Great post, I really like this series of posts from RP and look forward to the rest. I have a few comments about this one:
-Should a distinction be made between operant and classical (associative) conditioning in the requirement for valence to facility learning? I agree that learning to associate positive or negative experiences with an environmental state (such as probcius or sting extension reflexes in honeybees) require a valence cue.
However, the role of valence is less clear during operant condition which is often used to tune how a reflexive sensorimotor action is executed. For example, fixation paradigms have been used to study insect flight behaviour (an insect tries to position a visual object frontally) - if the coupling between their turning behaviour is artificially reversed (such that by turning right the object also appears to move right) an insect can learn to reverse the usual direction of their motor output to regain control visual position of the object. This is definitely (sensorimotor) learning, but doesn’t require an extrinsic valence cue to achieve (although the insect has an internal prefered world state it is comparing its sensory experience to, I’m not sure that the state error is analogous to an internal valence cue).
-The length of a life span correlating to the potential for learning are not entirely clear, as I think that most relatively long lived insects still have a lot of reflexive behavioral cues they rely on (and perhaps tune slightly with operant conditioning as above). Eusocial central place foragers a clear exception in that they are well known to have excellent capability for navigation and associative learning.
But in the example of long distance insect migrations (e.g. Monarchs butterflies or Bogong moths), most seem to simply follow genetically programmed instincts about where to go. Intuitively one might think that these insects will need to learn which flowers to forage on at different stages of their migration, although it could be that the have genetically programmed innate preferences for flowers that work well along the entire migration route. There is a bit of work on associative learning for Monarch butterflies—it seems they are capable of associative learning over a time scale of days (very slow compared to bees which can manage single trial learning), but they also have strong innate preferences for flower colours.
-How would you class an animal releasing a warning pheromone as a reaction to noxious stimuli? Lots of eusocial species do this to summon extra soldiers to attack a threat so I would probably call that case a defensive behaviour (in addition to being a physiological response).
Yet, in other cases warning pheromones are released to warn other conspecifics (for instance, aphid alarm pheromone causes dispersal) - for the insect being attacked this isn’t really defensive as it doesn’t benefit from the other aphids avoiding the threat (which are themselves moving away from the signal of a noxious stimulus); maybe it is almost analogous to a chemical vocalization?
Aside, even some plants issue chemicals that warn other plants or summon protective insects when they are attacked by herbivores.
Thanks for the compliment and especially for the thoughtful reply. I’ll take your comments in turn.
In the third part of the mini-series on features potentially relevant to invertebrate sentience, we discuss a number of learning indicators, including both classical and operant conditioning. That post is going up June 12. I would be interested to hear your take on the relevant sections.
There is certainly not going to be a perfect correlation between lifespan and potential for learning. (Indeed, there might not be any correlation at all.) The claim that we’re defending is that, in general, longer-lived organisms would benefit more from learning abilities than shorter-live organisms. We expect there to be exceptions both ways (i.e., relatively short-lived organisms that would benefit from learning abilities and relatively long-lived organisms that wouldn’t). Much depends on context of various kinds. Your point about the learning abilities of monarchs vs. bees is well-taken. In future work (to be published mid-July), we take an especially close look at eusocial insects, which are pretty amazing.
Your question about warning pheromones is a great example of a difficulty that has hounded us for the length of the project. Classifying and assessing complex behaviors is context-sensitive. I think you’re right that warning pheromones could fall into at least three categories. (Or maybe different pheromones fall into different categories?) Assessing the evidential force of these features is often even more context-sensitive. A behavior that looks like good evidence for sentience in one context doesn’t always look like good evidence for sentience in a different context. (e.g., a human reporting “I am in pain” is normally great evidence of painful experience. A very simple robot programmed to utter the same sounds is not great evidence of painful experience.)
Great post, I really like this series of posts from RP and look forward to the rest. I have a few comments about this one:
-Should a distinction be made between operant and classical (associative) conditioning in the requirement for valence to facility learning? I agree that learning to associate positive or negative experiences with an environmental state (such as probcius or sting extension reflexes in honeybees) require a valence cue.
However, the role of valence is less clear during operant condition which is often used to tune how a reflexive sensorimotor action is executed. For example, fixation paradigms have been used to study insect flight behaviour (an insect tries to position a visual object frontally) - if the coupling between their turning behaviour is artificially reversed (such that by turning right the object also appears to move right) an insect can learn to reverse the usual direction of their motor output to regain control visual position of the object. This is definitely (sensorimotor) learning, but doesn’t require an extrinsic valence cue to achieve (although the insect has an internal prefered world state it is comparing its sensory experience to, I’m not sure that the state error is analogous to an internal valence cue).
-The length of a life span correlating to the potential for learning are not entirely clear, as I think that most relatively long lived insects still have a lot of reflexive behavioral cues they rely on (and perhaps tune slightly with operant conditioning as above). Eusocial central place foragers a clear exception in that they are well known to have excellent capability for navigation and associative learning.
But in the example of long distance insect migrations (e.g. Monarchs butterflies or Bogong moths), most seem to simply follow genetically programmed instincts about where to go. Intuitively one might think that these insects will need to learn which flowers to forage on at different stages of their migration, although it could be that the have genetically programmed innate preferences for flowers that work well along the entire migration route. There is a bit of work on associative learning for Monarch butterflies—it seems they are capable of associative learning over a time scale of days (very slow compared to bees which can manage single trial learning), but they also have strong innate preferences for flower colours.
-How would you class an animal releasing a warning pheromone as a reaction to noxious stimuli? Lots of eusocial species do this to summon extra soldiers to attack a threat so I would probably call that case a defensive behaviour (in addition to being a physiological response).
Yet, in other cases warning pheromones are released to warn other conspecifics (for instance, aphid alarm pheromone causes dispersal) - for the insect being attacked this isn’t really defensive as it doesn’t benefit from the other aphids avoiding the threat (which are themselves moving away from the signal of a noxious stimulus); maybe it is almost analogous to a chemical vocalization?
Aside, even some plants issue chemicals that warn other plants or summon protective insects when they are attacked by herbivores.
Hi Gavin,
Thanks for the compliment and especially for the thoughtful reply. I’ll take your comments in turn.
In the third part of the mini-series on features potentially relevant to invertebrate sentience, we discuss a number of learning indicators, including both classical and operant conditioning. That post is going up June 12. I would be interested to hear your take on the relevant sections.
There is certainly not going to be a perfect correlation between lifespan and potential for learning. (Indeed, there might not be any correlation at all.) The claim that we’re defending is that, in general, longer-lived organisms would benefit more from learning abilities than shorter-live organisms. We expect there to be exceptions both ways (i.e., relatively short-lived organisms that would benefit from learning abilities and relatively long-lived organisms that wouldn’t). Much depends on context of various kinds. Your point about the learning abilities of monarchs vs. bees is well-taken. In future work (to be published mid-July), we take an especially close look at eusocial insects, which are pretty amazing.
Your question about warning pheromones is a great example of a difficulty that has hounded us for the length of the project. Classifying and assessing complex behaviors is context-sensitive. I think you’re right that warning pheromones could fall into at least three categories. (Or maybe different pheromones fall into different categories?) Assessing the evidential force of these features is often even more context-sensitive. A behavior that looks like good evidence for sentience in one context doesn’t always look like good evidence for sentience in a different context. (e.g., a human reporting “I am in pain” is normally great evidence of painful experience. A very simple robot programmed to utter the same sounds is not great evidence of painful experience.)