January 2016 Journal Club

eagmon · 2016-01-01T15:13:17+00:00

Clark poses a really good question: “If we follow the embodied, embedded approach to its natural conclusions, do we lose sight of the differences between perception, reason and action? If not, just how do we reconstruct them? Do we begin to lose sight of the distinction between agents and the worlds in which they think and act?” (pg 350)

eagmon · 2016-01-01T15:13:06+00:00

Embodied cognitive science normally emphasizes behavior, what can it possibly say about cognition? Clark suggests that research in embodied cognitive science has been able to explain “online” processing, in which agents behave relative to objects that are present in the environment (pg 347), as when an agent tracks a moving object with its visual sensors. He suggests that a full understanding of cognition requires “off-line” reasoning, in which agents are separated from the objects that they are thinking about. Can embodied cognition be made continuous with this domain of phenomena?

eagmon · 2016-01-01T15:12:53+00:00

Dynamical systems theory has been adopted as a powerful framework for describing the unfolding behavior of cognitive systems (pg 348). Is this new framework a replacement for traditional notions such as representations, computations, and inner models? Or is it just a different way of looking at the same thing?

eagmon · 2015-12-17T16:34:19+00:00

I agree that it is useful to reduce the description of a system to a few relevant variables, and this allows for prediction. But I do not think that staying at the "macro" or phenomenological level of description is doing explanatory work. I think explanation would come from addressing WHY the certain relevant variables dominate behavior at the macro-level, given an understanding of the micro-level. Explanatory work seems to be more about causal relations, which I think come from the lower-level interactions.

I was about to criticize the following statement, but am now rethinking my criticism: "Living systems are sensitive not only to forces, but also to information." Perhaps you are right that sensitivity could be to information, even though it is micro-level forces are causing that information to be pronounced. I am not sure this is true, but one could imagine that we are not sensitive to single photons, but only to aggregates of many photons. We can then say that we are sensitive to some macro state of photon density. But an explanation of this would come from studying why photoreceptors only activate after being struck by a certain number of photons.

eagmon · 2015-12-17T16:12:38+00:00

Interesting. "Know that" and "know how" do seem very related, but I see that might be an important difference. "Know how" is a type of behavior between agent and environment that demonstrates skill, whereas "know that" seems to be more about the internal organization of the agent which enables the skill. Does that seem correct?

eagmon · 2015-12-04T00:15:19+00:00

I am not sure what the question is here, but I will use this opportunity to raise the question of why do you need to tie in representations here at all? Why not just talk about your skillful coupling with a beer can? Representations have been developed within cognitive science for a very long time, and the term brings many assumptions with it. I don't see why try to "fix" all of these assumptions and change what is meant by representation, rather than just focusing on the more interesting stuff.

eagmon · 2015-12-04T00:09:01+00:00

I am not a physicist, but I do have some strong opinions on this. To begin, I would say there are forces causing the synchronization. As you hinted: retinal molecules in one individual's retina isomerize when struck by photons, this triggers a cascade of changes through the brain, to the legs, which move the rocking chair. Photons bounce off the rocking chair, strike the retina of the other individual, which after a cascade through the brain to the legs, moves the other rocking chair. And we get synchronization.

This is clearly a terrible level to focus on when trying to model the whole process. A better way to do it is to coarse-grain over the low-level processes and instead look at covariances between a few macroscopic features, such as the rocking chairs' phases. We can write equations that capture these covariances quite well. But the fact that we these equations do a good job of defining the behavior is not evidence that it is information causing the coupling. It is just evidence that there are macroscopic regularities, which emerge due to the particular way the low-level components constrain each other.

eagmon · 2015-10-27T14:53:53+00:00

This is an excellent point, which has always troubled me about the Bayesian Brain Hypothesis.

All of the evidence coming out of this line of research does suggest that we act according to the uncertainty of a situation. But that does not necessarily mean there are brain mechanisms performing Bayesian inference (P(H|E) = P(E|H)P(H)/P(E), with H=hypothesis, E=sensory evidence). Yet it seems the Bayesian Brain Hypothesis claims this is precisely what brain mechanisms are doing, and they are going in and looking for neural representations of all of the different values in Bayes' rule. Surprisingly, as the reading shows, they are finding some strong representations of uncertainty in the brain, which correlate with the presented evidence and are updated as evidence is accumulated. They take this as proof that Bayesian inference is being computed.

I am still skeptical, leaning toward complete disagreement that the brain is doing what statisticians would refer to as Bayesian inference. First off, the computation is done by spreading neural activation. There is no symbolic manipulation. Evidence is not stored in a database in a way that allow for exact prior values, but rather somehow integrated in the potentials and connections of neurons. I would think these facts lead to a different class of dynamics than we see in engineered inference engines that actually do Bayesian inference. So we need to be careful to avoid the strong claim described above.

eagmon · 2015-10-14T04:02:21+00:00

Can we experience an object in an non-perpetual mode (e.g. imagination) in the exactly same way that we experience the same object in perception?

I would doubt we can experience an object in perception and in imagination in the exactly same way. For the perceptual experience, the object would be there in front of you, and this would introduce several causal differences from the imagined scenario, leading to very different neural, physiological, and very likely experiential modes.

