What significant concept did Penfield discover during his experiments?

Penfield's significant discovery during his experiments was the cortical homunculus, which is a representation of the body's sensory and motor systems within the brain, specifically within the primary motor cortex and the somatosensory cortex. Through electrical stimulation of various regions of the brain during neurosurgery, he was able to map out which parts of the cortex corresponded to sensations and motor control in specific body parts. This mapping illustrated that different areas of the cortex activate specific body areas, leading to a distorted representation that resembles a small figure, or homunculus, emphasizing the portions of the body that have finer motor control or greater sensory sensitivity.

Understanding the cortical homunculus has profound implications in neuroscience and psychology, as it highlights how the brain encodes sensory and motor functions. This concept helps inform how brain injuries can affect bodily functions and is foundational in neurology and rehabilitation practices.