tag:blogger.com,1999:blog-6608508031853237690.post5844980586608670092..comments2023-10-12T04:43:02.170-07:00Comments on The Structure of Visual Space Group: The Disappearance of AppearanceUnknownnoreply@blogger.comBlogger7125tag:blogger.com,1999:blog-6608508031853237690.post-83064371429158659612010-11-01T09:57:46.077-07:002010-11-01T09:57:46.077-07:00I think we should continue comments on Simon's...I think we should continue comments on Simon's posting where they are relevant rather than in the context of Ray Tallis's posting. So I shall respond to Bob's points as a comment on Simon's posting (which see).Bill Rosarhttps://www.blogger.com/profile/11050087683794239783noreply@blogger.comtag:blogger.com,1999:blog-6608508031853237690.post-55470237739369426552010-11-01T07:42:05.041-07:002010-11-01T07:42:05.041-07:00The bare fact that Poincare holds that "a lit...The bare fact that Poincare holds that "a little good will" is required here I think is a good hint that there are dangers of conflating separate issues; including at a minimum 1.the dimensionality of memories vs. visual perceptions at a given time; 2. the dimensionality of a physical hologram vs. our visual perception of one; 3. the dimensionality of perceptions of holograms over a period of time (is time treated as a dimension here, and if so, in the same way as spatial perceptions?); 4. the dimensionality of viewing a hologram from different viewing angles vs. viewing it from one angle. This is not necessarily meant to be a complete list, but it does seem to me that if we are not careful about putting issues into context here there is a danger of just arguing past each other.Robert Frenchhttps://www.blogger.com/profile/16001286838161598884noreply@blogger.comtag:blogger.com,1999:blog-6608508031853237690.post-72079249772264166322010-10-31T12:21:05.882-07:002010-10-31T12:21:05.882-07:00Here are some my remarks on how I see the problem ...Here are some my remarks on how I see the problem of the tridimensionality of the space of perception. <br /><br />The dimensionality of “perception” by an information-processing apparatus is supposed to be established by the capacity of the computational device - its memory, in particular - to retain a given object for a characteristic time interval. For human brain, this time interval should be under about a fraction of one tenth of a second. <br /><br />Abstract information processing at a Turing machine operates with zero-dimensional objects – separate symbols. Practical von Neumann’s model operates with one-dimensional objects – machine words. According to the so-called Church-Turing Thesis, all reasonable computational models are equivalent in terms of their algorithmic capabilities; the differences among the computational models lie only in their performance, typically, determined by the consumed time and resources, or by compliance to some real-time constraints. Of course, any computational device can handle objects of any dimensionality, but to be “retained” in a short –time the structure of the objects has to match to the intrinsic architecture of a given device. For example, conventional computers employing machine words can quickly take hold of linear arrays, but need noticeably more time to handle multi-dimensional lists. <br /> <br />Holography provides the most plausible operational paradigm for the construction of the brain. The condition of a sharp propagation front leads to a computational model with 2D operational slices. Hence, holographic model can naturally process 3D objects as a sequence of 2D slices; in other words, by retaining the corresponding informational structures, say, by a fraction of one tenth of second, such a model is able to “perceive” 3D objects. Higher dimensionality objects cannot be “perceived” by a holographic model since they have to undergo a slower processing, which is beyond immediate retention by 2D operational slices.<br /><br />The presented consideration was incited by Poincare idea that the tridimensionality of the space of perception is determined by the physiological specifics of the brain. Before the age of information, the involved computer science concepts were not available, and Poincare treated the tridimensionality of the space of perception as an abstract problem with certain "a little good will" assumptions.Simon Berkovichhttps://www.blogger.com/profile/03294816541678388401noreply@blogger.comtag:blogger.com,1999:blog-6608508031853237690.post-4894298256127150982010-10-29T20:25:02.943-07:002010-10-29T20:25:02.943-07:00Of course the more fundamental question (IMO) is w...Of course the more fundamental question (IMO) is what these stroboscopically-induced effects have to do with ordinary visual perception? How are they--or are they--related to processes involved in seeing the world?<br /><br />I keep thinking of Sickles' interest in explaining patterns of this sort through his "chemical theory of perception," in which he saw a direct analogy between Gestalt characteristics and the behavior or liquid crystals (i.e., their liquid vs. crystal state). What you describe above, John, definitely brings to mind the known behavior of liquid crystals, more than it does anything observed an order of magnitude greater in the cellular activity of the visual cortex which, I argue, could readily and more accurately be interpreted as decomposing the structure of VS, rather than generating it (in some sense), in accord with the remarks of Hubel & Wiesel which I quoted in another posting.