The human brain, with its intricate network of neurons and synaptic connections, is a magnificent organ that orchestrates the wonders of human intellect and consciousness. Scientists have been intrigued by the inner workings of the brain for decades, but one intriguing feature that has drawn their attention is the phenomena of brain waves.
The secrets surrounding our mental states, including focus, relaxation, sleep, learning, and emotional health, can be fully understood by observing these periodic patterns of electrical activity that pulse through the brain. The synchronized firing of neurons within the brain results in electrical impulses known as brain waves, often referred to as neural oscillations. Electroencephalography (EEG), a non-invasive technology that records the electrical activity on the scalp, can identify and quantify them.
The frequency, amplitude, and location of brain waves are distinct patterns that change according to our mental and physical states. The various forms of brain waves that have been discovered over time are individually connected to particular cognitive functions and states of awareness. These waves range in frequency from the slowest, most contemplative waves to the quickest, most perceptive waves. They consist of gamma waves, beta waves, alpha waves, theta waves, and delta waves. Every wave type has a significant impact on our cognitive processes, affecting our perception, focus, memory, creativity, and general mental health.
As we know, Electroencephalography, sometimes known as EEG, is a method that allows us to detect brain waves by placing tiny electrodes on a person’s head. While portable devices like “Neuphony” have lately been produced that employ fewer electrodes and come in fancier-looking headsets, all of these electrodes are typically held in place by a cap/headband. Since every neuron generates too little electrical current, EEG cannot detect the electrical activity of individual brain cells. Only when numerous neurons are sending comparable electrical signals at the same time can these currents be detected.
On the EEG display, waveforms show the recorded brain waves. The frequency (measured in Hertz) and amplitude (measured in microvolts) of various types of brain waves differ. First, let’s learn how to interpret sensor names and what areas they cover. The electrode locations are identified by alphabetical abbreviations that identify the lobe or area of the brain from which each electrode records:
The localization of brain waves inside brain areas or lobes is restricted further by adding electrodes with numbers such as T3, T4, F3, F4. Even numbers represent electrode positions on the right side of the head, whereas odd numbers represent electrode positions on the left side. The label “z” indicates electrode locations in the midline of the head. Pz, for example, refers to the head’s midline parietal area.
Now let’s discuss brain waves a bit. Alpha waves are associated with relaxation and focus. They exist when you are awake yet have your eyes closed. They normally vanish when you open your eyes and focus your attention on anything. Beta waves are common in awake people. It makes no difference whether your eyes are open or closed. Sedatives, for example, can have an effect on these waves. Theta waves are associated with sleep. These sluggish waves are common during sleep for people of all ages. When grownups are awake, they are usually not visible. Delta waves are also associated with sleep. These waves are common in deep sleep adults and young children. Gamma waves are the fastest brain waves and rarely appear, generally found in veteran meditators or elite athletes, and are related to the “flow state” of the brain. It can be affected by stimulants like caffeine and nicotine.
Last but not least, we’ll understand the amplitude of these brain waves and what they tell about them. On the scalp, amplitude is measured in microvolts and is the height of a waveform, thereby acting as a stand-in for voltage. On the scalp, the average adult brain exhibits amplitudes between 10 and 100 microvolts, mainly between 10 and 50 microvolts. As was already mentioned, the connection between amplitude and frequency is typically inverse. Clarifying the amplitude of a discharge or pattern (low, moderate, or high) for epileptiform discharges and other activity is a crucial component of the descriptor. Contrary to popular belief, sensitivity is a technical decision that influences how the amplitude is perceived. Don’t mix amplitude with sensitivity because amplitude is an intrinsic variable of the waveform itself.
So, this is the basic guide to understanding how EEG works and what you can determine from it. Although to understand EEG patterns accurately one should seek the advice of a professional neuroscientist or an EEG expert. EEG has the potential to lead to many more breakthroughs and uses in the disciplines of neuroscience, psychology, and medicine as technology and research develop. We gain a greater understanding of the exceptional organ that characterizes our humanity—the remarkable and perplexing human brain—by solving the puzzles of brain waves.
