hunting pseudoscience in the internet jungle
Guest post on Skeptical Raptor by Matthew Facciani
There has been a news story creating some buzz lately regarding recent claims made by neuroscientist James Fallon, a Professor of Psychiatry at the University of California-Irvine School of Medicine. Dr. Fallon studied the brains of psychopaths for a few years and later saw that his brain was just like those of the psychopaths he studied. Many news outlets are picking up on this story as Dr. Fallon has just released a new book about it as well.
To summarize, Dr. Fallon had received a PET scan of his brain in conjunction with an Alzheimer’s disease study, and subsequently noticed that his PET scan image was eerily similar to PET scan images from those of the psychopaths he researched. These articles then reported how both the psychopaths and Dr. Fallon had less activity in the frontal and temporal lobes which he claimed are linked to empathy, self-control, and morality. Beyond the PET scan results, Dr. Fallon mentions how he his family has the “Warrior Gene” which is associated with aggressive behavior.
Additionally, he admitted to some history of violence in his family. Despite all of these observations, Dr. Fallon claimed that he has led a normal life without violence. He argued that despite having genes which can promote aggression, a psychopathic brain, and a history of family violence, he did not turn into a psychopath because he did not have a traumatic childhood which could trigger psychopathic tendencies. Of course, his book will probably be a best seller as it brings up interesting questions and discussions about free will and criminal behavior.
As a neuroscientist myself, I was curious about the particular details about the specifics of Dr. Fallon’s brain imaging research. I searched through several news articles, listened to his NPR interview, and watched a talk he gave on the subject and was always left puzzled over the lack of details. I searched for ANY details regarding the PET scans Dr. Fallon mentioned, but every article simply had a pretty brain picture with little information. I was curious as to how a single brain scan from an unrelated study could predict psychopathic behavior.
Why didn’t anyone mention the details or link to an article that did? Specifically, I was confused on why Dr. Fallon was comparing his brain scan from an Alzheimer’s study to an unrelated study about psychopaths. Did they do the same task in each study? PET scans measure real time brain activity, so these brain activations seen in the pretty pictures reflect activity from some task. Despite this empirical data being crucial to make any sort of scientific inference, no article mentioned what the individuals being scanned were actually doing during the PET scan. Dr. Fallon argues that his own brain activity in the regions of the frontal and temporal cortex is lacking, similar to psychopaths, but fails to mention anything more specific in these interviews.
Morality, like any other high level cognition, is terribly difficult to study in the brain and there are a significant number of scientific articles trying to tease apart morality’s functional neuroanatomy. Higher-level cognitive processes are often derived from a complicated network of neural activation which requires careful experimental design to tease apart. A crucial issue with Dr. Fallon’s story is that we can’t even critique such an experimental design because he wasn’t even doing any sort of morality study! So to say that less frontal and temporal activity equals less morality is a gross oversimplification to begin with and there isn’t even any details to support such a claim.
Furthermore, even if Dr. Fallon’s was identical to a group of psychopathic brains, it would only prove association, not causation. There could be many factors which create differences in neural activity and a third variable (exposure to violence for example) could be the cause. Finally, neuroimaging studies are often based on the results of group analysis. Rarely is a single brain scan discussed in the results. Thus, comparing a single brain scan from one study to an aggregate of brain scans from an entirely different study isn’t just wrong, it’s unethical.
This is a classic example of poor scientific journalism and I believe it became so popular due to widespread deficits in scientific literacy. You don’t have to be a neuroscientist to see that there are huge problems with his story. You simply have view this story objectively have a healthy dose of skepticism without quickly deferring to the authority figure. There are simple questions which are never addressed here. What experiment was being done during each PET scan? If the psychopaths and Dr. Fallon were both completing a morality task and they both had low activity in certain regions, THEN that would be something more tangible. This is simply showing a brain picture and not asking questions. We know that people are much more likely to believe something if there is a brain picture associated with it and this is further proof.
My intention is not to claim that Dr. Fallon is lying and purposefully simplifying science to make a profit. I would need much more evidence for that. However, I am arguing that the news articles covering his story do not provide enough details to support his claims. I find it rather troubling that no one is even addressing this so I wanted to blog about it. It is also troubling that Dr. Fallon has not been more explicit about the limitations of his findings as he should surely be aware of them as an accomplished neuroscientist. America often ranks pretty poorly in scientific literacy and this is an example of the result. People should at least have a working understanding of the scientific method and not blindly believe an authority figure with an interesting story.
Matthew Facciani is a 3rd year Ph.D. candidate focused on cognitive neuroscience at a major Southern US research university. If you have questions for Mr. Facciani and his critiques, please drop a comment.
Key citations:
- Bzdok D, Schilbach L, Vogeley K, Schneider K, Laird AR, Langner R, Eickhoff SB. Parsing the neural correlates of moral cognition: ALE meta-analysis on morality, theory of mind, and empathy. Brain Struct Funct. 2012 Oct;217(4):783-96. Epub 2012 Jan 24. PubMed PMID: 22270812; PubMed Central PMCID: PMC3445793.
- Crampton P, Parkin C. Warrior genes and risk-taking science. N Z Med J. 2007 Mar 2;120(1250):U2439. PubMed PMID: 17339895.
- Lea R, Chambers G. Monoamine oxidase, addiction, and the “warrior” gene hypothesis. N Z Med J. 2007 Mar 2;120(1250):U2441. PubMed PMID: 17339897.
- Illes J, Kirschen MP, Gabrieli JD. From neuroimaging to neuroethics. Nat Neurosci. 2003 Mar;6(3):205. PubMed PMID: 12601375.
- McCabe DP, Castel AD. Seeing is believing: the effect of brain images on judgments of scientific reasoning. Cognition. 2008 Apr;107(1):343-52. Epub 2007 Sep 4. PubMed PMID: 17803985.
