(Week 4 Update) Neurofeedback Databases: Neurorep

While I have still been setting up patients and training them myself, this week has been dedicated to creating QEEG reports. I was taught how to run a patient's test file, containing the raw EEG without any analysis, through a database. I was exposed to only the Neurorep database, but the ADD Clinic uses a total of four databases for each patients data. Below are the various databases. I have presented them in the following format.

Name: Name of Database
Developer: Dr./Social worker who compiled the data.
Affiliated With: The research agency who funded/endorsed the collection of all the data.
Recording Condition: Whether the database is for eyes closed or eyes open training.
Discriminant Analyses: Some databases will contain discriminants for various mental disorders, meaning they will have both norms and different subtypes for that disorder. For example, the NYU Database has discriminants for ADHD, which means that the database can identify the many ways ADHD can manifest itself in the brains of different individuals (high Beta or low Delta/Theta, etc.)  These databases are considered the most accurate.Other databases contain only norm (without mental disorder) files.
Number of Subjects: Number of people/files mapped and recorded in the database.
Age Range: Range of ages of people tested for that database. This is important because, ethically, a qEEG practitioner cannot run a client's file through a certain database if the client's age is not within the age range.
Other Notes: Any other important information.

The following databases are used by ADD Clinic to pinpoint areas of deficiency. I have also included examples of diagrams from each database's qEEG because each one displays results differently. For example, Neurorep may use the color green to display 0 standard deviations from the norm, and may only display up to 3 standard deviations. NX Link, on the other hand, may use black to display 0 standard deviations from the norm, and may display up to 1.5 standard deviations.

NX Link
Developer: John and Princhep
Affiliated With: New York University Medical School
Recording Condition: Eyes Closed
Discriminant Analyses: Head Injury, Depression, Delusions & Hallucinations, ADHD, Learning Disabilities, Memory, Substance & Alcohol Abuse
Number of Subjects: 782
Age Range: 6 yrs - 90 yrs
Other Information: This is perhaps the most extensive database for neurofeedback. The NYU Medical School tested 782 New Yorkers and mapped all the subtypes of the disorders listed above. Other countries (Japan, Korea, Nigeria, etc.) have ran their own citizens through the database and it has always been nearly 100% accurate at identifying mental disorders.

Neuroguide Lifespan Database
Developer: Dr. R. Thatcher
Affiliated With: Applied Neuroscience Inc.
Recording Condition: Eyes Closed & Eyes Open
Discriminant Analyses: Traumatic Brain Injury, Learning Disabilities
Number of Subjects: 625
Age Range: 2 months - 82 yrs

Neurorep
Developer: W. Hudspeth
Affiliated With: Brain Labs
Recording Condition: Eyes Closed & Eyes Open
Discriminant Analyses: Norms Only
Number of Subjects: 55 + 30 replicates
Age Range: 18 yrs - 59 yrs

Eureka LORETA
Developer: Sherlin and Congedo
Affiliated With: Nova Tech EEG
Recording Condition: Eyes Closed
Discriminant Analyses: Normalized Relative Current Source Density.
Number of Subjects: 84
Age Range: 18 yrs - 35 yrs
Other Information: This database is unlike any of the others; it pinpoints the brain's problem area on an x, y, and z axis, allowing a specific 3D area of the brain to be targeted. It produces 3 images, a horizontal slice of the brain, a vertical one, and an aerial view to show the problem in all dimensions.

Guide to Neurorep:

As I stated earlier, so far, I have only worked with the Neurorep program. So I will now detail the various aspects of the Neurorep database. The program itself is DOS based, with a very simple, keyboard-controlled system. When I run the files through the program, there are many "tests" (or interpretations) I have to perform. Keep in mind, each test/qEEG report creation is performed for both the Eyes Closed file and the Eyes Open one. The Neurorep database contains different norms for both EC and EO for all age brackets.

Analysis: A series of z-score database-created images that compares the brainwaves of the client to the normal brainwaves of others in their age group and gender.
Spectrum Report: A non-database (It uses only other references from the client's brain) graph that shows at which frequencies (9 Hz, 10 Hz, etc) occurs the most power/amplitude of the brainwaves. It shows an excess of power, which can help determine where the problem is.
Weighted Report: A non-database series of images that compares the power of brainwaves in a certain region of the brain to the powers of brainwaves in the surrounding regions. This will display any relative abnormalities.
NEI Image Creation: A series of non-database images that measures the connectivity between different regions of the brain. It measures if the brain is over connected (overly-excited connection between parts) or very disconnected (slow transfer of information), such as after a brain injury.

