About this site
Your Brain, Region by Region is a free interactive atlas of the human brain, built around the experiments and injuries that mapped it. It is part of a public library of interactive explanations, has no ads and needs no sign-up.
The 3D brain§
The brain you can turn on every page is an original schematic model, built on this site in code. No third-party mesh, scan or purchased model is used. Each structure (the two hemispheres, the cerebellum, the brainstem, the corpus callosum and the thalami) is the surface of a smooth mathematical shape, sized after textbook figures of an adult brain. The lobe borders and the functional areas are placed by rules that follow the standard landmarks; the gyri and sulci are drawn from deterministic noise so that they look like folds, and are not copied from any real brain. The model is rendered in your browser by a small software renderer written for this site, so it works on any device without special graphics support. Because it is a schematic, it is labeled as one wherever it appears.
The skull and the iron in the Phineas Gage chapter are drawn the same way: the iron's dimensions come from Harlow's 1848 and 1868 reports and from Van Horn and colleagues (2012), and the paths are schematic illustrations of what the published reconstructions concluded, not their coordinates.
How the science is checked§
Every computational model behind a figure is tested twice: by its author against worked examples and published values, and by an independent test suite written from the published sources without reading the model's code. Every factual claim is recorded in a claims register with its source and checked by a reviewer who did not write it. What each figure simplifies is stated next to the figure. Anatomy comes from open textbooks (OpenStax Anatomy and Physiology 2e and Psychology 2e) and the Queensland Brain Institute; experiments and the Gage case come from the original papers. The full list is on the sources page.
Not medical advice§
This site teaches normal anatomy, history and classic experiments. It is not medical advice and should not be used to diagnose or treat anyone. If you are worried about a head injury, a seizure, or a change in movement, speech, memory or personality, see a doctor.
Found an error?§
Please open an issue on the source repository. Corrections are welcome and are credited.
Reuse§
Text and figures are licensed CC BY 4.0; code is MIT. Teachers may use and adapt any of it, with attribution.