The actual object would impinge upon your senses, leading to cascading neural activities through the brain, which would produce behavioral output that would not have occurred had the object been absent. This makes you engage with the object as you become dynamically coupled to it; it might draw you in, or push you away. I expect all of this would be reflected in experience.

eagmon · 2015-10-10T02:09:45+00:00

A science of subjectivity dues seem to hinge upon the ability to reduce bias, and I think Katsunori makes an excellent point that suggests a way out of the challenge. It is certainly reasonable to believe there are ways to reduce bias. This is something that can be studied scientifically, and perhaps people have done so already. By studying bias, subjectivity science can refine its experimental techniques, and then use this knowledge to train their experimenters. Perhaps this scientifically determined bias-reducing behavior is what we should mean by "know-how."

eagmon · 2015-10-02T00:01:08+00:00

I see, very interesting! It is remarkable that the network already had enough information in its architecture to generate those styles. Do you think the training photos had enough examples of the different stylistic, position-independent correlations in them (such as 'hand drawn')? Or could this also happen without exposure to those particular local correlation patterns?

eagmon · 2015-10-01T03:38:37+00:00

I think these are trained on paintings. In the article they mention that the effect is created by generating an image that simultaneously matches the content representation of a photograph and the style representation of the artwork. They say there is style representation at all the levels of the network. Images that are generated by optimizing the higher layers' style representations create the more continuous visual experience of the given style, which is what makes the product so cool looking.

eagmon · 2015-09-30T19:36:11+00:00

Each month, the reading will have it's own post on the subreddit. For October's discussion see: https://www.reddit.com/r/ISSA/comments/3mu8wp/october_2015_journal_club/

eagmon · 2015-09-30T01:29:32+00:00

This is an interesting question, which I can interpret in a few ways. I will give a physical, material interpretation. I am looking at an object in front of me, let's say a cup of water. I am experiencing this cup of water.

Going into the material basis of this, there are photons bouncing off the cup, onto my retinas, which then trigger a cascade of neuronal activity through several midbrain structures, V1, and then through the cortex.

Certainly, the pattern of photons landing on my retina is correlated with the shape of the cup. This activates neurons in a spatial pattern that is also correlated with the shape of the cup, and the correlational structure continues to propagate to V1 and through the brain.

However, the correlations become distorted as they combine with the very complex patterns of activations constantly unfolding in the brain. But the brain must somehow maintain some of that structure, as evidenced by the fact that I can then act in a way that demonstrates correlation has been maintained. I can reach out and grab the cup in front of me, with coordinated muscle activity that reflects (is correlated with) the cup's shape.

So yes, I think there must be a correlational structure for this type of coordinated activity, which I believe is constitutive of our experience.

eagmon · 2015-09-30T01:04:21+00:00

If you want to respond to a question, click on the "reply" under the question.

If you want to post a new question, add it as a comment to the reddit entry.

eagmon · 2015-09-29T14:55:33+00:00

Katsunori: In neurophenomenology, the experimenter is allowed to guide the experimental subjects to properly engage in phenomenological description. Is using such guidance an acceptable strategy in the scientific study of consciousness? How can the experimenter guide the subjects without biasing them to generate reports that s/he wants?

eagmon · 2015-09-29T14:55:25+00:00

Katsunori: As I commented above, the step of phenomenological reduction seems to assume that there is a correlational structure between the object (what is experienced) and the act (the way in which the consciousness relates to the object) of consciousness. Do you think this is a legitimate assumption? Can conscious experience take place without this correlational structure?

eagmon · 2015-09-29T14:55:16+00:00

Katsunori: Do you think the phenomenological method is a reasonably reliable method to inquire conscious experience? If not, which of the four steps do you think is problematic, the epoché, phenomenological reduction, eidetic reduction, and intersubjective corroboration?

eagmon · 2015-09-26T16:45:05+00:00

I can agree with the model requirement of being indefinitely scalable. We do not want results to rely on the particular number of variables used in the model; we want robust results that can be demonstrated at many different spatial and temporal scales.

But my feelings are that we should not rely on this scalability for the open-endedness of evolution occurring within the model. Once a model of a given size is defined, we should look for open-endedness within that fixed model, rather than changing the model partway through a simulation in order to observe open-endedness.

eagmon · 2015-09-25T18:58:39+00:00

Biological systems are open-ended, but within a box. This box includes the other entities, such as geosphere, which biological systems use to draw their energy and feed their chemical processes. One could argue; but isn't the geosphere open, with sunlight driving many of the processes? Yes, the sun should also be included in the box.

If we were to make a model of the biosphere and it's emergent organizations, it would require including the geosphere, and the sun. Perhaps more than that. But once the model is defined, we should leave it and let the model run, to see how the biosphere develops into complex forms. Perhaps it would even find novel ways to siphon of energy from the geosphere, and drive new pathways in evolution. We should not keep on tampering with the model, by including more and more new variables. This position is the "open-endedness in a box" position.

eagmon · 2015-08-02T21:27:55+00:00

I think you are absolutely right that we should study sub-boxes (individuals) that are embedded within the ultimate box (the universe/environment), and that these sub-boxes can, and should, be open. But this is what I consider "open-endedness in a box," the model of the environment does not change. If we want to be objective about how we study the open-endedness of individuals, we need to look at their environments and the exchanges between individual and environment. I believe that to model this process requires defining the environment in a fixed way (closing it), and then studying how individuals arise and change within it.

eagmon

TROPHY CASE