Interesting. One thing ut doesn’t seem to explain is gender imbalance in onset time. Women start developing schizophrenia about a decade later I think. On the other hand, IIRC the usual explanation is “sth sth protective estrogens”, so if it turned out that estrogens inhibit pruning of medium/long-range cortico-cortical connections, then you get another puece of weak evidence.
Regarding context of discovery, I would expect effects like this one to work through local connections, perhaps not even in the visual cortex but LGN or even retina (?).
Regarding your explanation of “hearing voices”, wouldn’t it fit better with your hypothesis that the function of the cerebellum is to resuce latency between cortical(/telencephalic) regions by presicting advance what signal arrives where?
Yeah, I dunno. Random paper says “there are age-related sex differences in brain maturational processes” and more specifically “males had more prominent age-related gray matter decreases and white matter volume and corpus callosal area increases compared with females”. Guess it could be something like that? But I would want to look into that more. Thanks for the tip :)
Regarding context of discovery, I would expect effects like this one to work through local connections, perhaps not even in the visual cortex but LGN or even retina (?).
Can you say more about why you expect that?
Regarding your explanation of “hearing voices”, wouldn’t it fit better with your hypothesis that the function of the cerebellum is to [reduce] latency between cortical(/telencephalic) regions by [predicting in] advance what signal arrives where?
I don’t understand what you mean here. Yes I do think the cerebellum reduces latency like you said, but I’m not following how you think that’s related to hearing voices.
Hm, I had a vague memory that contrast detection relies on something like lateral inhibition but when I thought about it a bit more it doesn’t really make sense and I guess I conflated it with edge detection in the retina.
Regarding cerebellum in hearing voices: If I understand your model correctly, it goes something like this. Region S (sender) “generates voices” and region R (receiver) “hears voices” generated by S. R expects to receive those signals from S (or maybe even just expects to receive these kinds of signals in general, without specifying where they come from). R gets surprised when it receives unexpected signals and interprets them as “not mine”. R would expect to receive them, if it first got a message “hey, S is soon going to send some voice-signals to you”. Isn’t this exactly the role of the cerebellum, to learn that, e.g. if S activates in this particular way (about to “generate voices”), then R will soon activate in the other way (“hears voices”) and therefore it would make sense to preempt R, so that it can expect to get that particular signal from S and act accordingly even before receiving that signal?
(1A) there’s a message from S to Motor Area M that says to produce voices;
(1B) there’s a message from S to R that updates R on what S is doing (and in particular, it tells (R) that (1A) is happening right now);
(2) Motor Area M “does voices” (I’m hazy on the details), and some sensory consequence of those voices make their way back to R.
So then the auditory hallucination in my model would be if (1A) and (2) happen, but (1B) doesn’t happen.
Generally, I don’t think this story is very sensitive to timing. I think the nature of a hallucinated voice is that it feels exogenous not just for a tiny fraction of a second between the (2) signal and the (1B) signal arriving at R, but rather it continues to feel exogenous for many seconds.
Interesting. One thing ut doesn’t seem to explain is gender imbalance in onset time. Women start developing schizophrenia about a decade later I think. On the other hand, IIRC the usual explanation is “sth sth protective estrogens”, so if it turned out that estrogens inhibit pruning of medium/long-range cortico-cortical connections, then you get another puece of weak evidence.
Regarding context of discovery, I would expect effects like this one to work through local connections, perhaps not even in the visual cortex but LGN or even retina (?).
Regarding your explanation of “hearing voices”, wouldn’t it fit better with your hypothesis that the function of the cerebellum is to resuce latency between cortical(/telencephalic) regions by presicting advance what signal arrives where?
Thanks!
Yeah, I dunno. Random paper says “there are age-related sex differences in brain maturational processes” and more specifically “males had more prominent age-related gray matter decreases and white matter volume and corpus callosal area increases compared with females”. Guess it could be something like that? But I would want to look into that more. Thanks for the tip :)
Can you say more about why you expect that?
I don’t understand what you mean here. Yes I do think the cerebellum reduces latency like you said, but I’m not following how you think that’s related to hearing voices.
Hm, I had a vague memory that contrast detection relies on something like lateral inhibition but when I thought about it a bit more it doesn’t really make sense and I guess I conflated it with edge detection in the retina.
Regarding cerebellum in hearing voices: If I understand your model correctly, it goes something like this. Region S (sender) “generates voices” and region R (receiver) “hears voices” generated by S. R expects to receive those signals from S (or maybe even just expects to receive these kinds of signals in general, without specifying where they come from). R gets surprised when it receives unexpected signals and interprets them as “not mine”. R would expect to receive them, if it first got a message “hey, S is soon going to send some voice-signals to you”. Isn’t this exactly the role of the cerebellum, to learn that, e.g. if S activates in this particular way (about to “generate voices”), then R will soon activate in the other way (“hears voices”) and therefore it would make sense to preempt R, so that it can expect to get that particular signal from S and act accordingly even before receiving that signal?
The model would be:
(1A) there’s a message from S to Motor Area M that says to produce voices;
(1B) there’s a message from S to R that updates R on what S is doing (and in particular, it tells (R) that (1A) is happening right now);
(2) Motor Area M “does voices” (I’m hazy on the details), and some sensory consequence of those voices make their way back to R.
So then the auditory hallucination in my model would be if (1A) and (2) happen, but (1B) doesn’t happen.
Generally, I don’t think this story is very sensitive to timing. I think the nature of a hallucinated voice is that it feels exogenous not just for a tiny fraction of a second between the (2) signal and the (1B) signal arriving at R, but rather it continues to feel exogenous for many seconds.