“The brain is the last and grandest biological frontier, the most complex thing we have yet discovered in our universe.” — James D. Watson
What if I told you that your thoughts, dreams, and even your secrets leave traces of electricity on your scalp? This isn’t science fiction; it’s the everyday magic of EEG technology, a window into the human psyche that continues to astonish scientists and clinicians alike.
In ancient times, the understanding of the brain 🧠 and mind was steeped in mysticism and philosophy. Many believed that the mind resided in the heart🫀, while the brain was considered a mere cooling organ. Early civilizations, such as the Egyptians and Greeks, pondered the nature of consciousness, paving the way for the scientific exploration 🔎 of these concepts in later centuries.
However, our understanding of the brain and all the technologies surrounding it has evolved by a great deal over time. One of the main impactful advances in brain-related technologies are EEGs. As you read these words, trillions of neurons in your brain are firing away, creating a parade of electrical activity. With EEG technology, we can tap into the mesmerizing rhythm of your thoughts.
The science behind it all
An EEG, or Electroencephalography is a type of non-invasive BCI (Brain-Computer Interface) that detects abnormalities in your brain waves, or in the electrical activity of your brain. They are made up of electrodes consisting of small metal discs with thin wires 🔌 which are then attached onto your scalp. The electrodes detect minuscule charges of electricity ⚡️ that result from the activity of your brain cells. EEGs are thought to be primarily generated by cortical pyramidal neurons in the cerebral cortex that are oriented perpendicularly ⬆ to the brain’s surface.
How is EEG data interpreted?
EEG data is usually categorized into 5 main frequencies of brainwaves:
- DELTA (0.1 to 3.9 Hz): Delta waves are the slowest brainwave frequencies and are typically associated with deep sleep 😴, unconsciousness, and some abnormal brain activity. Delta waves are often observed in the frontal regions of the brain. These regions are located at the front of the head, near the forehead.
- THETA (4 to 8 Hz) Theta brainwave frequencies are usually associated with day-dreaming, light sleep, drowsiness 🥱 or a semi-conscious state of relaxation. Theta waves are typically recorded in different areas of the brain, and their location can vary. However, they are most prominently associated with the hippocampus, a structure deep within the brain that plays a crucial role in memory formation and spatial navigation.
- ALPHA (8 to 12 Hz) Alpha waves indicate that you’re most likely in a state of wakeful relaxation 🧘♀️ or have reduced cognitive load. Alpha waves are commonly observed in the occipital region of the brain, which is located at the back of the head. This area is involved in visual processing.
- BETA ( >12 Hz) Beta waves are a sign that the brain is active, alert, and attentive states of consciousness. For example, problem-solving like doing your math homework 🤓 usually occurs as Beta waves. Such as Delta waves, Beta waves are also most prominent in the frontal region of the brain, near the forehead.
- GAMMA ( >30 Hz) Gamma waves are high-frequency brainwaves that are associated with a range of cognitive and sensory processing functions 🙌. They can also be observed in various regions of the brain, often simultaneously with other types of brainwaves since they tend to involve the coordination of activity across different brain areas.
How do I know if I need an EEG test?
People who need an EEG test usually have symptoms related to neurological disorders such as seizures or migraines. To determine if you require an EEG test or not, you would typically have to consult your healthcare provider or a neurologist 🩺 . They would then assess your symptoms and medical history to decide if you require a test or not.
What are the main types of EEG tests?
There are serval types of EEG tests that can be performed. However, my top 3 selections are:
- Routine EEG: During the test, electrodes are placed on the scalp to detect and record brainwave patterns. These patterns (known as brainwave rhythms) can provide valuable information about brain function and detect unusual activity. They’re also commonly used to diagnose and monitor conditions such as epilepsy, seizures, and other neurological disorders. Patients usually need to prepare for the test by regulating hygiene (making sure they have clean hair) and may be asked to stay awake or sleep during the test to capture different brain activity states.
- Ambulatory EEG: During this test, the patient wears a portable EEG device that is connected to electrodes on the scalp, allowing for the continuous recording of brainwave patterns while the patient continues their normal daily activities. Ambulatory EEGs are typically employed when a standard, shorter-duration EEG may not capture the infrequent or scattered abnormalities in brain activity that are suspected but not confirmed. For example, cases of epilepsy or other neurological disorders. The data collected during an ambulatory EEG is analyzed by medical professionals like neurologists and neuro-diagnostic technicians to identify irregular brainwave patterns and to better understand the nature and frequency of the patient’s symptoms.
