Neuroscientists have a difficult time figuring out which parts of the brain are involved in different functions.  Naturally-occurring lesions to the brain are rarely specific to a particular anatomical region, the complications involved with the injury and treatment act as a smokescreen, and finding a patient who's damaged the particular spot you want to learn about is frustrating at best and nigh-impossible at worst.

Fortunately for researchers, inappropriate surgical interventions of the past can shed light on neurological questions.

The strange and horrifying history of psychosurgery is a topic beyond the scope of this site, and certainly beyond this post.  Interested readers can easily find a great wealth of relevant discussion on the Net and in libraries, even (in more extensive collections) works written by the physicians involved in such surgeries during the era in which they were popular.  Even a casually-curious individual can find lots of non-technical analysis and history to read - for such people, I particularly recommend Great and Desperate Cures by Elliot Valenstein.

Of especial relevance is the prefrontal leukotomy, more commonly (if somewhat imprecisely) known as the lobotomy.  There are several features in particular that are of interest to people interested in the nature of effective thought:

To begin, people with frontal lobe damage have problems with impulse control.  And by 'problems', I mean they're pretty much incapable of it.  It would be more precise to say that lobotomized patients display a remarkable degree of rigid, stereotyped behavior patterns.  Give one patient a broom, and she'll begin to sweep the floor; show another a room with a bed, and he'll lie down on it.  And do the same thing every time the stimulus is presented.  The precise response varies from person to person, but the general reaction is consistent and replicable.  Whatever the strongest association with the stimuli is in their mind, that's what they do when they encounter it - and every time they encounter it.

For this reason, it was at one time suggested that only patients with a reputation for rigorously moral behavior be lobotomized, because people who would characteristically break social mores would do so ostentatiously after the surgery.  Shoplifters and petty thieves who might have tried to steal particular kinds of things before they were lobotomized would immediately try to do so when they came across those things again - regardless of whether it was a good opportunity or even whether others were clearly watching.  Restraining such behavior, or even limiting it, was simply impossible.

Furthermore, such people don't get bored.  Present them with a simple task, and they'll carry it out... and keep doing so, even if the consequences become absurd.  Set them to building a picket fence and forget to check up on them, and they'll build it past your property line and down the street if given enough time.  Set them to washing dishes, and they'll keep washing - to the point of redoing the job several times over.  The ability to interrupt the sequence of behavior, to put a "Stop" order in the chain of macros built up, no longer existed once the connections between the frontal lobes and the rest of the brain had been severed.

Motivation becomes almost non-existent.  Left to themselves, lobotomized people often do not initiate action, or they do not begin to act in ways other than patterns they incorporated before.  They repeat things they did before, but mindlessly and without variation, and cannot adapt if the pattern is disrupted.  More alarmingly, the associations between concepts and basic responses are destroyed, to the point where sensations like pain are noted but not perceived as important, and actions to diminish or avoid the pain are not taken.  One well-known case ended when, after having been released to her home, a woman was scalded to death because she didn't leave a bath of too-hot water she'd drawn.

Learning in any abstract sense ceases.  Teaching the lobotomized new responses is virtually impossible.  And even basic conditioning, such as that is used with dogs to train them, becomes problematic due to lack of avoidance of pain and seeking of pleasure.

These points are only part of a general overview - the details are far, far worse.

There's one point which I have yet to discuss, and yet in the context of the information above, is the most shocking.  Lobotomization did not disrupt the IQ of patients to any degree.  This was actually one of the excuses made for why doctors didn't realize the utterly destructive effects of the surgery earlier.  If it didn't impair IQ, surely it couldn't be grossly harmful, it was claimed.  Well, it was.

This sets the stage for an important question:  If the lobotomy so profoundly levels the house of the mind, why don't IQ tests measure any of the mental aspects destroyed in the process?

That is a subject for the next posts.


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This post contains lots of info that I don't fully trust to be true, but I'm not interested enough to go hunt for references. Could you give some yourself?

