Neurofeedback for Stroke Recovery
What is EEG and Neurofeedback?
Before addressing the question of what is EEG Neurofeedback, we must first describe what an EEG is. EEG stands for Electro Encephalogram. Similar to its cousin, the ECG (or EKG), which measures the electrical activity of the heart; an EEG measures the electrical activity of the brain. The brain, with its millions of specialized nerve cells communicates via subtle electrical impulses to initiate everything from thought, to sending these electrical messages down the spinal column to stimulate the movement of a body part. Using EEG’s doctors and researchers have been able to listen in to these whispers of the brain. In doing so, there has been established what would be considered normal brain wave states for various states of consciousness, as well as abnormal.
Brain Waves |
Frequency |
Mental State |
| Delta | 0.5-3 Hz | Deep Sleep |
| Theta | 4-7 Hz | Light Sleep |
| Alpha | 8-13 Hz | Awake, relaxed |
| Beta | 14-18 Hz | Awake, excited |
In a normal focused wake state, the brain will display mostly Beta waves, while a relaxed state will be more Alpha. Theta wave activity is usually only seen in the initial stages of sleep, while Delta is seen only in the deepest stages of sleep.
Are there abnormal brain waves for various conditions?
For many conditions, the brain tends to have more Theta waves than it should. Let us take, for example, ADD/ADHD (Attention Deficit Disorder). Given what was just explained about Theta waves, the brain of the ADD/ADHD individual would be in a less focused state ñ not unlike the brain that begins to drift off to sleep. No wonder these people have such difficulty concentrating!
Different conditions may display different brain wave patterns, such as high Beta for people with anxiety. We will not be discussing all these patterns or conditions, but rather what can EEG Neurofeedback do to improve them.
What is Neurofeedback?
How many sessions are needed, and will the condition come back?
What does a patient see and do during a treatment session?
Immediately, the client and technician can see the raw EEG pattern on the screen (figure 3-A). Also seen are two wave patterns (known as passbands) that are digitally extracted from the raw EEG. These are usually the Theta waves (figure 3-C), and Beta wave (figure 3-B) patterns. On the left side of the screen are two bar graphs (figure 3 D&E) that represent the two passband patterns and the amplitude of the waves. It is by paying attention to these bar graphs that the patient tries to inhibit or promote one of these brain wave patterns.
For example, if a patient has too many Theta waves in their brain wave patterns, they will be asked to keep the bar graph that represents the Theta wave amplitude (figure 2-E) below a certain number of, such as 4 microvolts. Each time the brain stays in this desired pattern the computer outputs an audible beep, and a score counter (figure 2-F) records more reward points. The object and reward for the patient is to hear as many beeps and rack up as many points as possible in the 30-minute session. As time and treatment sessions progress, the brain retrains itself to keep this better pattern. This better pattern will eventually translate into an improvement in the patient’s condition.