: It marked the film debut of actor William Hurt as Dr. Edward Jessup, a scientist who uses sensory deprivation tanks and hallucinogenic drugs to explore "original" human consciousness.
In psychology and neuroscience, a "feature" refers to the specific subjective or biological markers that define an altered state: Classification schemes of altered states of consciousness Altered States
: The film is known for its Oscar-nominated score by John Corigliano and groundbreaking visual effects by Bran Ferren, which used "slit-scan" and in-camera techniques to depict psychedelic hallucinations. : It marked the film debut of actor William Hurt as Dr