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Saturday, June 23, 2018

Tomoko Ohyama: Action Selection in a Small Brain (Drosophila Maggot) (Friday, June 29, 9am)

Tomoko Ohyama:  
  (Friday, June 29, 9am)


Tomoko Ohyama (Speaker)
Professor McGill University


Jonathan Balcombe 
Independent Scientist and Author
Moderator

To make optimal decisions and adapt successfully to our environments, we need to make use of all the sensory cues we can detect (e.g., visual, olfactory, tactile, noxious), which initially arrive through selective channels. A central question in neuroscience concerns how nervous systems transform these originally segregated inputs into holistic multisensory representations, and how they use these representations to guide the selection of actions. Our research is focused on discovering the fundamental circuit principles that underlie these processes. To tackle this challenge, we have been studying escape behaviors in larval Drosophila melanogaster.

Ohyama, T., Schneider-Mizell, C. M., Fetter, R. D., Aleman, J. V., Franconville, R., Rivera-Alba, M., ... & Cardona, A. (2015). A multilevel multimodal circuit enhances action selection in Drosophila. Nature, 520(7549), 633.

Vogelstein, J. T., Park, Y., Ohyama, T., Kerr, R. A., Truman, J. W., Priebe, C. E., & Zlatic, M. (2014). Discovery of brainwide neural-behavioral maps via multiscale unsupervised structure learning. Science, 344(6182), 386-392.

Ohyama, T., Jovanic, T., Denisov, G., Dang, T. C., Hoffmann, D., Kerr, R. A., & Zlatic, M. (2013). High-throughput analysis of stimulus-evoked behaviors in Drosophila larva reveals multiple modality-specific escape strategiesPloS one8(8), e71706.


16 comments:

  1. Concerning personality, decision making has to happen to create the variability, that's in my understanding. From that definition, flowers would be out… I think.

    The last question about the power of processing of a single neuron is a good one. Our simulated models of neural network are not like that. Terrence Stewart from U of Waterloo was stressing how big numbers are important just to maintain quality of signal when trying to build artificial neurons, juging individual neurons as a «crappy components» 2 years ago, at the last ISC summer school. The integration produced by biological neuron transforms the signal into an holistic representation and this seems to be the key.

    Thank you very much for this exiting talk, I will enjoy reading your work!

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    1. Well... I have to go back on that one - flowers could very well decide things from what we have heard from M. Baluska!

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    2. The distinction between the decisional and the reflexive or robotic seems problematic, and perhaps even anthropomorphic or homuncular.

      Causality is causality. Biological organisms (like all physical systems) are causal systems.

      The "easy problem" of cognitive/behavioral science is to explain causally the mechanisms generating organisms' behavioral capacity: How and why can they do what they can do.

      The "hard problem" is to explain causally how and why (some) organisms can feel.

      The "other-minds" problem is to determine which organisms can feel (and what they feel).

      Human volition and decision-maiking feels causal.

      Can drosophila maggots (or drosophila) feel?

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  2. Thank you for this presentation!
    I found interesting that the public isn’t accepting “decision-making” but rather “action selection” towards the behaviour showed in your studies. Maybe 6 (or 7) options of actions aren’t enough to call the selection a “decision”. While there are a lot of different physical responses a human can do for a certain situation (even more with the language), the Drosophila Maggot is restraint to 6, for each situation they encounter, one of them being the “best” action to select each time, determining in some sense what will be selected. I don’t see that logical imperative in the action selection of more developed species.

    10 000 neurons may show a great level of complexity, comparable in its form to the human neuronal system. However 6 actions or type of behaviour in comparison to all that we can actually do limits greatly the possibility of what we could call a “decision” in my opinion. In that sense, it would be interesting to see the evolution of this “action selection” once the larvae evolve into flies and can do much more. It is quite an interesting opportunity as the actions possibilities of a same individual make a great leap. Could the fly be considered more able of “decision making” than the larva only because of this wider range of action?

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    1. Computers and robots have almost an infinity of possible actions (consider calculations whose outcome can be any number from 0 to googolplex).

      What is a "decision"?

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    2. Étienne, I think a "decision" is another of those words (a bit like consciousness vs feeling vs 20+ other annoying synonyms) that's surrounded by a bunch of what you may call weasel words: choice, selection, judgment, etc.

      If Darwin could argue that a "selection" is something which can be done without a conscious input, then another may logically argue that a "decision" can be unconscious too, as long in HIS understanding, they ARE equivalent. Formally correct reasoning based on an arguably incorrect definition means relatively incorrect reasoning? I'm making up new words. This is where my limited understanding of formal logic ends.

      It never seems to end. We are all stuck with different meanings in our individual heads, for each and every of those words. Human language works because we rely on a relatively small variance between those "personal meanings" and so, even if we're never fully "tuned" with one another, we manage to communicate with some efficiency. But the more abstract the subject (say: cognitive science), the more there will be inter-subject variance and the worse the probability of confusion. I'm pretty sure I'm just rewording some concepts I learned from you in ISC1000.

