Neurofeedback: A Comprehensive Review on System Design, Methodology and Clinical Applications


application of eeg pdf

recognised method that allows EEG electrode placement to be standardised. • Ensures inter‐electrode spacing is equal •Electrode placements proportional to skull size & shape •Covers all brain regions F = Frontal T = Temporal P = Parietal O = Occipital •Numbering system Odd = left side. Electroencephalography (EEG) is the recording of electrical activity In neurology, the main diagnostic application of EEG is in the case of epilepsy, as epileptic activity can create clear abnormalities on a standard EEG study.[3] A secondary clinical use of EEG is in the diagnosis of coma, encephalopathies, and brain death. EEG used to be. Recent Clinical Applications of Neurofeedback 10 Neurofeedback in alcohol and drug dependency David L. Trudeau, M.D., Tato M. Sokhadze, Ph.D. and Rex L. Cannon, M.A. I. Introduction II. SUD prevalence and QEEG changes A. EEG in alcoholism B. EEG in marijuana abuse C. EEG in heroin addiction

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Neurofeedback is a kind of biofeedback, which teaches self-control of brain functions to subjects by measuring brain waves and providing a feedback signal.

Neurofeedback usually provides the audio and or video feedback. Positive or negative feedback is produced for application of eeg pdf or undesirable brain activities, respectively. In this review, we provided clinical and technical information about the following issues: 1 Various neurofeedback treatment protocols i. To date, many studies have been conducted on the neurofeedback therapy and its effectiveness on the treatment of many diseases.

Neurofeedback, like other treatments, has its own pros and cons. Although it is a non-invasive procedure, its validity has been questioned in terms of conclusive scientific evidence. For example, it is expensive, time-consuming and its benefits are not long-lasting.

Also, it might take months to show the desired improvements. Nevertheless, neurofeedback is known as a complementary and alternative treatment of many brain dysfunctions. However, current research does not support conclusive results about its efficacy. Neurofeedback is not a new concept. It has been the subject of the study of researchers for several decades. Neurofeedback is a method that assists subjects to control their brain waves consciously.

In fact, application of eeg pdf electroencephalography EEG is recorded during the neurofeedback treatment. Then, its various components are extracted and fed to subjects using online feedback loop in the form of audio, video or their combination.

Accordingly, electrophysiological components are separately demonstrated. As an illustration, the power of a signal in a frequency band can be shown by a varying bar graph. For instance, the subject tries to improve the brain patterns based on the changes that occur in the sound or movie. Dempster, ; Vernon, In this review paper, we discussed various technical and clinical details of different neurofeedback treatment protocols. Activities of cerebral neurons have rich information about neuronal activities.

When neurons are activated, they produce electrical pulses, application of eeg pdf. By placing electrodes on the scalp, the electrical activity of the brain, known as EEG, can be recorded. In turn, EEG is generated by a specific type of synchronous activity of neurons which are known as pyramidal neurons and the electrical output is thus reflected in the following areas of the skin where the electrodes are located, application of eeg pdf.

Different patterns of electrical activity, known as brain waves, could be recognized by their amplitudes and frequencies. Different frequency components are categorized into delta less than 4 Hztheta 4—8 Hzalpha 8—13 Hzbeta 13—30 Hzand gamma 30— Hz where each represents a particular physiological function. However, there are differences in defining the application of eeg pdf range of frequency components in different studies.

These frequency components have subsets. For example, sensorimotor rhythm SMR frequency bands 13—15 Hz are related to the sensorimotor rhythm and entitled as low beta. Some studies claimed that alpha rhythm has two application of eeg pdf lower alpha in the range of 8—10 Hz and upper alpha in the range of 10—12 Hz.

Whereas some studies indicate that the alpha rhythm has 3 subsets. These definitions indicate that high and low alpha exhibit different behaviors and performances. It is believed that lower alpha is related to remembering action in semantic memory which is not the case for high alpha Dempster, Electrodes placed on the scalp can record those cortical activities of the brain regions that are close to them.

