Guest guest Posted May 20, 2012 Report Share Posted May 20, 2012 Hi Devidas, You asked about the concepts of polymorphic theta and 'good' theta. If the formatting (below) doesn't line up, let me know and I will send a pdf. In my experience there are few more important references than Stern and Engels' " Atlas of EEG Patterns " (Lippincott & Wilkins). It is a highly regarded new classic in the field of raw EEG classification. In the chapter of theta activity you will find excellent EEG charts that carefully explain the differences between the important types of theta signatures, namely frontal midline theta (Cigánek rhythm), polymorphic theta, and rhythmic midtemporal theta. First lets recall that polymorphic comes from two roots. " Poly " means more than one (maybe many) and " morphic " means shape (from Greek 'morphē'). Rhythmic EEG forms: may look as regular as the mathematical sine wave that looks something like this: * * * * * * * * * * * * * * * * * * * * * * * * *-------*-------*-------*-------*-------*-------*-------*- * *| * *| * * * * | * * | * * * * | * * | * * | | *---------------* period=250ms time -> Remember - the peaks and troughs are as smooth as the movements of a horse going up and down on a carnival merry-go-round. The horse slows at the top of its curve then goes down faster and faster until it starts slowing at the trough and reversing direction. This pattern is a fundamental pattern in most of mathematics and physics. It is particularly important in heart rate variability. Only if the HRV curve is very smooth on the peaks and troughs do you get rewarded at higher challenge levels. There is only one form of pure sign wave, but there are an infinite number of ways this pure form can be deformed. With 256 samples per second, there are 256 different spots that can be distorted above or below the line of the normal sine wave. Note the spacing between the above waves is uniform. If this were a 4 hz theta wave, then 4 cycles fit into a second. One second is equal to 1000 milliseconds. If 4 identical cycles fit into 1000 ms then every wave has a " period " of 1000 ms)/4 = 250 ms. The " period " of time taken to complete one cycle is often mistakenly referred to as " wavelength " which is a unit of distance. This usual only annoys physicists. Polymorphic EEG forms: See the little symbols * in the above chart. Imagine there were several hundred of them instead. Imagine how many ways an individual * could be raised 1 or many steps above or below normal. Please remember that the spacing between the waves (the period or 'wavelength') for theta varies from 125-250 ms (do the math as above). This means that in addition to raising the individual * points up or down we can mix and match literally an infinite number of periods between 125-250 ms and it is still a theta wave, but clearly of multiple shapes (polymorphic). Do you see that such distortions could easily lead to a wide variety of charts that are barely recognizable. You can roughly see two forms below that have wavelengths which identify them as theta. The concept is easy to see when you recognize that these theta waves cross the zero voltage line. Sometimes a theta wave only appears long enough to display 1/2 cycle. So anything that roughly trends up then down over a period of, say, 125 ms, may represent 1/2 of a theta cycle. * * * * ** * *** * * ** ** * * * * * *-------*-*----**------*--------*---*---* * | *** * **| *** | | * * | *| | | | | | | *---------------*-------* p=250ms p=100ms time -> " Good theta " vs " bad theta " as scientific terminology can only be seen as emblems for phenomena not yet well characterized. This also applies to delta waves as well. " Good " theta is usually the more rhythmic type found in frontal central distribution ('frontal midline theta'). But it is also absolutely essential over the entire cortex and is involved one way or another in most cognitive and autonomic functions. Polymorphic theta (except in non-REM sleep) is a potentially ominous sign. I will illustrate from one of my qEEGs where polymophic delta was a component: Findings: Polymorphic Delta Activity: The increased delta activity in this recording was found to be diffusely distributed, did not occur in bursts, and was without identifiable rhythmicity, thus qualifying it as polymorphic delta activity (PDA). Stern & Engel, 2005, give the following comparison of normal versus abnormal PDA. “PDA is a common finding on electroencephalograms (EEGs) that may be distinguished as either normal or abnormal based on features and circumstances. However, abnormal PDA may have several features of normal PDA, including bilateral symmetry in frequency and amplitude, superimposed faster frequencies, and an increase in frequency with alerting stimulation such as noise or touch. Nevertheless, abnormal PDA commonly and characteristically has consistent asymmetry, asymmetrically superimposed faster frequencies, and lack of change with alerting stimulation. Focal PDA that has a region of maximum slowing and minimal faster frequencies is especially abnormal and indicates a focal lesion in the white matter that is deep to the most abnormal region within the focal slowing.†“Generalized PDA indicates either encephalopathy or sleep, and encephalopathy in this context is a nonspecific state of diffuse neuronal dysfunction that may be as severe as coma.†“The encephalopathy producing generalized PDA may be a reversible state due to transient physiologic abnormality or due to endogenous or exogenous sedatives. Physiologic abnormalities may occur during migraine, syncope, and ischemia and after a seizure. [1, 2] Metabolic dysfunction is the principal source for endogenous sedation and may be produced by hepatic and renal disease. Exogenous sedatives are specific toxins and pharmaceuticals, such as narcotics. Generalized PDA also may be irreversible as from a diffuse cerebral insult such as anoxia, infection, hypoglycemia, and inflammation; developmental abnormality usually with global cognitive impairment; or certain degenerative or dementing illnesses such as stroke, advanced Alzheimer’s disease, and sometimes schizophrenia. Specifically, PDA occurs when serum glucose is less than 35 mg/100 ml, and all other frequencies are absent when the glucose drops below 18 mg/100 ml. Lower serum glucose concentrations will produce generalized attenuation. Inflammatory causes of PDA include encephalitis, purulent meningitis, and some autoimmune diseases such as Sydenham’s disease and Behçet’s disease.†“Regardless of its cause, generalized PDA is similar to focal PDA as a sign of cerebral white matter abnormality [3 ,4]. This abnormality must be significant and include either cellular toxicity or mechanical compression. Interstitial edema alone does not appear to produce abnormal slowing. Often the pathology is accompanied by cerebral cortical abnormality, but abnormality limited to the cerebral cortex does not produce slowing. It produces attenuation and loss of the faster frequencies.†[5] With respect to the above discussion it should be emphasized that this client has 1) asymmetric PDA with 2) lack of change between eyes closed and eyes open, with 3) attenuation and loss of faster frequencies which are asymmetrically superimposed. See also Figures 8 & 9. Careful attention to age-appropriate cognitive, nutritive and metabolic status may help elucidate the significance of these findings. This is just my interpretation of the literature. I hope it makes some sense. Best wishes, Dailey [1] Ramelli GP, Sturzenegger M, Donati F, Karbowski K. EEG findings during basilar migraine attacks in children. Electroencephalogr Clin Neurophysiol 1998: 107:374-378. [2] Ammirati F, Colivicchi F, Di Battista G, Garelli FF, Santini M. Electroencephalographic correlates of vasovagal syncope induced by head-up tilt testing. Stroke 1998: 29: 2347-2351. [3] Sharbrough FW. Nonspecific abnormal EEG patterns. In: Niedermeyer E, Lopes da Silva F, Eds. Electroencephalography, basic principles, clinical applications, and related fields. Baltimore: & Wilkins, 1999:215-234. [4] Zifkin BG, Cracco RQ. An orderly approach to the abnormal EEG. In: Daly DD, Pedley TA, eds. Current practice of clinical electroencephalography. 2nd ed. New York: Raven Press. 1990: 253-267. [5] Schaul N. Pathogenesis and significance of abnormal nonepileptiform rhythms in the EEG. J Clin Neurophysiol 1990:7:229-248. -----Original Message----- From: [mailto: ] On Behalf Of devidasbhonde Sent: Sunday, May 20, 2012 7:02 AM Subject: Re: Theta Synchrony , very thought provoking. thank you. Can you please elaborate polymorphic theta ? And Good theta ? Is it that presence of harmonics make it polymorphic ? And fundamental theta with harmonics makes it bad ? Regards, Devidas Quote Link to comment Share on other sites More sharing options...
