Homunculus - Modern Science

Modern Science

The homunculus is commonly used today in scientific disciplines, such as psychology, as a teaching or memory tool to describe the distorted scale model of a human drawn or sculpted to reflect the relative space human body parts occupy on the somatosensory cortex (sensory homunculus) and the motor cortex (motor homunculus). Both the motor and sensory homonculus usually appear as a small man superimposed over the top of the precentral or postcentral gyrus, for motor and sensory, respectively. The homunculus is oriented with feet medial and shoulders lateral on top of both the precentral and the postcentral gyrus (for both motor and sensory). The man's head is depicted upside down in relation to the rest of the body such that the forehead is closest to the shoulders. The lips, hands, feet and sex organs have more sensory neurons than other parts of the body, so the homunculus has correspondingly large lips, hands, feet, and genitals. The motor homunculus is very similar to the sensory homunculus, but differs in several ways. Specifically, the motor homunculus has a portion for the tongue most lateral while the sensory homunculus has an area for genitalia most medial and an area for visceral organs most lateral. Well known in the field of neurology, this is also commonly called "the little man inside the brain." This scientific model is known as the cortical homunculus.

In medical science, the term homunculus is sometimes applied to certain fetus-like ovarian cystic teratomae. These will sometimes contain hair, sebaceous material and in some cases cartilagous or bony structures.