I've done the googling that Annoyance considers so vital to our moral development. Here are the results, for those who wish to remain slothful and debased. For the truly pious, youtube has a video of the so-called icepick psychosurgery from a PBS documentary.

  1. Googling "effect of lobotomy on IQ" returns a Google Books excerpt from a Neuroscience textbook. The author is professor of Neuroscience at MIT. The text claims that "...lobotomy can be performed with little decrease in IQ..." It also says that in the most popular lobotomy technique, it was impossible for the doctor to see what sections of the frontal lobe he was "treating."

  2. An online psychology textbook here describes the behavior of lobotomy patients as "stimulus-bound," and reports that they were easily distracted by their immediate surroundings and had little ability to plan or set goals.

  3. This site and this book (see p. 20) have more information on the general effects of damage to the frontal lobe.

I googled for reference about the lack of iq reduction and it's not as easy as Annoyance claims.

I found:

In the case of Rosemary Kennedy the lobotomy lead to mental retardation although I don't know if IQ was specifically measured:

In other places I read that although the IQ is maintained the victim loses the capability for abstract reasoning.

Rosemary Kennedy was considered mentally retarded before the operation.

That is, her intellectual prowess (or lack thereof) was a pre-existing condition.

(edited for clarification)

I just read the wikipedia article more carefully. Her mental retardation before the procedure is highly disputed.


She was not mentally retarded. … It could be she had an IQ of 90 in a family where everyone was 130, so it looked like retardation, but she did not fall into IQ 75 and below, which is the definition of mental retardation. … There is no way I can picture her at less than a 90 IQ, but in that family, 90 would be considered retarded."

This reminds me of this post about the difference between emotionlessness and rationality. The lobotomy patients, assuming that you describe them accurately, suffer a failure of motivation and initiative and generative thought; that doesn't necessarily mean they can't solve IQ test problems that are presented to them. That is, after all, what one does with IQ test problems, in much the same way that washing is what one does with dishes and lying down is what one does with beds.

Your point is well-made. However, you miss the deep issue - why is it that IQ test problems don't require the vastly important functions and capabilities that lobotomized patients lack?

The answer to that question, I believe, reveals the difference between being bright - which IQ is an approximate measure of - and being intelligent - which IQ doesn't indicate.

Can you elaborate on your working definitions of "bright" and "intelligent"? They don't seem to map onto mine.

Yeah. I'd prefer to do so in a post rather than a comment, though. I should have something ready in a few days.

Interesting stuff. The fact that lobotomy was often used to treat schizophrenia - a catastrophic failure of rationality - is suggestive.

I vaguely remember a neuroscience lecturer of mine saying that a possible factor in the bizarre nature of dreams was that frontal regions were inhibited during sleep, so the dreamer has no way of telling the difference between plausible and implausible scenarios among those they are perceiving. I can't find any references to substantiate this though. Maybe I dreamt it.

The fact that lobotomy was often used to treat schizophrenia - a catastrophic failure of rationality - is suggestive.

Unfortunately, it was used to 'treat' so many things that the suggestiveness is lost in the noise.

Really, it was actually used (regardless of the excuses people made at the time) because it rendered difficult patients so tractable and easy to handle in an institutional setting. Pretty much the same reason all the old antipsychotics were used, too.

If the lobotomy so profoundly levels the house of the mind, why don't IQ tests measure any of the mental aspects destroyed in the process?

The obvious reason, I guess, is, as you said yourself, their motivation is lost. You can possess vast intelligence and still do nothing if doing nothing has the same utility as doing anything else. Present the person with an object, and the first impulse or association sort of hijacks the utility function. That's a pretty simplistic explanation, of course.

Yes, it is. And I'm pretty sure there's more to it than that.

But that's a topic for another post.

The author of "My lobotomy" seems to be highly functional.

He appears to be an extreme(ly lucky) case in the distribution of outcomes.


Apparently, Annoyance knew what he's doing when he chose his nickname.

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