Each action creates a series of files/images, that are unreadable without Neurofeedback programs. So, using a program call L-Link, I convert each file and combine them into a single PDF file. The compilation of all completed PDF files from each database is the completed qEEG report.

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Database References

Since I will include many examples of qEEG reports in my next post, here is a brief guide to interpreting them. This is a very simplified version, and I will upload the more detailed one in the future. But before even attempting to understand the report, we must discuss common statistic terminology.

Database: Organized collection of data (in this case, brain maps)

Z-score Tables: Tables of data which indicates how many standard deviations an element is away from the mean. Brain map z-scores will display how far away the client's brainwave amplitudes are away from the normal.

Standard Deviation: A measure used to quantify the amount of variation between different elements in a data set. Concerning brain mapping, standard deviations away from the norm will reveal the severity of the problem; more standard deviations away indicates a more severe problem. 

 Interpreting the qEEG - Introduction

My next post will be about the databases used to create qEEG. Each database contains files for "normal brains" in each age bracket. Some also contain norms, or the various forms, of different mental disorders, which allows for a more accurate diagnosis. By running a client's data through the norm database, we can determine how much brainwave deviation there is. The file is converted into a series of colored aerial diagrams of a head. Each different color represents a certain number of standard deviations in the brainwave amplitudes in a particular region. Let's look at some examples. Below is an excerpt from a qEEG that has ran a client's file through the Neuroguide database.

If the patient's brainwave levels were normal, the aerial view would be completely green (0 standard deviations have been deemed green by the spectrum below the diagram). However, the client seems to have Delta levels 6 standard deviations below the norm (dark blue), which may cause anxiety, nervousness, or insomnia. On the other hand, their Theta levels seem to be relatively normal, with only up to 1.5 standard deviations away from the norm in the right-frontal lobe. Running a patient's raw EEG (literally just brainwaves) through the database will help diagnose their mental disorder. Without the qEEG reports, the area of deficiency/type of disorder would not be known, which would lead to very inefficient neurofeedback training.

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The Brodmann Areas

Created by German anatomist Korbinian Brodmann, the Brodmann Areas separate the brain into regions with similar cytoarchitecture (layering of neural tissue). Previously a psychiatric physician, Brodmann was introduced to the field of theoretical neuroscience research by Alois Alzheimer, who first identified Alzheimer's disease. Brodmann worked with the University of Berlin's Neurological Library to write his 1909 thesis on regions of different neural layering (which would later be named Brodmann areas). He employed the glial staining technique -- glial fibers are made visible with crystal violet and made resistant to decolorization with alkaline aniline-chloroformmixture. These glial fibers are non-neuronal cells, which are to hold neurons in place and supply them oxygen (the glue of the nervous system). By staining these cells, Brodmann was able to observe neural tissue density under a light microscope. After finding that the tissue density varied greatly even within the same brain, he grouped the brain's regions in accordance with his data. These are now known as the Brodmann Areas.

The divisions of the brain correspond with particular body functions. Even though we previously discussed the purposes of brain lobes, different parts of each brain lobe are in charge of different functions. For example, the frontal lobe controls all forms of executive action. But certain areas of the frontal lobe specialize in different forms of executive action: the primary motor cortex controls basic movement while the outer prefrontal lobe controls judgement abilities.

Brodmann Areas and Functions

There are 52 total Brodmann areas, which have been grouped into 11 areas with similar cytoarchitecture. Below are Korbinian Brodmann's actual diagrams of the brain.

Lateral Surface:Side Surface of Brain

Medial Surface:Middle Slice of Brain

Primary Somatosensory Cortex (Areas 1, 2, 3): Primary receptive area for touch sensations.

Primary Motor Cortex (Area 4): Communicates with spinal cord to coordinate large muscle movements.

Primary Visual Cortex (Area 17): Processes visual information, such as visual stimuli and object recognition.

Primary Auditory Cortex (Area 22): Processes auditory information, such as source of sound identification, sound recognition, and frequency recognition.

Wernicke's Area (Areas 39, 40): Produces written and spoken language, and is one of two linked speech areas in the brain (linked with Broca's Area)

Broca's Area (Areas 44, 45): Associated with more complex language production, such as inferences, complex sentences, sarcasm, etc.

The most important (for this project) Brodmann areas have been labeled. While these areas provide more detailed insight into the functions of each brain area, for the purposes of this project, I will use a simpler diagram. 

Previously unidentified areas in the diagram above are explained below. Please refer to the previous set of definitions as well.

