Frankenstein

Early on in James Whale’s classic film Frankenstein (1931), Dr. Henry Frankenstein and his hunchbacked assistant Fritz plan to steal a hanged man’s body. However, when the body falls to the ground, the neck breaks and makes the brain “useless.”

The new brain that Fritz steals from the laboratory of Henry’s former professor, Dr. Waldman, is in a jar labeled “abnormal.”

Waldman had explained that the “scarcity of convolutions on the frontal lobe” and the “distinct degeneration of the middle frontal lobe” corresponded exactly with its owner’s life “of brutality, violence, and murder.” Without noticing its anatomical flaws, Henry uses the brain for his creature and urges a bewildered Fritz to “think of it: the brain of a dead man, waiting to live again in a body I made with my own hands!”

Frankenstein highlights the ontological function of the brain. Unless the brain lives, the person doesn’t.
The film certainly illustrates how natural it was in the 1920s to think of a person’s inclinations as determined by the brain and to believe that a diagnosis could be established by observing cortical morphology with the naked eye.

Vidal, Fernando and Ortega, Francisco. Being Brains: Making the Cerebral Subject (Forms of Living)....

James Whale on IMDb