What is TAG Sync?
TAG Sync refers to Theta-Alpha-Gamma Synchrony. In 2009 I started a company, "A Matter of Mind", to provide
neurofeedback resources and also to share some observations and innovations through a particular approach to
understanding technology-assisted self-regulation. A few practitioners have used this approach with my software for
Nexus Biotrace since 2010 and for ThoughtTechology's ProComp Infiniti since 2011 and in 2013 BioExplorer as well..
I call this approach theta-alpha-gamma synchrony (TAG Sync) because of the emphasis on the experience with those
three EEG frequency bands while modifying a particular type of brain-computer-brain interface called EEG operant
conditioning or, more commonly, neurofeedback.
In order to understand the clinical implementation of this sort of neurofeedback it is necessary to look at the steps that
lead to its discovery.
I saw the useful and interesting cognitive and physiological changes that took place with Technology-Assisted Self-
Regulation (TASR) using simple biofeedback. Consider using a BCB (brain-computer-brain) interface to assist in learning
self regulation of the moment-to-moment heart rate. Control of heart rate variability, whether it remains completely sub-
conscious or not, is discussed in over 15,000 scientific articles at pubmed.gov. The graph of the heart rate can look
complicated and chaotic just as the electroencephalogram (EEG). Both time-series (ECG and EEG) can be broken into
individual frequency bands with individual functions.
I wondered if there might be a very simple signal that might be as generally useful for neurofeedback as simple
temperature, electrodermal skin response (EDR) and heart rate variability (HRV) were for biofeedback.
I wanted to use the BCB interface to enable the client to recognize and self-regulate a fundamental signal that guided the
brain toward its normal developmental dynamics. As discussed later the brain waves organize themselves around a
certain type of persistent variability that shows self-similarity over time. This is the fractal organization that characterizes
living systems, including the EEG. This required that the BCB interface feeds back information regarding two reward
frequencies such as alpha (8-10 Hz) and gamma (30-50 Hz) at the same time. A simple way to describe the nature of the
EEG signal is that the timing (phase) between the low frequency waves (e.g., theta) at two locations is coupled to
amplitude as well as phase changes at higher frequencies such as gamma.
To simulate the normal developmental trajectory of the brain's networks I chose, for starts, the developing midline anterior
to posterior theta-alpha synchrony that characterizes in particular 1) brains of mammals, 2) networks of neurocognitively
mature adults, and 3) the advanced synchronization features of practitioners of mindfulness techniques. So since 2009
my designs have presented the trainee with such signals as phase and amplitude coupling between Fz and Pz. Those
who duplicate these efforts will find during the session increased theta, alpha and gamma phase resets indicating more
frequent updating of operational state.
I based my early design on studies implicating long distance alpha and theta synchrony and phase resets in valid
cognition. I also looked at development of global synchronization in healthy cognitive aging and in advanced meditation
techniques. I started with 2 channel amplitude synchrony training between frontal and parietal sites, primarily midline, and
rewarded synchrony increases between sites in two frequency bands that were chosen based on the client's on-screen
Typically the client is rewarded for increased synchrony, say between Fz and Pz, at a lower frequency such as theta and
a higher frequency such as gamma at the same time. It appears important when training phase shifts at lower
frequencies to give feedback regarding synchrony at higher frequencies so that signals can be coupled effectively to
themselves as well as to signals at other frequencies. This coupling is called Phase-Amplitude coupling. When optimized
according to on-screen behavior and client report, the result is more observable phase resets on screen and, with
training, reduced intra-subject variability.
During TAG Sync training it is common to see large phase resets in theta and alpha bands accompanied by sudden
insight and/or behavioral changes over the following days. It is also common to see intra-subject variability (such as z-
scores) reduced as the results of training develop. Preliminary evidence suggests that the Fz theta to Pz alpha ratio
decreases, consistent with improved multi-tasking and cognitive reserve, and enhanced novelty detection, etc..
Other clinicians who have implemented and extended this work have found this technique to be capable of accelerating
change and maturation.
