cognitive psychology – PsyPhi

Back on the anti-representation train

I have the wonderful opportunity at the moment to teach methods of Ecological Psychology and Dynamic Systems Theory, their philosophical basis, theoretical concepts, how they require certain analyses, and what kinds of explanations this/these perspective/s give. I am lucky to be in a department that is (as of yet) wholly representation-dominant, yet are curious, interested, and promotes theoretical plurality. I just personally keep running into the wall of not being able to believe in representations as an ontological foundation for psychology.

Perhaps someone can convince me otherwise. Four different ways of defining representations are as follows. The ‘literal-structural’ version, which amounts to old-school phrenology, i.e., it is literally neurons/physical structures in the brain that are/store representations. I do not meet many researchers that hold this belief. Mostly, I find this belief in folk psychology, because I think it is an easily envisionable version that has surface validity through movies and tv-series that talk about brain function in this way (the British “knowledge”-panel program QI is an example of this). Second, you have a ‘literal-activational’ version, which amounts to what I would call modern phrenology, i.e., it is the electrical activity in the brain that are representations. This and the literal-structural version are sometimes unhelpfully combined. fMRI, MRI, PET and similar techniques try to get at this by measuring blood flow to different parts of the brain, although it is an indirect technique since the assumptions go 1) thoughts, feelings, reactions, cognitions, etc, are produced in the brain, 2) in the brain there is electrical activity presumed to indicate usage of a particular brain area, 3) when a brain area is used, increased blood flow is seen to the area, 4) blood flow can indicate brain-part-usage and therefore thoughts, feelings, reactions, cognitions, etc. Third, we leave the literal kinds and hop the fence to ‘symbolic-mathematical’ accounts, that representations aren’t literal parts in the brain, but a more abstract version, instantiated by mathematics. This version is often combined with the methods of the ‘literal-activational’ version, and I’ve listened to several, prominent cognition scholars that have expressed beliefs in how mathematical equations are running in/produced by the brain… somehow. And several of them, upon explaining how the math got there to begin with, used various kinds of nativism as explanations. I’ve also found network-explanations, or ‘patterns of activation across groups of neurons’ and similar, both here and in the fourth grouping. Fourth, the ‘symbolic-abstract’ version, which often amounts to more hand-waving than the third, where representations are not mathematics, they can be groups of patterned activity, sometimes explained as dynamic clouds of activation of different kinds.

I just don’t find myself believing in any of them. With the literal-structural versions, there’s actually been attempts at finding them. Or, they were called Engrams at the time, and could simply not be found. There is little wiggle room in this description, either you can show empirically that a literal neuron/structure changes when you memorize something new or change a memory, or you are more or less forced to accept that this story isn’t the best one. Which is why I think so few ascribe to it beyond non-experts (e.g. folk psychology and AI researchers, the latter of which are almost exclusively dependent on this version).

The literal-activational version is far more popular however. In part, a lot of support comes from the medical sciences, where, if you poke a brain with electricity while talking or playing an instrument, are often disrupted in their activities. Or, if you have particular cognitive issues, a neurosurgeon can often quite easily pick out where a tumor is pushing up against (if you have a tumor, which isn’t always the case). This evidence is a muddle to me, since you can also completely remove brain parts, even half the brain(!), and still maintain functioning -which seems to me to break down the validity of this narrative. It is usually explained away with brain plasticity, but if brain plasticity is true (in reference to literal-activational representations), then the reliability across time when looking at the same brain, or when looking at different brains, break down (Anderson’s book After Phrenology is an interesting read). In fact, if either of the literal accounts are true, we should have specific structures and/or patterns of activation found to be stable across time for a single person, or across people. And if this were substantiated by research and industry, where the f* are our mind-reading helmets? Often when I bring this point up in discussions, neurocognitivists retreat back to neurons and how we don’t have the technical expertise to measure individual neurons in the entire brain simultaneously to answer that question. There are a couple of practices that seem to support the view however, sending a whole bunch of electricity down the spine seems to help people with motor-function constraints to regain/less disruptive movements. Which is great. But it is a far cry from being specific in the sense that’s needed to support the theoretical position. There are also toy versions like moving cubes on a screen using EEG, and beyond taking a surprising amount of time to train, once the person leaves the room and comes back the next day, the process restarts and cannot be continued the next day. I understand this position though, I do, I can deal with living alongside it (although I am extremely frustrated by grant-decisions heavily favoring neuroscience). However, the evidence surrounding it promises a specificity, a specificness, of identifying recurring activation/al patterns, that very clearly both empiricism and practical implementation does not live up to.

