Brain Scan Smokescreen

Have you seen the pretty pictures of brain scans that supposedly prove that addiction is a brain disease?  Unfortunately, these brain scans are always presented as part of an incomplete argument, and they don’t prove that the addict’s “free will is hijacked by drugs”.  They merely show us what goes on in the brain of an active substance user.  This doesn’t matter to those who promote the brain disease model of addiction though, what matters to them is that the brain scans are persuasive.  Not being able to put together a sound argument, they opt for putting together a convincing/persuasive argument to accomplish their main goal of convincing us that addiction is a brain disease which robs the user of the power to choose to stop abusing substances.  They rely on our trust in modern science, our lack of experience in interpreting research data, and their authority as scientists to con us into believing a theory they haven’t been able to prove

When we hear and see these random facts and “evidence” we easily lose sight of the fact that there is no logical explanation tied to them. A recent study examined the effect of adding irrelevant mentions of neuroscience information to otherwise unsound explanations of psychological phenomena. In the study they showed good and bad explanations of psychological phenomena to 3 groups of people- neuroscience experts, psychology students (both before and after the completion of psychology classes), and lay-people who know nothing about psychology. They presented the descriptions both with and without additional, completely irrelevant neuroscience information, specifically they used the phrase “brain scans indicate” to present the irrelevant neuroscience facts. The results:

“Subjects in all three groups judged good explanations as more satisfying than bad ones.But subjects in the two nonexpert groups additionally judged that explanations with logically irrelevant neuroscience information were more satisfying than explanations without. The neuroscience information had a particularly striking effect on nonexperts’ judgments of bad explanations, masking otherwise salient problems in these explanations.”

Furthermore, the authors explain why this happens:

“Seductive details, related but logically irrelevant details presented as part of an argument, tend to make it more difficult for subjects to encode and later recall the main argument of a text. Subjects’ attention is diverted from important generalizations in the text toward these interesting but irrelevant details, such that they perform worse on a memory test and have a harder time extracting the most important points in the text.”

So the use of these brain scans and other neuroscientific “proof” of the disease of addiction are effective because us ordinary people are easily smokescreened with this stuff. We often hear phrases like “brain scans indicate..” and suspend our judgment from the rest of the shaky argument presented. But just because this happens and just because we’re not experts doesn’t mean we can’t stop to question their logic. If you really take the time to think about this brain disease theory of addiction you’ll see that it never adds up.  Beware of this tactic, don’t be fooled by colorful brain scans or pretty charts and graphs – examine the facts and see whether the conclusions logically follow.

For more on the brain disease theory, see Addiction is NOT A Brain Disease

Citation:

Deena Skolnick Weisberg, Frank C. Keil, Joshua Goodstein, Elizabeth Rawson, Jeremy R. Gray, The Seductive Allure of Neuroscience Explanations. Journal of Cognitive Neuroscience 20:3, pp. 470-477, 2008

5 comments

  1. Just read the Stanton Peele article about the lack of evidence for genetic inheritance, and it mentioned Nora Volkow, director of the National Institute on Drug Abuse talking about dopamine (which can be secreted in response to many different stimuli) & about brain scans of drug users showing the same areas that light up during the use of the drug lighting up when the person just *thinks* about the drug. To which I say, “So what?” It proves nothing. Brain imaging of paralyzed people who can’t even communicate show that when told to think about playing tennis, the same areas of the brain that light up while playing tennis will light up when the paralyzed person thinks about playing tennis. (I read this in Dick Teresi’s fantastic book “The Undead”)

  2. Thanks, Steven,

    Actually, this was a test that demonstrated that some people who were thought to be in persistent vegetative states were actually capable of awareness – aka, “locked-in,” rather than being in a state of unawareness.

    The whole idea that brain states change in response to drugs being an indication that “addiction” exists is ridiculous: 1. the whole reason people take recreational drugs is to influence their brain states (duh), 2. everything we do changes our brain states – even thinking about doing things changes the states of the brain (hence, paralyzed people show a change in brain state when told to think of playing tennis – I bet the brain state shown when told to think about tennis would be different from the scan shown when told to think about playing tennis.

  3. Recently watched the Nova episode about dreaming & learned another great tidbit about brain imaging – scientists who study sleep can’t tell what stage of sleep a subject is in by the brain scan. Even though there are brain scans that are typical of, or consistent with, dreaming, that doesn’t mean that if you wake the subject up while that pattern shows up on the brain scan, that the person will turn out to be dreaming. And vice versa – if the scan looks typical for not dreaming, you an wake the subject up & – quel surprise – they turn out to be having a dream.

    Except for showing where radioactive sugars are collecting in a person’s brain, brain scans seem to be a reliably unreliable measuring instrument.

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