5 ms·

[c-f] nociception -> zero hits This surprised me. Nociception is the term you will find in the biological literature because we can't quantify how (for example

by Reelin 6y ago

[c-f] nociception -> zero hits This surprised me. Nociception is the term you will find in the biological literature because we can't quantify how (for example) a mouse "feels" when it's tail is dipped in hot water but we can quantify the behavioral response and use it as a proxy for the underlying biological mechanism. Once you separate the biological and psychological responses in this manner the reasoning seems (to me) to become much cleaner. Without higher level reasoning, nociception just needs to trigger any learning response in order to achieve survival. That's an incredibly open ended requirement. In the presence of higher level reasoning then, pain could be viewed as a secondary effect that in turn triggers some learning response. So if you have higher level reasoning you don't necessarily need pain, but you probably do need nociception plus some other robust downstream response for a reliable organism. (This seems to mostly match up with the observations about useful nonpainful pain in the article.)

gwern 6y ago
"Nociception" is one of those words which assumes its conclusion, and is a kind of dormitive fallacy. "What is pain?" "Well, it is a behavioral response to a nociceptive stimuli..." Talking about nociception may be useful once you have already gone through all of the anomalies about pain and made a good case for distinguishing between the different parts and have an implicit taxonomy. But it's not useful for my essay to just jump straight to a handwavy 'oh, you have "nociception" (whatever that is) vs motivation as an example of bi-level optimization'. And once it's all been covered, there's still no particular reason to bring in that jargon unless I need a quote or something using it, which I haven't so far.
- Reelin 6y ago
  I'm having trouble seeing it as fallacious and what (I think?) you're describing there doesn't seem to capture what I was taught nor the usage I'm accustomed to encountering in the literature. Rather I see it as splitting along an intuitive boundary - namely a whole host of low level biological responses (seriously there's a lot) versus higher level psychological (ie perceptive, conscious, whatever) phenomena. This seems particularly meaningful to me in part because most low level multicellular organisms that otherwise lack anything resembling emotion or psychology of any sort still possess (often highly conserved) analogous pathways. My understanding is of nociception being a biological phenomenon that can be measured by proxy via behavior. It's important to note that the behavior itself isn't the nociception but rather a downstream response to it. That might sound like nitpicking but it's important because nociceptive responses can and do occur (and are of clinical significance) in patients who have lost consciousness. (At absolute minimum it seems weird to me to talk about an unconscious patient experiencing pain. Surely we benefit from being able to draw a distinction here?) So (for example) the mouse tail flick test is a means of quantifying the nociceptive response which presumably also causes the rodents some mild pain. In fact it's (presumably) pain that actually results in the behavior that's measured but we can't quantify it on account of (at minimum) being unable to meaningfully communicate with them. Compare this to a physician collecting periodic "pain level" survey responses from a postoperative patient. Semi-related thought: The term nociception allows avoiding confusing turns of phrase such as "painful pain" and "nonpainful pain". Surely the apparently contradictory term "nonpainful pain" should alone be sufficient evidence that there are important distinctions to be made here (and hence justify the additional terminology)? Another semi-related thought: I find things much easier to reason about once they're "stacked" like this. Otherwise, trying to make sense of nonpainful pain, or the C. elegans thermal response, or the physiological responses of unconscious patients is downright confusing to me. Modeling it as "damage -> nociception (ie sensing) -> pain (ie psychology) -> response (ie behavior)" is much more intuitive to me. Importantly, it provides a framework for differentiating between cases that have more or less of a psychological response involved in mediating any behavioral ones, as well as allowing for cases that exhibit only physiological responses (ie nothing psychological or behavioral). (Or perhaps it just helps scientists sleep at night after they throw a few hundred plates with thousands of C. elegans each into the autoclave?)
  - gwern 6y ago
    > My understanding is of nociception being a biological phenomenon that can be measured by proxy via behavior...At absolute minimum it seems weird to me to talk about an unconscious patient experiencing pain. Surely we benefit from being able to draw a distinction here? It may be weird, but I think it's very valuable to have a taxonomy which lets you ask about kinds of pain which are not merely yoked to immediate verbalizable things. As you say, it is complex. For example, if you thought 'unconscious pain' is a contradiction in terms, then what do you make of things like anesthesia awareness or the troubling long-term PTSD-like symptoms in some people who undergo anesthesia ( https://www.lesswrong.com/posts/wzj6WkudtrXQFqL8e/inverse-p-zombies-the-other-direction-in-the-hard-problem-of https://www.lesswrong.com/posts/wzj6WkudtrXQFqL8e/inverse-p-... )? That may be 'behavior' but they certainly are not classic indicators of pain. They are not like dipping a mouse's tail in hot water and observing its movement. They do, however, despite the lack of qualia, look like learning processes about avoiding damage. And why do we apparently have consciously-perceived damage signals which can in fact motivate behavior (if the person chooses