Expanding on Shinma's write-up about the idea of the homunculus inside the human brain now, I'd like you to touch your computer screen with your left index finger. Now, even if you aren't looking, you will know that you are touching the screen with your left index finger. This occurs because when you touch the screen an electrical impulse is sent down the length of your finger, down your hand and arm, up your spinal cord to your brain. This electrical impulse stimulates a certain part of your brain called the somatosensory cortex (also known as the primary sensory cortex). This is found immediately behind the primary motor cortex. The central sulcus, which is a deep groove running across the cerebrum, separates the two.
Now within the somatosensory cortex is apparently a representation of the human body called the homunculus or yes, the ubiquitous "little man". Neurons in this location can identify the area of the body being stimulated by the information they receive from the somatic receptors in the skin. So the impulse sent when you touched the screen gets sent to a particular part of the somatosensory cortex that represents the tip of the right index finger. As Shinma said, the density of the neurons on each particular body part determine how much of the somatosensory cortex the projection occupies, that is the neurons form a geometrically distorted projection of the body surface.
This concept was central in the search for the explanation of the phantom limb phenomenon.
The symbol of the homunculus also means many things in many different cultures. To the Cabbalists, he is the “little man” because he reflects the “great man” of the macrocosmos. There are various forms of homunculi. Some, as described in W. B. Yeats’ poem the dolls, are dolls serving as vessels harbouring a spirit or entity by means of blood and/or spermae. Other mystics, such as the Chelas of Hindu magick, summon earthbound spirits to infest the body of a corpse also by means of vitae sustenance. More mythically, the ancient alchemists apparently had a secret of secrets, called an arcanum arcanorum which was a recipe for the little man called the homunculus, supposedly perfected by Paracelsus.
Paracelsus states that spagyric substances, namely a man’s semen and blood, as well as a woman's menstrual blood (although it cannot be just any woman's blood, as other people's blood is hard to control), must be put into a hermetically sealed retort or alembic, buried in horse manure for forty days, and magnetised.
During this time, it begins to live and move, and at the end of the forty days it resembles a human form, but is transparent and without a body. It must now be fed daily with the arcanum (or hidden mystery) of human blood (or arcanum sanguinis hominis), and be maintained at the constant temperature of a mare’s womb, for a period of forty weeks, and it will grow into a human child, with all its limbs developed, as normal as any child born of a woman, except that it will be much smaller. It may be raised and educated like any other child, until he grows older and obtains reason and intellect, and is able to take care of himself.
-The spermae and/or blood involved are regarded as carriers of the pneumamaterial prima, or elemental matter of which (in alchemical theory) all substances were ultimately composed.
To raise such life-forms it is believed that one must fully understand the Power of Self and the Powers which surround. When one has attained such levels, they may use any form of ceremony to bring life into inanimate objects. But this is temporary, as the life-force becomes deprived of its energy (which is either arcanum sanguinis hominis or spermae), then it begins to wither and requires sustenance.
Legend has it that many homunculi have difficulty with movement. This is probably due to the mechanical make-up of the figure. Some simply sit there and hold conversation with slight, robotic gestures.
Modern television has preserved the literature and folklore of previous homunculi archetypes. There is the classic Pinocchio; Marry Shelley’s Frankenstein (1818); The Ginger Bread Man; Puppet Master; Chucky from Child's Play; and the teenage soap opera Passions which features Timmy, the living doll of a witch.
This type of magick has apparently paved the way for today’s science, which has perfected developing the test-tube baby as well as potential cloning projects.
Much of this information was discovered at geocities.com/sekhemu/demonpuppet.html