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Author | Topic: My problem with evolution | |||||||||||||||||||
Quetzal Member (Idle past 5898 days) Posts: 3228 Joined: |
This is an interesting question. Before offering an answer, however, I'd like to ask you for your definition of two terms: "mind" and "spirit". You seem to be defining mind as "self-awareness". Is this correct? You have not, however, made a stab at defining what you mean by spirit. I'd appreciate a clarification.
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Quetzal Member (Idle past 5898 days) Posts: 3228 Joined: |
quote: Okay, I think you’re confusing a couple of concepts, here. Mind is much more than self-awareness. After all, there are numbers of other species — at least primates — that are self-aware. I don’t think you mean that. In addition, there are huge numbers of species that have memory — learned responses are quite common, which is one of the tests of memory. After all, how many bears do you see riding bicycles through the woods or seals balancing balls on their noses in the Arctic? These behaviors are taught them by (learned from) their trainers — and they remember them. Any time you see an organism that shows variation in behavior patterns based on learned behavior — for example dialects in songbirds based on paternal imprinting, or potato washing in Macaca fuscata - you are observing memory. From the standpoint of logic, or the cognitive ability to extrapolate relationships based on differential experience, chimpanzees show an ability to assess, plan, and form strategic alliances within a troop — which would indicate at least some form of abstract reasoning. They also have demonstrated the ability to consider optional behaviors before acting, another indicator of the ability to reason (although a case could be made that the observed behavior was equivocal). Obviously, unless you’re willing to postulate that all these organisms also have whatever you’re defining as spirit, then I’d say that that piece of your argument is falsified. This is why I asked you for a definition of spirit. Is it a mental affect? Is it some intrinsic property of an organism (or even only humans)? How can you determine whether or not an organism that otherwise shows evidence of mind as you’ve defined it has a spirit?
quote: You’ll be hard pressed to show this is the case. Please provide a specific reference that supports your assertion. Or at least more of an explanation of how mind is non-physical.
quote: Hunh? I don’t follow you. Please clarify.
quote: You have not shown that mind is non-physical, nor that it represents some other type of reality. If this is the only evidence of spirit, then without further explanation and evidence, I’d have to say that spirit doesn’t exist.
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Quetzal Member (Idle past 5898 days) Posts: 3228 Joined: |
You're invoking several strawmen and/or misunderstandings of what I wrote. Please re-read the post to which you were responding, and be more careful in the future. You also failed completely to either answer my questions or object to any of my points. Try again.
quote: You "may have doubts about" self awareness in other animals, but that merely shows you haven't read much recent literature on animal behavior. Mirror self-awareness (MSR) - probably one of the better objective tests - has been known in chimps for 30 years, and a number of recent studies have shown provocative results for bottlenose dolphins (Tursiops truncatus). Even human infants don't respond positively to MSR until about 18 mos-2 yrs of age. Moreover, studies using distorted mirrors with chimps show an ability for abstract reasoning - the importance here is that the distortion must be rationalized before self-recognition occurs, and the chimps tested showed this ability. The same ability to a lesser extent has been observed in MSR studies on gorillas and orangutans (as I said, higher primates...). The bear/seal example shows not self awareness, as you would know if you read my post, but rather the operation of memory - which you stated was another quality that defines "mind".
quote: This is a complete non sequitor that has nothing to do with my post. In addition, you've now introduced two NEW terms that you're going to have to define: "thought" and "feeling". In any case, no one was talking about pets. My dog always greets me ecstatically when I come home from work (she's more demonstrative than my kids!), but I would in no way attribute her behavior to cognition, rather to an associative memory of daddy=pack leader {safety, food, petting, walkies, etc}. Please respond substantively to my posts, thanks. [This message has been edited by Quetzal, 11-19-2002]
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Quetzal Member (Idle past 5898 days) Posts: 3228 Joined: |
Okay, I think I’m starting to understand your question a bit better. Although I’m directly responding to this post for simplicity, I am basing my response also in part on your posts 37, 38, and 40. For those familiar with cognitive neuroscience, please forgive the gross oversimplification that follows.
One of the interesting things about the brain is its ability to select information from the environment, shape it, combine it with information from memory, and produce action, new memories, or thoughts as you’ve defined the term. Much of normal day-to-day thinking depends on environmental stimuli of one form or another triggering one or more of the functional, distinct neural networks in the brain that process such things as object recognition, movement recognition, auditory cues, etc (most of these are from various parts of the temporal cortex). Environment in this context can include internal state. The incoming signal is then processed/coordinated by the prefrontal cortex and parietal cortex (in humans), and an action, new neural linkage or physiological change is initiated. In essence, the brain acts to create a representation of the moment-to-moment environment through the linking of external cues, internal cues, and previously stored memory patterns. Since humans are primarily visual organisms, this representation is often a visual image. (Here’s an excellent, peer-reviewed on-line journal article from the Journal of Cognitive Neuroscience that explains it better than I can: Mental Imagery of Faces and Places Activates Corresponding Stimulus-Specific Brain Regions. The article also explains how your imagination of the lady from post #40 works.) Basically, the exact same regions of the brain are activated during processing of certain classes of external stimuli as are activated during imagination of those classes. There is, in fact, no difference between mind, thought and physical. These terms are simply convenient labels for the neuroarchitecture of the brain and how it processes information. All thought is physical — it has no extrinsic reality outside the confines of the neural networks that are preferentially activated when the particular class of object you’re thinking about is processed. Imagining a beautiful woman is based on stored memories of: the class of object women, the learned social/semantic affect beautiful, and manipulation or modification of learned and pre-existing attributes (everything from object class dress to color perception to emotional lading). The fact that we see the mental image is simply the activation of the visual cortex in conjunction with the executive control function of the prefrontal cortex. For those interested in current literature on the subject, here are a few interesting on-line journal articles from PNAS:
Emotion-induced changes in human medial prefrontal cortex: I. During cognitive task performanceEmotion-induced changes in human medial prefrontal cortex: II. During anticipatory anxiety Medial prefrontal cortex and self-referential mental activity: Relation to a default mode of brain function Integration of emotion and cognition in the lateral prefrontal cortex A resource model of the neural basis of executive working memory (I think this one is pretty cool because it discusses actual functioning of the executive processor in pulling together other brain resources and memory to accomplish specific tasks). I guess what all this boils down to robin, is that you don’t have matter producing mental — it’s all physical.
