A tiny man, especially the completed homunculus depicting the surface of the human body, with each part drawn in proportion to its representation in the somatosensory cortex (see illustration), or the somatosensory homunculus often used to depict the layout of the sensory projection areas of the somatosensory cortex. The term was formerly used to denote the minute but fully formed human form that was believed by the preformationists to be present in every spermatozoon or ovum. [From Latin homunculus a little man, diminutive of homo a man]
Homunculus. The distorted body parts indicate the relative sizes of their sensory projection areas in the somatosensory cortex; adapted from Penfield and Rasmussen's The Cerebral Cortex of Man (1950).