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visits member for 2 years, 5 months
seen Jan 29 at 18:36

Mar
6
comment Why does the human visual system produce a bright patch after staring at a bright light source and looking away?
isn't it a dark patch, not a bright patch?
Feb
29
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
My position is that it implements pleasure and pain in a machine, but most people would of course say I am an idiot for making such a claim. :) If you'd like to see and discuss this offline so that I can get feedback prior to seeking a wider audience, email me: rjbrown at gmail.
Feb
29
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
Thank you everyone who participated in this. If anyone is interested, I have been developing a little program (it runs in javascript on a web page) that implements the mechanism I described. In other words it implements operant conditioning, and graphically demonstrates the "weighting of recently followed decision paths in response to a reward or punishment".
Feb
28
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
@GaëlLaurans I don't want to debate philosophy with you. Not here anyway. I don't think that "consciousness" is anything other than an illusion, but this is not what this question is about. It is about a particular biological mechanism and what we understand of it. I used words you didn't think were appropriate, so I reframed the question for you, not using those words. I think others understood what I was getting at, so I'll leave it at that.
Feb
28
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
fyi, this is a pretty good answer, I'm going to dig through those articles. I'm come back and accept this answer soon, unless of course someone else posts one that gets even closer to what I'm trying to understand. :)
Feb
28
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
... The way I use "pleasure" as a shortcut is identical to how I might use the word 'perceive redness' as a shortcut for saying 'whatever happens in the eye and brain typically caused by light in the wavelength range of roughly 630–740nm striking the retina but occasionally being caused in other ways'. Note that I am not concerned about the qualia of redness, as I think that is a concept that is outside of hard science.
Feb
28
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
@GaëlLaurans : "reward" is not particularly accurate because it can be interpreted as being external...for instance, the treat given to the dog is the reward, but whatever happens in the dogs brain that causes it to be "positively reinforced" due to receiving the treat is the _____. (I used the word "pleasure" for lack of a better term)
Feb
28
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
And I don't really know what you mean by "dopamine neurons"...are these just things that are saying "this feels good!" or are they actually things that can contain logic for future behavior, which is the link that I am looking for? Unfortunately I can't get at the article without paying so all I have to go on is your paraphrase...
Feb
28
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
Where you say "they note that dopamine neurons suppress their activity in response to noxious stimuli"...this is getting at what I am looking for. Obviously it would be nice to see the other side, that 'dopamine neurons increase their activity in response to pleasurable stimuli', although I suppose this might be implied.
Feb
27
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
Interesting. I have to say the way they describe this "pleasure gloss" seems so subjective, since it never seems tied back to anything concrete, like a tendency to repeat the behavior in the future.
Feb
26
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
While I don't argue that there are all kinds of complexities, especially in higher mammals....I suspect that at the core, there is something fairly straightforward going on. Say it is "dopamine causes axon growth on neurons that are in their refractory period" -- that simple mechanism would explain simple learning by reward, from heroin addiction in humans to the kind of learning observed in nematode worms (C elegans). But I've never seen any literature that actually makes a such a connection (heh). About as close as I can get is wireheading.com/article/addiction.html
Feb
25
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
Actually I should probably not say "Pavlovian" as much as Operant conditioning, since I'm talking about responses we might see as voluntary. For instance, if I say 'sit', and the dog sits, and then I give the dog a treat....the pleasure from the treat somehow causes the decision path from stimulus (hear the word 'sit') to the response (sit) to be reinforced so that the dog will do the same thing in the future. A naive implementation might be as simple as "pleasure bathes the brain in a chemical that causes all the 'warm' neurons to grow stronger"
Feb
25
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
@ChrisS , I guess I'm looking for the neurobiological explanation of Pavlovian response. Specifically, how the thing that we interpret as "pleasure" causes reinforcement, and the thing we interpret as "pain" causes suppression, of previously taken stimulus -> response decision paths. The best I can find is stuff like this annualreviews.org/doi/pdf/10.1146/annurev.neuro.24.1.897 , which of course doesn't explain anything unless you shell out money.
Feb
24
comment Do we understand the non-subjective mechanisms behind pleasure and pain?
Call it "reward / punishment mechanism" if that makes more sense to you. I'm from the "brain is a biological computer" camp, so I don't see consciousness or qualia as relevant, since they aren't definable in objective terms anyway (in my opinion). Regardless, if it helps, forget I used the terms "pleasure" and just look at it as "do we understand the mechanism by which detection of goal satisfaction by the nerves causes the brain to cause recently used stimulus-response connections to be reinforced such that they are more likely to be reused in the future?"