We get to the symbolic version of brain activity, particularly mathematical accounts, the story about activation standing in for representations seems to me to either give up the ontological foundation of representations (hand-wavy “it’s maths” explanations), or simply add another step of assumptions to the literal-activational account. Now, not only do you have to solve the above problems, but you also have to explain why a conglomerate of biology-chemical-electrical activity would instantiate an accounting tool that humans created to begin with. A good tool, mind you, but human-created nonetheless. From this point, of course, you get all kinds of half-to-non-scientific abstractions about how everything in the world is made up of mathematics, a tall-tale version of ruthless reductionism, and you of course lose the ontology of the phenomena you are trying to explain. You’d be surprised who I have heard literally say, in very public circumstances, that babies run physics equations in their brain that they are born with. And they are given so much research funding. My personal grievances aside, we have the symbolic-abstract version, which I find the most convincing, perhaps surprisingly. In some ways it can be seen as a less specific version of the literal-activational/structural versions of representations. Often, the explanation begins from the point that larger structures in the brain are not specific specific, but rather, there may be particular patterns of activation across structures that are recruited in a kind of online fashion. The patterns can thus “move around” the brain in part-deterministic-part-stochastic ways, meaning that, if you think about a cat, you come into that time-period from a different point than if you had been asked to think about it the next day. So, a similar pattern would repeat, but, not necessarily the same neurons and not necessarily all the same structures. This account would additionally fit the empirical findings detailed in After Phrenology. It would also explain how fMRI and MRI studies find general trends (averages over both spatial structures, and averages over time -how much time of course depends on imaging technique) across people. However. If this account is true, then I will most likely never get my mind-reading helmet, because it would be near-impossible to know how a particular pattern of activation would only stand for one object, and, what that pattern would look like the next day. Of course, an objection could be that it is not objects that are represented, but everything that we are exposed to continuously at the same time (plus memories, plus …). But then it would be nigh impossible to sort out which components of input lead to what activational pattern, particularly if that pattern changes over each instance. I do have some sympathy for this position though, as it seems to me to better fit more of the empirical data, but it gives a version of representations that is practically unusable except as a theoretical description.

To sum up. The more literal narratives of representations gives promises of specificity (particularly the medically inspired accounts), but this just hasn’t materialized on the practical-functional end, and, there is plenty of contradictory empirical evidence. The symbolic-mathematical perspective seems to explain some of the contradictions due to the shift of ontological basis to mathematics, but this step seems fantastical as it requires another set of beliefs to accept an ontological reality of maths. The world isn’t maths. The world is the world. Although it can be described in detail by maths. Lastly, we have the more symbolic-abstract-network version, which seems to me to cover most of the empirical literature and dispel the contradictions of the literal account. However, this perspective seems to me to not live up to the definition of a representation to begin with, losing the ‘specificness’ of representations that at the outset make them attractive to AI-researchers. In a recent interview with a prominent Ecological Psychological researcher, they were reacted to with a “I don’t see how anything could be anything else than computation”, and I have the exact opposite view, I have a very hard time seeing how anything could really be computational (that says something of value about psychological phenomena beyond simple, mechanical, surface level generalisations).So what is the brain up to? Biology does not preserve components that are not used.

