SEALs are indeed pretty elite. This being a British blog, I wouldn't want to say that they're the world's elitest naval special forces unit. That's the British Special Boat Service. But they could still kill you ten times before you knew they were there (unless you're in the Special Boat Service.)Anyway, San Diego researchers Paulus et al scanned 11 SEALs and 23 healthy civilian men during an emotional face matching (originally developed by Hariri et al) that involved seeing happy, angry, and fearful faces.
Such tasks are very popular in neuroimaging at the moment because looking at faces of people expressing strong emotions reliably activates emotion-related brain areas, without needing to actually induce emotions in your volunteers which can cause practical problems, i.e. people getting scared and maybe panicking in the MRI scanner. Whether studying emotional-face-induced activation is a valid substitute for studying emotion-induced activation is an open question.
What happened? fMRI being a sensitive way of measuring human brain activation, they found some differences between the two groups in neural responses to seeing the faces:
elite warfighters relative to comparison subjects showed relatively greater right-sided insula, but attenuated left-sided insula, activation. Second, these individuals showed selectively greater activation to angry target faces relative to fearful or happy target faces bilaterally in the insula.
These findings support the notion that elite warfighters... deploy greater neural processing resources toward potential threat-related facial expressions and reduced processing resources to non-threat-related facial expressions. This finding suggests that rather than expending more effort in general, elite warfighters show more focused neural and performance tuning, such that greater neural processing resources are directed toward threat stimuli and processing resources are conserved when facing a nonthreat stimulus situation.
But the unsurprisingness of this result is a problem. We don't need neuroscience to tell us that elite soldiers are good at detecting and responding to threats. That's rather obvious. I'd guess that most of them were pretty good at it before they got selected, and then they got even better with training. This must have something to do with the brain, because your brain is what allows you to learn stuff.
What we don't understand very well yet is how training (or other forms of learning) works, on a neural level, i.e. what the molecular and cellular mechanisms are. It would be really nice to find out. Unfortunately, fMRI studies like this are unable to tell us that, because they only study the very last stage in the process, the final product.
This is in no way a problem with this paper alone, and it's no worse than many other articles. The same issue applies to many neuroimaging studies of abnormal states like depression or, as I've posted about previously, psychological trauma. Such results can form the basis for investigations into mechanisms, and as ways of testing theories, but on their own, finding that abnormal brains react in abnormal ways is not, in itself, very useful.
Paulus, M., Simmons, A., Fitzpatrick, S., Potterat, E., Van Orden, K., Bauman, J., & Swain, J. (2010). Differential Brain Activation to Angry Faces by Elite Warfighters: Neural Processing Evidence for Enhanced Threat Detection PLoS ONE, 5 (4) DOI: 10.1371/journal.pone.0010096
16 comments:
Ping!
http://neurodojo.blogspot.com/2010/04/lemme-see-your-war-face.html
What brain areas are activated in elite killer chauvinism?
"Whether studying emotional-face-induced activation is a valid substitute for studying emotion-induced activation is an open question." Not if you want a few more publications on your CV it isn't.
I hear you, dearime... this is a Ho-Hum finding at best.
It seems to me that it's only when we decide current technologies have pretty much shown us all there is to see, that's when the new technologies get developed. I'm really interested in what the fMRI is showing us, especially as a tool looking into mental illnesses, but I can't wait for the next tech leap.
BTW: JTF2 would totally kill you twenty times before you woke up. Just saying.
http://www.cbc.ca/news/background/cdnmilitary/jtf2.html
@ saltedlithium
I thought you were talking about Jason Bourne.
Well Britain actually has an even eliter force, so elite that anyone who knows what they're called, or how many times they can kill you before you hit the ground, is killed. Actually I'm not even sure I should be mentioning them... aagh
I disagree with the conclusion of your post. As someone researching neuroplasticity with fMRI, I think these kinds of studies are an important first step towards understanding the types of learning mechanisms you complain about us not understanding. A great deal of ongoing research has begun to unravel the neurobiological foundations of neural adaptation, yet these cannot provide us with much insight into how large scale dynamical networks integrate or decouple in response to precise learning tasks.
The fighter pilot study is interesting precisely because it provides a unique starting point to ask about specific types of perceptual expertise. I do agree that the study could have been betrer, with a Maguire et al style control group, lets say a group of commercial pilots rather than fighter.
