If you are to understand the brain and human psychology, then understanding brainwaves and what they mean is a key component. You may have heard of ‘alpha’ or ‘beta’ brainwaves in the past and you might have seen or even used electroencephalograms. But what really do these waves actually represent? What’s going on in the brain that causes them? How can a brain… wave?
What Are Brainwaves?
Our brains are made from billions of cells called ‘neurons’ that store our memories, our opinions and our goals. Each of these cells is connected to billions of neighboring cells creating the ultimate ‘mind map’ and encoding all of our mental existence (this ‘web’ is sometimes referred to as the ‘connectome’).
Whenever we have any kind of thought, idea or sensation, these neurons are firing electrical impulses that spread throughout our brain in particular ways – just like a circuit. Activity in specific areas tends to denote certain types of experience, but generally areas all throughout the brain will be ‘lit up’ at any one time – even when we’re asleep.
All this firing means that there is a lot of electrical activity going on in our brains at any time. This activity can then be measured, giving us our ‘brainwaves’. The more our brain is active, the more electrical firing will go on inside the brain, and the greater the frequency of brainwaves. As activity quietens down meanwhile, we will begin to experience less frequent firing thus resulting in lower frequencies.
All this can be measured using a device called an electroencephalograph, which usually requires you to attach pads to your scalp in order to pick up electrical activity in the brain that gets translated into a wiggly line that looks much like a heart rate monitor. These devices, invented by Hans Berger, have allowed us to study this brain activity and to see how it correlates with various mental states. EEG machines are generally expensive and complicated to operate, though commercial options are now available that allow you to observe your own brainwaves via a desktop computer or smartphone.
Note however, that despite common parlance, we do not tend to experience solely one kind of brainwave at any given time. In other words, it is inaccurate really to say a person is experiencing ‘alpha waves’ because in fact they will be displaying all five types of brainwave at once. Rather, it is more accurate to say that one type of brainwave is dominant. What does this mean? It means that some parts of the brain will be buzzing more than others at any given time, but we can take an average in order to roughly estimate how someone is feeling.
The Five Types of Brainwave
Now you know what brainwaves are, it’s time to look at the different kinds and what they denote. While brainwaves will vary greatly and are in constant flux, they can also generally be broken down into five main frequencies: gamma waves, beta waves, alpha waves, theta waves and delta waves. We will look at each here.
Note: As well as frequency (how many waves occur over a set time), brainwaves also vary in amplitude which is the depth and height of each wave. We will look at both here.
Gamma Waves: Gamma waves are waves that occur between 40Hz to 100Hz. These are involved in ‘higher processing’ and are the waves we want to generate when learning new information or engaging in sports. Gamma waves are also associated with communication across different areas of the brain. Those with learning disabilities will often have lower levels of gamma waves than average, whereas too much can lead to anxiety and stress. Gamma waves are also ideal for binding the senses making us highly alert and on edge. Meditation has been shown to help encourage gamma waves.
The stimulation of gamma waves has been shown to lead to notable cognitive enhancement (1) on numerous measures. Interestingly, it completely disappears when a patient is under general anesthetic. It is actually believed by some, that gamma waves are the key to consciousness due to their function in uniting different areas of the brain.
Beta Waves: Beta waves are high frequency and low amplitude: meaning they are rapid and shallow. These types of waves are similar to gamma waves, being involved in learning, focusing and thinking logically, though they are somewhat less intensive when compared to gamma waves and occur at 12Hz-40Hz. Again they can cause stress in high amounts, whereas low amounts might be associated with daydreaming, ADHD or low motivation. You can increase beta waves by using stimulants such as energy drinks, caffeine or nootropics.
Beta waves can also be broken down into three categories of their own: low-beta (12-15Hz), beta (15-22Hz) and high-beta (22-38Hz). These are also known as Beta1, Beta2 and Beta3 respectively. The lower ends of beta brainwaves are the most common and tend to dominate our waking lives. While high frequencies may increase focus and awareness, they reduce creativity and emotional awareness and they drain us of energy.
Alpha Waves: Alpha waves are the slow we experience in normal waking life when we’re relaxed or absent minded. These are the brainwaves likely present when you unwind with a book or get ready to fall asleep, occurring at 8Hz to 12Hz. Alcohol, marijuana and antidepressants can all also contribute to alpha waves. Generally, more alpha waves means fewer beta and gamma waves and vice versa.
While we might normally associate alpha waves with relaxation, they can also be associated with states of productivity, awareness and even ‘flow states’ (which border alpha and theta waves). This lower amount of mental activity, seems to help us to be more ‘present’ and ‘in the now’, allowing us to work without distraction and to respond more quickly and instinctively to events. The flow state lies somewhere around 3Hz-5Hz and is the state that athletes describe when they hit perfect home runs or break world records. This is the state that many productivity gurus and sports coaches strive for, but the key has always remained somewhat elusive. Meditation however once again seems to help (by enabling us to remain calm in the face of stress), as may green tea and specifically L-Theanine.
Theta Waves: Theta waves occur between 4Hz and 8Hz and are associated with daydreaming and sleep. Theta waves are also present during trance, meditative or hypnotic states, as well as ‘hypnagogia’ which is the period just before we fall asleep and certain restorative points during sleep. Theta brainwaves are thought to contribute to creative thoughts, as our brain explores loosely connected ideas and topics in an unstructured way.
Delta Waves: Occurring between 0.5 and 3Hz, delta brainwaves are the lowest frequency recorded in human beings. They also have high amplitude. Delta waves are associated with the deepest levels of (dreamless) sleep, as well as intensive meditation. They suspend our awareness of the external world and are thought to be connected to empathy.