Guest guest Posted May 22, 2012 Report Share Posted May 22, 2012 Hello Bruce, It's nice to hear from you. I hope you are well. I will repeat your questions/observations below. I apologize in advance for some of my unusual analogies, and hope there might be something useful. 1: Your mention of Beta spindling within the context of Othmer's low frequency training due to Harmonic effects has me wondering about the same for breath training. In other words given the low frequency components of breathing at certain rates, isn't there a danger of triggering beta spindling with this too? 1. I suspect this is exactly true. Hyperventilation (along with photic stimulation) is a regularly used activation technique to provoke epileptiform responses on the EEG and thus assist in diagnosis. Even people breathing at 6 breaths per minute (0.01 Hz) often hyperventilate. In the deepest recesses of the fractally folded lung tissue, the precise balance between ventilation and blood perfusion is under control of the social engagement system via the myelinated ventral vagus system. 2: On the topic of harmonic or resonant effects, can this work the other way too with higher frequencies rippling down the spectrum when trained? 2. I believe the answer is yes, but I prefer to phrase it differently because I think we are talking about different phenomena than harmonic or resonant effects. I predict that huge paradigm shifts are in the works and they will involve several topics currently exciting the physics community. mountain of salt or sand (or neural avalanches) self organized criticality. Shifting the relationship in the bottom of the mountain can have a profound effect on the amplitude of the structures at the top of the mountain. The neural avalanches appear to be accompanied by phase resets. The concepts of harmonic and resonant effects are more related to Pythagorean and linear relationships. You might really enjoy the following link. http://www.youtube.com/watch?v=u573PyXo-pY & feature=related I prefer to focus on the fact that phase modulation of lower frequencies controls amplitude of higher frequencies. This is a characteristic of 1/f power law systems. The deeper relationship between phases of all the lower frequencies to the amplitude of the higher frequencies is like the self-recurring similarities no matter how you scale the fractal. If you train a person to vary gamma for example, without checking you can't be sure whether or not you are actually phase shifting in any band all the way down to the EEG frequencies associated with the resting state networks. Sometimes I try to pretend NFB didn't yet exist. Since self-regulation of temperature has been shown to help a variety of conditions, and self-regulation of HRV has shown to help as well, then I ask myself what would be the best sort of self regulation to encourage in the brain with the help of some sensor. I won't bother you with the details of my thoughts, but I would feed back a signal designed to always allowed the brain (if possible) to explore its own use of the relationship of low frequency phase and high frequency amplitude shifts. I would want the signal to be scale invariant and safe to use anywhere on the head. I would like it, for starts, to train self-regulation in the midline. In those trained in mindfulness meditation the midline gamma (DMN) is higher at rest than in controls; during tasks it is lower in meditators than in meditators. 3: There is an important theoretical and empirical hurdle that needs to be crossed before any hypothesis of LFT causing beta spindling can be supported. What is the theoretical rational that this can be trained with such large time lags due to the nature of the signal? I don't think operant conditioning as a model would support that such signals can be trained. Also where is the empirical evidence to support that Low frequency components have actually been trained during sessions? Client reports of effects is not evidence that any training of Low Frequency dynamics occurred. 3. Bruce, that is a fantastic point. I don't mind calling it low frequency training. I do mind calling it low frequency amplitude training. 0.01 Hz and 0.1 Hz respectively represent waves that take between 10 and 100 seconds to complete. At these low frequencies I often find that changing the filter settings provides the brain with an additional challenge to master. It is like going rock climbing and getting to the top. If you need more training you don't necessarily have to go up further. Instead you can go sideways. I hear of people programming their software so they can dial in frequencies of 0.00001 Hz. This is a wave that takes precisely 1 day (24 hours) to roll by and reveal its peak to peak amplitude. It is indeed a strain when someone claims they measured and then trained the amplitude of a wave that takes from 15 min to 24 hours. Even at 0.10 Hz (6 per minutes) to train the peak to peak amplitude would require 15 minutes to measure at least one cycle, then 15 minutes more to train one cycle only, and then 15 minutes to measure the result. This 45 minutes. 3 waves have occurred. I myself would like to know where the NFB training is in this model. So let's forget amplitude a while. Besides, the 1/f power laws suggest that underneath every amplitude manipulation (even at infra low frequencies), there may be a phase shift in even a lower frequency which is responsible. This is a difficult concept for some people so I prepared 2 stories. When you read them, remember that when the story talks about the amplitudes of waves on the sea, we are going to be talking about surface ripples like regular EEG, and then the ultimate phase shifts at lower frequencies. Consider if you were riding on a boat in a very choppy sea. As you bobbed up and down you could measure the peak-to-peak amplitudes of the various waves. But, without additional instrumentation, you would not be aware of the slow rise and fall due to the tide. Story 1: One day a simple blind person from the mountain, who never heard about tides or the moon or gravity, made a visit with a local person to the sea. The blind person asks, " The water is going up and down some - is it safe? " Yes " , says his companion, " those are fast and slow waves, but the tide comes and goes every 24 hours (0.00001 Hz) and you should be concerned about the amplitude. " " Don't worry, " said the blind person, " I just measured the variations in the amplitude of the water for a full clinical 50 minutes. I know how high the tide will be today. " Of course this is a silly story. Clearly there is no algorithm he could have known (even if he had Ben lin's Almanac) that allows him to predict the future. He returned to the mountain. His best friends congratulated him for measuring the tide. Story 2: The blind man who measured the " tide " in 50 minutes received word that shortly after his visit the tide had been uncharacteristically low and the water could not irrigate the low-lands. The blind man studied and mediated several years until he realized that if he could shift the Earth's core to change the gravitational center away from the sea, then the sea might raise enough to irrigate the land. He wondered how to do it. [Note: at this point I am writing science fiction since we barely know how to do feedback training to people and certainly not to planets.] Suppose, like the ancients said, Gaia (Earth) is sentient. Certainly her core shifts spontaneously and, along with the moon, alters the gravitational pull on the water. What if we could put in sea-brakes (filters/inhibits) to stop every single higher frequency wave on the surface of the water, to have it like the smoothest lake? Then certainly our dipsticks will be monitoring the moment-to-moment slow shifting of the earth's core. In a stroke of genius he decided to plant a tree every time the core shifted and the water rose. After 40 sessions (twice per day because Gaia was acute) the water rose and the lowlands were irrigated. The villagers planned to give him a reception with great honors, and to support him in his efforts. Unfortunately the leaders wanted to siphon all discretionary funds into a war chest in order to disadvantage and plunder the neighbors, who they had already carefully painted as the axis of evil for the sake of those with moral issues. They had a very clever statistician come to the sea and do exactly what the blind man had done before. He measured the sea amplitudes for 50 minutes and declared that it was exactly the same as before. The treatment was pronounced worthless. The blind man left disappointed. But once per month he was paid by private citizens to come raise the tide and moisten the fields. All the other planets were envious that Gaia's ecosystem was learning self-regulation. End of silly stories. I am not as keen as you on finding support that low frequency components have actually been trained. I think it nice but not necessary. During a session you can train a person a lot. You can see in the movements on the instruments the client's brain shifting every time the terrain is switched. The person may feel a variety of states. I ask " would this state be useful for you? " And I get real interesting answers. At the end of the session I don't care at all if I changed amplitude of the low frequency waves permanently. I will simply be with the client while he/she explores the enriched interactive environment that points toward state changes. The real value of a brain state to the neural networks resides in how easy that state is to obtain when needed. White willow bark was used for pain and inflammation for centuries before it was discovered that it's active component could be synthesized. It is commonly called Aspirin. Somehow people felt better using it now that we knew it alters the cyclooxygenase (COX) pathways. Now that everyone is comfortable with the explanation, death and disease due non-steroidal anti-inflammatory drugs is on the increase. New discoveries continue to lead to new theories about how things are connected. And that is the thing about theories. I can't remember who said " Theories are neither true nor false, they are simply useful or not useful. " As far as support for the hypothesis of LFT causing beta spindling, this is not an hypothesis - it is an easy observation to make. The reason, I think, that more LFT practitioners are not aware of this is because they use their gear with auto-thresholds activated. Besides, it can become daunting to think of meaningfully fussing with so many inhibit bins. I find it quite common that a client will start feeling some discomfort accompanied by an elevation in a particular inhibit beta inhibit bin. It is up to you what to do at this point. I might bring the frequency up until the rogue beta bin goes down and behavior returns to normal; or I might mute all feedback from the " low frequency " reward and only focus on shaping beta manually. I have one client who can raise or lower any one of 4 individual beta bins at will. He practiced to visualize my screen which he calls a dashboard. When he starts to get an anxiety attack he visualizes the dashboard and repeats what he had done to control the beta spindling. Best wishes, From: [mailto: ] On Behalf Of Bruce Z. Berman Sent: Sunday, May 20, 2012 1:29 PM Dailey; Subject: Re: Theta Synchrony Hi , Glad to see you posting. Some associations and questions below; 1: Your mention of Beta spindling within the context of Othmer's low frequency training due to Harmonic effects has me wondering about the same for breath training. In other words given the low frequency components of breathing at certain rates, isn't there a danger of triggering beta spindling with this too? 2: On the topic of harmonic or resonant effects, can this work the other way too with higher frequencies rippling down the spectrum when trained? 3: There is an important theoretical and empirical hurdle that needs to be crossed before any hypothesis of LFT causing beta spindling can be supported. What is the theoretical rational that this can be trained with such large time lags due to the nature of the signal? I don't think operant conditioning as a model would support that such signals can be trained. Also where is the empirical evidence to support that Low frequency components have actually been trained during sessions? Client reports of effects is not evidence that any training of Low Frequency dynamics occurred. Bruce Z. Berman ----- Original Message ----- From: Dailey Sent: Saturday, May 19, 2012 7:50 PM Subject: Theta Synchrony Hi Mark, You asked my thoughts about " theta left frontal to posterior synchrony " as the underlying mechanism of alpha-theta training. You cited Gruzelier [1]. Gruzelier cited von Stein [2] and Aftanas [3]. Let me know if you need those articles. I apologize in advance for my errors in interpreting the literature. I don't think this is the mechanism behind typical alpha theta effects, since that tradition involves only posterior electrodes and may train theta and alpha amplitudes individually. That is why in theta-alpha amplitude training the hallmark feature is the alpha-theta amplitude crossover. This is an indicator of drowsiness or hypnagogic state. , et al [4] found no correlation between the TA crossover and production of imagery. In traditional alpha-theta amplitude training there is no built in flexibility for the fact that one is changing the amplitudes of frequency bands (theta and alpha) that normally take much of their cues from phase shifts at lower frequencies. This AM-PM (amplitude modulation - phase modulation) relationship is a characteristic of 1/f power law systems such as neuronal assemblies. In contrast to amplitude training, synchrony training can be configured to use theta phase shifts to drive alpha or gamma amplitude shifts. The hallmark of this approach is not the T-A amplitude crossover, but rather is the theta-alpha phase reset with its relationship to intelligence and valid perception. Another characteristic of T-A amplitude training is that it is done eyes closed and with relaxing sounds (both the sound and the flow of water exhibit a type of 1/f feature described as " pink noise " ). However, I have found TAG synchrony to be best performed eyes open, although, depending upon network targets, one may want to avoid using central foveal vision because it is anti-correlated with the default mode network. Since I conceive of T-A synchrony training as different than T-A amplitude training, I do not hold that the goal of synchrony is also the hypnagogic state accompanying T-A crossover, so I usually do not try to reward with hypnagogic sounds. My preferred reward for adults (that rarely works with troubled children) is to have theta synchrony reward by turning off a loud hum, and to reward alpha synchrony by turning off pink noise. If the client can avoid excess beta activity (e.g., spindling) then a loud alert sound can be avoided as well. I simply point out the 3 types of noise and ask the client to make them all go away. Thus the reward and encouragement for being in this state is to sit in utter quiet paying attention to the mental states, however they might be perceived. I believe this is an important goal since much of infant affect management is learned by the mother withdrawing stimulation when appropriate and allowing the infant to self-regulate in quiet when possible. Theta alpha synchrony, primarily in the anterior-posterior communications, is required for valid perception according to Varela [5], et al. In his studies of meditation [6] Aftanas (Russian Academy of Medical Sciences) documented the particular importance of theta and alpha synchrony between the left frontal cortex (e.g., F3) and the parietal areas (P3, Pz & P4). Like Klimesch he breaks the alpha clinical band into 3 sub-bands: Low alpha (6-8 Hz), Mid alpha (8-10 Hz) and hi alpha (10-12 Hz). Desynchronization in these 3 bands is associated with 1) alertness and vigilance (Lo Alpha), 2) expectancy (Mid Alpha), and 3) cognitive processing (Hi Alpha). The particular NFB alpha parameters used for a session can thus have individual significance for the client. Because of the effects of theta and alpha phase modulation on gamma amplitude (a consequence of the 1/f power law), it is interesting to look at different gamma patterns in meditators as well. Last month in Israel Berkovich-Ohana et all published a study [7]. Frontal and midline gamma is associated with default mode network functions (self-referential) and, of course, is decreased with attentional demands. However the lateral and posterior gamma is increased in attention and especially in meditators. Lehmann [8] showed that a skilled meditator could change gamma distribution at will by altering the meditation technique: increased right posterior occipital gamma activity in image visualization, increased left central-temporal area in mantra verbalizers. Those practicing emptiness meditation and reconstitution of the self produced increased gamma activity in the right superior frontal and right temporal-parietal sites - areas linked to altered sense of self [9]. Interestingly they also showed that very early in the practice of mindfulness meditation neural plasticity is increased in the self-referential networks (DMN) as well as the attentional networks. I like to paraphrase Siegel's definitions of mindfulness meditation: being aware of the modifications of the mind accompanied by the attitudes of curiosity, openness, acceptance and appreciation. In my opinion this is a useful definition for neurofeedback training as well. If so, then the data of meditation studies may have special relatedness to neurofeedback training. Here is another interesting thing about 8.5-12.5 Hz periodicity. Now I am not talking about the posterior dominant (alpha) rhythm, but I am talking about discrete state changes in the brain which occur in this frequency range and involved the entire cortex. These are called microstates. They have nothing to do with the brain state technology company. Most people chronically display 4 or 5 characteristic states. They occur in different sequences and last varying times. These microstates have been found to correlate to 4 of the resting state networks (not including the DMN), [10] and their sequencing is disordered in common conditions such as depression, dementia and schizophrenia. This may be one reason that 10 Hz light flicker improves recognition memory in older people [11]. This may be one of the reasons that alpha training (also in the 8.5-12.5 Hz range) is also important in brain state regulation. One important point to remember as we study brain microstates, is that we are used to thinking of the 1/f EEG in terms of the frequency domain, i.e., the power and coherence in the different clinical frequency bands. We have not looked completely yet at the time domain itself. As you will see from the literature, monitoring brain microstates, each lasting 80-120 ms, is very different than watching frequency bins change. When I started neurofeedback in 2008 I was fortunate to learn about the resting state networks. They have been well documented as disordered in a wide range of difficult clinical conditions including addiction, Alzheimer's disease, anxiety, autism, ADD, bipolar disorder, chronic depression, chronic pain, fibromyalgia, Parkinson's disease, PTSD, schizophrenia, etc. [12] The default mode network has anterior connectivity hubs involving the med prefrontal cortex and anterior cingulate, and a posterior connectivity hub at the precuneus and posterior cingulate area. When I was first exposed to alpha-theta training for PTSD I was surprised the training was all posterior. I was commonly met with skepticism about the safety or suitability of up-training frontal theta. Two facts made me persist. One is that although the presence of polymorphic theta (as in ADHD) is associated with inflammation and cytokine imbalance, the type of theta trained is, by the nature of the Fourier transform, may be rhythmic theta. Rhythmic theta is sometimes known as the Cigánek rhythm or frontal midline theta. Its presence is associated with improved self-regulation. Another reason I persisted and started trying theta alpha gamma synchrony in the midline is because the anterior cingulate and the insula are part of the salience network that directs resting state network changes. In my opinion it begs to be included in the neurofeedback. And in order for the salience network to have valid input, there must be long distance alpha-theta synchrony. Although I need to be discrete with the details for a few weeks, a group I am working with has shown that SMR neurofeedback for ADHD strengthens default mode network functionality! A common question I hear is how can SMR training at Cz strengthen resting state functional connectivity (rsFC) across the cortex? This may be because one of the microstates, " D " , has activity centered around the combined Fz-Cz area. And as we now know, brain microstate management has a direct link to resting state activity. This is, of course, in addition to the other benefits that come from learning to self-regulate corticothalamic loop timing. I find it interesting that heart rate variability training often involves about 6 breaths per minute. The frequency of 6 per minute (6 per 60 seconds) is exactly the same as the frequency of 1 per 10 seconds (1/10s) and is the same as 0.01/1 second = 0.01 Hz. Since the resonant frequency of the default mode network is 0.013 Hz and that of the anti-correlated attentional network is 0.016 Hz (both very close to 0.01 Hz, it is very possible that resonant breathing at the same frequency pumps these networks. This may be the basis for Takahashi et al's 2005 suggestion [13] that deviation from the normal power spectrum of the heart rate variability interfered with appropriate modulation of alpha and theta in naive meditators. Here again we see a little into the nature of the 1/f power laws that model reality. Phase modulation of low frequencies (such as 0.01 Hz or even 10 Hz) feeds amplitude modulation of higher bands such as beta and gamma. Monto, et al (2008) said very clearly that " infraslow fluctuations reflect the excitability dynamics of cortical networks. This is as clear and believable explanation for both the positive effects of infra-slow frequency training and also the adverse reactions. This 1/f characteristic of " feeding of high frequency amplitude shifts by low frequency phase shifts " is probably the main reason why neurofeedback can be dangerous. Both infra-low frequency NFB and synchrony NFB can encourage beta spindling. Beta spindling, when observable, usually appears as a fairly isolated peak of beta activity in a very narrow range, such as 20-22 Hz. It may best be considered a sign of irritated or kindled cortex. If your " inhibit instruments " are set to auto-threshold then beta in a narrow range, say 20-22 Hz can increase significantly, and your auto-threshold will merely elevate in order to accommodate the increased amplitude. Forty percent of frontal lobe epilepsy is not apparent on routine EEG even with provocation. If you see any change in beta spindling that is accompanied by any behavioral sign, such as sudden restless legs or change in demeanor, you may be dealing with paroxysmal kindled cortex - seizure by definition. Ultimately attempting to change frontal metabolism with neurofeedback may lead to problems if the client has imbalance in glutathione and glutamate. One of the first questions I ask clients is whether or not there is any bipolar disorder or schizophrenia in the family. If so, there is likely a 20-40% reduction in frontal glutathione. This is actually a very common condition. In my " theory of synaptic recidivism " (www.cortexercise.com) I summarize some of the literature showing that all of the disorders that are so common and difficult to treat (such as the list I gave above and [12]) are characterized by disordered excitation (glutamate poorly moderated by the reduced levels of glutathione). Because all learning (and neuroplasticity in general) requires significant inflammation for synaptic remodeling, and since the anti-inflammatory glutathione is in short supply in chronic illness, and since the average American diet contains possibly 20 times more excitotoxins (such as MSG) than it did 15 years ago when MSG was relabeled " natural spices " , change is difficult or impossible for some clients. N-acetyl-cysteine (NAC) is a generally safe dietary amino acid that provides the cysteine that is rate limiting in glutathione synthesis. Perhaps that is why the journal Biological Psychiatry has just pre-published results of a study showing effectiveness of NAC in treating autistic children [15]. Other problems find significant benefit from NAC, e.g., bipolar disorder, schizophrenia, trichotillomania, gambling, addiction. When attempting to optimize any sort of neurofeedback it may be important realize that there is already an imbalance in excitation, and microstate management will be difficult without neuroprotection. I have seen over-arousal occur with tDCS as well, and it is often relieved by NAC (best accompanied by other nutraceuticals). Neuroprotection and neuroplasticity are largely related to the infra-slow frequencies characteristic of resting state networks [16]. These lower frequencies are the Archimedean lever that raises the higher clinical EEG bands. Thank you for the question, Mark. I find it thought provoking. Perhaps others could chime in here. Best wishes, Dailey Near San Francisco CA [1] Gruzelier J (2008) - A theory of alpha-theta neurofeedback, creative performance enhancement, long distance functional connectivity and psychological integration. Cognitive Processes. Published online 11 Dec 2008. [2] von Stein A, et al (2000) - Different frequencies for different scales of cortical integration - From local gamma to long range alpha-theta synchronization. International Journal of Psychophysiology 38 2000. 301-313 [3] Aftanas LI, et al (2001) - Human anterior and frontal midline theta and lower alpha reflect emotionally positive state and internalized attention - EEG investigation of meditation. Neuroscience Letters 310(2001);57-60, [4] JP, et al (2000) - Comparison of alpha-theta, alpha and EMG neurofeedback in production of alpha-theta crossover and occurrence of visualizations. Journal of Neurotherapy, Vol. 4(1) 2000 [5] Varela F, et al (2001) - The brainweb - Phase synchronization and large-scale integration. Nature Reviews Neuroscience, Volume 2 April 2001 p 229. [6] Aftanas LI, et al (2001) - Human anterior and frontal midline theta and lower alpha reflect emotionally positive state and internalized attention - EEG investigation of meditation. Neuroscience Letters 310(2001);57-60, [7] Berkovich-Ohana A, et al (2012) - Mindfulness-induced changes in gamma band activity – Implications for the default mode network, self-reference and attention. Clinical Neurophysiology 123(2012);700-710. [8] Lehmann D, et al (2001) - Brain sources of EEG gamma frequency during volitionally meditation-induced, altered states of consciousness, and experience of the self. Psychiatry Res 2001;108:111–21. [9] BL, et al )2001) - Neuroanatomy of the self: evidence from patients with frontotemporal dementia. Neurology 2001;57:817–21. [10] Britz J, et al (2010) - BOLD correlates of EEG topography reveal rapid resting-state network dynamics. NeuroImage 52 (2010) 1162–1170 [11] J, et al (2006) - 10 Hz flicker improves recognition memory in older people. BMC Neuroscience 2006, 7:21 [12] Broyd SJ, et al (2009) - Default-mode brain dysfunction in mental disorders - A systematic review. Neuroscience and Biobehavioral Reviews 33 (2009) 279–296 [13] Takahashi T, et al (2005) - Changes in EEG and autonomic nervous activity during meditation and their association with personality traits. International Journal of Psychophysiology 55 (2005) 199– 207. [14] Monto S, et al (2008) - Very slow EEG fluctuations predict the dynamics of stimulus detection and oscillation amplitudes in humans. The Journal of Neuroscience, August 13, 2008 • 28(33):8268–8272. [15] Hardan AY, et al (2012) - A Randomized Controlled Pilot Trial of Oral N-Acetylcysteine in Children with Autism. Biol Psychiatry in press. Quote Link to comment Share on other sites More sharing options...
Guest guest Posted May 22, 2012 Report Share Posted May 22, 2012 Hello Bruce, It's nice to hear from you. I hope you are well. I will repeat your questions/observations below. I apologize in advance for some of my unusual analogies, and hope there might be something useful. 1: Your mention of Beta spindling within the context of Othmer's low frequency training due to Harmonic effects has me wondering about the same for breath training. In other words given the low frequency components of breathing at certain rates, isn't there a danger of triggering beta spindling with this too? 1. I suspect this is exactly true. Hyperventilation (along with photic stimulation) is a regularly used activation technique to provoke epileptiform responses on the EEG and thus assist in diagnosis. Even people breathing at 6 breaths per minute (0.01 Hz) often hyperventilate. In the deepest recesses of the fractally folded lung tissue, the precise balance between ventilation and blood perfusion is under control of the social engagement system via the myelinated ventral vagus system. 2: On the topic of harmonic or resonant effects, can this work the other way too with higher frequencies rippling down the spectrum when trained? 2. I believe the answer is yes, but I prefer to phrase it differently because I think we are talking about different phenomena than harmonic or resonant effects. I predict that huge paradigm shifts are in the works and they will involve several topics currently exciting the physics community. mountain of salt or sand (or neural avalanches) self organized criticality. Shifting the relationship in the bottom of the mountain can have a profound effect on the amplitude of the structures at the top of the mountain. The neural avalanches appear to be accompanied by phase resets. The concepts of harmonic and resonant effects are more related to Pythagorean and linear relationships. You might really enjoy the following link. http://www.youtube.com/watch?v=u573PyXo-pY & feature=related I prefer to focus on the fact that phase modulation of lower frequencies controls amplitude of higher frequencies. This is a characteristic of 1/f power law systems. The deeper relationship between phases of all the lower frequencies to the amplitude of the higher frequencies is like the self-recurring similarities no matter how you scale the fractal. If you train a person to vary gamma for example, without checking you can't be sure whether or not you are actually phase shifting in any band all the way down to the EEG frequencies associated with the resting state networks. Sometimes I try to pretend NFB didn't yet exist. Since self-regulation of temperature has been shown to help a variety of conditions, and self-regulation of HRV has shown to help as well, then I ask myself what would be the best sort of self regulation to encourage in the brain with the help of some sensor. I won't bother you with the details of my thoughts, but I would feed back a signal designed to always allowed the brain (if possible) to explore its own use of the relationship of low frequency phase and high frequency amplitude shifts. I would want the signal to be scale invariant and safe to use anywhere on the head. I would like it, for starts, to train self-regulation in the midline. In those trained in mindfulness meditation the midline gamma (DMN) is higher at rest than in controls; during tasks it is lower in meditators than in meditators. 3: There is an important theoretical and empirical hurdle that needs to be crossed before any hypothesis of LFT causing beta spindling can be supported. What is the theoretical rational that this can be trained with such large time lags due to the nature of the signal? I don't think operant conditioning as a model would support that such signals can be trained. Also where is the empirical evidence to support that Low frequency components have actually been trained during sessions? Client reports of effects is not evidence that any training of Low Frequency dynamics occurred. 