to) without the accompanying painful qualia, if nociception is merely behavioral effects? When Tanya decides to react to burning her hand on a stove by moving it away, is she really experiencing the exact same kind of nociception that you or I experience when we burn our hand on a stove and move it away? It's the same behavior, after all. I'm sure you can extend 'nociception' as a word to cover some but not all of these cases, but by that point, nociception needs the entire essay as a preface just to explain what one means by that, which is why I don't use it. It is a pointer to an entire theoretical & empirical apparatus the reader does not have. Anyone who already knows all that doesn't need to read the pain section at all as it's obvious why pain in humans is an example of bi-level losses. > Or perhaps it just helps scientists sleep at night after they throw a few hundred plates with thousands of C. elegans each into the autoclave? I think it was Steven Pinker who said he stopped doing animal experiments when he could no longer convince himself that hitting mice on the head with tiny hammers to give them brain damage was not the most evil thing he did...
    - Reelin 6y ago
      I can't escape the impression that you aren't using the same definition I am for nociception. I otherwise agree with everything you've said as far as I can tell. > And why ... if nociception is merely behavioral effects? ... This is definitely not consistent with the definition I'm using. Rather, I'm using nociception to refer to the low level _physiological_ responses to damage (specifically the set of molecular pathways that are in some way organized as part of a larger systemic response to said damage). The term pain can then be assigned to a particular qualia, leaving a few other phenomena on the levels in between the two. This makes nociception easy to speak and reason about and helps avoid some of the most confusing or apparently contradictory situations but otherwise leaves the higher level stuff (pain, motivation, various other qualia) as difficult to figure out as before. In the case of complications related to anesthesia I'd say it's squarely in a grey area that the classification scheme I'm applying here doesn't handle as well. That's due partly to the line between physiology and psychology blurring at times, and partly to the (related) fuzziness of the term unconscious as it applies to an organism's biology. Even when you're unconscious, a great deal of your nervous system still has to be functioning on some level in order to keep you alive. Since psychology arises from your nervous system, which is in turn made up of innumerable physiological effects, then it's not inconsistent with the definitions I'm using that we can observe nociceptive pathways resulting in changes to some of the higher level systems even if someone was unconscious while they were active. > When Tanya decides to react to burning her hand on a stove by moving it away, is she really experiencing the exact same kind of nociception that you or I experience when we burn our hand on a stove and move it away? I'd point out that (given the definition I've been using) we don't experience nociception but rather some higher level qualia that's downstream of it. Not knowing all that much about her case other than what appears in your article (ie pain insensitivity) I honestly have no idea. She obviously doesn't experience what any of us would describe as pain. Beyond that, how can we know what qualia someone else experiences? If we assume her to be otherwise identical to us then I suppose it would depend on exactly where in the pathway that runs from nociception to pain response her genetic abnormality manifested. > ... despite the lack of qualia, look like learning processes about avoiding damage. Precisely! As I'm modeling it, useful (evolutionarily) nociceptive pathways can give rise to avoidance or learning processes in any way whatsoever. All that's required is that their presence increase organism fitness! In the case of many simpler organisms I suspect there might not be any qualia or learning whatsoever (and thus no loss function, bi-level or otherwise, on the level of an individual organism). Rather, nociceptive pathways might simply trigger some set of immediate, hard coded, higher level responses. (Consider C. elegans in particular and I think this will make a lot of sense.) Up organism complexity a bit and you might encounter learning in the form of something resembling a simple state machine. In other words, employing nociceptive pathways to form a very basic set of associations between specific environmental conditions and some sort of danger or avoidance response. This could allow preemptively avoiding something that caused damage (and thus lowered fitness) in the past. (This might or might not be bi-level depending on what other learning pathways, if any, it interacted with.) Under such a model, it's only when you make it up to incredibly complex organisms whose behavior is governed (to at least some extent) by higher level reasoning that you might encounter things we could identify as psychology, qualia, or pain. This is where bi-level losses seem to become particularly important and also where things rapidly become incredibly complicated to model. That being said, it seems to me that a hardwired avoidance response (ie an outer loss) is likely only necessary for initial bootstrapping (in the case of sufficiently well educated humans) or in an organism where higher level reasoning is present (and thus driving behavior) but not sufficiently advanced. For example, it seems at least plausible that Tanya might have been fine if only there were some way to imbue her with a well developed understanding of the world. Then again, maybe not - it's quite possible that other internal processes have developed a dependence on the pain response being present, and so ripping it out without doing any other remodeling might well result in a "pain sized hole" and a nonviable organism.

