Your Brain, Region by Region

Your brain, region by region

Turn the brain with a finger or the mouse and tap any part to see what it does. Each color is one region, and each one got its job description from an experiment or an injury.

Plate A schematic model of the adult human brain, seen from the front left: the four lobes of the cerebral cortex in color, the cerebellum beneath them and the brainstem below. Drag it to turn it, tap a region to name it, and use View from to look from above, from below, or at the midline cut that shows the corpus callosum. The folds are drawn to look like gyri and sulci but are not copied from a real brain; the lobe boundaries follow the textbook landmarks.

Begin: the lobes and what they do →

Seen whole, an adult human brain looks like one wrinkled lump. It is not one thing. Its surface divides into four lobes on each side, each with a recognizable job; tucked under the back of it is the cerebellum, which holds most of the brain's nerve cells; and running down from its center is the brainstem, which keeps you breathing.

Almost every one of those job descriptions was written by an experiment or an injury: a surgeon's electrode that made a thumb twitch, a cell in a cat's visual cortex that fired only for a tilted line, a patient who could not name a word his own left hand could find, a railroad foreman who lived for nearly twelve years after an iron bar went through his head. The chapters below put you at those experiments, on the same 3D model you can turn above.

How this is made and checked

The 3D brain is a schematic model built on this site in code: no scan, no purchased model. Its proportions follow textbook figures, its lobe borders follow the standard anatomical landmarks, and its folds are illustrative. Every experiment you can rerun here follows the published record, and every place a figure simplifies is named next to it. Each factual claim is listed with its source and checked by a reviewer who did not write it. More about the model and the sources.