<br /><br />Lothar Kleine-Horst has been reading the blog and I am hoping that he may offer an opinion of these effects, based on his own Gestalt-based theory of visual perception. What do you think Simon?Bill Rosarhttps://www.blogger.com/profile/11050087683794239783noreply@blogger.comtag:blogger.com,1999:blog-6608508031853237690.post-50292269313918078792010-10-29T14:45:41.162-07:002010-10-29T14:45:41.162-07:00On the question of what it is about neuronal activ...On the question of what it is about neuronal activity that ‘results’ in phenomenal events appearing in the VF;— Ray has given us an finely honed account of the shortcomings of action potentials to fill this role. So I would like to present some experimental data of my own that might give us ideas on this question. In the mid-50s I spent 2 years in the Psychology Department at Cambridge studying the stroboscopic patterns (the geometrical hallucinations induced by looking at a flickering light). If one uses binocular stimulation, one sees only the geometrical patterns (grids, checker boards, concentric circles, spirals mazes, etc. mostly in jiggly movement) displayed on a completely flat field before one. These are called the ‘bright phase’ patterns. <br />But with uniocular stimulation one gets a different effect—the emergence of ‘dark phase’ patterns. At first one sees the geometrical patterns. Then a new type of pattern appears called the ‘dark phase’. These consist of oily swirls like an oil film on water in two colours, usually red and green. The effect is very clear and with no jiggles—just a slow continuous oily swirl. Sometimes another effect is seen like an elaborate mosaic covered by clear rippling water. Sometimes fully formed hallucinations of scenes occur, as are seen in the psychedelic state. Then, with continued viewing, the ‘bright’ and ‘dark’ phase patterns start to appear in regular retinal rivalry. From this I deduced that the dark phase patterns are arising from activity related to the cortical neurons belonging to the shut eye. (Of course I am not suggesting that these patterns are composed of activated neurons as IT would have it. They are produced in the VF by causally related events in the visual cortex).<br />In V1 the R and L eye connected neurons form an alternating array. So the dark phase could be ‘produced’ by dendodendritic synaptic connections between R and L eye neurons. How than could we account for the marked difference between the two phases? Axo-dendritic connections from the LGN produce simple geometrical patterns in jiggly movement, whereas dendo-dendritic connections produce oily swirls. Why so????? Various theories to do with wave fronts have been put forward to explain the bright phase patterns, but none to explain the dark phase. Dendodendritic circuits are known to play a role in the olfactory system. Would a wavelike fluctuating dendrodendritic potential ‘result’ in oily swirls in the VF? How do these get coloured?? We need to know more about the microanatomy of these visuocortical neurons!john smythieshttps://www.blogger.com/profile/13607582690174724189noreply@blogger.comtag:blogger.com,1999:blog-6608508031853237690.post-13984318660594171632010-10-29T09:56:42.887-07:002010-10-29T09:56:42.887-07:00Bravo, Ray Tallis! Just looking at some old notes ...Bravo, Ray Tallis! Just looking at some old notes of mine from 1993 entitled "Qualia Qualified; Dennett Disqualified," I noted that while he discusses so-called "quality spaces," he does not discuss the characteristics of perceptual space (ergo: the space of qualia), and that while there was much discussion of the *conditions* of qualia occurring relative to various physical happenings (light, surface reflectance, "brain states") only very little about qualia as such, which struck me as odd since the latter rather than the former are presumably the focus of his book. His battle cry should rightly be "Back to Behaviorism!"<br /><br />The "price" ontology has paid in developing an ontology based on scientific observation (viz. mensuration) is to make a hash out of the perceptual world in the process, taking from it what it needs and discarding the rest as being "subjective." As I have asked rhetorically already, "What is wrong with this picture?" The scientific "physical" picture, unrecognizable to the lay person as being "the world," does away with appearance as Ray has so delightfully exposed, something which in itself does not seem to strike scientists as being a problem, given how that verity has been trivialized and, as Dennett would like to think, *explained away.* The fact that it has fallen upon a philosopher to do the "explaining"--and in the process doing the bidding of science or being not much more than a public relations spokesman for science as some philosophers have become--says something about the status granted to consciousness as a phenomenon in the world of science. <br /><br />No wonder consciousness is such a mystery--it might as well not exist or, as some patronizingly ask, "Why is there consciousness?" What never seems to occur to many interested in consciousness is that that question could really be interpreted as being the flip side of the question "Why is there something rather than nothing?"Bill Rosarhttps://www.blogger.com/profile/11050087683794239783noreply@blogger.comtag:blogger.com,1999:blog-6608508031853237690.post-23689554752636324402010-10-29T08:43:26.628-07:002010-10-29T08:43:26.628-07:00I agree with essentially everything said here. Den...I agree with essentially everything said here. Dennett's work on consciousness is notorious; it was initially enthusiastically reviewed by the New York Times, but then Ned Block in a review in the Southern Journal of Philosophy said a better title than "Consciousness Explained" would have been "Consciousness Ignored." Among other things Dennett gives a third person analysis of consciousness while it is clearly a first person concept, and shifts from talking about "seemings" in a phenomenal sense to a linguistic sense without apparently being aware that he has done so.Robert Frenchhttps://www.blogger.com/profile/16001286838161598884noreply@blogger.com