3. Bruce, that is a fantastic point. I don't mind calling it low frequency training. I do mind calling it low frequency amplitude training. 0.01 Hz and 0.1 Hz respectively represent waves that take between 10 and 100 seconds to complete. At these low frequencies I often find that changing the filter settings provides the brain with an additional challenge to master. It is like going rock climbing and getting to the top. If you need more training you don't necessarily have to go up further. Instead you can go sideways. I hear of people programming their software so they can dial in frequencies of 0.00001 Hz. This is a wave that takes precisely 1 day (24 hours) to roll by and reveal its peak to peak amplitude. It is indeed a strain when someone claims they measured and then trained the amplitude of a wave that takes from 15 min to 24 hours. Even at 0.10 Hz (6 per minutes) to train the peak to peak amplitude would require 15 minutes to measure at least one cycle, then 15 minutes more to train one cycle only, and then 15 minutes to measure the result. This 45 minutes. 3 waves have occurred. I myself would like to know where the NFB training is in this model. So let's forget amplitude a while. Besides, the 1/f power laws suggest that underneath every amplitude manipulation (even at infra low frequencies), there may be a phase shift in even a lower frequency which is responsible. This is a difficult concept for some people so I prepared 2 stories. When you read them, remember that when the story talks about the amplitudes of waves on the sea, we are going to be talking about surface ripples like regular EEG, and then the ultimate phase shifts at lower frequencies. Consider if you were riding on a boat in a very choppy sea. As you bobbed up and down you could measure the peak-to-peak amplitudes of the various waves. But, without additional instrumentation, you would not be aware of the slow rise and fall due to the tide. Story 1: One day a simple blind person from the mountain, who never heard about tides or the moon or gravity, made a visit with a local person to the sea. The blind person asks, " The water is going up and down some - is it safe? " Yes " , says his companion, " those are fast and slow waves, but the tide comes and goes every 24 hours (0.00001 Hz) and you should be concerned about the amplitude. " " Don't worry, " said the blind person, " I just measured the variations in the amplitude of the water for a full clinical 50 minutes. I know how high the tide will be today. " Of course this is a silly story. Clearly there is no algorithm he could have known (even if he had Ben lin's Almanac) that allows him to predict the future. He returned to the mountain. His best friends congratulated him for measuring the tide. Story 2: The blind man who measured the " tide " in 50 minutes received word that shortly after his visit the tide had been uncharacteristically low and the water could not irrigate the low-lands. The blind man studied and mediated several years until he realized that if he could shift the Earth's core to change the gravitational center away from the sea, then the sea might raise enough to irrigate the land. He wondered how to do it. [Note: at this point I am writing science fiction since we barely know how to do feedback training to people and certainly not to planets.] Suppose, like the ancients said, Gaia (Earth) is sentient. Certainly her core shifts spontaneously and, along with the moon, alters the gravitational pull on the water. What if we could put in sea-brakes (filters/inhibits) to stop every single higher frequency wave on the surface of the water, to have it like the smoothest lake? Then certainly our dipsticks will be monitoring the moment-to-moment slow shifting of the earth's core. In a stroke of genius he decided to plant a tree every time the core shifted and the water rose. After 40 sessions (twice per day because Gaia was acute) the water rose and the lowlands were irrigated. The villagers planned to give him a reception with great honors, and to support him in his efforts. Unfortunately the leaders wanted to siphon all discretionary funds into a war chest in order to disadvantage and plunder the neighbors, who they had already carefully painted as the axis of evil for the sake of those with moral issues. They had a very clever statistician come to the sea and do exactly what the blind man had done before. He measured the sea amplitudes for 50 minutes and declared that it was exactly the same as before. The treatment was pronounced worthless. The blind man left disappointed. But once per month he was paid by private citizens to come raise the tide and moisten the fields. All the other planets were envious that Gaia's ecosystem was learning self-regulation. End of silly stories. I am not as keen as you on finding support that low frequency components have actually been trained. I think it nice but not necessary. During a session you can train a person a lot. You can see in the movements on the instruments the client's brain shifting every time the terrain is switched. The person may feel a variety of states. I ask " would this state be useful for you? " And I get real interesting answers. At the end of the session I don't care at all if I changed amplitude of the low frequency waves permanently. I will simply be with the client while he/she explores the enriched interactive environment that points toward state changes. The real value of a brain state to the neural networks resides in how easy that state is to obtain when needed. White willow bark was used for pain and inflammation for centuries before it was discovered that it's active component could be synthesized. It is commonly called Aspirin. Somehow people felt better using it now that we knew it alters the cyclooxygenase (COX) pathways. Now that everyone is comfortable with the explanation, death and disease due non-steroidal anti-inflammatory drugs is on the increase. New discoveries continue to lead to new theories about how things are connected. And that is the thing about theories. I can't remember who said " Theories are neither true nor false, they are simply useful or not useful. " As far as support for the hypothesis of LFT causing beta spindling, this is not an hypothesis - it is an easy observation to make. The reason, I think, that more LFT practitioners are not aware of this is because they use their gear with auto-thresholds activated. Besides, it can become daunting to think of meaningfully fussing with so many inhibit bins. I find it quite common that a client will start feeling some discomfort accompanied by an elevation in a particular inhibit beta inhibit bin. It is up to you what to do at this point. I might bring the frequency up until the rogue beta bin goes down and behavior returns to normal; or I might mute all feedback from the " low frequency " reward and only focus on shaping beta manually. I have one client who can raise or lower any one of 4 individual beta bins at will. He practiced to visualize my screen which he calls a dashboard. When he starts to get an anxiety attack he visualizes the dashboard and repeats what he had done to control the beta spindling. Best wishes, From: [mailto: ] On Behalf Of Bruce Z. Berman Sent: Sunday, May 20, 2012 1:29 PM Dailey; Subject: Re: Theta Synchrony Hi , Glad to see you posting. Some associations and questions below; 1: Your mention of Beta spindling within the context of Othmer's low frequency training due to Harmonic effects has me wondering about the same for breath training. In other words given the low frequency components of breathing at certain rates, isn't there a danger of triggering beta spindling with this too? 2: On the topic of harmonic or resonant effects, can this work the other way too with higher frequencies rippling down the spectrum when trained? 