I know what
you’re thinking: what does it feel like for a human to have his or her medial
forebrain reward circuitry stimulated with an electrode? Does it produce a crazy pleasure that’s
better than food or sex or sleep or even “Seinfeld” reruns? We know the answer. However, the bad news is that it comes,
in part, from some deeply unethical experiments. Dr. Robert Galbraith Heath was the founder and
Chairman of the Department of Psychiatry and Neurology at Tulane University in
New Orleans, Louisiana. He served
from 1949 to 1980 and during that time, one major focus of his work involved stimulation of the brains
of institutionalized psychiatric patients, often African Americans, using
surgically implanted electrodes.
His main goal was laudable:
to use brain stimulation to relieve the symptoms of major psychiatric
disorders such as severe depression and schizophrenia. However, there was not proper informed
consent from the patients and in the experimental design, decisions could spin
way out of control.
Perhaps the most egregious example of this is reported in the paper entitled “Septal stimulation for the initiation of heterosexual behavior in a homosexual male” published in the Journal of Behavioral Therapy and Experimental Psychiatry in 1972. The idea behind this experiment was that stimulation of the septal area would evoke a pleasurable sensation and if this were combined with heterosexual imagery it could “bring about heterosexual behavior in a fixed, overt homosexual male.” And so, Patient B-19, a 24-year male homosexual of average intelligence who suffered from depression and obsessive-compulsive tendencies, was wheeled into the operating room. Electrodes were implanted at nine different sites in deep regions of his brain, and 3 months were allowed to pass after the surgery to allow for healing. Initially, stimulation was delivered to all nine electrodes in turn. However, only the electrode implanted in the septum produced pleasurable sensations. When he was finally allowed free access to the stimulator, he soon started mashing the button like a 9-year-old playing Donkey Kong.
“During these sessions, B-19 stimulated himself to a point that, both behaviorally and introspectively, he was experiencing an almost overwhelming euphoria and elation and had to be disconnected despite his vigorous protests.” (Moan and Heath, 1972)
So, not to put too fine a point on it, Heath’s patient responded just like Olds and Milner’s rats. If given the chance, he would stimulate his pleasure circuit to the exclusion of all else. Lest you think that it is only men (those creatures of base urges) who would respond in this way, there is another case, performed by a different group, in which a woman received an electrode implant in her thalamus (an adjacent deep brain structure) to control chronic pain. This is a technique that has been effective for many patients whose severe pain is not well-controlled by drugs. However, in this case, the stimulation spread to nearby brain structures, producing an intense sexual/pleasurable feeling.
“At its most frequent, the patient self-stimulated throughout the day, neglecting her personal hygiene and family commitments. A chronic ulceration developed at the tip of the finger used to adjust the amplitude dial and she frequently tampered with the device in an effort to increase the stimulation amplitude. At times she implored her family to limit her access to the stimulator, each time demanding its return after a short hiatus” (Portenoy et al., 1986)
Clearly, in both rats and humans, it’s
not just a guy thing—anyone would get hooked on this pleasure button.
Returning to patient B-19: before his
brain stimulation began, he was shown a “15 min long ‘stag’ film featuring
sexual intercourse and related activities between a male and female.” Not surprisingly, he was indifferent
and even a bit angry. Following
pleasure circuit self-stimulation, however, he readily agreed to re-view the
‘stag’ film “…and during its showing became sexually aroused, had an erection
and masturbated to orgasm.” So, with the patient starting to exhibit
heterosexual tendencies, what are the experimenters to do? Would he ever actually do the deed with
a woman? After careful
consideration of all the options, Drs. Moan and Heath made a sober medical
decision: they hired a hooker to come to the lab at Tulane and attempt to
seduce him. Really. I couldn’t make this stuff up if I
tried. So what happened? She succeeded—they had sexual
intercourse. The concluding
sentence to the lengthy, overly descriptive paragraph relating their two hour
long sexual encounter concludes “Then, despite the millieu and the encumbrance
of the electrode wires [poor B-19 was attached to an EEG machine the whole
time], he successfully ejaculated.”
Did
patient B-19 actually become heterosexual? Following discharge form the hospital, he had a sexual
relationship with a married woman for almost 10 months. His homosexual activity was reduced
during this period, but did not stop completely. Long-term follow-up information is not available. Writing in their Discussion section,
Moan and Heath seem excited about the prospects for this therapy: “Of central
interest in the case of B-19 was the effectiveness of pleasurable stimulation
of new and more adaptive sexual behavior.” This study is morally repugnant on
so many different levels, it’s hard to fathom—the arrogance of “correcting”
someone’s sexual orientation, the risk of unjustified brain surgery, the gross
violations of privacy and human dignity.
Fortunately, homosexual conversion therapy with brain surgery and
pleasure center stimulation never did catch on. What we are left with, from this and a handful of other
studies is the appreciation of the immense power of direct electrical
stimulation of the brain’s pleasure circuitry to influence behavior.