[HN Gopher] The Trouble with Brain Scans
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       The Trouble with Brain Scans
        
       Author : dnetesn
       Score  : 21 points
       Date   : 2021-04-01 10:57 UTC (12 hours ago)
        
 (HTM) web link (nautil.us)
 (TXT) w3m dump (nautil.us)
        
       | arafa wrote:
       | This article reads like a longform version of why statistical
       | power/effect size is important but doesn't mention it by name,
       | only alluding to it. I suspect there would be much less of a
       | replication crisis if, instead of just focusing on statistical
       | significance, there was also a focus on effect size, or both.
        
       | checkyoursudo wrote:
       | As a cognitive scientist with only 1 graduate level fMRI course
       | and no hands-on experience outside of playing around with
       | Neurodebian, I will not be so bold (haha) as to make a claim that
       | there is absolutely nothing to fMRI.
       | 
       | However, I am very skeptical.
       | 
       | I would not be willing to make any strong claims about causality
       | when the alleged neural event and the measurement thereof are
       | 15-30 seconds apart, and the thing being measured (blood flow) is
       | not the event itself (neural activity), and there are so, so many
       | potential sources of error.
       | 
       | Now, structural MRI is super cool.
       | 
       | I have a bunch of friends at my university who work in fMRI brain
       | imaging. I feel bad, but when we talk about their work, I can't
       | help but think they are chasing alchemy. Or maybe a better
       | analogy is that it is almost like they are trying to learn about
       | the world (brain, cognition) based on the shadows at the back of
       | Plato's cave (fMRI BOLD signals).
       | 
       | I sincerely hope they overcome the challenges, but I expect they
       | will be facing the exact or nearly the same challenges 20 years
       | from now.
        
       | jessriedel wrote:
       | My impression is that Nautilus and Quanta are, among pop science
       | magazines, fairly high brow, but that Nautilus is substantially
       | more likely to use human-interest narratives (e.g., the opening
       | vignette) to keep the reader's attention. Is that right, or do I
       | have the wrong impression?
        
       | Sephr wrote:
       | You'll never get a full brain scan with fMRIs. For real detail,
       | you'll need a planetary-scale XFEL with a human head-sized
       | reticule and be okay with your irl head being vaporized.
       | 
       | Optimized models for simulating your brain accurately don't exist
       | yet either. I highly suspect that we will have to finish the
       | above first.
        
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       (page generated 2021-04-01 23:01 UTC)