3: There is an important theoretical and empirical hurdle that needs to be crossed before any hypothesis of LFT causing beta spindling can be supported. What is the theoretical rational that this can be trained with such large time lags due to the nature of the signal? I don't think operant conditioning as a model would support that such signals can be trained. Also where is the empirical evidence to support that Low frequency components have actually been trained during sessions? Client reports of effects is not evidence that any training of Low Frequency dynamics occurred. Bruce Z. Berman ----- Original Message ----- From: Dailey Sent: Saturday, May 19, 2012 7:50 PM Subject: Theta Synchrony Hi Mark, You asked my thoughts about " theta left frontal to posterior synchrony " as the underlying mechanism of alpha-theta training. You cited Gruzelier [1]. Gruzelier cited von Stein [2] and Aftanas [3]. Let me know if you need those articles. I apologize in advance for my errors in interpreting the literature. I don't think this is the mechanism behind typical alpha theta effects, since that tradition involves only posterior electrodes and may train theta and alpha amplitudes individually. That is why in theta-alpha amplitude training the hallmark feature is the alpha-theta amplitude crossover. This is an indicator of drowsiness or hypnagogic state. , et al [4] found no correlation between the TA crossover and production of imagery. In traditional alpha-theta amplitude training there is no built in flexibility for the fact that one is changing the amplitudes of frequency bands (theta and alpha) that normally take much of their cues from phase shifts at lower frequencies. This AM-PM (amplitude modulation - phase modulation) relationship is a characteristic of 1/f power law systems such as neuronal assemblies. In contrast to amplitude training, synchrony training can be configured to use theta phase shifts to drive alpha or gamma amplitude shifts. The hallmark of this approach is not the T-A amplitude crossover, but rather is the theta-alpha phase reset with its relationship to intelligence and valid perception. Another characteristic of T-A amplitude training is that it is done eyes closed and with relaxing sounds (both the sound and the flow of water exhibit a type of 1/f feature described as " pink noise " ). However, I have found TAG synchrony to be best performed eyes open, although, depending upon network targets, one may want to avoid using central foveal vision because it is anti-correlated with the default mode network. Since I conceive of T-A synchrony training as different than T-A amplitude training, I do not hold that the goal of synchrony is also the hypnagogic state accompanying T-A crossover, so I usually do not try to reward with hypnagogic sounds. My preferred reward for adults (that rarely works with troubled children) is to have theta synchrony reward by turning off a loud hum, and to reward alpha synchrony by turning off pink noise. If the client can avoid excess beta activity (e.g., spindling) then a loud alert sound can be avoided as well. I simply point out the 3 types of noise and ask the client to make them all go away. Thus the reward and encouragement for being in this state is to sit in utter quiet paying attention to the mental states, however they might be perceived. I believe this is an important goal since much of infant affect management is learned by the mother withdrawing stimulation when appropriate and allowing the infant to self-regulate in quiet when possible. Theta alpha synchrony, primarily in the anterior-posterior communications, is required for valid perception according to Varela [5], et al. In his studies of meditation [6] Aftanas (Russian Academy of Medical Sciences) documented the particular importance of theta and alpha synchrony between the left frontal cortex (e.g., F3) and the parietal areas (P3, Pz & P4). Like Klimesch he breaks the alpha clinical band into 3 sub-bands: Low alpha (6-8 Hz), Mid alpha (8-10 Hz) and hi alpha (10-12 Hz). Desynchronization in these 3 bands is associated with 1) alertness and vigilance (Lo Alpha), 2) expectancy (Mid Alpha), and 3) cognitive processing (Hi Alpha). The particular NFB alpha parameters used for a session can thus have individual significance for the client. Because of the effects of theta and alpha phase modulation on gamma amplitude (a consequence of the 1/f power law), it is interesting to look at different gamma patterns in meditators as well. Last month in Israel Berkovich-Ohana et all published a study [7]. Frontal and midline gamma is associated with default mode network functions (self-referential) and, of course, is decreased with attentional demands. However the lateral and posterior gamma is increased in attention and especially in meditators. Lehmann [8] showed that a skilled meditator could change gamma distribution at will by altering the meditation technique: increased right posterior occipital gamma activity in image visualization, increased left central-temporal area in mantra verbalizers. Those practicing emptiness meditation and reconstitution of the self produced increased gamma activity in the right superior frontal and right temporal-parietal sites - areas linked to altered sense of self [9]. Interestingly they also showed that very early in the practice of mindfulness meditation neural plasticity is increased in the self-referential networks (DMN) as well as the attentional networks. I like to paraphrase Siegel's definitions of mindfulness meditation: being aware of the modifications of the mind accompanied by the attitudes of curiosity, openness, acceptance and appreciation. In my opinion this is a useful definition for neurofeedback training as well. If so, then the data of meditation studies may have special relatedness to neurofeedback training. Here is another interesting thing about 8.5-12.5 Hz periodicity. Now I am not talking about the posterior dominant (alpha) rhythm, but I am talking about discrete state changes in the brain which occur in this frequency range and involved the entire cortex. These are called microstates. They have nothing to do with the brain state technology company. Most people chronically display 4 or 5 characteristic states. They occur in different sequences and last varying times. These microstates have been found to correlate to 4 of the resting state networks (not including the DMN), [10] and their sequencing is disordered in common conditions such as depression, dementia and schizophrenia. This may be one reason that 10 Hz light flicker improves recognition memory in older people [11]. This may be one of the reasons that alpha training (also in the 8.5-12.5 Hz range) is also important in brain state regulation. One important point to remember as we study brain microstates, is that we are used to thinking of the 1/f EEG in terms of the frequency domain, i.e., the power and coherence in the different clinical frequency bands. We have not looked completely yet at the time domain itself. As you will see from the literature, monitoring brain microstates, each lasting 80-120 ms, is very different than watching frequency bins change. When I started neurofeedback in 2008 I was fortunate to learn about the resting state networks. They have been well documented as disordered in a wide range of difficult clinical conditions including addiction, Alzheimer's disease, anxiety, autism, ADD, bipolar disorder, chronic depression, chronic pain, fibromyalgia, Parkinson's disease, PTSD, schizophrenia, etc. [12] The default mode network has anterior connectivity hubs involving the med prefrontal cortex and anterior cingulate, and a posterior connectivity hub at the precuneus and posterior cingulate area. When I was first exposed to alpha-theta training for PTSD I was surprised the training was all posterior. I was commonly met with skepticism about the safety or suitability of up-training frontal theta. Two facts made me persist. One is that although the presence of polymorphic theta (as in ADHD) is associated with inflammation and cytokine imbalance, the type of theta trained is, by the nature of the Fourier transform, may be rhythmic theta. Rhythmic theta is sometimes known as the Cigánek rhythm or frontal midline theta. Its presence is associated with improved