Dr. Frederick attempts to find a way to ease the aggressive nature of soldiers by developing a microchip to access the pleasure centers of their brains. The film was also known as The Mind Snatchers. It is based on Dennis J. Reardon’s acclaimed play The Happiness Cage, which opened at Joseph Papp Public Theater’s Newman Theater in New York on October 4, 1970.

References:
https://en.wikipedia.org/wiki/The_Happiness_Cage