I came of age in neurology before clinicians had the means to show activity in specific parts of the brain as can be done now with PET and fMRI. In the late 20th century neurologists discussed restful eyes-closed waking. We used the EEG to follow alterations in mental states. Being any movement at all would overwhelm the very tiny electrical potentials seen on the EEG, we strove to record the EEG in a state of restful waking, eyes closed. The bottom of the illustration shows electrical activity at the back of the brain, namely the occipital lobes on both sides. The occipital lobes subserve visual function.
When I was in college during the 1970s, before med school, in psychology departments, people sought to increase their alpha EEG activity. They were pleasantly surprised to find it was fairly easy. Many thought they’d found a back-door mechanism to mind-control of the bodily functions. But exact path wasn’t obvious.
At the time, the mental control of what were felt to be automatic (“autonomic” in the parlance of the nervous system) was a hot topic. Maharishis and fabulists influenced by Eastern cultures, talked about teaching the skills that would enable everyone to control blood pressure, galvanic skin response (sweating), and their own brain waves, especially rhythmic alpha. People were fascinated. They could achieve a mystical state related to Nirvana or ultimate in mental blankness, through meditation.
Reality proved to be more straightforward and less magical. Over time it was plain, there was little to mind control at all. Maharishis were doing little more than relaxing and concentrating on nothing. But this turning off and tuning out much resembles the Default Mode Network. It is appreciated on the EEG as well as with more advanced imaging techniques, PET and fMRI.
Below is a EEG which looks at brain waves from the front (top) to back (bottom) of the brain. The alpha pattern of beautifully rhythmic waves or waxing and waning amplitude is best seen in the bottom or back of the brain. Here are pairs of rows each pair coming from the L then R of the cerebral cortex.
