> Until recently, a model like the one Menon’s team employed would help researchers sort brains into different groups but wouldn’t provide information about how the sorting happened. Today, however, researchers have access to a tool called “explainable AI,” which can sift through vast amounts of data to explain how a model’s decisions are made.
> Using explainable AI, Menon and his team identified the brain networks that were most important to the model’s judgment of whether a brain scan came from a man or a woman. They found the model was most often looking to the default mode network, striatum, and the limbic network to make the call.
What's more fascinating it that it's not just a parlor trick and actually can be "validated" in some sense by doing a cognition test for just that part of the brain and observing the differences. So the model said "check here and you'll see a difference," and apparently, they did.
> They developed sex-specific models of cognitive abilities: One model effectively predicted cognitive performance in men but not women, and another in women but not men. The findings indicate that functional brain characteristics varying between sexes have significant behavioral implications.
> “These models worked really well because we successfully separated brain patterns between sexes,” Menon said. “That tells me that overlooking sex differences in brain organization could lead us to miss key factors underlying neuropsychiatric disorders.”
FWIW, feature maps are not really reliable (to put it mildly). Knowing what area the model is "looking at" is virtually meaningless if you don't know what it's looking at. We already knew it was looking at the brain so is it turtles all the way down? Those maps are great for confirming what people want to see "oh look it tells a cat from a dog by the eyes" but have no explanatory power. If they did then the paper would be about AI finding a physiological difference and would tell us what it is, not some handwaving about "here's where it looked".
> Knowing what area the model is "looking at" is virtually meaningless if you don't know what it's looking at. We already knew it was looking at the brain so is it turtles all the way down?
Huh?
I’m not sure what you are saying here.
If there’s some subset of the pixels or whatever which the models predictions depend on more than the others, then, it depends on those more than it depends on the others.
Obviously it would be using the data it is given. That, doesn’t mean that looking into “what part of the data that it is given, is it using?” not meaningful.
> “These models worked really well because we successfully separated brain patterns between sexes,” Menon said. “That tells me that overlooking sex differences in brain organization could lead us to miss key factors underlying neuropsychiatric disorders.”
Although never demonstrated, it's always been most intuitive to me that sex-related brain differences underlie gender dysphoria. I would feel exceptionally relieved and vindicated to finally have some objective, falsifiable observation to point at that suggests the reality of dysphoria.
Ah, but this is science. How would you feel if it were not vindicated? What if it were not a matter of "born that way"?
Plus, there's a whole ton of confounding business we'll have to look out for. Just off the top of my head, you've got certainty intervals. And wouldn't it be prudent to at least examine the effects of various hormones like testosterone, dihydrotestosterone, estradiol, progesterone on the brain? Say, post age twenty five, pre age twenty five. And so on. Might exist, might not.
We're a long way from being able to have much certainty at all.
I would be shocked if hormones didn't have some effect on the brain considering how much of an effect they have everywhere else. Hell, I know some people who take the "brain sex" angle re. transness speculate that varying levels of hormonal exposure in utero could be what causes gender dysphoria post-utero... in which case, would adult endogenous hormones be responsible for brain structures, or would brain structure dictate which kind of hormones your body expects?
I think, in utero, the effects would be strong and likely visible, but through childhood, puberty, and then young adulthood, I would expect diminishing degrees of impact. Certainly, I've read case studies of various pre-natal exposures to particular chemicals having large and unmistakable impacts on sexual orientation. It's of especial interest to me as one of the very last DES babies.
Brain structure, as in the gross features visible on imaging, would probably not dictate what kinds of hormones you body might expect. I think that sort of thing would occur at a much lower level, right on the receptors of the tissues, and would not be visible.
I think it would be the same as right now, absence of evidence and all that. Would still be short one explanation explaining the observed phenomenon. You're absolutely right that it wouldn't be proof in any sense, just a sign that the avenue would be worth pursuing.
I love that idea! Honestly even if it doesn't show up as a sex-difference doing this same trick might be nonetheless fruitful by asking it to predict say cis woman / trans man.
> Until recently, a model like the one Menon’s team employed would help researchers sort brains into different groups but wouldn’t provide information about how the sorting happened. Today, however, researchers have access to a tool called “explainable AI,” which can sift through vast amounts of data to explain how a model’s decisions are made.
> Using explainable AI, Menon and his team identified the brain networks that were most important to the model’s judgment of whether a brain scan came from a man or a woman. They found the model was most often looking to the default mode network, striatum, and the limbic network to make the call.
What's more fascinating it that it's not just a parlor trick and actually can be "validated" in some sense by doing a cognition test for just that part of the brain and observing the differences. So the model said "check here and you'll see a difference," and apparently, they did.
> They developed sex-specific models of cognitive abilities: One model effectively predicted cognitive performance in men but not women, and another in women but not men. The findings indicate that functional brain characteristics varying between sexes have significant behavioral implications.
> “These models worked really well because we successfully separated brain patterns between sexes,” Menon said. “That tells me that overlooking sex differences in brain organization could lead us to miss key factors underlying neuropsychiatric disorders.”