- Sleep EEG: A specialized diagnostic test used to monitor and record brain activity during different stages of sleep. During a sleep EEG, electrodes are placed on the scalp to measure brainwave patterns, allowing for the assessment of sleep cycles, stages, and any abnormalities in sleep architecture. It provides valuable insights into sleep disorders such as Insomnia, Sleep Apnea, Narcolepsy, and Parasomnias, helping clinicians to make accurate diagnoses and treatment recommendations. Sleep EEG is often conducted in a controlled environment, such as a sleep lab. The information gathered from a sleep EEG is crucial for developing tailored treatment plans, evaluating the effectiveness of interventions, and improving overall sleep quality and health.
What kind of equipment is used during an EEG test?
EEG tests are generally done using an EEG machine. An EEG machine consists of electrodes, amplifiers, filters and an analog to digital converter. Portable EEG machines will contain a battery whereas wired EEG machines will be hooked up directly to a computer.
However, the electrodes are what sit on your head. The precise placement of electrodes is crucial for accurate EEG readings since it directly influences the accuracy of the recorded brainwave data.
The main areas of electrode placement on the scalp are fronto-polar (Fp), frontal (F), central (C), temporal (T), parietal (P), and occipital (O) regions of the brain.
The 10–20 System: The 10–20 system is a widely used and standardized method for electrode placement in EEG. The name comes from the fact that electrodes are positioned at intervals of either 10% or 20% of the total distance between specific anatomical landmarks on the scalp. But first, you need to identify key anatomical landmarks on the scalp. These landmarks are the nasion (the bridge of the nose), the inion (the bump at the base of the skull), and the preauricular points (the points just in front of the ears).
In this system, electrodes are positioned based on the following principles:
- Electrodes are labeled with letters (e.g., F for frontal, C for central, P for parietal, and O for occipital) to indicate their general location on the scalp.
- Odd-numbered electrodes (e.g., F3, C5, P7) are positioned on the left side of the head, while even-numbered electrodes (e.g., F4, C6, P8) are positioned on the right side.
- Additional electrodes are positioned in the midline and can be identified by a “z” (e.g., Fz, Cz, Pz).
Keep in mind: Before attaching the electrodes, it’s crucial to prepare the scalp. This typically involves gently scrubbing the area with a mild abrasive gel to remove dead skin cells, oils, and other substances that may impede electrode conductivity. Conductive gel or paste is then applied to the electrodes to ensure good contact with the scalp.
Clinical applications of EEGs
There are various clinical implications of EEG technologies. But my top 4 picks are:
Diagnosing Epilepsy: EEGs are one of the most important tools in diagnosing epilepsy because it helps identify abnormal electrical patterns or sudden high frequency change in electrical activity 🪫 (epileptiform brain activity) can be seen on an EEG recording.
Sleep Disorders: EEGs can detect and assess changes in brain activity that can indicate various brain disorders such as epilepsy or other seizure disorders. A sleep-deprived 😪 EEG can be used to diagnose and differentiate various types of epilepsies.
Assistive Devices Control: EEG-BCI technologies can enable patients to control assistive devices such as wheelchairs, robotic arms 🦾, or environmental control systems. This technology can provide independence and mobility for those with physical impairments 👩🦼.
Neurofeedback Therapy: EEG-based neurofeedback therapy is used to help individuals regulate their brain activity and manage conditions such as ADHD and anxiety. It essentially aims to change the way the brain responds to certain stimuli. It has real-time monitoring 🖥️ and feedback of an individual’s brain activity as well as teaches each patient to regulate their brainwaves and be able to guide it toward more functional patterns.
So..What’s Next? Wearables.
Wearable EEG technology has the potential to be revolutionary by enabling seamless, real-time monitoring of brain activity in everyday life. This innovation can give us valuable insights into mental health, cognitive performance, and overall well-being. This would ultimately lead to more personalized healthcare and early intervention for neurological disorders. Additionally, the integration of wearable EEG into various industries , such as gaming and education, could create entirely new experiences and opportunities for human-computer interaction, transforming the way we interact with technology and enhancing our quality of life.
