Thanks for this thoughtful post, Guillaume! I appreciate your work here. Out of curiosity, how plausible do you think it is that some of those physiological markers of stress are region-specific—i.e., increased mucus production just on the left side (if that’s the one that’s injured) or something like that. The point of the flexible self-protection criterion is, in part, to assess whether the response is targeted in a way that suggests some kind of self-representation. Obviously, region-specific mucus production is not good evidence on its own of self-representation, but it’s more interesting than the alternative!
Thanks, Bob! From experience and footnote n°19, mucus seems to be relatively homogeneously produced but it’s actually difficult to tell the production apart from different areas of their ventral side. We usually stain the glass they were gliding on so we can see that they produced more mucus when in noxious environments, but since mucus is spread along the path of the animal, it’s not clear if any part produces more than the other. When cut, we can usually see an accumulation of mucus at the site of the wound, as it has a protective role, but to me it would be better explained as some sort of inflammatory response to cell death and exposure to the environment rather than a regulatory process from the nervous system.
We have some evidence that they can react region-specifically to UV lasers where only the exposed body portion contracts/shrinks on itself, but here also we could argue that muscle contraction can be the consequence of local nerve activation (in this case: by ROS produced from UV exposition) rather than from central regulatory processes.
Thanks for this thoughtful post, Guillaume! I appreciate your work here. Out of curiosity, how plausible do you think it is that some of those physiological markers of stress are region-specific—i.e., increased mucus production just on the left side (if that’s the one that’s injured) or something like that. The point of the flexible self-protection criterion is, in part, to assess whether the response is targeted in a way that suggests some kind of self-representation. Obviously, region-specific mucus production is not good evidence on its own of self-representation, but it’s more interesting than the alternative!
Thanks, Bob! From experience and footnote n°19, mucus seems to be relatively homogeneously produced but it’s actually difficult to tell the production apart from different areas of their ventral side. We usually stain the glass they were gliding on so we can see that they produced more mucus when in noxious environments, but since mucus is spread along the path of the animal, it’s not clear if any part produces more than the other. When cut, we can usually see an accumulation of mucus at the site of the wound, as it has a protective role, but to me it would be better explained as some sort of inflammatory response to cell death and exposure to the environment rather than a regulatory process from the nervous system.
We have some evidence that they can react region-specifically to UV lasers where only the exposed body portion contracts/shrinks on itself, but here also we could argue that muscle contraction can be the consequence of local nerve activation (in this case: by ROS produced from UV exposition) rather than from central regulatory processes.
Maybe the best bet to search for self-representation would be in the way they extrude their pharynx to search their surroundings for food; but current evidence shows that these mechanisms are almost entirely based on chemotaxis, especially since their pharynx can basically keep searching for food and munching while cut from its host (yes, it’s weird). However, there is still definitely some sort of communication between the pharynx and the brain to decide when to stop and when to continue moving.
I never tried drawing a white spot on their head and placing them in front of a mirror—maybe we should try!
All very helpful, Guillaume! Thanks for the quick reply.