How does neurofeedback work?
Let’s start with how the brain works.
The brain is literally a symphony of electrochemical activity. The instruments that produce the symphony are the networks of neurons, or nerve cells. Neural networks play the brain’s equivalent of sheet music – patterns – just like a symphony orchestra plays notes.
All of the brain’s activity is accomplished using electrical or chemical mechanisms. Brain activity can be measured by looking at things such as changes in blood flow, changes in sugar metabolism and changes in electrical activity. New brain imaging technologies now allow us to see this activity with precision. The most typical types of brain scans, fMRI, PET and SPECT, use blood flows to show us which areas of the brain are active. EEG’s show the amount and type of electrical activity the brain generates.
Electrical activity and the brain
All electrical activity is measured in terms of frequency of waves or cycles. Different electrical frequencies are measurements of how many cycles occur during one second.
The electrical gadgets that surround us operate at high frequencies. Personal computers and laptops operate between one and three million cycles per second, or hertz (Hz). Cell phones operate on network frequencies generally in the one to two million cycles per second, Wi-Fi networks at 2.8 million cps.
Compared to these devices, our brains operate much more slowly. Virtually all of our brain activity occurs between 2 cycles per second and 42 cycles, or hertz, per second. Within this range, we have given names to five different bands of frequency. At the high, fast end of the range, at 42 cycles per second, are gamma waves. Beta waves occur between 21 and 35 cps, alpha waves between 8 and 20 cps, theta waves between 2 and 7 cps, and delta waves between 0 and 2 cps.
Brainwave frequencies have associated characteristics
Each of these frequency ranges are characteristic of different types of mental activity. For example, delta waves are present in deep sleep; theta waves are present in the face of physical pain or emotional trauma; alpha waves ( perhaps the most famous of all brain waves) are the unfocused, soothing, spacy waves that are overly present in ADD; beta waves operate focus and alertness in the lower part of the 21-35 Hz range with vigilance, hyper vigilance and on to anxiety states in the upper part; gamma waves have to do with successful mental effort and appear when the brain lassos far flung brain functions and connects them.
The ‘neuro’ in neurofeedback
The electrical activity of the brain can be measured by EEG much more quickly than the biochemical activity measured by scans such as fMRI, PET, and SPECT. Electrical activity is measured on the order of milliseconds, biochemical scans take several seconds.
These different types of scans also measure different aspects of brain activity. Biochemical scans show us where in the brain activity is taking place. EEG tells us what type of activity is taking place. An EEG is the electrical signature of brain activity – it reflects active brain patterns.
The ‘feedback’ in neurofeedback
The combination of two elements – that brainwave frequencies are associated with characteristic mental activity, and that they can be sensed quickly – are what enable neurofeedback to occur.
This immediacy and correlation enables a real time evaluation of brain functioning, and allows the brain itself to notice its own activity.
Noticing something is at the heart of things. It is how we figure out how the world works. It is how we learn. For example, we might notice when we step on a plank on a pier that it gives more than we expected under the weight of our foot. This noticing, this feedback, causes us to choose a next action that is different from the one we would have chosen had the plank been solid.
Feedback informs the brain’s choice about where to go next – what to pay attention to. It is constantly deciding where to go next and what to pay attention to. The way it does this is by matching patterns. Patterns are the language of the brain – its very architecture is structured to store and recall patterns. The brain is really a giant feedback machine.
Each moment, the brain is processing literally tens of millions of bits of information. The vast majority of this activity takes place below our level of awareness. It remains outside of our conscious awareness because we get very good at pattern matching. We can walk down a pier without really thinking about it. That is, until a plank doesn’t respond to our foot in a way that matches our (unconscious) pattern of what solid feels like. Until something like this occurs, something that disturbs the predicted pattern, the pattern keeps running silently because we keep getting feedback that tells us that everything is matching up as expected.
Most feedback is internal
The most remarkable discovery that neuroscientists have made about feedback and the brain is not, however, that the essential mechanism of the brain is feedback. It is that that most of that feedback is internal. In many brain systems, neural networks devoted to internal feedback outnumber those devoted to external sensory input by 10 to 1. The brain spends the vast majority of its resources not on gathering external information but rather on interpreting its meaning and significance.
This explains why it is that we are not aware of most of our own brain activity. Our brain is explicitly designed to do as much work as possible while requiring the minimum amount of attention from us. The more patterns we have of how the world works, the more work we can do, and the less we have to consciously pay attention to.
Functional and dysfunctional patterns
Patterns are an astonishingly effective mechanism. But not all neurological patterns are equal. Some work well and some don’t.
We recognize poorly functioning patterns by the symptoms they produce. We classify these symptoms clinically with names such as ADD/ADHD, anxiety, PTSD, insomnia, learning disabilities, and autism spectrum disorders.
Neurofeedback systems recognize dysfunctional patterns by the electrical signature they generate. Research data has correlated different symptoms with specific EEG profiles.
Interrupting dysfunctional patterns
The goal of any therapy is to reduce symptoms and restore healthy function. Different therapies use different mechanisms to accomplish this. Pharmaceutical drugs use chemical methods to change brain function by changing the levels of chemicals, called neurotransmitters, that are involved in transmitting the basic electrochemical signals that combine to form patterns. Direct electrical stimulation of the brain is sometimes used to correct how the brain’s signals flow – for example in the treatment of epilepsy and Parkinson’s disease. Neurofeedback works by recognizing and then interrupting dysfunctional electrical patterns by re-directing the brain’s attention.
The symptoms mentioned above (ADD/ADHD, etc.) can be thought of as a neurological failure in feedback. The brain is not able to tell itself to stop running these patterns because they have become habitual. In effect, the brain does not recognize that it has a choice, that it is possible to not run the dysfunctional pattern.
The role of neurofeedback is to show the brain that it is indeed possible to sidestep dysfunctional patterns. It does this by interruption. If a pattern can be interrupted, it follows that it is not inevitable.
A neurological wake-up
Habitual dysfunctional neural processes occur while one is, neurologically speaking, asleep at the wheel. Put differently, if you can stay awake, you can avoid the neural ‘driving into the ditch’ at the level of brain function. Neurofeedback helps the brain remember to stay awake.
The course correction that occurs inside the brain is immediate, just like it would be on the physical road – we all know immediately, and instinctively, where to pull the wheel.
How do we know this works? You can’t be asleep at the wheel and awake at the wheel at the same time. It’s not possible. The feedback wakes up the brain and causes it to pay attention. In that moment the brain cannot be asleep.
A Whisper to Wake You Up
Waking someone up requires first recognizing that they have gone to sleep. Our neurofeedback system does this by watching your brain function in real time and determining your individual profile of good brain functioning. Because it is done in real time, your profile will change with each session. The system always takes its cue from where your brain is at, in the moment.
Once it knows what your good neurological function looks like, it can identify and intervene to stop bad neurological function.
When the mind gets rolling along and starts to go into the ditch, this system can correct course by causing the driver to notice the ditch-ward movement. In the brain, this ditch-wards movement happens really fast. Because the electrical activity of the brain is sensed so quickly, the system is able to act in a timely enough fashion such that the driver (your neural patterns) wakes up and turns the wheel appropriately.
The image of the neural driver and ditch illustrates the essence of what neuroscientists call plasticity, or neuroplasticity. It’s the brain’s intrinsic way of functioning that it changes in response to experience. The mechanism of neurofeedback provides a way for the brain to make deep structural changes, gently. If you notice the instant a driver has started to nod-off, a mere whisper will wake him up.