PROTECT THE BRAIN CAMPAIGN
EEG BRAIN SCANS
An electroencephalogram (EEG) is a test used to evaluate the electrical activity in the brain. It is a safe, painless, and non-invasive that tracks and records brain wave patterns using electrodes which are attached to the scalp with wires. Brain cells communicate with each other through electrical impulses and electrodes analyze impulses in the brain and send signals to a computer that records the results to help detect potential problems associated with abnormal patterns in brain activity.
EEG technology gives doctors a more accurate picture of a patient’s brain health and is positioned to be one of the most robust and comprehensive sources for brain health analysis in the world.
Quantitative EEG (qEEG) is the analysis of the digitized EEG. Often called “Brain Mapping”, the process where EEG is commonly converted into color topographs. It enables a visual of a unique pattern of mental strengths and weaknesses - areas of the brain where there is too little or too much activity, and areas that are not coordinating their activity the best they could. The qEEG is an extension of the analysis of the visual EEG interpretation which may assist and even augment our understanding of the EEG and measuring brain function. A qEEG can identify not only brainwaves, their amplitude, location and whether these patterns are typical or anomalous, but also coherence (quality of communication between regions), phase (thinking speed), and network integration. These are all crucial patterns involved in optimal mental functioning.
EEG BRAIN MEASUREMENTS
Brain Power / Brain Speed
The EEG Audio P300 is an event-related potential (ERP) and a subconscious measure of attention and memory that measures the brain’s speed (roughly 300 milliseconds) in recognizing an odd (high) tone and the quality or power of this recognition.
The latency (ms) is a measure of classification speed and how quick the tone was recognized. The amplitude (µV)is considered proportional to the strength and power devoted to recognizing the tone. Although the P300 is a positive voltage change occurring approximately 300 milliseconds after the rare tone is delivered, by convention it is displayed in an inverted form as a downward moving voltage.
An increase in latency and/or a decrease in amplitude has been observed in various conditions associated with reduced cognitive function, including aging, dementia, depressive disorders, trauma, and vascular issues. (1-3)
Coherence is a measure of the correlation between two EEG locations as a function of frequency and provides information about functional connectivity between cortical regions. It is the mathematical measure of the degree of similarity of the EEG recorded at two locations and ranges from 0 to 1. If the phase—rising and falling—of the two signals are more similar over time, then it suggests functional connectivity--that those two areas of the brain are working together.
When EEG presents prominent alpha waves, sensory inputs tend to be minimized and your mind is generally clear of unwanted thoughts. When your brain shifts gears to focus on a specific thought—in either a positive or negative way—alpha waves tend to disappear and higher frequency beta waves begin running the show.
Alpha waves have a moderate frequency (8-12 Hz) in a relaxed, calm, not thinking, reflection, resting state for the brain.
Differences in the alpha waves between the left and ride sides of the brain, recorded from an EEG at the F3 and F4 electrode locations, can give information about emotional states. Studies have found large differences in alpha waves between the left-front and right-front of the brain have been associated with anxiety and depression, often found in PTSD. (4) The link between hemispheric asymmetry in frontal regions of the cortex and depressive symptoms suggests both depression and anxiety may be meaningfully related to relative frontal EEG asymmetry at rest. has been proposed that an atypical pattern of resting frontal cortical asymmetry can serve as a stable, trait-like risk factor for the subsequent development of depression or other emotion-related disturbances, where hemispheric specialization for cortical systems mediates motivational and emotional processes.
EEG theta and beta waves are associated with cortical arousal, which increases wakefulness, vigilance, muscle tone, heart rate, and minute ventilation of the brain. The theta and beta brain waves recorded from an EEG scan shows the balance struck between logical/rational and creative/intuitive processing.
Beta waves have a high frequency (13-21 Hz) and in a state of awake, actively engaged in mental activities.
Theta waves have a low frequency (4-8 Hz) in a state of deep relaxation, meditation, imagery with good/creative ideas.
Theta and beta wave correlation have been shown to consistently differentiate between people with and those without ADHD from ratios collected from measuring Cz channel placement on the EEG. High theta/beta ratios have been shown to consistently differentiate between ADHD and normal samples with meta-analyses reporting up to 94% sensitivity and specificity. (5-6)