by Reelin 6y ago

gwern 6y ago

"Nociception" is one of those words which assumes its conclusion, and is a kind of dormitive fallacy. "What is pain?" "Well, it is a behavioral response to a nociceptive stimuli..." Talking about nociception may be useful once you have already gone through all of the anomalies about pain and made a good case for distinguishing between the different parts and have an implicit taxonomy. But it's not useful for my essay to just jump straight to a handwavy 'oh, you have "nociception" (whatever that is) vs motivation as an example of bi-level optimization'. And once it's all been covered, there's still no particular reason to bring in that jargon unless I need a quote or something using it, which I haven't so far.

Reelin 6y ago
I'm having trouble seeing it as fallacious and what (I think?) you're describing there doesn't seem to capture what I was taught nor the usage I'm accustomed to encountering in the literature. Rather I see it as splitting along an intuitive boundary - namely a whole host of low level biological responses (seriously there's a lot) versus higher level psychological (ie perceptive, conscious, whatever) phenomena. This seems particularly meaningful to me in part because most low level multicellular organisms that otherwise lack anything resembling emotion or psychology of any sort still possess (often highly conserved) analogous pathways. My understanding is of nociception being a biological phenomenon that can be measured by proxy via behavior. It's important to note that the behavior itself isn't the nociception but rather a downstream response to it. That might sound like nitpicking but it's important because nociceptive responses can and do occur (and are of clinical significance) in patients who have lost consciousness. (At absolute minimum it seems weird to me to talk about an unconscious patient experiencing pain. Surely we benefit from being able to draw a distinction here?) So (for example) the mouse tail flick test is a means of quantifying the nociceptive response which presumably also causes the rodents some mild pain. In fact it's (presumably) pain that actually results in the behavior that's measured but we can't quantify it on account of (at minimum) being unable to meaningfully communicate with them. Compare this to a physician collecting periodic "pain level" survey responses from a postoperative patient. Semi-related thought: The term nociception allows avoiding confusing turns of phrase such as "painful pain" and "nonpainful pain". Surely the apparently contradictory term "nonpainful pain" should alone be sufficient evidence that there are important distinctions to be made here (and hence justify the additional terminology)? Another semi-related thought: I find things much easier to reason about once they're "stacked" like this. Otherwise, trying to make sense of nonpainful pain, or the C. elegans thermal response, or the physiological responses of unconscious patients is downright confusing to me. Modeling it as "damage -> nociception (ie sensing) -> pain (ie psychology) -> response (ie behavior)" is much more intuitive to me. Importantly, it provides a framework for differentiating between cases that have more or less of a psychological response involved in mediating any behavioral ones, as well as allowing for cases that exhibit only physiological responses (ie nothing psychological or behavioral). (Or perhaps it just helps scientists sleep at night after they throw a few hundred plates with thousands of C. elegans each into the autoclave?)
- gwern 6y ago
  > My understanding is of nociception being a biological phenomenon that can be measured by proxy via behavior...At absolute minimum it seems weird to me to talk about an unconscious patient experiencing pain. Surely we benefit from being able to draw a distinction here? It may be weird, but I think it's very valuable to have a taxonomy which lets you ask about kinds of pain which are not merely yoked to immediate verbalizable things. As you say, it is complex. For example, if you thought 'unconscious pain' is a contradiction in terms, then what do you make of things like anesthesia awareness or the troubling long-term PTSD-like symptoms in some people who undergo anesthesia ( https://www.lesswrong.com/posts/wzj6WkudtrXQFqL8e/inverse-p-zombies-the-other-direction-in-the-hard-problem-of https://www.lesswrong.com/posts/wzj6WkudtrXQFqL8e/inverse-p-... )? That may be 'behavior' but they certainly are not classic indicators of pain. They are not like dipping a mouse's tail in hot water and observing its movement. They do, however, despite the lack of qualia, look like learning processes about avoiding damage. And why do we apparently have consciously-perceived damage signals which can in fact motivate behavior (if the person chooses to) without the accompanying painful qualia, if nociception is merely behavioral effects? When Tanya decides to react to burning her hand on a stove by moving it away, is she really experiencing the exact same kind of nociception that you or I experience when we burn our hand on a stove and move it away? It's the same behavior, after all. I'm sure you can extend 'nociception' as a word to cover some but not all of these cases, but by that point, nociception needs the entire essay as a preface just to explain what one means by that, which is why I don't use it. It is a pointer to an entire theoretical & empirical apparatus the reader does not have. Anyone who already knows all that doesn't need to read the pain section at all as it's obvious why pain in humans is an example of bi-level losses. > Or perhaps it just helps scientists sleep at night after they throw a few hundred plates with thousands of C. elegans each into the autoclave? I think it was Steven Pinker who said he stopped doing animal experiments when he could no longer convince himself that hitting mice on the head with tiny hammers to give them brain damage was not the most evil thing he did...