Auditory Association Area: Processes auditory signals so they can be interpreted in context.
Speech Center: see Broca's Area

Pre-frontal Cortex: Coordinates concentration, judgement, and problem-solving abilities.

Motor Association Cortex: Coordinates more complex and fine movements
Sensory Association Cortex: Processes multisensory information and associated them together and in context.

Visual Association Cortex: Processes visual information and associates them with memory.

Importance - Diagnosis

So what is so important about the Brodmann Areas? An understanding of the regions and their associated functions is essential to treating mental disorders. If the QEEG reports abnormalities in portions of the brain, those functions are likely to be affected as well. Excess/lack of brainwaves in those regions will either speed up or slow down associated functions of that region. For example, if excess Theta is found in the frontal lobes, a client will not be attentive or concentrated. Therefore, the client is likely to have Attention Deficit Disorder. Any noticeable behavioral problems in a client will allow a therapist to pinpoint a Brodmann area of disorder. This will result in faster detection of problems, more effective treatment specific to that problem, and an understanding of the physical problems of the client's brain.

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The 10/20 System

The 10/20 Locations
As I mentioned before, in neurofeedback, electrodes are placed on the scalp according to the internationally recognized 10/20 system. The name stems from the fact that all electrode placements are either 10% or 20% of the entire across-head distance away from each other. The placements of each electrode are chosen based on the underlying portion of cerebral cortex (the outer covering of the brain.) Below is a diagram of the cerebral cortex, which is divided into four lobes.

Frontal Lobe: associated with thinking, motor skills, and reasoning.
Parietal Lobe: associated with tactile sensory information (pressure, touch, pain), and processing of senses.
Temporal Lobe: associated with memory formation, sound/speech interpretation, and memory recall.
Occipital Lobe: associated with receiving and processing visual information from the eyes, as well as visual recognition of objects and colors.

These locations correspond with the first letter in all the 10/20 locations because they lie right underneath where the electrode is placed. Below is a map of the locations on the scalp. It is an aerial view of a person's head. In this case, the person is facing upwards (triangle = nose, ovals = ears)
 

As seen above, each electrode is placed 10% or 20% away from the next electrode (either vertically or horizontally). The name of each electrode begins with the first letter of the underlying lobe of the cerebral cortex. For example, P4 lies above the parietal lobe. The only exception is the Center (horizontal axis of symmetry over head). The second letter of the name is added based on where the electrode is placed on the head as a whole. Z is added if the electrode is on the head's vertical line of symmetry. Even numbers are added if the electrode is on the right hemisphere; odd numbers are added if the electrode is on the left hemisphere.

Here are some examples: 

Electrode C4: It must be placed on the horizontal axis of symmetry over the head, in the right hemisphere, and must be 20% away from Cz (the exact center of the head).

Electrode P3: It must be placed over the parietal lobes, in the left hemisphere, and 20% away from Pz (the location above the parietal lobe and on the vertical axis of symmetry of the head).

Using other locations as references, we can determine the harder, more difficult locations, like O2. Despite seeming like an inaccurate system, there is room for error. One has approximately a dime's area of error space around each location to place the electrode.

But why are these electrode locations even necessary? Even though the purpose of neurofeedback is to train all the brain's waves to the proper levels, certain problems will be located in specific areas of the brain. For example, a typical case of ADD will have excessive Theta amplitudes in the Frontal lobes (F locations). This slows the task-performing region of the brain, causing distractedness. 

Brainmap of ADD: The Z-score table on the left indicates that the child's Theta frequencies are 5+ standard deviations away from normal frequencies. I will later post how to read brainmaps and use them to diagnose mental disorders.

To treat this case of ADD, one must downtrain Theta waves in specifically those regions. Therefore, the electrode locations allow neurofeedback therapists to treat the problem area which is associated with the client's specific disorder. It minimizes training time and solves the problem effectively. In single channel, the main electrode is placed on a single electrode locations. In 19-channel neurofeedback, the electrode cap covers all 19 locations on the head, allowing analysis of all regions of the brain simultaneously. As a result, 19-channel is used for far more complex/intricate issues with a variety of indicators. A simultaneous view of all brainwave activity in every region of the brain allows for a better wholesome understanding of the patient's problem.

In a future post, I will discuss common mental problems and their associated brainwave patterns/defective brain regions.

