Rafferty was admitted to Good Samaritan Hospital in Cincinnati, Ohio in 1874 with a 2-inch-diameter (51 mm) hole in her skull caused by a cancerous ulcer.

His report detailed the first observations of how electrical stimulation of the brain affects motor functions of the body, but many ethical concerns were raised about the way in which he carried out his experiments.

In his view, performing experiments on live animals helps uncover basic biological mechanisms, which provides insight into what treatments are effective.

Although his findings are considered by many to be the basis of neurology research, Bartholow faced much criticism for using Mary Rafferty as a test subject and invading the “sacred organ”.

[2] Prior to the experiments on Marta "Mary" Rafferty, Bartholow studied the effects of electrotherapy, and used electricity in his practice at Good Samaritan Hospital for polyps, tumors, aneurysms and peripheral paralyses.

These treatments used either faradic (alternating) and galvanic (direct) current, and Bartholow's main goal was to test the effects of each when applied to the human cortex.

Bartholow recorded the patient's blood pressure, arterial tension, and body temperature during the experiments to determine how safe the procedure was, and possibly study function specialization and locate cerebral embolisms.

[2] Using a pair of electrolytic needles inserted into the dura and underlying tissues, Bartholow applied a small electric current to different sections of Rafferty's exposed brain and noticed that this caused movements in corresponding parts of her body.

In order to develop more decided reactions, the strength of the current was increased ... her countenance exhibited great distress, and she began to cry.

She returned to consciousness in twenty minutes from the beginning of the attack, and complained of some weakness and vertigo.Bartholow published his findings in his paper "Experimental Investigations into the Functions of the Human Brain" in April 1874.

[4] The paper was favorably reviewed by Ferrier, who found Bartholow's observations "quite in accordance" with the results of his own experiments when applying current to the brains of monkeys.

He was also heavily criticized for carrying out the experiments with no intention of healing the patient, and for proceeding without administering anesthesia until after Rafferty experienced several seizures and was nearly unconscious.

In the aftermath of the controversy, the American Medical Association banned any human experimentation that disregards saving the life of the patient.

[4] The anti-vivisectionist movement in Great Britain cited Bartholow's unethical treatment to successfully lobby bills restricting experiments on animals.