  - Reelin 6y ago
    I can't escape the impression that you aren't using the same definition I am for nociception. I otherwise agree with everything you've said as far as I can tell. > And why ... if nociception is merely behavioral effects? ... This is definitely not consistent with the definition I'm using. Rather, I'm using nociception to refer to the low level _physiological_ responses to damage (specifically the set of molecular pathways that are in some way organized as part of a larger systemic response to said damage). The term pain can then be assigned to a particular qualia, leaving a few other phenomena on the levels in between the two. This makes nociception easy to speak and reason about and helps avoid some of the most confusing or apparently contradictory situations but otherwise leaves the higher level stuff (pain, motivation, various other qualia) as difficult to figure out as before. In the case of complications related to anesthesia I'd say it's squarely in a grey area that the classification scheme I'm applying here doesn't handle as well. That's due partly to the line between physiology and psychology blurring at times, and partly to the (related) fuzziness of the term unconscious as it applies to an organism's biology. Even when you're unconscious, a great deal of your nervous system still has to be functioning on some level in order to keep you alive. Since psychology arises from your nervous system, which is in turn made up of innumerable physiological effects, then it's not inconsistent with the definitions I'm using that we can observe nociceptive pathways resulting in changes to some of the higher level systems even if someone was unconscious while they were active. > When Tanya decides to react to burning her hand on a stove by moving it away, is she really experiencing the exact same kind of nociception that you or I experience when we burn our hand on a stove and move it away? I'd point out that (given the definition I've been using) we don't experience nociception but rather some higher level qualia that's downstream of it. Not knowing all that much about her case other than what appears in your article (ie pain insensitivity) I honestly have no idea. She obviously doesn't experience what any of us would describe as pain. Beyond that, how can we know what qualia someone else experiences? If we assume her to be otherwise identical to us then I suppose it would depend on exactly where in the pathway that runs from nociception to pain response her genetic abnormality manifested. > ... despite the lack of qualia, look like learning processes about avoiding damage. Precisely! As I'm modeling it, useful (evolutionarily) nociceptive pathways can give rise to avoidance or learning processes in any way whatsoever. All that's required is that their presence increase organism fitness! In the case of many simpler organisms I suspect there might not be any qualia or learning whatsoever (and thus no loss function, bi-level or otherwise, on the level of an individual organism). Rather, nociceptive pathways might simply trigger some set of immediate, hard coded, higher level responses. (Consider C. elegans in particular and I think this will make a lot of sense.) Up organism complexity a bit and you might encounter learning in the form of something resembling a simple state machine. In other words, employing nociceptive pathways to form a very basic set of associations between specific environmental conditions and some sort of danger or avoidance response. This could allow preemptively avoiding something that caused damage (and thus lowered fitness) in the past. (This might or might not be bi-level depending on what other learning pathways, if any, it interacted with.) Under such a model, it's only when you make it up to incredibly complex organisms whose behavior is governed (to at least some extent) by higher level reasoning that you might encounter things we could identify as psychology, qualia, or pain. This is where bi-level losses seem to become particularly important and also where things rapidly become incredibly complicated to model. That being said, it seems to me that a hardwired avoidance response (ie an outer loss) is likely only necessary for initial bootstrapping (in the case of sufficiently well educated humans) or in an organism where higher level reasoning is present (and thus driving behavior) but not sufficiently advanced. For example, it seems at least plausible that Tanya might have been fine if only there were some way to imbue her with a well developed understanding of the world. Then again, maybe not - it's quite possible that other internal processes have developed a dependence on the pain response being present, and so ripping it out without doing any other remodeling might well result in a "pain sized hole" and a nonviable organism.