Hmm. Do different humans produce relatively the same brain images for a given scene? If not, I’d imagine training this would be a real PITA.
I was wondering the same thing, hopefully someone in the comments will know more about it.
Deep image reconstruction from human brain activity (2017)
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Re: Deep image reconstruction from human brain activity (2017)
#32Does the 50GB of data include the MRI measurements from both during training and testing?
Re: Deep image reconstruction from human brain activity (2017)
#33Earlier quoted context omitted.
I think what's maybe misleading here is that while there may be an accurate representation of a bicycle somewhere in someone's brain, that does not mean they're able to consciously access it and, e.g., recreate it through a task of complex motor coordination etc. (in order to produce a drawing, I mean). However, if you are using an fMRI, as in the paper, all you need is the accurate representation somewhere (and you…
I don't think the "draw a bicycle" task involves complex motor coordination. It's drawing 2 circles and ~10 straight lines. Doesn't need to be photorealistic, just in the correct configuration. For example, I cannot visualize a 13-sided polygon accurately, but I can draw one pretty easily without having any drawing skills.
True. I hesitated to use that as an example because of the potential for confusion—but to clarify, I just meant that the motor skills are an example of another thing being involved beyond a clear representation somewhere, not that they are actually the limiting factor for reproducing the drawing.
A more realistic problem in the case of the bicycle drawing has to do with the procedural knowledge they use for drawing. For instance, maybe they approach it analytically, top-down, breaking it into major components to draw first, and those into sub components. Well, in order to do that, they need explicit knowledge of that hierarchy; they may have an accurate representation of the image somewhere, but they can't bring it directly into consciousness, and they didn't break it into that hierarchy while they had it around. So now what's left to them is to attempt to produce the hierarchy from an imperfectly recalled image, which leads to the strange configurations.
Just a guess—but I wouldn't be surprised to learn it's something on those lines.
Re: Deep image reconstruction from human brain activity (2017)
#34Reminds me of this project from 2011: https://www.youtube.com/watch?v=nsjDnYxJ0bo If I were a billionaire, one of the projects I'd do would be to apply this sort of technology at scale, upon volunteers who were witness to poorly recorded historic events. WWII, Beatles concerts, JFK assassination, 9/11... all of them have been recorded from angles/perspectives that exist only in peoples' memories, and the longer we wa…
You’re vastly overestimating the human brain’s ability to accurately recall first hand accounts. It’s actually kind of shocking how bad eyewitnesses are at remembering details.
Re: Deep image reconstruction from human brain activity (2017)
#35Reminds me of this project from 2011: https://www.youtube.com/watch?v=nsjDnYxJ0bo If I were a billionaire, one of the projects I'd do would be to apply this sort of technology at scale, upon volunteers who were witness to poorly recorded historic events. WWII, Beatles concerts, JFK assassination, 9/11... all of them have been recorded from angles/perspectives that exist only in peoples' memories, and the longer we wa…
You’re vastly overestimating the human brain’s ability to accurately recall first hand accounts. It’s actually kind of shocking how bad eyewitnesses are at remembering details.
Isn't it a Russian saying - "He lies like an eyewitness"
Re: Deep image reconstruction from human brain activity (2017)
#36Wouldn’t that training set be valuable!
Re: Deep image reconstruction from human brain activity (2017)
#37Acknowledging that I know nothing about psychology or neuroscience... It's interesting that they were not able to extract good images from the test when they just asked the subjects to imagine the pictures. I speculate that is because the vast majority of people are able to recognize images of things, but not produce those images. For a simple example, see this article about people trying to draw a bicycle. Before cl…
there is also evidence this ability to conjure imagery in our minds simply does not exist for some: https://en.wikipedia.org/wiki/Aphantasia which leads me to wonder if the capability exists on a spectrum and is stronger or weaker in some. A stronger capability might correlate to a stronger 'signal' ...?
Do people actually see images of things in their head?
I can close my eyes and think of something, but I won't perceive anything more than a linear description of it.
At best, I can use these visual descriptions to draw an outline in my head, but it instantly fades out if I don't continuously re-draw it.
Kind of like this: https://i.imgur.com/0zuPIPV.gifv
Re: Deep image reconstruction from human brain activity (2017)
#38Acknowledging that I know nothing about psychology or neuroscience... It's interesting that they were not able to extract good images from the test when they just asked the subjects to imagine the pictures. I speculate that is because the vast majority of people are able to recognize images of things, but not produce those images. For a simple example, see this article about people trying to draw a bicycle. Before cl…
> It's interesting that they were not able to extract good images from the test when they just asked the subjects to imagine the pictures. I speculate that is because the vast majority of people are able to recognize images of things, but not produce those images.
It seems reasonable to me. To use a computer as an analogy, the set of signals produced by a webcam recording a video to a hard drive are not going to be the same as the ones of the video playing from the hard drive on to the screen.
Re: Deep image reconstruction from human brain activity (2017)
#39The code and data for these amazing results have been generously made available here: https://github.com/KamitaniLab/DeepImageReconstruction The code is well-commented Python and a pleasure to read.
Very impressive! I was quite skeptical until I read your comment. Now I'm just a little skeptical.
Re: Deep image reconstruction from human brain activity (2017)
#40Earlier quoted context omitted.
there is also evidence this ability to conjure imagery in our minds simply does not exist for some: https://en.wikipedia.org/wiki/Aphantasia which leads me to wonder if the capability exists on a spectrum and is stronger or weaker in some. A stronger capability might correlate to a stronger 'signal' ...?
Do people actually see images of things in their head? I can close my eyes and think of something, but I won't perceive anything more than a linear description of it. At best, I can use these visual descriptions to draw an outline in my head, but it instantly fades out if I don't continuously re-draw it. Kind of like this: https://i.imgur.com/0zuPIPV.gifv
I have no issue conjuring clear images when closing eyes. I guess it depends how your brain is wired and this is probably why we have ways to refer people who are good at drawing, painting, etc. They probably have a mix of clear visualization and very good hand/finger coordination.