Well, finally, we have the Raja-ian version of brain-activity, but we have left the realm of representations. Where the brain and central nervous system is seen more as a tuning fork, a resonance device, than something harboring ‘the real world’ in one way or another. As a non-content explanation of the brain I have high hopes for this perspective, and perhaps it is compatible with some versions of the abstract-variational-network version of representations (which do not live up to the demands of what a representation would be in the first place). But, just as more literal proponents of representations wait for the technological solutions to their theoretical problems, I’ll have to wait out the empirical evidence and theory-building required for a fuller account of the resonance narrative.

A non-content brain. 2/2

There is some misreading of Ecological Psychology due to the way direct perception and information detection are spoken about. Direct perception seems to carry with it a connotation of specificity (guarantee), that the world is in the specific way it is seen, we cannot be wrong and we have all of it available at once. There is an explicit rejection of the poverty of the stimulus. But pause here a second, because this is what information detection is about.

First, the production of photons exist regardless of my existence. They will bounce around on surfaces, be partly absorbed/reflected depending on surface makeup, and create structure (if we were to put an observer somewhere in this space). In this instance, it would be most appropriate to simply refer to this as the optic array, or structured light. It is not that this structure carries content, it simply is structured (and continuously re-restructured) in a manner specific, and guaranteed, by the surfaces around it and the medium(s) by which it came to any specific point.

Second, for a very long time, organisms have grown to be able to detect such structures. I cannot remember the organism, I think it’s a deep water fish, but a precursor to our eyes was sensitive only to ‘light’ or nothing. Since, eyes seemed to catch on as an important way (in an evolutionary sense) to keep developing, which in our case meant becoming more and more sensitive to the structure that light carries with it. There is no reason to believe that at once, in any given slice of time, that we can perceive all of the structures that light carries with it. ‘We see what we see’ and if we want to see more, we have to explore whatever we are trying to see by moving, to literally detect structure that may be occluded to us from one vantage point (like “illusions”), or, we simply have not looked at something for enough time that we have yet to learn to discriminate between smaller differences in structure in the optic array. I can, in the end, come to the same or a different conclusion about what I saw, depending on the history with which I came into the situation, but also depending on which parts of the array I was detecting, or trying to detect, at the time.

Third, we see and hear and detect pressure and other things at the location at which that information is available (but as you might expect, we do not necessarily detect it, but, we have the possibility to). The firing of cells in the eye that propagate to the brain, never held content, and was always in a ‘language neutral’, ‘symbol neutral’, non-content “signal”.

However. Vicente Raja Galian pointed out that so far, I have yet to assign any function to the brain, and it seems appropriate that we should since it is a curious structure and we have kept it evolutionarily. Keeping a biological structure does not entail function or even importance (in the strictest interpretation of the word), but it seems to me to be a very valid point. So far, I am having issues arguing against that the brain is for ‘where’ (on/in the body) and ‘in what order’. Something is detected at the foot as intense pressure, I look down and see a dog biting it, this (in a sense) creates a loop where whatever signals are propagated back from the retina together with the pressure of the foot are happening simultaneously. There is simultaneous increased firing from two directions into the brain. Solely by being simultaneous in a close (geographically) space, intertwines the two. Experience does not happen in the brain, it happens in the relationship between body and environment, but one thing happening before, after or simultaneously, may come to be through having a space within a body where the ‘where and when’ co-exists. Because a lot of neural propagation going on in the body, in one way or another, travels to one collected structure, the brain. No content is needed, all we need to “know” is where and when, which is simply (although plastic) a matter of bodily geography.

I also have a sneaking suspicion that the brain is for drawn-ness and repulsion, but that currently requires more thought and explication before I feel comfortable laying it out publically.

A non-content brain. 1/2

In search for a non-content perspective of brain activity, I often feel I come up empty handed. Either non-content is not really directly spoken about (e.g. Anderson, 2014, and isn’t really intended to -it does however very importantly free us from other assumptions), or when a positive account is languaged like “but the brain does this or that” is more confusing to me than clarifying. So I’ve been criticized for not having my own positive account, or even a reasonable idea of what I expect or accept as a good answer. So here’s a minimal start.

