Using clay, build a skull in sections that can be opened from the top, revealing winding stairs leading to different rooms, each a separate part of the brain, containing weird figures, machinery and furniture.
Alternatively, build a skull from coils and, when leather-hard, apply pressure from flat boards to distort its shape; then light it from the interior for dramatic effect.
The human skull has been regularly used in art as a symbol of death, as in the distorted skull in "The Ambassadors" by Hans Holbein, or a photograph by Jodie Coston where the skull is juxtaposed with a pile of pills.
Use these works as stimulus for a graphic project designing a poster which contains a symbolic skull as part of the subject matter.
Alternatively, produce surrealistic paintings where ambiguous skulls merge with other imagery as in "Ballerina in the Head of Death" and "Skull of Zurbaran", both by Salvador Dali.