Defining a Few Strange Terms: the Homunculus and the Hypnogogic State

By Linda Oshins

I don’t interrupt my students’ personal experience of the physical body scan in Yoga Nidra by explaining the structure of the practice conceptually. Too much thinking and too little first-hand experience obscures its meaning. Trying to figure out Yoga Nidra as you experience it is impossible since you would have to interrupt the flow of sensations in the moment to pin one down. Then you are outside the flow, and likely lost in thought. But I have an intellectually curious student in class who wanted a peek behind the curtain so a few of us met for an impromptu class during break week to talk.

Yoga Nidra as taught by Richard Miller pays particular attention to the sense organs and other parts of the body that contain a high concentration of sensory nerves. In understanding the sensory map of the body an image, the sensory homunculus, is worth a thousand words, but most people have never seen it. When I refer to it in teacher trainings I’m met by blank faces all around. Here are a couple versions of that image. The larger body parts contain more sensory nerves than the smaller body parts.

This one shows which area of the brain is related to each body part and roughly how much brain area is devoted to each. Obviously the tongue, mouth, lips and the sensory organs in the head (eyes, ears, and nose) are prominently represented, followed by the dexterous and sensitive hand and fingers.

The common body scan that beginning yoga teachers are taught to lead and that most, if not all, students at YOHI have experienced isn’t mapped to the sensory homunculus. It starts at the foot and slowly moves toward the head bringing attention to each body part as an invitation to relax it. Sometimes it’s accompanied by instructions to tense and release the body. For example, the instruction might be, “Lift the leg a couple inches off the floor. Tense all the muscles of the leg, foot, and toes. Hug the muscles to the bone as tightly as you can. On an exhalation, gently release the leg to the floor. Relax all the muscles of the leg, foot and toes.” It handles each body part in turn, referencing each once, relaxing the big muscles of the body like the leg and arm muscles and the muscles of the pelvic belly as well as smaller muscles that are chronically tense like the neck and facial muscles. This in turn relaxes the mind, and leaves you properly prepared for Savasana at the end of an asana practice or relaxed enough to fall asleep.

The iRest Yoga Nidra body scan is a different experience entirely. It is mapped to the sensory homunculus and follows the order of body sensitivity across the brain beginning at the corpus callosum, which connects the brain’s left and right hemispheres. Therefore, it begins in the mouth, maps the sensations of the other sense organs in the head, and moves down the body lingering and detailing sensation in the hands and feet. It also moves from one side of the body to the other, revisiting body sensations. A set of instructions might be, “Notice sensations in the right side of the body, the whole right side of the body. Feeling the right side of the body…. Now notice sensations in the left side of the body, the whole left side of the body. Feeling sensation in the left side of the body only…. At your own pace and rhythm move back and forth, noticing sensations in the right side of the body, then the left side of the body, back and forth….” And then the glorious, integrative experience, “Notice sensation in the whole body. The whole body, one globe of radiant sensation vibrating is all directions simultaneously.”

The Yoga Nidra scan does not just relax the body, although it may have that effect. It stimulates the entire sensory network, awakening the sense organs and awakening the mind. Some people seem to fall asleep during Yoga Nidra, but they are actually in a hypnogogic state, a state of “threshold consciousness,” between waking and sleeping. The body is asleep, the mind may or may not be conscious of the teacher’s voice, but the student is alert on some level. The hypnogogic state is characterized by openness, sensitivity, receptivity, associative fluidity and insight. It is related to semantic memory, the memory of meanings and understandings, rather than episodic or autobiographical memory. In other words it is fertile ground for seeing beyond the many daily concerns and value judgments of the personality.

When I do the tense and release body scan, I can feel the difference between the greater sensitivity in my fingertips and the lesser sensitivity in my calves. But I have a different experience during Yoga Nidra. Those distinctions erode because Yoga Nidra speaks to every cell in my body. Everything vibrates and is so alive and conscious that the parts become the whole, indistinguishable from one another. Boundaries disintegrate.

Both body scans have their place and their purposes and they are by no means the only possibilities. The practice of yoga offers many ways to hold a discussion between the mind and body and open doors into consciousness.

I hope you are entertained and informed by a couple images and concepts useful to me in my practice.

Anne Douglas, a teacher from the iRest Institute will give a public lecture on Friday, November 16, on the philosophical underpinnings of Yoga Nidra. Linda Oshins teaches iRest in her Thursday morning classes.