Hi Telmo Menezes The electronics presumably requires a digital signal.
But the brain presumably uses analog signals. And there is the raster line and sync signal problem. There is the digital pixel problem, which uses only 3 colors: blue,green,red. How can all of this work ? [Roger Clough], [rclo...@verizon.net] 1/8/2013 "Forever is a long time, especially near the end." - Woody Allen ----- Receiving the following content ----- From: Telmo Menezes Receiver: everything-list Time: 2013-01-07, 19:24:24 Subject: Re: Re: Subjective states can be somehow extracted from brains viaacomputer Hi Craig, On Tue, Jan 8, 2013 at 12:41 AM, Craig Weinberg wrote: On Monday, January 7, 2013 6:19:33 AM UTC-5, telmo_menezes wrote: On Sun, Jan 6, 2013 at 8:55 PM, Roger Clough wrote: Hi Craig Weinberg ? Sorry, everybody, I was snookered into believing that they had really accomplished the impossible. So you think this paper is fiction and the video is fabricated? Do people here know something I don't about the authors? The paper doesn't claim that images from the brain have been decoded, Yes it does, right in the abstract: "To demonstrate the power of our approach, we also constructed a Bayesian decoder [8] by combining estimated encoding models with a sampled natural movie prior. The decoder provides remarkable reconstructions of the viewed movies." http://www.cell.com/current-biology/abstract/S0960-9822%2811%2900937-7 ? but the sensational headlines imply that is what they did. Starting with UC Berkeley itself: http://newscenter.berkeley.edu/2011/09/22/brain-movies/ ? The video isn't supposed to be anything but fabricated. ALL videos are fabricated in that sense. ? It's a muddle of YouTube videos superimposed upon each other according to a Bayesian probability reduction. Yes, and the images you see on your computer screen are just a matrix of molecules artificially made to align in a certain way so that the light being emitted behind them arrives at your eyes in a way that resembles the light emitted by some real world scene that it is meant to be represented. ? Did you think that the video was coming from a brain feed like a TV broadcast? It is certainly not that at all. Nice straw man + ad hominem you did there! ? ? The hypothesis is that the brain has some encoding for images. Where are the encoded images decoded into what we actually see? In the computer that runs the Bayesian algorithm. ? ? These images can come from the optic nerve, they could be stored in memory or they could be constructed by sophisticated cognitive processes related to creativity, pattern matching and so on. But if you believe that the brain's neural network is a computer responsible for our cognitive processes, the information must be stores there, physically, somehow. That is the assumption, but it is not necessarily a good one. The problem is that information is only understandable in the context of some form of awareness - an experience of being informed. A machine with no user can only produce different kinds of noise as there is nothing ultimately to discern the difference between a signal and a non-signal. Sure. That's why the algorithm has to be trained with known videos. So it can learn which brain activity correlates with what 3p accessible images we can all agree upon. ? It's horribly hard to decode what's going on in the brain. Yet every newborn baby learns to do it all by themselves, without any sign of any decoding theater. Yes. The newborn baby comes with the genetic material that generates the optimal decoder. ? ? These researchers thought of a clever shortcut. They expose people to a lot of images and record come measures of brain activity in the visual cortex. Then they use machine learning to match brain states to images. Of course it's probabilistic and noisy. But then they got a video that actually approximates the real images. You might get the same result out of precisely mapping the movements of the eyes instead. Maybe. That's not where they took the information from though. They took it from the visual cortex. ? What they did may have absolutely nothing to do with how the brain encodes or experiences images, no more than your Google history can approximate the shape of your face. Google history can only approximate the shape of my face if there is a correlation between the two. In which case my Google history is, in fact, also a description of the shape of my face. ? ? So there must be some way to decode brain activity into images. The killer argument against that is that the brain has no sync signals to generate the raster lines. Neither does reality, but we somehow manage to show a representation of it on tv, right? What human beings see on TV simulates one optical environment with another optical environment. You need to be a human being with a human visual system to be able to watch TV and mistake it for a representation of reality. Some household pets might be briefly fooled also, but mostly other species have no idea why we are staring at that flickering rectangle, or buzzing plastic sheet, or that large collection of liquid crystal flags. Representation is psychological, not material. The map is not the territory. I agree. I never claimed this was an insight into 1p or anything to do with consciousness. Just that you can extract information from human brains, because that information is represented there somehow. But you're only going to get 3p information. ? Craig ? ? ? [Roger Clough], [rcl...