Electrode System 10—20 is a method for standardizing areas of the skull and comparing data. Studies have shown that these placements correlate with application of eeg pdf corresponding cerebral cortical regions.

Of 21 electrodes, 19 are used for recording cortical areas and 2 other electrodes as reference electrodes Figure 1. The skull regions are named using letters and numbers. Letters correspond with the brain regions and numbers to the hemisphere of the brain or the locations of this hemisphere. The letters F, application of eeg pdf, P, T, Oand C are related to frontal, parietal, temporal, occipital, and central areas, application of eeg pdf, respectively.

The letter z is used as P Z suggests that scalp location falls along the central line running between the nasion and the inion. F P1 and F P2 are respectively related to the left and right poles of the forehead. Traditionally, two types of unipolar and bipolar montage are used in the neurofeedback treatment. In unipolar mode, the active electrode is placed on the skull and the recorded signal by the active electrode is compared to the second electrode entitled as the reference electrode.

The activity of the active electrode minus the activity of the reference electrode represents the brain activity at the active electrode. On the other hand, in the bipolar mode, application of eeg pdf, two active electrodes are used that are separately placed on the skull. The difference between the recorded signals by these 2 electrodes, is the basis of the neurofeedback Demos, ; Dempster, One of the advantages of the bipolar recording is the common mode rejection that occurs during the recording procedure.

It means that any external artifact occurring at both channels and at the same time, its amplitude and phase are subtracted and the spatial selectivity is improved. Neurologists have observed that lesions occurring in specific regions of the brain produce specific symptoms mostly related to these regions.

For example, frontal lobes, F P1F P2F PZF ZF 3F 4F 7 are responsible for immediate and sustained attention, time management, social skills, emotions, empathy, working memory, executive planning, moral fiber or character. Each region represents a specific feeling or task; Thus identification of these areas provides the best and the most accurate neurofeedback treatment. Parietal lobes, P ZP 3 and P 4solve problems conceptualized by the frontal lobes.

Complex grammar, naming of the objects, sentence construction, and mathematical processing are identifiable application of eeg pdf the left parietal lobe while map orientation, spatial recognition, and knowing the difference between right and left are entirely functions of the right parietal lobe.

Temporal lobes, T 3T 4T 5 and T 6 have various functions. Left hemisphere functions are associated with reading word recognitionmemory, learning and a positive mood, while right hemisphere functions are related to music, anxiety, facial recognition, and sense of application of eeg pdf. On the other hand, visual memories, accurate reading and traumatic memories accompanying visual flashbacks are usually processed in the occipital lobes, O 2O 1 and.

The other functions of this lobe include helping to locate objects in the environment, seeing colors and recognizing drawings and correctly identifying objects, reading, writing, and spelling. Sensory and motor sensorimotor cortex, C ZC 3 and C 4 have functions of conscious control of all skeletal movements such as typing, playing musical instruments, handwriting, operation of complex machinery, speaking, and the ability to recognize where bodily sensations originate. Neurologists have mentioned that the motor cortex helps the cerebral cortex to encode both physical and cognitive tasks.

Therefore, subjects who have trouble seeing the logical sequence of cognitive tasks may benefit from neurofeedback training along the left hemisphere sensorimotor cortex C 3. Training along the right hemisphere sensorimotor cortex C 4 may invoke feelings, emotions, or calmness.

Training at the median or may facilitate a mixed response. The subjects who suffer from epilepsy are usually trained along the sensorimotor cortex C 3 to increase SMR. Brain lobes with their functions and areas Demos, For instance, low beta and beta are trained on the right C 4 and application of eeg pdf C 3 brain side, respectively. If they were switched to the opposite brain side, undesirable results could be obtained.

For example, training low beta wave on the left side will result in a depletion of mental energy instead of improvements in concentration. Thus, the location of the EEG electrodes during the neurofeedback procedure is important Evans, There are 7 types of Neurofeedback for the treatment of various disorders:.