Why another approach to neurofeedback? Although there were several earlier attempts to develop modulated self-
regulation of the electroencephalogram, current neurofeedback techniques recognize the enduring discovery by Sterman,
et al, that teaching timing at a very special central spot above the cortex (called Cz), one could modulate seizure
formation and attention. Further fascinating modulations have been encouraged through neurofeedback including
creativity, peak performance, pain relief, and issues of attention and sleep. Much of the further history of neurofeedback
has to do with how practitioners moved off the midline (Cz) and started learning about the brain's networks and their
I went back to the midline and added a second electrode and asked "what is the most important signal, according to the
literature, that would support both normal and mindfulness-enhanced cognition. What two-channel signal could extend
the fundamental control of a single-channel (e.g., Cz sensory-motor rhythm operant conditioning) to the communication
between the main hubs of the brain. These are in the region of the anterior cingulate (Fz) and the precuneus and
posterior cingulate (Pz).
As one studies the development of oscillatory specialization in mammalian cortex one sees the self-organizing impetus
toward increased global synchronization at higher frequencies, especially along the midline. Early loss of such signals is
seen in developmental disorders, or, latter in life, dementia. In highly functioning professionals as well as in advanced
mindfulness practitioners there is a higher level of organization apparent. It involves synchrony including gamma. It can
be trained. The result may be increased prefrontal phase resets with increased gamma. The ultimate result, as to be
expected, is reduced reduced intra-subject variability, often with a new-found sense of gracefulness. FzTheta/PzAlpha
ratio is also expected to decline.
The literature, in my opinion, is fairly clear on all this. I have included a few references at the bottom. The literature is, in
my opinion, the tie that binds neurofeedback to neuroscience, and neuroscience to the functioning of the natural mind, at
its most efficient, and error-free.
The mindful brain state appears to be characterized by global broad band synchrony, the kind that allows a group of fish
or birds to suddenly coordinate into a super-organism when confronted with predator stress - all without an identifiable
central command. The development of a network that supports such synchrony is profoundly distressed by maternal
immune activation and epigenetic alteration surrounding environmental shifts in the last 2 centuries. The nature of the
signals travelling across our networks, at least in current EEG terms, is a fractal 1/f power law carrying memory in the
form of self-similarity. This informational signal flows over a more physical yet dynamic network of hubs and connectors
whose development is stunted at the age of 7-9 years all to often when there is overwhelming stress to the child's
developing neural networks.
TAG Sync may work because it exercises the networks involved in intelligence, error-correction and maturation. With
improved valid cognition and error correction phase resets herald updated neurophysiological networks. The upregulated
networks are also those involved in the epigenetic changes seen in advanced meditation states.
How is transcranial direct current stimulation used in these situations?
Two channel transcranial direct current stimulation (tDCS) is often used as a pre-treatment, often with anodes both
prefrontally and around Oz and cathode(s) on the arm(s). tDCS has been shown to enhance network connectivity, to
improve glucose tolerance, and to generally enhance cortical functioning when applied as described in many studies.
Visit http://www.mindsupplies.com for screen designs and manuals.
Ahmadi K, et al (2013) - Brain activity of women is more fractal than men. Neuroscience Letters 535 (2013) 7– 11.
Khan S, et al (2013) - Local and long-range functional connectivity is reduced in concert in autism spectrum disorders.
PNAS Early Edition. Abstract.
Ravnik-Glavac M, et al (2012) - Genome-wide expression changes in a higher state of consciousness. Consciousness
and Cognition. Sep;21(3):1322-44. Abstract.
Daniels JK, et al (2011) - Default mode alterations in posttraumatic stress disorder related to early-life trauma - a
developmental perspective. J Psychiatry Neuroscience. Jan;36(1):56-9. Abstract.
Bohacek J, et al (2013) - Transgenerational Epigenetic Effects on Brain Functions. Biological Psychiatry
Lanius RA, et al (2012) - The dissociative subtype of posttraumatic stress disorder - rationale, clinical and neurobiological
evidence, and implications. Depression and Anxiety, Vol 29 Issue 8
Copyright © 2013, 2015 by Douglas Dailey
Last Modified: Oct 19, 2015