From 1913 to 1951, Dr. Leo Stanley, chief surgeon at the San Quentin Prison, performed a wide variety of experiments on hundreds of prisoners at San Quentin. Many of the experiments involved testicular implants, where Stanley would take the testicles out of executed prisoners and surgically implant them into living prisoners. In other experiments, he attempted to implant the testicles of rams, goats, and boars into living prisoners.

When the needle entered the brain substance, she complained of acute pain in the neck. In order to develop more decided reactions, the strength of the current was increased ... her countenance exhibited great distress, and she began to cry. Very soon, the left hand was extended as if in the act of taking hold of some object in front of her; the arm presently was agitated with clonic spasm; her eyes became fixed, with pupils widely dilated; lips were blue, and she frothed at the mouth; her breathing became stertorous; she lost consciousness and was violently convulsed on the left side. The convulsion lasted five minutes, and was succeeded by a coma. She returned to consciousness in twenty minutes from the beginning of the attack, and complained of some weakness and vertigo.
—Dr. Bartholow's research report[4