It is used to change the amplitude or speed of specific brain waves in particular brain locations to treat ADHD, anxiety, and insomnia. This type of neurofeedback has been used to treat traumatic brain injury, ADHD, insomnia, fibromyalgia, restless legs syndrome, anxiety, depression, and anger. Live Z-score neurofeedback is used to treat insomnia.

This neurofeedback technique is used to treat addictions, depression, and obsessive-compulsive disorder. The alpha mood is described as a calm and pleasant situation. All alpha frequencies describe creative activity of the brain, so that it is used in the process of relaxation relaxing the muscleswhich eventually leads to sleep; Such waves emerge and expand rapidly on the skin. The evidence shows that alpha waves increases during meditation. Alpha training is usually used for the treatment of various diseases such as pain relief by 9 Hz simulationreducing stress and anxiety by 10 and 30 Hz simulationmemory improvement, improving mental performance, and treatment of brain injuries by Various studies have been performed on the alpha protocol Table 3.

The most common frequency bandwidth for the alpha treatment is 7—10 Hz frequency range, which is used for meditation, sleep, reducing stress and anxiety, application of eeg pdf. Also frequency of 10 Hz causes deep muscle relaxation, pain reduction, regulating breathing rate, and decreasing heart rate Dempster, ; Vernon, application of eeg pdf, Beta brain waves are associated with conscious precision, strong focus, and ability to solve problems.

Medications that are used to stimulate alertness and concentration such as Ritalin and Adderall also cause the brain to produce beta brainwaves, application of eeg pdf.

Beta training is used to improve focus and attention simulation of increased beta Hzimprove the reading application of eeg pdf simulation of 7—9 Hzand introduce positive changes in school performance. It also improves the computational performance, cognitive processing, reduction of worries, over-thinking, obsessive compulsive disorder OCDalcoholism, and insomnia simulation of 14—22 Hz and 12—15 Hz. Meanwhile, this type of neurofeedback improves sleep cognitive performance as well as reducing fatigue and stress simulation of light and sound of beta Table 4.

Also, application of eeg pdf, this treatment is used for deep levels of depression, addiction, anxiety while it increases creativity, relaxation, musical performance, and promotes healing from trauma reactions. They represent increased comfort, reduced pain, and sleep. Thus, they are used to alleviate headaches, traumatic brain injury, learning disorders, and to treatment hard and sharp contraction of muscles by simulation of 1—3 Hz delta wave.

They also reduce concerns and improve sleep Vernon, Thus, when these waves are faster, the speed of recalling memory is faster. They are mainly observed in the hippocampus an area of the brain which is responsible for converting short-term to long-term memory.

Also, these rapid rhythms are observed in sudden attacks like seizure and spasm. Hence, gamma training is used for promoting cognition, mental sharpness, brain activity, application of eeg pdf, and problem-solving tasks.

It not only improves poor calculation, but also organizes the brain, application of eeg pdf, improves the speed of information processing, short-term memory, and reduces the number of migraine attacks Hughes, Vernon, Theta brain waves are related to a number of brain activities such as memory, emotion, creativity, sleep, meditation, and hypnosis.

These waves are also associated with the first phase of sleep when the sleep is light and the person easily wakes up. Basically, there are two classical directions in neurofeedback training.


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application of eeg pdf


recognised method that allows EEG electrode placement to be standardised. • Ensures inter‐electrode spacing is equal •Electrode placements proportional to skull size & shape •Covers all brain regions F = Frontal T = Temporal P = Parietal O = Occipital •Numbering system Odd = left side. Recent Clinical Applications of Neurofeedback 10 Neurofeedback in alcohol and drug dependency David L. Trudeau, M.D., Tato M. Sokhadze, Ph.D. and Rex L. Cannon, M.A. I. Introduction II. SUD prevalence and QEEG changes A. EEG in alcoholism B. EEG in marijuana abuse C. EEG in heroin addiction applications for the EEG will Came into being, now, in the psychology, physiology, co gnitive science, neuroscience, medicine and othe r life science related ar eas, very high, at the sam e time.