      Best we can do is what you just did: ask others what they mean, clarify definitions at the beginning of each serious conversation of this kind... which is hard, perhaps because most people, even the smartest I meet, don't often seem to realize that the meanings in their heads are NOT universal (and to their defense: it IS awfully easy to forget).

      Here's my take on "decision" : a decision would be a selection that involves a felt state by the cognizer of being the "true" causal agent of whatever direct consequences this choice may lead to. (And here I am, crossing my fingers that the words I just used do mean pretty much the same thing in both our heads! :)

      For Prof Ohyama, "decision" probably DIDN'T mean this, which would explain why she felt its use appropriate as an exact equivalent for what we call "selection" (like... mindless natural selection can be as non-cognitive as "choices" get). Or maybe it's something totally different and we'll never know what she meant.

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    3. And maybe this is crazy, but this inter-subject thing (by subject I meant cognizer, not domain of research) vaguely reminds me of CP: perhaps in order for human language to keep doing its magic, we mostly-unconsciously tune our "understanding" of most words (the ones not part of that ensemble d'encrage, maybe), based on mostly-implicit feedback from verbal exchanges with other cognizers and as a result... my "perceived meaning" of what a "decision" and a "selection" are may end up looking so much alike that I don't notice the difference anymore (ex: Prof Ohyama) and as I am pushed to learn to view them as different, either explicitly or implicitly, I then begin to perceive their individual meanings as more and more different (ex: me after listening to you for a while)... distinct categories solidify... or something of that sort, I wonder if that might make any sense to you)

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  3. Hi, thanks for the talk. This conference has me thinking a lot about the way concepts are 'reduced' in a sense to be manageable for empirical investigations. In connection to this, I was wondering about the 6 different actions that you said that a larvea can perform and how you arrived at 6. They are all clearly distinct from eachother, but would it be possible to make a longer list of intermediate sorts of action? (for example, is the same action pathway used for slow vs fast crawling, or to turn partway around vs all the way around?). Maybe a better way to say this would be to ask if these 6 actions are all or nothing responses triggered by reaching some sort of sensory threshold, or whether there are other intermediate states.

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    1. Indeed, now that you mention it: it's one thing to say that there are 6, but the categories are necessarily arbitrary... I hope you get an answer eventually! :)

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  4. C’est très astucieux d’étudier une espèce plus «simple» pour comprendre des comportements plus complexe, mais l’interprétation du phénomène reste différente. Pour le même input, il semble y avoir différent output (réaction motrice), ce qui suggère que le système nerveux traite l’information et prend des décisions. Mme Ohyama a bien mentionné qu’elle ne savait pas si l’insecte prenait cette décision ou si son système nerveux le faisait. Son point me rappelle le concept de dualisme corps/esprit. Définir la différence entre un réflexe et un mouvement volontaire dans le cas de l’insecte étudié permettrait de se rapprocher de la réponse… ou de poser encore plus de questions!

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    1. What do you mean by the distinction between whether it is the organism or the organism's nervous system that decides?

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  5. L’environnement nous bombarde de stimuli sensoriels. Ceux-ci peuvent être de différentes modalités. De cette manière, le cerveau doit intégrer les stimuli multisensoriels pour en faire sens et pour pouvoir générer l’action adéquate selon le contexte du moment. La conférencière Tomoki Ohyama nous a montré que les “Drosophila larvae” combinent différents signaux (dont la nociception) pour avoir le mode de fuite le plus efficace. Je me demande si la chercheuse pense aller regarder cela chez d’autres spécimen dans le futur.

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  6. Dr Ohyama doesn’t know if the nociception of Drosophila larvaes can be qualified of pain, or is rather just detection/reflex (she is sure they «don’t like it», but how and how much). She also said we don’t know yet where we can draw the line where a neural system can feel pain the way we usually understand or conceive this word or notion (as human beings). I think this is the main problem we face when wanting to assert the notion of sentience for legal or ethical purpose.

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  8. Thank you for the presentation. I find it amazing that such a small animal could have a sensory system as varied as the one humans have. Mr Harnad, you mention in one of your blog posts that the hard problem in cognitive science is to explain causally how and why (some)organism can feel. How can an organism that has receptors for heat, pain or proprioception not feel anything?

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  9. Progresser dans la complexité d'un système qui semble être basé sur les mêmes fonctions fait-il émerger de nouvelles propriétés?

    Quand on parle d'un réflexe pour l'être humain, on parle d'une action dont l'origine est dans la moelle épinière (l'influx nerveux n'atteint pas le cerveau). Pour les petits organismes dont il est question, nous serions donc uniquement dans le réflexe ou uniquement dans l'action réfléchie?

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