Re: Re: Re: Re: Subjective states can be somehow extracted from brainsviaacomputer
Hi Telmo Menezes Yes, but the display they show wouldn't work if there were no sync signal embedded in it. There's nothing in the brain to provide that, so they must have. [Roger Clough], [rclo...@verizon.net] 1/7/2013 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, 09:33:30 Subject: Re: Re: Re: Subjective states can be somehow extracted from brainsviaacomputer Hi Roger, On Mon, Jan 7, 2013 at 1:28 PM, Roger Clough rclo...@verizon.net wrote: Hi Telmo Menezes Well then, we have at least one vote supporting the results. Scientific results are not supported or refuted by votes.? ? I remain sceptical because of the line sync issue. The brain doesn't provide a raster line sync signal. The synch signal is a requirement of a very specific technology to display video. Analog film does not have a synch signal. It still does sampling. Sampling is always necessary if you use a finite machine to record some visual representation of the world. If one believes the brain stores our memories (I know you don't) you have to believe that it samples perceptual information somehow. It will probably not be as neat and simple as a sync signal. A trivial but important point: every movie is a representation of reality, not reality itself. It's just a set of symbols that represent the world as seen from a specific point of view in the form of a matrix of discrete light intensity levels. So the mapping from symbols to visual representations is always present, no matter what technology you use. Again, the sync signal is just a detail of the implementation of one such technologies. The way the brain encodes images is surely very complex and convoluted. Why not? There wasn't ever any adaptive pressure for the encoding to be easily translated from the outputs of an MRI machine. If we require all contact between males and females to be done through MRI machines and wait a couple million years maybe that will change. We might even get a sync signal, who knows? Either you believe that the brain encodes images somehow, or you believe that the brain is an absurd mechanism. Why are the optic nerves connected to the brain? Why does the visual cortex fire in specific ways when shown specific images? Why can we tell from brain activity if someone is nervous, asleep, solving a math problem of painting? ? [Roger Clough], [rclo...@verizon.net] 1/7/2013 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, 06:19:33 Subject: Re: Re: Subjective states can be somehow extracted from brains viaacomputer On Sun, Jan 6, 2013 at 8:55 PM, Roger Clough ?rote: 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 hypothesis is that the brain has some encoding for images. 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. It's horribly hard to decode what's going on in the brain. 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. 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? ? ? ? [Roger Clough], [rclo...@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
Re: Re: Re: Re: Subjective states can be somehow extracted from brainsviaacomputer
Hi Roger, Imagine a very simple brain that can recognise two things: a cat and a mouse. Furthermore, it can recognise if an object is still or in motion. So a possible perceptual state could be cat(still) + mouse(in motion). The visual cortex of this brain is complex enough to process the input of a normal human eye and convert it into these representations. It has a very simple memory that can store states and temporal precedence between states. For example: mouse(still) - cat(in motion) + mouse(still) - cat(still) + mouse(in motion) - cat(still) Through an MRI we read the activation level of neurons that somehow encode this sequence of states. An incredible amount of information is lost BUT it is possible to represent a visual scene that approximates the meanings of those states. In a regular VGA screen with a synch signal I show you an animation of a mouse standing still, a cat appearing and so on. Of course the cat may be quite different from what the brain actually perceived. But it is also recognised as a cat by the brain, it produces an equivalent state so it's good enough. Now imagine the brain can encode more properties about objects. Is is big or small? Furry? Dark or light? Now imagine the brain can encode more information about precedence. Was it a long time ago? Just now? Aeons ago? And so on and so on until you get to a point where the reconstructed video is almost like what the brain saw. No synch signal. On Mon, Jan 7, 2013 at 5:22 PM, Roger Clough rclo...@verizon.net wrote: Hi Telmo Menezes Yes, but the display they show wouldn't work if there were no sync signal embedded in it. There's nothing in the brain to provide that, so they must have. [Roger Clough], [rclo...@verizon.net] rclo...@verizon.net] 1/7/2013 Forever is a long time, especially near the end. - Woody Allen - Receiving the following content - *From:* Telmo Menezes te...@telmomenezes.com *Receiver:* everything-list everything-list@googlegroups.com *Time:* 2013-01-07, 09:33:30 *Subject:* Re: Re: Re: Subjective states can be somehow extracted from brainsviaacomputer Hi Roger, On Mon, Jan 7, 2013 at 1:28 PM, Roger Clough rclo...@verizon.net wrote: Hi Telmo Menezes Well then, we have at least one vote supporting the results. Scientific results are not supported or refuted by votes.� � I remain sceptical because of the line sync issue. The brain doesn't provide a raster line sync signal. The synch signal is a requirement of a very specific technology to display video. Analog film does not have a synch signal. It still does sampling. Sampling is always necessary if you use a finite machine to record some visual representation of the world. If one believes the brain stores our memories (I know you don't) you have to believe that it samples perceptual information somehow. It will probably not be as neat and simple as a sync signal. A trivial but important point: every movie is a representation of reality, not reality itself. It's just a set of symbols that represent the world as seen from a specific point of view in the form of a matrix of discrete light intensity levels. So the mapping from symbols to visual representations is always present, no matter what technology you use. Again, the sync signal is just a detail of the implementation of one such technologies. The way the brain encodes images is surely very complex and convoluted. Why not? There wasn't ever any adaptive pressure for the encoding to be easily translated from the outputs of an MRI machine. If we require all contact between males and females to be done through MRI machines and wait a couple million years maybe that will change. We might even get a sync signal, who knows? Either you believe that the brain encodes images somehow, or you believe that the brain is an absurd mechanism. Why are the optic nerves connected to the brain? Why does the visual cortex fire in specific ways when shown specific images? Why can we tell from brain activity if someone is nervous, asleep, solving a math problem of painting? � [Roger Clough], [rclo...@verizon.net] 1/7/2013 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, 06:19:33 Subject: Re: Re: Subjective states can be somehow extracted from brains viaacomputer On Sun, Jan 6, 2013 at 8:55 PM, Roger Clough 爓rote: 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 hypothesis is that the brain has some encoding for images. 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
