Did you ever stop and wonder why you have two nostrils instead of one? Science has long been aware of a nasal “dominance” that alternates back and forth between the right and the left nostrils. An increase, for example, of blood circulation to the right nostril causes a tumescence, or swelling, of internal structures in the right nasal cavity, thus narrowing the air passage and restricting the flow of breath.
At the same time, the opposite process takes place in the left nostril. In short, one nostril tends to congest or close as the other becomes clear and open. This pattern repeats itself in a rhythm that oscillates back and forth, from right to left, from left to right, throughout the day. And so, an alternating current of dominance—in the nose and also, it turns out, in the brain.
Psychologist Debra Werntz was the first to glimpse a connection, and she went on to make this important discovery: the opening of one side of the nose activates the opposite side of the brain: thus, when the left nostril opens, the right hemisphere becomes dominant. This can be clearly seen in EEG readings of subjects who are hooked up to an electroencephalograph.
Note the elegance of this doubly biphasal process: opening the right nostril shifts dominance to the left side of the brain with its rational, analytical mode, whereas opening of the left nostril engages the more intuitive, holistic mode of the right hemisphere.
In other words, there is a perpetual oscillation between LN and RN that is mirrored, in reverse, by a perpetual oscillation between RH and LH dominance. Here we can marvel at the “wisdom of the body” in providing access to both modes, at regular intervals, so that we can achieve a more integral balance in our mental processing.
Werntz went one step further and showed that this process need not be automatic but could be consciously controlled. And Ernest Rossi, whose writings I draw on here, came up with what may be the simplest way to control the cycle. It’s as easy as lying down. For it turns out that lying on your right side will cause your right nostril to partially close, and thus activate the right hemisphere of the brain. And vice versa.
One phase of nasal cycle is shown in the above CT scan. On the right is the more clear and open airway; on the left, the more congested or closed . (Note: right and left by your perspective in viewing the image)
HyC