@verizon.net] 1/6/2013 "Forever is a long time, especially near the end." - Woody Allen ----- Receiving the following content ----- From: Craig Weinberg Receiver: everything-list Time: 2013-01-05, 11:37:17 Subject: Re: Subjective states can be somehow extracted from brains via acomputer On Saturday, January 5, 2013 10:43:32 AM UTC-5, rclough wrote: Subjective states can somehow be extracted from brains via a computer. No, they can't. ? The ingenius folks who were miraculously able to extract an image from the brain that we saw recently ? http://gizmodo.com/5843117/scientists-reconstruct-video-clips-from-brain-activity somehow did it entirely through computation. How was that possible? By passing off a weak Bayesian regression analysis as a terrific consciousness breakthrough. Look again at the image comparisons. There is nothing being reconstructed, there is only the visual noise of many superimposed shapes which least dis-resembles the test image. It's not even stage magic, it's just a search engine. ? There are at least two imaginable theories, neither of which I can explain step by step: What they did was take lots of images and correlate patterns in the V1 region of the brain with those that corresponded V1 patterns in others who had viewed the known images. It's statistical guesswork and it is complete crap. "The computer analyzed 18 million seconds of random YouTube video, building a database of potential brain activity for each clip. From all these videos, the software picked the one hundred clips that caused a brain activity more similar to the ones the subject watched, combining them into one final movie" Crick and Koch found in their 1995 study that "The conscious visual representation is likely to be distributed over more than one area of the cerebral cortex and possibly over certain subcortical structures as well. We have argued (Crick and Koch, 1995a) that in primates, contrary to most received opinion, it is not located in cortical area V1 (also called the striate cortex or area 17). Some of the experimental evidence in support of this hypothesis is outlined below. This is not to say that what goes on in V1 is not important, and indeed may be crucial, for most forms of vivid visual awareness. What we suggest is that the neural activity there is not directly correlated with what is seen." http://www.klab.caltech.edu/~koch/crick-koch-cc-97.html What was found in their study, through experiments which isolated the effects in the brain which are related to looking (i.e. directing your eyeballs to move around) from those related to seeing (the appearance of images, colors, etc) is that the activity in the V1 is exactly the same whether the person sees anything or not. What the visual reconstruction is based on is the activity in the occipitotemporal visual cortex. (downstream of V1 http://www.sciencedirect.com/science/article/pii/S0079612305490196) "Here we present a new motion-energy [10, 11] encoding model that largely overcomes this limitation. The model describes fast visual information and slow hemodynamics by separate components. We recorded BOLD signals in occipitotemporal visual cortex of human subjects who watched natural movies and fit the model separately to individual voxels." https://sites.google.com/site/gallantlabucb/publications/nishimoto-et-al-2011 So what they did is analogous to tracing the rectangle pattern that your eyes make when generally tracing the contrast boundary of a door-like image and then comparing that pattern to patterns made by other people's eyes tracing the known images of doors. It's really no closer to any direct access to your interior state than any data-mining advertiser gets by chasing after your web history to determine that you might buy prostate vitamins if you are watching a Rolling Stones YouTube. a) Computers are themselves conscious (which can neither be proven nor disproven) ? ? and are therefore capable of perception. Nothing can be considered conscious unless it has the capacity to act in its own interest. Computers, by virtue of their perpetual servitude to human will, are not conscious. ? ? ? or 2) The flesh of the brain is simultaneously objective and subjective. ? ? Thus an ordinary (by which I mean not conscious) computer can work on it ? ? objectively yet produce a subjective image by some manipulation of the flesh ? ? of the brain. One perhaps might call this "milking" of the brain. ? The flesh of the brain is indeed simultaneously objective and subjective (as are all living cells and perhaps all molecules and atoms), but the noise comparisons being done in this experiment aren't milking anything but the hype machine of pop-sci neuro-fluff. It is cool that they are able to refine the matching of patterns in the brain to patterns which can be identify computationally, but without the expectation of a visual image corresponding to these patterns in the first place, it is meaningless as far as understanding consciousness. What it does do though is provide a new hunger for invasive neurological technologies to analyze the behavior of your brain and draw statistical conclusions from...something which promises nothing less than utopian/dystopian level developments. Craig ? [Roger Clough], [rcl...@verizon.net] 1/5/2013 ? 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