The Chemistry of Thought (Part Two)
The brain takes in experience in chunks. We call them “process bursts”. Chunks come in raw, cooked and stale. The “process burst” takes in the “experience” that feeds it, and it has a life of its own. It is initially “raw”, being only aware that something has happened. Shortly later, it “ripens”, and contains information regarding the details of the input. Still later, it relaxes, and “chews on” the data, and reaches a stable plateau of “understanding”. Still later, it introspects, ponders the information, produces intuitive and deeper interpretation. Finally, it dies away. The “process burst” is like a bubble that starts out small, grows, pauses, grows some more, and finally disappears either by bursting or by collapsing. These bursts occur in parallel. There may be thousands of them at once, in different parts of the brain, processing different types of information, different modalities, different views. They are also coordinated by cross- communication with each other, using combinations of feedback, feed-forward, and collateral connections. This provides the spatio-temporal binding that fuses thousands of responses into the cohesive experiences that we interpret as perception, conscious awareness, and the sense of identity.
Chunks of reality can be homemade or can come out of a box. Amidst the cacophony of signals recorded in the EEG, we can see these bursts coming and going. The key to the brain’s function is in processing these bursts in trains, one after another. The intrinsic EEG is built of these bursts as produced by lower brain centers creating rhythms via the reticular formation, ascending brain tracts, and thalamus, as well as intracortical reverberatory activity. The EEG waves produced by light and sound stimulation are of course temporally and casually related to the incoming trains of stimulation. In fact, these bursts are in this case what we call “evoked potentials”, and that have been studied for many years, albeit with limited insight and few conceptual breakthroughs. The common ground in both is that process bursts are produced at a certain rate. When a neural sub-circuit in mid-burst is hit with another incoming stimulus, the burst that is in process is interrupted, and the sub-circuit now begins processing, using the state that was produced by the preceding burst. This is why the rate at which the bursts are produced is important. We can think of the next stimulus as “opening” or “cracking” the existing burst. It “probes” the neural sub-circuit by stimulating it when it is in the state produced by the previous burst. This state can be the state of being in a “raw” burst, a “cooked” burst, a “stale” burst or, if long enough, no burst. These bursts are the “chunks” of experience that the brain uses to create reality. By using these bursts as stepping stones on a vast pool of possible thoughts, the brain navigates its way on the sea of mind, and thus go where it will go, based on the progress from one stone to the next.
You feed on the chunks of reality that you create. If bursts are produced at a certain rate, then the process of brain states will take a certain path. For example, if the bursts are processed at the “alpha” rate, 10 per second, then successive bursts are produced while the sub-circuits are in a relaxed state, hence each burst finds itself built upon a relaxed sub-circuit. The relaxed state of the brain is thus created and reinforced.
This also explains why 10 Hz stimulation is relaxing. It in essence “puts” the brain from stone to stone, as though the brain were a marionette on strings, and were being walked along by guidance. Now if the bursts are produced at a very slow rate, say 5 per second, then each new burst is built upon a sub-circuit that is in a deeper, introspective state. This can lead to an intuitive state of mind, but it can also lead to a distracted, understimulated one. This is why kids with ADD typically show a lot of theta waves. Their brains are processing bursts at a slow rate, and the resulting brain state is in accordance with that. If the bursts are produced at a rapid rate, say 15 per second, each stimulus finds the neural substrate in a stimulated, alert state. It is aware of its input, but has not had a lot of time to ponder it, relax, or find the deeper meaning. Kids with Attention Deficit Disorder typically have a low level of beta, so they do not have enough of this going on. Light and Sound stimulation primes the pump, giving you a taste of another reality.
What happens with photic stimulation is that you give the brain practice with creating and “opening up” the bursts at a given rate. It is like training wheels, or pushing a child along on his bicycle. The brain gets to experience it. It is spoon feeding the cortex with the experience of processing information in a certain way, without the brain having to produce the rhythms on its own. This also explains why external stimulation can produce a temporary effect, but generally little or learning. The cortex gets to experience the state produced by the burst processing, but it has not learned how to keep that state going. It has not learned to produce the rhythm on its own. Light and sound stimulation can be fun, invigorating, deepening, tiring or even agitating. What it is doing is force-feeding your cortex with bursts, and then forcing you to process the trains at a given rate. You get to practice processing information at a certain pace, but you have not learned to pace yourself using internal mechanisms. This is why auditory and visual stimulation cannot replace EEG neurofeedback. EEG neurofeedback rewards the brain for producing (or inhibiting) the driving stimulation at the desired rate. This is in addition to allowing the brain to learn the experience of processing the bursts at the given rate.
Ultimately, these bursts are taken in a very long sequence. After thousands and thousands of such stepping stones, the brain learns to find its steady-state points. These points may be locations of alertness, focus, distractedness, agitation, depression, joy, whatever. The brain tends to recover and find its equilibrium, which is presumably some state of rest or relaxation. But processing information and “lifting” itself out of the equilibrium point, the brain uses energy to reach a more excited state. This is what the bursts do. They “push” the brain into a higher state.
Where that state is, and what its attributes are, depend on the trajectories of the processing of each burst. It is hoped that these considerations may motivate methods that combine auditory and visual stimulation with EEG, to produce useful and objectively designed protocols for training the individual.
Tom Collura is founder and President of BrainMaster Technologies, Inc, Oakwood Village Ohio, where he conducts research and development of EEG neurofeedback systems for clinical and home use. He received an AB in Philosophy of Science and an Sc.B. in Biology from Brown University, Providence, Rhode Island (1973), and an MS and Ph.D. in Biomedical Engineering from Case Western Reserve University, Cleveland, Ohio (1978). He is a registered professional engineer in Ohio and Illinois. He served on the technical staff of AT&T Bell Laboratories from 1978 to 1987, where he supervised silicon integrated circuit technology development and multiuser computer systems engineering. He was on staff with the Department of Neurology, The Cleveland Clinic Foundation, from 1987 to 1996, where he developed systems for invasive EEG recording and analysis for epilepsy diagnosis and surgical planning and monitoring. He has also served as a consultant to industry in the areas of computerized tomography, digital signal processing, automated radiometry, and electrophysiological telemetry. His current interests focus on the neurophysics of the mind/brain boundary, development of EEG feedback systems, and the use of volitional and nonvolitional techniques for brain modification with applications in neurotherapy, consciousness development, and personal improvement. Thomas F. Collura, Ph.D., P.E. / BrainMaster Technologies, Inc. 24490 Broadway Ave. / Oakwood Village, OH 44146 440 232-6000 / fax 440 232-7171
Copyright: T. F. Collura, Ph.D., P.E., Author and AVS Journal, Michael Landgraf, Publisher (2006) CA.