Brainwave – User Guide

A brief introduction to EEG

As you think, dream, see, and sense, your brain is constantly active. It does not only absorb all information, process, and re-connect existing data, but also integrate everything into a consistent experience. For you, that experience constitutes your reality.

Your brain is constantly active, shaping how you see your environment, filtering or highlighting objects and information most relevant to you. It creates its own stories based on your thoughts, emotions, desires, and experiences, ultimately driving your behavior.

1. Electrical activity of the brain

  1. The brain consists of billions of cells, half of which are neurons, and the other half of which are synapses that help and facilitate the activity of neurons. The neurons and synapses are all interconnected and forming a vast network. These neurons generate an electrical field which is strong enough to spread through tissue and bone and can be measured from the scalp.
  2. Each neuron is composed of a body and dendrites, making it possible for neurons to communicate with each other. When the brain reacts, these neurons release chemicals, called neurotransmitters, to neighboring neurons. Neural networks construct information and create an electrical field through the changes in chemical balance in the brain. These changes, often referred to as potentials, don’t last long because the brain continuously creates information that causes this balance to change. The sensors in EEG machines quickly pick up these electric fields in a very precise manner which are later used by amplifying these recordings.

2. What is EEG and how does it work?

  1. Grasping the essentials of electrical activity of the brain is surprisingly simple. Electroencephalography, or EEG, is the method of choice to record the electrical activity generated by the brain via electrodes placed on the scalp. Electrode sensors amplify the small voltage changes that arise from the synchronized activity of thousands of neurons. EEG provides excellent time resolution, allowing you to detect activity within cortical areas even in the scale of milliseconds. One of the biggest advantages to EEG is that it is one of the fastest and cheapest imaging techniques available and often has a high sampling rate.
  2. The number of EEG sensors varies among devices, but the more sensors used, the more regional data can be obtained. The 10-20 system is an international method that standardizes the placement of the electrodes, or sensors, on the individual’s scalp.
In yellow – the sensors used in the LooxidVR and Looxid Link
In yellow – the sensors used in the LooxidVR and Looxid Link
  1. For better understanding, the image below illustrates how this method works. It demonstrates where the electrodes are placed, where regions A1 and A2 are the left and right ears respectively, the nasion as the point between the eyes, and the inion as the back of the head. Each placement of the electrodes is at a 10% or 20% distance of the front-back or left-right distance of a person’s head.
  1. As for the placement of the 10-10 system, divide all the 20% distance regions of the 10-20 system by half, and you will be able to see the regions that are used for the EEG electrode placement.
Sensor placement for 10-20 EEG system
Sensor placement for 10-20 EEG system
Sensor placement for 10-10 EEG system
Sensor placement for 10-10 EEG system

3. How can EEG data be interpreted?

EEG is significant in that it allows us to record the voltage changes for post analysis that can help us determine if there are certain incongruencies in patterns or understand how our brains operate and react under certain conditions. It is important to know that EEGs cannot diagnose disorders but allows us to have a clear overview of our brain’s activity.

  1. As EEG monitors the time course of electrical activity generated by the brain, you can interpret which areas of the cortex are responsible for processing information at a given time:
    • Occipital cortex: responsible for processing visual information including low-level visuo-spatial processing (orientation, spatial frequency)
    • Parietal cortex: accountable for motor functions and is active during self-referential tasks (objects or information that is important to us)
    • Temporal cortex: responsible not only for language processing and speech production (left temporal cortex including Broca’s and Wernicke’s areas) but also for long-term memory (deep temporal structures including the hippocampus)
    • Frontal cortex: in charge of maintaining control and monitoring our behavior (executive function)
      • Prefrontal cortex: The prefrontal cortex is implicated in planning complex cognitive behavior, personality expression, decision making, and moderating social behavior. At Looxid Labs, we focus on the prefrontal lobe because we are aiming to provide a compatible interface for virtual reality (VR) and comfortability in terms of the usability of VR headsets. By placing the sensors in an area that does not obstruct the functionality of a head-mounted display, the most logical area to place these electrodes is the forehead area, which corresponds to the prefrontal cortex of the brain.

  1. According to the previous neuroscience studies, whenever your brain is in a certain state of the mind, the frequency patterns of brainwave changes, giving insight into cognitive processes. The frequency patterns of brainwaves are categorized into 5 different types:
    • Delta Waves (0.5Hz ~ 4Hz)
      The lowest frequency of all brainwaves, delta waves are prominent when an individual is in deep stages of sleep, more specifically during the non-REM sleep. When these waves are the strongest, one can infer that the individual is going through good rest, consequently allowing for the brain to process learned information and skills. Abnormalities in the presence of this wave frequency mean that your body will not be able to produce the hormones that promote healing and regeneration of the body, such as the Human Growth Hormone. When it comes to sleep disorders, these are the waves to search for.
    • Theta Waves (4Hz ~ 7Hz)
      Theta waves appear frequently in younger children and adults. These are indicators of drowsiness or meditative states. Also, these waves appear before an individual is about to receive new information, showing that theta waves have a role in focused attention and processing of information. In other words, theta waves are noticeable during more difficult tasks. The general consensus is that these waves are related to working memory and are present during REM sleep, which is when the brain is organizing and learning information.
    • Alpha Waves (8Hz ~ 15Hz)
      Alpha waves are present when an individual is in a relaxed state of mind. In other words, high levels of alpha waves are an indication of deep relaxation. When undergoing intense cognitive situations, these levels decline and one can induce these brainwaves by closing their eyes. Studies suggest that when alpha wave levels decrease, one is preparing themselves to pick up information or is thinking. Alpha waves aid in increasing levels of imagination, visualization, learning, and concentration.
    • Beta Waves (16Hz ~ 31Hz)
      Beta waves are indicators of active thinking. When an individual is alert, attentive, or awake, beta waves will be present. In particular, these oscillations correlate with execution of bodily movements. Studies have shown that certain beta waves are indicators of an anxious or busy state of mind. In other words, this means that an increase of beta waves can determine that an individual is performing some kind of mental activity. The more complex mental activity required, such as critical thinking and reasoning, the more beta wave will be present.
    • Gamma Waves (31Hz ~ 100Hz)
      Unlike other frequencies known to be indicators of a specific state, gamma waves haven’t quite reached the same consensus as other waveforms. However, it is suggested that the presence of gamma waves indicates simultaneous processing undergoing in the brain. The presence of gamma waves during wakefulness compared to during sleep suggests that it might be a link for different stages of conscious awareness. Other studies speculate that gamma waves have control over consciousness, perception, other virtues such as altruism, and spiritual development.
  1. Obtainable information using Looxid Link
    As stated in the previous section, each wave frequency indicates different conditions in the brain. Likewise, depending on what you are specifically looking for, a combination of frequency might be necessary. Our brains react to certain situations in forms that we sometimes cannot convey, which is why physiological signals like brainwaves can be a very useful tool to determine an individual’s state of mind. You can determine if a person is attentive to a university lecture, if they are stressed because of family problems, or if they are relaxed by watching a good movie. It is important to notice that not one brainwave frequency equals a certain state of mind but are merely indicators. EEG does not read your emotions or feelings; it makes sense of what one is going through.