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Week 1/Week 2 Update

I realize that this is a little late, but I wanted to better understand what I was observing before I started posting weekly updates. My first day was nothing like I expected -- there were brief introductions then I was thrown right into my work. But I'm not complaining; it was very helpful to begin that early. Initially, I just sat in on training sessions, watching either Jimmy or Josh (the EEG technicians) attach the electrodes to the patient and program their individualized treatment.

The electrodes are placed according to the internationally recognized "10/20 System" of  locations. In a future post, I will discuss all these locations in detail. For now, it is necessary to know that there are 19 possible electrode locations on the scalp. Locations are chosen in accordance with the intent of that particular training session (what behaviors are being targeted). The electrodes are then plugged into an electroencephalogram amplifier, which augments any detected brainwaves so analysis is possible. The amplified waves appear on a computer screen in front of the patient. As mentioned in previous posts, the display helps the patient associate their brainwaves with their mental state, which eventually trains the brain to inhibit/encourage certain associated behaviors.

Types of Neurofeedback
But while all Neurofeedback forms function on the same principle, there are two different types of training.  

Single channel uses two reference electrodes for the ears but only one scalp electrode, which is placed on a single 10/20 location. This type is typically used when the patients disorder/problem isn't complex (only ADD or Depression). The single scalp channel can target certain areas of the brain from the surface and is all that is necessary to treat a relatively simple disorder.  

19 channel neurofeedback uses an electrode cap placed over the scalp to cover all 10/20 locations. This is used for more complex issues, such as multiple disorders or severe conditions. 19 channel has the ability to 3-dimensionally target regions of the brain, and, as a result, can treat multiple issues at once. But this type of training is very new, so all evidence for this type is theoretical. The majority of neurofeedback studies have been conducted with single channel training.  Both types use an amplifier and a monitor setup.

Electrode Cap

Within each type, there are two possible options of treatment: eyes open and eyes closed. These aren't really types of neurofeedback as much as possible treatment routes. So a possible route would be 19 channel eyes open, single channel eyes closed, etc.

Eyes open allows the patient to play a game, or watch a movie with their eyes open. All the while, the patient will be training their brain. If their brainwave levels are too high, the player loses points or the movie will dim.

Eyes closed training shuts out any outside interference with brain activity, such as visual processing. The patient closes their eyes and listens to music. If they are performing well, the music volume stays the same or increases; if they are not, the volume decreases.

I have mostly been watching single channel sessions because they are much less complicated to understand. Within the next few weeks, I will be posting a guide to the training program (how to program a treatment into the single channel computer system) and the setup.

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Brainwaves

Before I can begin describing my daily internship activities, I need to provide some essential background information on common subjects in the field of neurofeedback. Neurofeedback therapy targets specific brainwave frequencies and, based on the desired outcome, encourages/discourages those waves. But what are brainwaves?

Brainwaves
The brain is composed of millions of neurons, or nerve cells, which are able to transfer information through electric signals. Brainwaves are exactly that - the electrical impulse passed between two neurons. To understand how brainwaves are created, it is necessary to discuss structure of a neuron itself.

Neuron Structure and Chemical Signal

In the picture above, the neuron has a cell body (with a nucleus) and several branches called dendrites, which are used to receive signals from other neurons. The dendrites receive an electrical signal, passing it through to the axon. The axon is comprised of Schwann's cells wrapped in a Myelin Sheath, which insulates the electrical signal. After traveling through the axon, the electrical signal travels through the axon terminals into the dendrites of another neuron through a process named neurotransmission.

Neurotransmission triggers the relay of an electrical signal through a chemical action potential (an impulse). The potential travels down the axon, prompting the Na+ and K+ membrane channels to open and release chemicals. This creates a polarization; outside the membrane is positive, inside is negative. The ion channels allow ions to pass in and out of the membrane in accordance with the signal from a previous neutron. The Na+ and subsequent K+ ion releases cause depolarization then repolarization, allowing an electrical impulse to travel down the axon into the axon terminals/synapses. At the synapse (see above), the electrical impulse triggers the release of molecules named neurotransmitters across the gap and into the dendrites of another neuron. The neurotransmitters are carried in vesicles then fired into dendrite receptor sites across the gap. This process allows the electrical signal to continue into another neuron.

Electrical Impulse Down the Axon

 Each band on a EEG report is a grouping/range of brainwave frequencies measured in Hertz (Hz). Essentially, they measure how fast each signal is traveling between neurons. Since brainwaves are sinusoidal, their frequencies and amplitudes give insight into their functions and their significance.  The frequency correlates with the level of mental activity/associated behavior. Below are common properties of periodic waves.