With a non-content view of the brain, I mean that, any and all activity in the brain is not representational, symbolic, or in any way carries any content in the sense that if I show you a picture of a cat then your cat neurons are firing (simplified of course). To clarify this further, Anderson to me gets close, talking about the brain in a functional sense, non-reductionally. Instead, everything “magic” already happens in a) the continuously ongoing relationship in a given organism-environment system, but importantly, b) in the sensory system(s) (e.g. eyes, ears, legs, body at large, etc.).

All that really would happen after sense-making at the sensory system organs, would be probabilistic (and likely functional as Anderson suggests) networks of directed firing. I mean this in quite a specific way. For example, eyes connect to brain at specific sites, electrical signals propagate from eye to brain at specific sites and an initial direction, but after that, neuronal firing is (due to specific reasons) a matter of what current state immediately neighbouring neurons are in. So, if one neighbour is in post-firing and another not, the latter has a higher likelihood of firing. At a larger scale, what we will see in an image of the brain is a dendritic spreading that at the time is part stochastic (and re-used) because neurons in this sense are non-essential. Of course, if a network of neurons (with part stochastic spread) are firing together, like the oscillators they are, they are more likely to fire together again at a short time scale (they are also likely to fire together again at a longer time scale, but less so. Here is where a lot of the misinterpreting of brain images (by cognitivists usually) exist if you ask me, neurons and often networks of neurons are seen as essential or carrying content so we make a one-to-one mapping between an image of a cat and the specific neurons that are firing -but there are far too many confounds for this to be a confident finding.

Like anything dynamic systems tells us, future (or current) state depends on the history of the system, and because there is no real beginning to any one individual’s brain activation, I cannot bring myself to believe that the brain ‘starts a series of neuronal firings to achieve a body movement’. Body movement is in relation to environment, that’s where the decision is made to move a certain way, that’s where “cognition” is. Actually moving a body part, yes, that is connected to brain firing -but not (necessarily) in a causal manner. Direction, intentionality, agency, mind, is not in the brain, it is in the relationship between organism and environment, a course of body movements is already given by that relationship, at most and only in this sense, is the brain a “mediating” structure.

An aside. Blood flow through the brain is already always ongoing. Co-developing with all our other organs, will also play a (perhaps minor) part in where and how a probabilistic dendritic neuronal network of firing will move through the brain. Then, wherever that was, will need more blood flow (as is the basis of most imaging techniques), however (and again), because the route through the brain is part stochastic anyways, it makes no sense to talk about brain regions, networks, or neurons in any detached, representational, contenty, essential, manner. Re-use, on the other hand, and functional (roughly similar from time 1 to time 2) networks of firing, over time, is what the brain is up to. Because of this, with current imaging techniques, they can get us worse or better probabilities of ‘what’s going on’, and interventions can hit or miss depending on individual and time of intervention. But if you are interested in human behavior, it is probably not the most productive scale or scope at which to analyse it (although there’ll be some absolutely beautiful oscillator dynamics going on at a neuronal level).

The first response ever to anything non-representational, ‘yeah, well, how do you explain closing your eyes and thinking to yourself “I am going to move my hand now” and then move your hand?’ Well, firstly, the question already assumes the brain did it, so it is always an unfair question. But. Nevertheless it needs to be answered. As always, closing your eyes and remaining still isn’t some kind of magical state where you are closed off to the world, you are still continuously co-constituted with it. In fact, I can predict that sentence above to be said because of the type of conversation we are having -the history of the system already determines and constrains direction and force into and with the future. But most importantly, the experience of the “decision” in the ‘word-sentence’ that you are thinking doesn’t ‘come from’/isn’t instantiated in the brain, it is already a decided course due to the relationship between you and the environment that you are in -alike other body movement through the world. I could respond and say “do you know how many people choose their arm/hand to move when we get to this point in the conversation? 100% so far”, that is how constraining our history is (and the direction it already gives us) even on a short timescale. You could respond “ok well now I can think of anything and maybe I won’t even move, just think that I will but don’t”, and we can go around forever in this type of dialogue, entrenching us further into that dissonant attractor state. The last point is, that question doesn’t really tell us what is going on, at worst it is a defensive reaction, at best a curiosity that likely can be satisfied empirically or by appealing to the continuously ongoing activity of our senses and sense-making.