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Quetzal Member (Idle past 5898 days) Posts: 3228 Joined: |
Don't feel bad robin, none of the rest of us understand Brad either.
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Quetzal Member (Idle past 5898 days) Posts: 3228 Joined: |
Hi robin: Thanks for your reply.
quote: Pretty much. However, I want to clarify that it’s not really the brain parts that control vision, rather the brain parts that process and integrate visual imagery that are activated. Again, I apologize for the oversimplification, but for the purposes of this discussion, I think you’ve got it. Seeing something and imagining it are essentially the same thing — they use the same parts of the neocortex. The primary difference comes from processing input from external vs stored patterns. I think it’s significant (from the article) that there is apparently weaker activation when imagining a scene than when the scene is actually witnessed. This would be consistent with the idea that the brain doesn’t need to access all the neural networks responsible for seeing a new image — but is rather recall of memory and processing of a visual object class already stored in the brain.
quote: Not in so many words, no. What you are seeing in your mind’s eye as it were is an image presented to your visual cortex (or rather that portion of the brain that processes visual images) based on a representation created from coactivation of distributed patterns of neurons stored in discrete areas of the brain. In other words, your brain is making it up from whole cloth based on memorized patterns, stored emotional responses, semantics, stored perceptions (such as colors, sounds, etc). All of these neural impulses are brought together, melded/integrated, and presented as an image. She is not physical, in the sense that you can touch her. She IS physical in the sense that she is a pattern of neural impulses that can be measured — and in fact can be in some measure predicted. Where the problems arise — to forestall the obvious objection here — is that it is (currently?) impossible determine the specific neurons in a specific individual that will generate the parts/patterns/etc that compose a mental image. Why? Simply because every single individual has a different set up when you get down to that scale.
quote: Actually, that’s not a very good analogy. Look at it this way: the televised football game in your example is a representation of an actual event. A video copy of that football game is ALSO a representation of an actual event — and a fairly accurate one. There is a linear, one-to-one correlation between the object (the football game) and either the image on your screen or the video. However, the way your brain works is not like a video tape. I’m not sure how I can describe this without getting bogged down, so I’ll try another analogy (which is simplistic and collapses under its own weight as well fairly quickly, but is closer to the way I understand how the brain/memory/etc works). The functioning of the brain is more akin to a distributed computer network with some odd programming. When this computer stores something in memory (say, a picture of a woman), it doesn’t store a complete woman-image. Rather, it breaks the image down into discrete patterns consisting of various attributes of the image (say, arm at one location, mouth at another, face at another, beautiful at several others, etc although it’s obviously more complicated and not as easily quantified as that). It also stores the linkage/association between the various patterns, so that you can retrieve the whole image if desired. However, the computer ALSO has the capability to select any given attribute and combine it with other attributes stored at different times and locations, and come up with a completely NEW image based on the parts. If this new image is important enough to the computer, then the associative linkage is stored for later retrieval — not the image itself. This is how you can imagine your beautiful, non-existent woman, and even recover and manipulate it later on. However, the physical existence of the image is in the linked neural networks that store the various attributes and associations. Where the analogy breaks down is that in the brain there is no functional differentiation between the software and hardware, unlike in a computer. They are indissoluable, not discrete — the brain’s software (patterns of neurons) and hardware (the neurons themselves and the tissues that form the brain) are for all practical purposes one and the same. You'll never be able to "measure" the image in your mind, because it doesn't actually exist as an image. I hope I haven't just confused things more. [edited to remove an exceptional number of "actuallys" ] [This message has been edited by Quetzal, 11-21-2002]
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Quetzal Member (Idle past 5898 days) Posts: 3228 Joined: |
Thanks Obsidian! I didn't see your reply before I posted the above. Great description.
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Quetzal Member (Idle past 5898 days) Posts: 3228 Joined: |
Hi robin,
Obsidian pretty much covered what I wanted to say. The only thing I would stress here is that mind and brain are basically just two descriptions of attributes of cognition - the result/output of differential coactivation of various neurons ("mind") and the neuroarchitecture that supports it ("brain"). I think you're pushing the dichotomy bit a little too hard, here. They are functionally indissoluable - mental images are affects, not effects (if that makes sense).
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Quetzal Member (Idle past 5898 days) Posts: 3228 Joined: |
quote: This may be a valid statement from a metaphysical sense, but from an empirical one there's really no problem. Just as Rationalist discussed how the brain processes incoming perception and memory, the "mental image" is merely an internally generated version of the same thing - except it doesn't rely on external cues. I'm not sure this can be considered an "illusion" except maybe in a philosophical sense (i.e., questions on the nature of reality and whether a mental or cognitive affect is "real"). It certainly has no extrinsic existence outside the brain. IMO, it is nonetheless real (because measurable) for all that.
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