just three minutes?   (quote)

"In 1953 John Lilly, of the National Institute of Mental Health, discovered that by placing electrodes inside the brain of a monkey, he could stimulate pain, anger, fear—and pleasure. He placed one inside the brain of a male monkey and gave the monkey a switch that would trigger an immediate erection and orgasm. (The monkey hit the switch roughly every three minutes, thus confirming the gender stereotype.)"
 -Robert Bowden, The Dark Art of Interrogation