I'm going to the ice down some of the claims here, with the caveat that I can only read the abstract and access the open data of the study.
Foremost, this is a behavioral fMRI study with n = 20, which inherently merits some skepticism until it's replicated with a larger sample.
Second, belief-dependent activation was only seen in the thalamus. The area of the brain most directly implicated in addiction (striatum) did not show a change in response, which is what I'd wager the authors were expecting/hoping for instead. Given that only the thalamus (a very busy chunk of tissue) showed a difference, there's no way to know whether this reflects some kind of auto-simulation of nicotine consumption, or another process. The same applies to the thalamic-vmpfc connection.
Third, no comparison is made to the effects of actually vaping low, medium, and high amounts of nicotine. A difference is observed between the groups, but it could be a trivial one by comparison to the actual effects of variable levels of nicotine, or have a different function over dose.
Fourth, the activation was dependent on receiving nicotine to begin with.
It's therefore not accurate to say that "the brains of chronic smokers can be conditioned to the level that they can autonomously activate the neural circuits causing a physiological response in proportion to the dosage of nicotine that a person merely imagines." Activation was neither autonomous nor (as far as we know) in proportion to the dosage the person believed they received, nor are we sure these are the relevant neural circuits. Whether you want to call a change in thalamic activity 'physiological' might be a thing to quibble over, but most readers would think you meant something like heart rate, not how much blood is flowing to a specific spot in the brain. And even if that thalamic activation perfectly matched expected nicotine response, it's one small piece of what happens when nicotine is used. When your conditions are "low, medium, and high" all you can really see is if the effects are in the expected direction, and as mentioned, there is no comparison group which did receive variable levels of nicotine. As subjects in this study did not generate changes in activation patterns in the most addiction-relevant brain structures, and had to consume nicotine to generate the effect, I don't see the "major implications for addiction treatment" myself.
I do not see at all how the findings suggest "that it is not only possible to easily implant beliefs in a conditioned human brain, but one can fine-tune the beliefs to precisely produce the desired behavioural outcomes". There's no such thing as a 'conditioned human brain'--subjects here were addicted to nicotine, and the findings, such as they are, are limited to this population. In the sense that you mean, every brain is 'conditioned' by all kinds of things in the environment. There is no suggestion in this study that one can "precisely produce the desired behavioral outcomes" by "implant[ing] beliefs". We're talking about small changes in performance on tasks people voluntarily signed up to do. And the only sense in which beliefs were "implanted" is that people were told things and (probably) believed them. There is an ocean of literature in the vein of "changing task performance by lying to the participants," and I'm sure that loads of those studies, if conducted in fMRI, would turn up associated activation differences.
"Changing one’s beliefs (e.g. using cognitive behavioural therapy) would often mean completely rewiring one’s brain at the molecular level which is, as you can guess, not a trivial task." This, I'm sorry to say, is either far afield or vacuous. Of course changing your beliefs involves changing your brain--it would be shocking if it were otherwise. People who haven't integrated that all thoughts and behaviors ultimately flow from the brain will be surprised again and again when "neural correlate of x" is discovered (not what happened in this study). But as far as "completely rewiring one's brain at the molecular level," I have no idea what that would mean. No brains were 'rewired' in this study; regions were activated more or less at different timepoints. And there's a sense in which everything in the brain is happening at the molecular level (though we don't always operate at that level of analysis). But if you meant something like "changing beliefs can involve changing the strength of connections between different regions of the brain," that has both meaning and evidential support. If you're interested, there are some studies that look at the effects of CBT specifically, as seen in the fMRI scanner:
Thank you! I hope the tone wasn't too harsh. I'm no expert myself, especially not in imaging, but I was studying to be cognitive scientist once upon a time. Keep the GWAS stories coming!
You are spot-on. Lots of caveats to this study. In general, I think biologists who are familiar with a strong inference paradigm in highly experimental areas of biology often mistakenly transfer their faith to fMRI which can be problematic.
It is still very exciting! Thanks for sharing it. And yes, the sample size is small and the statements from the paper might seem bold, but we all started somewhere. I hope this study will pave a way to larger studies of this kind. Can’t wait to see their results!
I'm going to the ice down some of the claims here, with the caveat that I can only read the abstract and access the open data of the study.
