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Dahlen comments on What are the resolution limits of medical imaging? - Less Wrong Discussion
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Hi, biomedical engineering undergrad here. I have to go review some materials before I can give you a more precise answer to the question you're interested in, but my first thought upon reading this is that it's not just a matter of structural makeup, but mainly one of patterns of electrical activity in the brain. Most studies I've seen that touched upon high-level concepts like emotions, attention, or interest used fMRI scans to correlate brain activity in certain areas with exposure to certain stimuli. I'm not sure how much this says about the problem of consciousness, but if it is relevant, then you have an additional parameter to consider other than spatial resolution -- namely, time.
Beyond the hypothermia angle, also, big shocks to the brain have been survived.
Thanks for looking into it. FYI, it seems like the time dimension won't be necessary since people have recovered after their brain activity stops e.g. Profound Hypothermia and Circulatory Arrest
I don't think you can conclude that "the time dimension won't be necessary" from the paper you linked.
(A) Because the brain temp in fig 1 (and many of the other experiments reported) was about 20 deg C, and neurons still fire at that temperature. (It's routine in many experiments to record synaptic activity in neurons at or near these temperatures). So you can't infer from the metabolic measures that neural firing has ceased. Neural firing patterns are almost certainly preserved to some substantial extent under the conditions in this paper (albeit with a lower expected spike probability).
(B) The figures show (to quote the paper) that "...cerebral damage is evident in biochemical terms at 30 minutes, as judged by cells at 37 minutes and by functional impairment at 45 minutes." During that same time interval, ATP consumption declined only slightly and indices of mitochondrial stress increased only slightly (<20% in each case). That makes it seem to me like arresting normal metabolic function even slightly causes widespread dysfunction.
Why did this paper make you think that time-varying patterns of neural activity wouldn't be necessary to reconstruct/understand psychological phenomena?