    • If you try the VR Mind Care solution which comes along with Looxid Link, you will notice our sensors will pick up your brainwave signals and quantify your frequencies so that you can compare your mental state before and after sessions you selected. Certain indicators such as left-right asymmetry, concentration, relaxation, and stress levels are provided. These indicators will help users understand how their brain reacts and contributes to their wellness.

4. In what fields is EEG applicable?

EEG is used in a variety of fields where unbiased, unconscious data are pivotal. Different factors can affect how one expresses their minds. Hence, EEG is widely used in fields where user feedback is necessary. The following are some fields where EEG is widely known to be utilized.

  1. Neuro-Entertainment
    Have you ever watched a movie where you thought “man, it is not engaging enough” or “this is boring”. This new field uses feedback from your brain to make the content more intense or engaging. EEG signals are effective to utilize the person’s engagement or attention levels in making a movie more appealing to the consumer or not letting a movie be more than what the consumer can handle.
  2. Wellness & Healthcare
    Therapy is important to recover from certain trauma or issues that one cannot overcome. EEG applied to guided therapy sessions allows for monitoring of EEG signals to observe if a certain session is helpful to the user. Physiological signs provide deeper insights than self-expressed statements. The materialization of signals before and after sessions as well as the history of these records can soothe a user’s mind. Meditation and exposure therapy are some examples of uses in the wellness area. In addition, abnormal EEG signals of the user can help detect certain conditions before they are fatal.
  3. Neuromarketing
    Consumer research focuses on the effectiveness of marketing campaigns. Getting to understand what catches customers’ attention and acknowledging the ways in which people perceive a marketing strategy can save a company unnecessary expenses from facts performed by neuromarketing. Self-reporting may not give deep insights, hence, EEG data can be a more resourceful option.
  4. Education & Training
    Imagine going to class and having a lecture where the professor is able to effectively teach you, customizing the material to be more engaging and actually being able to understand everything he or she is talking about. EEG in education is widely used in this manner, where the EGG recordings during classes allow teachers to obtain reports of students’ engagement levels. As in training, companies and institutions can use EEG along with VR to allow trainees to experience real situations and get effective feedback from their mistakes in the training sessions. It allows them to be better prepared for real life situations by known what to expect.
References
  • Cantero, JL. et al. (2004). “Gamma EEG dynamics in neocortex and hippocampus during human wakefulness and sleep”. NeuroImage 22 (3): 1271-1280.
    doi: 10.1016/j.neuroimage.2004.03.014
  • Davidson, RJ. (2004). “What does the prefrontal cortes ‘do’ in affect: perspectives on frontal EEG asymmetry research”. Biological Psychology 67(2004) 219-233.
    doi:10.1016/j.biopsycho.2004.03.008
  • Klimesch, W (1999). “EEG alpha and theta oscillations reflect cognitive and memory performance: a review and analysis”. Brain Research Reviews 29 (2-3):169-195.
    doi: 10.1016/S0165-0173(98)00056-3
  • Liu, NH et al. (2013). “Recognizing the Degree of Human Attention Using EEG Signals from Mobile Sensors”. Sensors 13(8): 10273-10286. doi: 10.3390/s130810273. PMID: 23939584
  • Palmiero, M and Piccardi L. (2017). “Frontal EEG Asymmetry of Mood: A Mini-Review”. Front Behav Neurosci 2:224. doi: 10.3389/fnbeh.2017.00224
  • Sander, C. (2018). “Changes in brain arousal (EEG-vigilance) after therapeutic sleep deprivation in depressive patients and healthy controls”. Scientific Reports 8:15087 DOI:10.1038/s41598-018-33228-x
  • Whishaw IQ, Vanderwolf CH (1973). “Hippocampal EEG and behavior: changes in amplitude and frequency of RSA (theta rhythm) associated with spontaneous and learned movement patterns in rats and cats”. Behav Biol. 8 (4): 461–84. doi:10.1016/S0091-6773(73)80041-0.PMID 4350255. (Theta)
  • Zhao, G et al. (2018). “Asymmetric hemisphere activation in tenderness: evidence from EEG signals”. Scientific Reports 8 (8029): DOI:10.1038/s41598-018-26133-w