Foremost, this is a behavioral fMRI study with n = 20, which inherently merits some skepticism until it's replicated with a larger sample.
Second, belief-dependent activation was only seen in the thalamus. The area of the brain most directly implicated in addiction (striatum) did not show a change in response, which is what I'd wager the authors were expecting/hoping for instead. Given that only the thalamus (a very busy chunk of tissue) showed a difference, there's no way to know whether this reflects some kind of auto-simulation of nicotine consumption, or another process. The same applies to the thalamic-vmpfc connection.
Third, no comparison is made to the effects of actually vaping low, medium, and high amounts of nicotine. A difference is observed between the groups, but it could be a trivial one by comparison to the actual effects of variable levels of nicotine, or have a different function over dose.
Fourth, the activation was dependent on receiving nicotine to begin with.
It's therefore not accurate to say that "the brains of chronic smokers can be conditioned to the level that they can autonomously activate the neural circuits causing a physiological response in proportion to the dosage of nicotine that a person merely imagines." Activation was neither autonomous nor (as far as we know) in proportion to the dosage the person believed they received, nor are we sure these are the relevant neural circuits. Whether you want to call a change in thalamic activity 'physiological' might be a thing to quibble over, but most readers would think you meant something like heart rate, not how much blood is flowing to a specific spot in the brain. And even if that thalamic activation perfectly matched expected nicotine response, it's one small piece of what happens when nicotine is used. When your conditions are "low, medium, and high" all you can really see is if the effects are in the expected direction, and as mentioned, there is no comparison group which did receive variable levels of nicotine. As subjects in this study did not generate changes in activation patterns in the most addiction-relevant brain structures, and had to consume nicotine to generate the effect, I don't see the "major implications for addiction treatment" myself.
I do not see at all how the findings suggest "that it is not only possible to easily implant beliefs in a conditioned human brain, but one can fine-tune the beliefs to precisely produce the desired behavioural outcomes". There's no such thing as a 'conditioned human brain'--subjects here were addicted to nicotine, and the findings, such as they are, are limited to this population. In the sense that you mean, every brain is 'conditioned' by all kinds of things in the environment. There is no suggestion in this study that one can "precisely produce the desired behavioral outcomes" by "implant[ing] beliefs". We're talking about small changes in performance on tasks people voluntarily signed up to do. And the only sense in which beliefs were "implanted" is that people were told things and (probably) believed them. There is an ocean of literature in the vein of "changing task performance by lying to the participants," and I'm sure that loads of those studies, if conducted in fMRI, would turn up associated activation differences.
"Changing one’s beliefs (e.g. using cognitive behavioural therapy) would often mean completely rewiring one’s brain at the molecular level which is, as you can guess, not a trivial task." This, I'm sorry to say, is either far afield or vacuous. Of course changing your beliefs involves changing your brain--it would be shocking if it were otherwise. People who haven't integrated that all thoughts and behaviors ultimately flow from the brain will be surprised again and again when "neural correlate of x" is discovered (not what happened in this study). But as far as "completely rewiring one's brain at the molecular level," I have no idea what that would mean. No brains were 'rewired' in this study; regions were activated more or less at different timepoints. And there's a sense in which everything in the brain is happening at the molecular level (though we don't always operate at that level of analysis). But if you meant something like "changing beliefs can involve changing the strength of connections between different regions of the brain," that has both meaning and evidential support. If you're interested, there are some studies that look at the effects of CBT specifically, as seen in the fMRI scanner:
https://doi.org/10.1016/j.biopsych.2012.07.026
https://doi.org/10.1093/scan/nst009
https://doi.org/10.1176/appi.ajp.2013.12111484
Thank you for your detailed criticism. Very useful (I am not an imaging neuroscientist, so this is outside my area of expertise).
Thank you! I hope the tone wasn't too harsh. I'm no expert myself, especially not in imaging, but I was studying to be cognitive scientist once upon a time. Keep the GWAS stories coming!
You are spot-on. Lots of caveats to this study. In general, I think biologists who are familiar with a strong inference paradigm in highly experimental areas of biology often mistakenly transfer their faith to fMRI which can be problematic.
It is still very exciting! Thanks for sharing it. And yes, the sample size is small and the statements from the paper might seem bold, but we all started somewhere. I hope this study will pave a way to larger studies of this kind. Can’t wait to see their results!
❤️