But it is worth nothing that such a study would probably benefit immensely from the one you rag on here. If I am going to invest the time and effort into investigating two groups of pilots, I want to first be sure that there is some discernible difference in the first place. You hand wave away this finding on the basis that 'we know we have to learn somehow' yet you neglect the fact that we have no actual knowledge what the domain-specificity of threat-processing expertise is.
There are several possibilities in a case like this. It could be that this specific type of processing invokes a domain-general faculty, lets say anterior cingulate response inhibition or something like that. Or it could be that it is a very specific domain, recruiting empathy/emotion processing circuits. Another possibility could bet that expertise comes from an increased ability to predict actions and has little to do with actual sensory threat processing. Another possibility is that this is a recruitment of some traditional learning mechanism that would not differ from everyday learning and thus would not show up at all on this kind of paradigm. All of these are testable hypotheses and are things that this study is a step towards addressing.
fMRI studies such as this one cannot definitively answer these questions, and I am the first to advocate totally multidisciplinary and multimodal investigations- but your attack here is simply off base. I value the authors of this study for taking the chance of a totally null finding and for demonstrating a unique and interesting brain adaptation.
However used paradigms like that: showing pictures of different emotional content (except with sexual content) in a scanner, in an EEG cabin, or with GSR knows: people get adapted to the pictures _very_ quickly. However, these paradigms are used on and on. And what do you obtain in the end?
Watch the figures: SEALs show a _negative_ BOLD effect in one condition while controls show a really small BOLD effect (was this 0.5 Tesla?) in the "left insula". As we know, the insula is a rather broad area including different cortical subregions probably being a neuronal correlate of rather different functions (see the literature, if interested) usually overlapping in different individuals after the normalisation procedure of SPM et al. So what does "greater activation bilaterally in the insula" mean in the end? Obviously not much if anything...
You know whose brain we should look at with fMRI? MacGyver's. The man used sodium metal and a cold capsule to make an explosive... that's the kind of brain usin' we all need.
There should also be a show featuring a neuroscientist who goes around with a MRI scanner in a truck (they exist) solving mysteries... the mysteries of the brain.
I always think that one of the problems with this sort of study is the underlying reasoning (group x is more Z than group y), if that's the case then we want to demonstrate this fact using classical psychological tests. If there then really is a difference in performance then the brain scan doesn't tell us much more than that two groups which perform differently on a task have different brain activation, which isn't massively surprising.
Really what you want to do is demonstrate that your elite killers have different task performance than controls, then go on to demonstrate that different task performance is correlated with activity in some brain region (in some way) in controls as well as your elite killers and that the task performance of the elite killers is largely explained by the difference in activity.
Then of course many investigators regard differential performance as actually biasing the results and they want to match performance and show differences in brain function persist to argue for differences in underlying neural processing.
Somehow these approaches don't seem like they can all be right.
Neuroskeptic wrote:
"...What we don't understand very well yet is how training (or other forms of learning) works, on a neural level, i.e. what the molecular and cellular mechanisms are..."
You want to know how the brain works? Now, that kind of information comes with a fee attached! Besides which, if I told you, you'd probably manage to blow yourselves up, or worse, blow somebody else up!
I'll give you a pointer, though: the question's couched too generally to assist you. That is, much like Deep Thought's observation, knowing that the answer is 42 is useless, unless one understood the question.
Matt
Understand the appeal of faux-skepticism and easy dismissal of stuff...a lot easier to process, less brain power required, but also pretty dull.
Being skeptical abt this post’s skepticism...
- It points out the preliminary and partial nature of the study….that's trivial. Neuroscience and it's technologies are imperfect and new. You're not basing your whole blog on that blinding insight, we hope!
More clever, but also trivial, is the rhetorical trick of damning the authors for not studying what you imply they should have!? Then the results not addressing the issues you wanted addressed.
C’mon, how about a lil more brain power here!
SleepRunning wrote:
"...C’mon, how about a lil more brain power here!"
Ah, I get it: irony! How should NS critique this study, such that his/her criticism is more rounded (if one is going to criticize, it's always worth demonstrating one's superiority by explaining how a thing should be done, I think)?
While you're at it, try writing a blog, yourself, instead of installing dummy pages... It's not that difficult, if one has something to say.
Matt
please read my blog!
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