John, who most knew as a brain researcher, though he had so much more to offer… did you know he was “blacklisted” as a liberal, or that he worked on the Manhattan Project making Plutonium? Did you know he is considered the grandfather of Cuban Neuroscience? How about his love of boating…
Perhaps a quick look through his obituary will make us all appreciate just a bit more the actual magnitude of our loss from his passing…. And then you can look over the diagram of the brain and see some of the complexity of the models Roy passed on to those who now have to carry on without his wise counsel.
Joyful in having known him, and saddened by our loss,
Jay
Three part video by Jay Gunkelman discussing Technical Issues in qEEG.
Technical Issues in qEEG Power point Presentation
The qEEG represents the statistical manipulation of the raw EEG, so an understanding of these manipulations should precede any discussion of the qEEGs clinical indications for protocols. Without such knowledge any given finding may be misinterpreted.
Following the careful recording of the EEG, the quantitative analysis is begun with the sampling of the data to be used in the analysis by the Fourier transform. The Fourier analysis assumes there are no transients (epileptic discharges, episodic voltage changes etc.) or state changes (light sleep, drug effect, mental task, etc.), so these must be avoided when selecting data for analysis in qEEG for eyes closed resting database comparison. There are some eyes open and task databases available more recently (Hudspeth, Sterman, Duffy etc.)
There are many in the field of Neurotherapy who do not perform qEEGs prior to designing a clinical intervention. These people are currently practicing well within the standard of practice for this rapidly evolving field. Many within this group have standard protocols which are used on all clients, with various alterations to respond to the client’s reported experiences during the treatment.
The ascending reticular activating system stimulates the diffuse thalamic projection system and sets the general arousal level of the brain. With an increase in the CNS arousal level, there is an increase in the mean frequency of alpha and a decreased slowing. With decreases in arousal there is a slowing of the alpha, as well as eventually an increase in diffusely distributed slowing ( a mixture of diffuse lower voltage delta and theta, usually with a weak vertex prominence in linked ear montages).
I often get questions about Alzheimer’s Disease (AD) and the EEG.
Whenever a client presents with the question of dementia, all other forms of
dementia need to be ruled out before you are left with the diagnosis of AD.
There are many EEG signatures of various forms of dementia, all of which are
helpful in evaluating a client’s presentation of dementia.
Done by experts in EEG in dementia, the EEG and qEEG may be of substantial
additive value in the differential diagnosis puzzle that all cases of
dementia represent clinically.
One EEG pattern seen in dementia is the presence of periodic triphasic
slowing in the EEG, which is actually diagnostic of subacute sclerosing
panencephalitis (SSPE). SSPE is a “spongiform encephalopathy” where the
brain becomes like “Swiss cheese”, with holes scattered throughout. This
periodic triphasic finding is differentiated from MULTIFOCAL triphasics
which are diagnostic of Crutzfeld-Jacob Syndrome (CJD), which in lay terms
is a form of mad cow disease in humans.