A few examples of advanced wearable EEG technology today are:
1. Neurable Enten Headphones
Their headphones incorporate advanced EEG technology to read and interpret the wearer’s brain activity. It allows users to control various devices, applications, and even virtual environments through their thoughts, providing a new level of hands-free interaction. For example, you could decline a phone call by just thinking about it. Additionally, they’re engineered for premium sound with features such as balanced mic pickup, all-day battery life and noise cancellation 🔇.
2. Muse S headband
Muse is a smart headband that acts as your personal meditation coach. It has advanced sensors which can detect when your mind wanders and gives you gentle audio cues to bring your focus back. The device uses dry sensor technology and advanced digital signal processing, making it easier to track your brain activity and gain insights into your overall mental states. They use 7 advanced sensors that track your brain & body and have measurable & accurate Results. It’s also backed up by research and certified by many neuroscientists globally 🌐.
3. Roga Life Device
The Roga Life stimulation device is another great example of an advanced EEG. It essentially uses electrical pulses to interrupt stress sigoals and help you with anxiety or stress. These pulses are done through the stimulation pads that would sit behind your ears. It is designed to deliver non-invasive brain stimulation (NIBS) and has digital on-demand programs like self assessment (a simple onboarding guide) and self-guided video sessions. It’s also super personalized since the software has an AI coach! 🤖
My thoughts on the future of EEG
In my view, EEG technology has the potential to be truly revolutionary. By decoding the electrical activity of the brain, it offers a window into our thoughts and intentions, making it possible to control devices and interfaces with our minds. This not only opens doors for people with disabilities, but it also gives us a glimpse at a future where communication and interaction will exceed beyond traditional boundaries. Moreover, the insights obtained from an EEG can transform healthcare by enabling early detection of neurological disorders and personalizing treatments, allowing for an era of more effective and patient-specific care. In conclusion, I believe that the revolutionary impact of EEG technology will simply define the boundless potential of human creativity and innovation.
TL;DR:
Introduction: What if I told you that your thoughts, dreams, and even your secrets leave traces of electricity on your scalp? This isn’t science fiction; it’s the everyday magic of EEG technology.
Science Behind It: It’s essentially a type of non-invasive BCI (Brain-Computer Interface) that detects abnormalities in your brain waves, or in the electrical activity of your brain which mainly uses electrodes to track the data.
How it’s Interpreted: EEG data is usually analyzed in the form of the brainwave frequencies; DELTA (0.1 to 3.9 Hz), THETA (4 to 8 Hz), ALPHA (8 to 12 Hz), BETA ( >12 Hz) and GAMMA (>30 Hz).
EEG tests: A brief overview of EEG tests; How to know if you need an EEG test, how they are conducted, equipment being used, etc.
Clinical Applications of EEGs: Talking about how the technology improves and aids clinical and medical implications such as diagnosing Epilepsy or sleep disorders like insomnia.
Who’s ahead in this field of tech: Listing wearable EEG tech like Neurable and how they can improve and revolutionize this space.
My prespective on the future of EEG: Stating how I think EEG technology can be highly transformative towards lives.
Bonus Video
Here’s the link to the video that got me invested and interested about the area of EEGs In BCI technology!
Citations and Resources
https://www.sciencedirect.com/science/article/abs/pii/S0149763420304991
https://www.ncbi.nlm.nih.gov/books/NBK390346/
https://imotions.com/blog/learning/best-practice/5-basics-eeg-data-processing/
C. He et al., “Diversity and Suitability of the State-of-the-Art Wearable and Wireless EEG Systems Review,” in IEEE Journal of Biomedical and Health Informatics, vol. 27, no. 8, pp. 3830–3843, Aug. 2023, doi: 10.1109/JBHI.2023.3239053.
Ghosh K, Nanda S, Hurt RT, et al. Mindfulness Using a Wearable Brain Sensing Device for Health Care Professionals During a Pandemic: A Pilot Program. Journal of Primary Care & Community Health. 2023;14. doi:10.1177/21501319231162308
Amin, U., Nascimento, F. A., Karakis, I., Schomer, D., & Benbadis, S. R. (2023). Normal variants and artifacts: Importance in EEG interpretation. Epileptic Disorders, 25(5), 591–648. https://doi.org/10.1002/epd2.20040
