the little man from Wikimedia Commons
Posted in Journeys to the brain Resources

“Two little humans”: Journeys to the brain-3

The little man from Wikimedia Commons 

This journey will meet “Two little humans” who “live” on the brain surface. Dr. Wilder Penfield and Edwin Boldrey “discovered” them in 1937.

That is an amazing story.

They began their expedition while working at McGill University. Dr. Wilder Penfield served there as a brain surgeon. During that time, while operating under local anesthesia, they mapped corresponding brain regions where the sensory information are received from different body parts. They also succeeded in demonstrating the corresponding brain regions which send signals to move relevant body parts.

Together with Edwin Boldrey, he published their story in the “Brain” journal writing a 50-page long article with drawings.

Figure 1: Dr. Penfield and Boldrey and their little men Courtesy: https://academic.oup.com/brain/article/140/11/3055/4566636

“Two little humans” (Figure 1) – now famously called “Homunculus of the brain” – lie along the Central sulcus which separates the Frontal lobe from the Parietal and Temporal lobes.

Homunculus in the brain

Figures 2 and 3 depict the two little humans who lie along the Central sulcus – a groove that separates the Frontal lobe from the Parietal lobe (You can read this on the Journeys to the brain -2: A walk over the brain surface).

As you can see in Figure 4 (below), the upper inside surface area controls our foot and legs. Let us start from Figure 2. When we begin to climb, we will step on the areas that receive information from and send commands to the facial structures. Further up, we will find areas that receive information and send commands to arms, body, legs, and feet. It follows a highly organized distinct pattern. And, the more complex the job is, the larger the designated area.

This information is very useful for carers because most of the time, these are the body parts affected due to stroke You can read about the brain’s blood supply by joining me on another journey.