Elizabeth Cox: What causes hallucinations?

What causes hallucinations?

A condition called Charles Bonnet Syndrome can cause blind patients to hallucinate scenes in vivid color. fMRI studies show that these hallucinations activate the same brain areas as sight — areas that are not activated by imagination. Other hallucinations also involve the same brain areas as real sensory experiences. What's going on? Elizabeth Cox details the science of hallucinations. [TED-Ed Animation by Nerdo]. 

Hallucinations are not just signs of illness or drug use, but windows into how the brain constructs reality. A blind woman vividly saw circus scenes through Charles Bonnet Syndrome, a condition where the brain fills in missing visual input with colorful, detailed hallucinations. Brain scans show these visions activate the same regions as real sensory experiences. Studying hallucinations helps illuminate the hidden, creative processes the brain uses to interpret the world.