self-regulation. Another reason I persisted and started trying theta alpha gamma synchrony in the midline is because the anterior cingulate and the insula are part of the salience network that directs resting state network changes. In my opinion it begs to be included in the neurofeedback. And in order for the salience network to have valid input, there must be long distance alpha-theta synchrony. Although I need to be discrete with the details for a few weeks, a group I am working with has shown that SMR neurofeedback for ADHD strengthens default mode network functionality! A common question I hear is how can SMR training at Cz strengthen resting state functional connectivity (rsFC) across the cortex? This may be because one of the microstates, " D " , has activity centered around the combined Fz-Cz area. And as we now know, brain microstate management has a direct link to resting state activity. This is, of course, in addition to the other benefits that come from learning to self-regulate corticothalamic loop timing. I find it interesting that heart rate variability training often involves about 6 breaths per minute. The frequency of 6 per minute (6 per 60 seconds) is exactly the same as the frequency of 1 per 10 seconds (1/10s) and is the same as 0.01/1 second = 0.01 Hz. Since the resonant frequency of the default mode network is 0.013 Hz and that of the anti-correlated attentional network is 0.016 Hz (both very close to 0.01 Hz, it is very possible that resonant breathing at the same frequency pumps these networks. This may be the basis for Takahashi et al's 2005 suggestion [13] that deviation from the normal power spectrum of the heart rate variability interfered with appropriate modulation of alpha and theta in naive meditators. Here again we see a little into the nature of the 1/f power laws that model reality. Phase modulation of low frequencies (such as 0.01 Hz or even 10 Hz) feeds amplitude modulation of higher bands such as beta and gamma. Monto, et al (2008) said very clearly that " infraslow fluctuations reflect the excitability dynamics of cortical networks. This is as clear and believable explanation for both the positive effects of infra-slow frequency training and also the adverse reactions. This 1/f characteristic of " feeding of high frequency amplitude shifts by low frequency phase shifts " is probably the main reason why neurofeedback can be dangerous. Both infra-low frequency NFB and synchrony NFB can encourage beta spindling. Beta spindling, when observable, usually appears as a fairly isolated peak of beta activity in a very narrow range, such as 20-22 Hz. It may best be considered a sign of irritated or kindled cortex. If your " inhibit instruments " are set to auto-threshold then beta in a narrow range, say 20-22 Hz can increase significantly, and your auto-threshold will merely elevate in order to accommodate the increased amplitude. Forty percent of frontal lobe epilepsy is not apparent on routine EEG even with provocation. If you see any change in beta spindling that is accompanied by any behavioral sign, such as sudden restless legs or change in demeanor, you may be dealing with paroxysmal kindled cortex - seizure by definition. Ultimately attempting to change frontal metabolism with neurofeedback may lead to problems if the client has imbalance in glutathione and glutamate. One of the first questions I ask clients is whether or not there is any bipolar disorder or schizophrenia in the family. If so, there is likely a 20-40% reduction in frontal glutathione. This is actually a very common condition. In my " theory of synaptic recidivism " (www.cortexercise.com) I summarize some of the literature showing that all of the disorders that are so common and difficult to treat (such as the list I gave above and [12]) are characterized by disordered excitation (glutamate poorly moderated by the reduced levels of glutathione). Because all learning (and neuroplasticity in general) requires significant inflammation for synaptic remodeling, and since the anti-inflammatory glutathione is in short supply in chronic illness, and since the average American diet contains possibly 20 times more excitotoxins (such as MSG) than it did 15 years ago when MSG was relabeled " natural spices " , change is difficult or impossible for some clients. N-acetyl-cysteine (NAC) is a generally safe dietary amino acid that provides the cysteine that is rate limiting in glutathione synthesis. Perhaps that is why the journal Biological Psychiatry has just pre-published results of a study showing effectiveness of NAC in treating autistic children [15]. Other problems find significant benefit from NAC, e.g., bipolar disorder, schizophrenia, trichotillomania, gambling, addiction. When attempting to optimize any sort of neurofeedback it may be important realize that there is already an imbalance in excitation, and microstate management will be difficult without neuroprotection. I have seen over-arousal occur with tDCS as well, and it is often relieved by NAC (best accompanied by other nutraceuticals). Neuroprotection and neuroplasticity are largely related to the infra-slow frequencies characteristic of resting state networks [16]. These lower frequencies are the Archimedean lever that raises the higher clinical EEG bands. Thank you for the question, Mark. I find it thought provoking. Perhaps others could chime in here. Best wishes, Dailey Near San Francisco CA [1] Gruzelier J (2008) - A theory of alpha-theta neurofeedback, creative performance enhancement, long distance functional connectivity and psychological integration. Cognitive Processes. Published online 11 Dec 2008. [2] von Stein A, et al (2000) - Different frequencies for different scales of cortical integration - From local gamma to long range alpha-theta synchronization. International Journal of Psychophysiology 38 2000. 301-313 [3] Aftanas LI, et al (2001) - Human anterior and frontal midline theta and lower alpha reflect emotionally positive state and internalized attention - EEG investigation of meditation. Neuroscience Letters 310(2001);57-60, [4] JP, et al (2000) - Comparison of alpha-theta, alpha and EMG neurofeedback in production of alpha-theta crossover and occurrence of visualizations. Journal of Neurotherapy, Vol. 4(1) 2000 [5] Varela F, et al (2001) - The brainweb - Phase synchronization and large-scale integration. Nature Reviews Neuroscience, Volume 2 April 2001 p 229. [6] Aftanas LI, et al (2001) - Human anterior and frontal midline theta and lower alpha reflect emotionally positive state and internalized attention - EEG investigation of meditation. Neuroscience Letters 310(2001);57-60, [7] Berkovich-Ohana A, et al (2012) - Mindfulness-induced changes in gamma band activity – Implications for the default mode network, self-reference and attention. Clinical Neurophysiology 123(2012);700-710. [8] Lehmann D, et al (2001) - Brain sources of EEG gamma frequency during volitionally meditation-induced, altered states of consciousness, and experience of the self. Psychiatry Res 2001;108:111–21. [9] BL, et al )2001) - Neuroanatomy of the self: evidence from patients with frontotemporal dementia. Neurology 2001;57:817–21. [10] Britz J, et al (2010) - BOLD correlates of EEG topography reveal rapid resting-state network dynamics. NeuroImage 52 (2010) 1162–1170 [11] J, et al (2006) - 10 Hz flicker improves recognition memory in older people. BMC Neuroscience 2006, 7:21 [12] Broyd SJ, et al (2009) - Default-mode brain dysfunction in mental disorders - A systematic review. Neuroscience and Biobehavioral Reviews 33 (2009) 279–296 [13] Takahashi T, et al (2005) - Changes in EEG and autonomic nervous activity during meditation and their association with personality traits. International Journal of Psychophysiology 55 (2005) 199– 207. [14] Monto S, et al (2008) - Very slow EEG fluctuations predict the dynamics of stimulus detection and oscillation amplitudes in humans. The Journal of Neuroscience, August 13, 2008 • 28(33):8268–8272. [15] Hardan AY, et al (2012) - A Randomized Controlled Pilot Trial of Oral N-Acetylcysteine in Children with Autism. Biol Psychiatry in press. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.