The non-existent brain image being circulated by anti-pornography activists
The public is enamored with images of brains. As a neuroscientist, they should not be. By the end of this article, you should be able to describe why this image may be evidence against the existence of pornography addiction.
This shows images that appear to be from single-photon emission computed tomography (SPECT). SPECT images often are generated by injecting the patient with a biological tag used to highlight a particular molecule of interest, but SPECT images also can be created without tracers. Online we often see this image used by anti-porn extremists as if to claim science supports their claims. For example, today December 15, 2021, this was posted:
Let’s get a better look at their evidence. This is the image from their tweet. There are many methods to image the brain. SPECT is a bit less common in psychological studies than fMRI or EEG, but SPECT is a well-known tool. The image appears to show the brains of three different people. One claims to be “your brain”, which presumably means a “healthy” brain. The other claims to be a brain “on heroin”. Now, direct administration of drugs in laboratories to humans is exceedingly rare, although it can be done. Presumably the label is actually intended to imply this is the brain of a person who has used heroin for some period in the past. The last brain is labelled “on porn”. We show pornography to test subjects all the time in the laboratory, so that one is more likely. However, SPECT does not capture time series well, it is more of a snapshot imaging technique. So, once again, I am assuming they meant that this person consumed pornography in the past. Interestingly, they are not labelled a “pornography addict” or similar, suggesting that merely viewing pornography will cause greater loss of brain matter than some amount of heroin use.
“Extraordinary claims require extraordinary evidence” — The Sagan Standard
There are no published studies of SPECT for pornography or pornography addiction. This created a real puzzle. Initially, I assumed these were pulled from an old case series of SPECT images claiming to be of sex addicts. Here is a sample image from that SPECT study by Daniel Amen:
These were not in color, so I thought perhaps someone got creative with MS Paint. On further inspection, however, I found the SPECT image of the purported “pornography addict” actually did not exist anywhere in this paper. Also, this case series has been widely criticized as all the claimed “behavioral” addicts also reported substance addictions.
So where did the image come from?
I found the original blog where I believe it first appeared, which has an accompanying YouTube video with a Dr. Lawrence Tucker. I was able to verify that Dr. Tucker is a licensed physician in California. The PLLC (Professional Limited Liability Company) refers to his business structure and is not a medical boarding or qualification. However, I was a little perplexed. This is Dr. Tucker pointing at a brain while describing the parietal lobe. The parietal is nowhere near where he is pointing. Let’s give him the benefit of the doubt. Maybe they asked him to point over and over and he was getting tired of it. It is very likely that Dr. Tucker knows where the parietal lobe is.
The Conquer Series appears to be selling a “quit porn” intervention. It describes itself as “The Conquer Series is a powerful cinematic study that is transforming the lives of men around the world. Now in two action packed volumes, each containing Biblical teaching and proven principles to help men conquer porn and walk in freedom.” As I was reading about the company, their helpful chat popped up offering to answer my question! Unfortunately, the live person on the chat was not aware of the provance of the image. Luckily, Dr. Tucker offers an email on his website. I have requested the source and will update this article if I receive a response from him.
Also, I have never seen a published SPECT image colored like that, seemingly reflecting no activity. What do SPECT images normally look like? Here is an example of a SPECT with tracer from a 2021 publication:
Here is a SPECT image without a tracer to show perfusion coloring. And yes, I grabbed one in a dog just to show how “blobby” these techniques tend to be:
In summary, this image has been widely circulated as evidence of pornography addiction. It appears to come from a for-profit corporation selling religious porn addiction treatments. It may be an unpublished (non- peer-reviewed) image from an unknown patient with no analysis applied and no tracers used.