A brainwave is a measurable and recognizable pattern of electrical impulses in our brains. Any emotion, thought and behavior is the result of the communication between neurons, which produces synchronized electrical pulses.
Brainwaves are measured in cycles per second or hertz (Hz) and are called delta, theta, alpha, beta and gamma. The latter are not thoroughly understood in neuroscience yet, but we know that their rhythms modulate perception and consciousness.
When the brain is aroused and actively engaged in mental activities, it generates beta waves. These beta waves are of relatively low amplitude, and are the second-fastest of the different types. They tend to dominate during most of our everyday lives.
Alpha brainwaves are slow in frequency and high in amplitude, occurring during states of non-arousal. Frequency ranges from nine to fourteen cycles per second. When closing the eyes and picturing something peaceful, there is an increase in alpha brainwaves. They have been associated with storage and retrieval of information (Rodriguez-Larios, Faber, Achermann, Tei & Alaerts, 2020). Theta brainwaves are slower in frequency and higher in amplitude than alpha brainwaves. Frequency ranges from five to eight cycles per second. When someone is daydreaming or does a task automatically, they are in a theta brainwave state. When we are in theta states, the hemisphere of the brain that is more active is the right one. These waves are associated to hypnotic or subconscious states and are related to spontaneous healing, spiritual connections, and intuitive states. Theta brainwave states have been associated with the manipulation of information (Rodriguez-Larios et. al, 2020). Delta waves are even slower in frequency and greater in amplitude than alpha and theta waves. Delta wave frequency ranges from one to four cycles per second, with lowest frequencies occurring in deep sleep.
Mindful breathing, which consists of paying attention to the sensation of the breath coming in and out of the body, can change our brainwaves. Paying attention to the breath in the present moment puts us into Alpha brainwaves. According to the study by James Hardt (2012), Alpha brainwaves are responsible for reducing anxiety and symptoms of generalized anxiety disorder. According to Rodriguez-Larios et al. (2020), from a cognitive perspective, breathwork practices require retention and manipulation of information to gain this state of thoughtless awareness. Various EEG studies have provided evidence into an increase in alpha and theta band power during meditation, by those who are experienced in the practice (Ziegler et. al, 2019; Lomas, Ivtzan & Fu, 2015). No wonder that the original Rebirthing Center in San Francisco was called “Theta House”. Acceleration of alpha peak frequency is induced by effortful cognitive tasks (such as when initially engaging in breathwork) and theta peak occurs when such cognitive tasks are complete or effortless (Mierau, Klimesch & Lefebvre, 2017). In regard to delta waves, a study (by Jaiswal, Tsai, Juan, Muggleton, & Liang, 2019) found that those who were skilled in mindfulness had lower delta oscillations during task completion than the other participants present. This indicates an increase in attentiveness from practicing meditative breathwork, aligning with the concept of being in the present moment.
In addition, a study by Rodriguez-Larios et. al, (2020) found that compared to being in a state of rest, experienced meditators have reduced retrieval, retention and manipulation of information during a meditative state. This is in line with the common experience of reduced mind wandering and heightened sense of thought awareness during meditation (Brandmeyer & Delorme 2016), reflected in an interplay between alpha and theta waves. Further elaborating on this, a study by Tang, Holzel and Posner (2015), provided evidence suggesting meditative breathwork might be associated with greater cortical thickness and might lead to enhanced white matter integrity in the Anterior Cingulate Cortex (ACC). The ACC enables executive attention and control and is part of a network facilitating cognitive processing. In other words, breathwork can improve the practice of sustained attention.
Brandmeyer, T. & Delorme, A. (2016). Reduced mind wandering in experienced meditators and associated EEG correlates. Exp. Brain Res.
Hardt, James, “Alpha Brain-Wave Neurofeedback Training Reduces Psychopathology in a Cohort of Male and Female Canadian Aboriginals”, 2012, National Library of Medicine
Jaiswal, S., Tsai, S. Y., Juan, C. H., Muggleton, N. G., & Liang, W. K. (2019). Low delta and high alpha power are associated with better conflict control and working memory in high mindfulness, low anxiety individuals. Social cognitive and affective neuroscience, 14(6), 645-655.
Lomas, T., Ivtzan, I., & Fu, C. H. (2015). A systematic review of the neurophysiology of mindfulness on EEG oscillations. Neuroscience & Biobehavioral Reviews, 57, 401-410.
Mierau, A., Klimesch, W., & Lefebvre, J. (2017). State-dependent alpha peak frequency shifts: Experimental evidence, potential mechanisms and functional implications. Neuroscience, 360, 146-154.
Rodriguez-Larios, J., Faber, P., Achermann, P. et al. (2020). From thoughtless awareness to effortful cognition: alpha – theta cross-frequency dynamics in experienced meditators during meditation, rest and arithmetic. Sci Rep 10, 5419
Ziegler, D.A., Simon, A.J., Gallen, C.L. et al. (2019). Closed-loop digital meditation improves sustained attention in young adults. Natural Human Behaviour 3, 746–757