In a chimeric Ted-Ed lesson written by educator Elizabeth Cox and animated by Nerdo, narrator Susan Zimmerman explains what causes hallucinations, what happens when hallucinations occur, the medical and pharmacological effects upon the brain that cause hallucinations and the specific syndrome that causes those who are blind to see hallucinations and those who are deaf to hear them.
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 experience
