Hand positions used in the practice of yoga are called mudras. Like the breathing practices of pranayama, there are many different mudras for evoking certain physiological responses. The mudras have wide ranging effects on the sensory functions within the body. What is behind this experience?

Enter Homunculus man! Images of the “little man” or homunculus show body parts scaled to their relative sensory function in the brain. The sculpture pictured above is a graphic representation by Sharon Price-James. It is one of three of her Homunculus man sculptures (the other two are motor and sexual versions). This is the sensory version showing those parts that make the greatest contribution in our cortical functioning. Look at those hands! Hmm… could this be a scientific basis for mudra effectiveness?
Let’s continue. The fastest and most detailed information we can gather for our nervous system is through the rate of our breathing and our sense of touch with the hands. In yoga our controlled connection to that nervous system is through the breath in pranayama and with the hands in mudra. These two yogic practices are our direct connection between the relationship between the body and the mind, in their combined relationship to our environment.
The concept of mudras has its detractors and its supporters. Some discount mudras as simply ritualistic or symbolic. The experiential evidence (that’s real people doing real activity) shows a number of related techniques using the hands and fingers as having similar effectiveness. Think tapping, Super Brain Yoga, Kirtan kriya yoga advocated by the Alzheimer’s Research and Prevention Foundation using SA-TA- NA-MA mantra with finger movements. Other yogic techniques such as meditation and mediation of the body have been studied using technology to measure and evaluate the mystery of the practice. Don’t get me started.
So back to Homunculus man and mudra. How does a topographical map of the body’s sensory areas inform our practice? Would that we could ask Dr. Wilder Graves Penefield, a pioneer in mapping the regions of the brain. Not a guy satisfied with the amazing feat of describing the cortical homunculus, he really was interested in the science behind consciousness and the soul. Wow. His early work on brain stimulation gives us many threads to follow. After all, he branched out into the study of hallucination, out-of-body-experience, deja vu – seamlessly and without hesitation. We should be such doubters.
Bottomline. Hands are innervated in a way that has huge significance to dedicated brain activity (can we call that activation?). Hand gestures and mudras communicate outwardly and inwardly. The brain and body has developed in a way to collect loads of data from the hands. Find a mudra that works for you.
Now, how about the lips and tongue on Homunculus man? Kiss someone today and let me know if its love or pseudoscience!