Amplitude - strength/intensity of the wave (height of wave on graph)
Wavelength (λ) - distance between successive wave peaks
Frequency - the rate at which the wave oscillates, often measured in wavelengths/second

The following brainwaves are associated with a particular mental state/behavior that are commonly found on a qEEG report. They are listed in order from largest (highest amplitude to lowest amplitude) along with their corresponding frequencies.

Types of Brainwaves (largest to smallest)

Delta 1/Delta 2 (0-2 Hz / 0-4 Hz): associated with sleep/very deep mental state of relaxation
Theta (4-8 Hz): associated with day-dreaming and an idle state of mind.
Alpha (8-12 Hz): associated with a relaxation period or the transition from mental activity to idleness.
Beta 1/Beta 2 (13-21 Hz / 13-32 Hz): promote mental activity, alertness, concentration, etc.
EMG (25-32 Hz): associated with muscle tension (unimportant in EEG).

Discouraging/encouraging any of these bandwidths during training will discourage/encourage any associated behavior. For example, after a session of beta-decreasing therapy, a client is likely to feel calm and relaxed. Similarly, after theta-decreasing therapy, a client should expect to feel more alert and focused. Below, I have collected examples of each wave's appearance on an EEG.

 

 However, on an EEG, these waves will often be found together. Each line represents all brainwave activity, of all frequencies, from a single location on the scalp. As a result, one line on an EEG will have Beta, Alpha, Theta, etc. waves combined.

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What is Neurfoeedback Therapy?

During my first week of my internship, I have learned so much-- so much that I don't even know where to begin. But before I describe all the grueling details of neurofeedback therapy, let me give you a brief introduction.

What Even Is Neurofeedback Therapy?

Neurofeedback is a form of physical therapy that centers around improving mental performance. During a typical training session, a patient is seated in front of two monitors. Electrodes are placed on their ears and head, allowing the first monitor to display their brainwave frequencies. Based on the goal of the training session, an individualized treatment is programmed into the computer (for example, decreasing beta waves). Throughout the session, the first monitor displays brainwave readings, while the second monitor can be used for visual training, such as playing movies/games.

But how can just seeing brainwave frequencies improve mental performance? Neurofeedback therapy uses self-awareness to promote subconscious mental conditioning. This phenomenon is called "operant conditioning." For example, if a client wanted to feel more focused, their individualized neurofeedback training would discourage theta wave frequencies (see below about types of brainwaves.) The monitor would display a reading of the client's theta wave levels. Through practice and awareness of their levels, the client would eventually understand the correlation between the display and their state of mind, giving him/her the ability to influence the theta wave levels. The brain slowly reconditions itself, manipulating its own brainwaves to receive a reward. In training terms, this reward is given in many forms: more points on a therapy game, a reward sound, or a clearer resolution of the display monitor. If the client's brainwaves are not in accordance with the session's intent, the reward is revoked (the points decrease, a sound is not played, or the screen becomes darker.) All these signals are recorded in a EEG reading. 


The EEG Recording

EEG Recording

EEG stands for "electroencephalogram," and is a recording of all brainwave activity measured from the scalp. Through the use of electrodes, brainwaves can be measured and displayed through EEG. An EEG measures the neural oscillations over a short period of time, often a 30 minute training period. It fully captures all neural voltage fluctuations and records them on a graph (micro-Volts/time). As seen above, the EEG recording fully captures the physical nature of the brainwaves, allowing its various properties to be analyzed after the training session. In the report above, the y-axis lists electrode locations on the patient's scalp (see "The 10/20 System"), while the x-axis is time. In a future post, I will dissect an EEG reading and the significance of all present frequencies.

The qEEG Report 

qEEG stands for a "quantitative electroencephalogram." This report quantifies the brain's numerous electric signals into "bands" of frequencies. This report gives an EEG report some actual meaning. An EEG really means nothing when it is first recorded. It's just a jumble of brainwaves that reflect the patients state of mind; but until a qEEG report is written, an EEG is useless. qEEG uses the EEG data and transforms it into a qualitative analysis, showing what exactly needs to be targeted and where the deficiencies are. Rather than displaying the brainwaves, the qEEG color codes the patients brain itself to depict any abnormalities in specific brain regions. It is often referred to as EEG interpretation and analysis. Below is an example of such a report.

This is often performed as an initial test (to determine what treatment should be used) and a final test (to show improvement). However, a brain map can be very expensive so a large percent of patients do not pursue it. For most, it isn't even necessary -- people with many mental conditions will notice improvement (behavior changes, more focus, etc.) after training, so proof is not really necessary.  

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