Films such as "Total Recall" have popularized a thread of films that explore the concept of reprogramming the human mind. The theme of brainwashing in several films of the sixties and seventies including "A Clockwork Orange" and "The Manchurian Candidate" coincided with secret real-life government experimentation during Project MKULTRA. Voluntary erasure of memory is further explored as themes of the films "Paycheck" and "Eternal Sunshine of the Spotless Mind". Some films like "Limitless" explore the concept of mind enhancement. The anime series "Serial Experiments Lain" also explores the idea of reprogrammable reality and memory.