Theory of Mind really is dead.

Ecological Strategy Favoured Over Computational

I am in the process of writing up my master thesis experiment but can reveal that in this specific task, participants use ecological strategy 53% of trials, computational strategy 26%, a second ecological type strategy 13% and other/non-distinguishable 8%. Also, accuracy is higher when using ecological strategy (63%) compared to computational (32%) and the other two. Inter-rater reliability ~.85. Exciting! It may support the ideas that screen-based research can indeed yield empirical results in Ecological Psychology (and add to that, in favour of Ecological Psychology). I have however yet to analyze the data statistically, to be continued!

Disappointment as a consequence of EP. Good riddance, I say.

I believe many will be disappointed to find out that there is no entity called consciousness. There is no entity called self. There is, in fact, nothing of any of this kind. All there is is a half-assed semi-reproduction of sensory input. Reproduction here almost misleads one however, it is not production, it just is perception. Conscious cognitive acts, just are perceptions. There is nothing over and above perception to be had. Creativity is just the rearrangement of perceptions. Imagination is just the semi-production of perceptions.

Our brain doesn’t store anything in that sense, it is solely repeated exposure to specific parts of the ambient energy array, allowing perception to continue past the now and lend itself to re-perception without the need for the concurrent exposure in the environment. It solely speaks to the persistence of environment, objects and agents. We are truly active explorers, and what we explore the most, we become able to more so specifically explore. It is about perceiving what is there to be perceived, what was there to be perceived before but because of repeated exposure we are more and more able to discriminate between smaller and smaller changes in that ambient energy array. Indeed it is what experience is. Perception and movement is all there is. “All”. It gets us very far.

Perceived sense of control, is just that. Perceived. Ecological Psychology or rECS leads to discussions on free will, and rightly so. Many proponents of free will argue that we need it to be able to be held accountable for offenses. I argue we still can even without. It is enough that we perceive our actions to be of free will, it doesn’t have a bearing on the metaphysical account of free will. As long as humans experience the world as if we control our actions in it, we can still be held accountable.

Unofficial lecture on representations, intro to rECS and Master Thesis

So I’m writing my thesis on abandoning representations and replacing it with ecological psychology, and this is bits and pieces of what I’m writing. To fit one lecture I obviously had to leave out a whole lot of information. Even information that would change some of the subject matter. The idea I had was to introduce, not even all of, the basic stuff I have in my thesis and was hoping to get some critique and comments on it.

Link to video; http://bit.ly/ZiqZo3

Most sources used in the video;

Blogs and blogposts
Scandinavia And The World (illustrations); http://satwcomic.com/
Eric Charles blog post; http://fixingpsychology.blogspot.se/2013/04/what-do-we-know-for-sure-about-brain.html
Wilson and Golonka’s blog; http://psychsciencenotes.blogspot.se/

Books
James Gibson – The ecological approach to visual perception
Anthony Chemero – Radical embodied cognitive science
Pfeifer and Bongard – How the body shapes the way we think
Gerd Gigerenzer – Rationality for mortals
Bem and de Jong – Theoretical issues in psychology

Articles
Tim van Gelder – What might cognition be if not computation
Fodor and Pylyshyn – Connectionism and cognitive architecture: A critical analysis

Nonsense.

The traditional misperception of the brain as infinitely complex perpetuates unfounded credit towards it when rationalising behaviours. Participants compare their strategy in retrospect to that of mathematical capability of a computer. That is, the participant is not capable of mathematically computing rapidly enough an interception point, thus explaining their failure to live up to a clear predictive strategy. “If only we could realise the full potential of our brain.” Nonsense. The fallacy of the brain as the pinnacle of biological evolution, is used as a norm and blamed in an explanation of failure. It is thus perpetuated in every aspect of rationalising, but not for the observable behaviour. If you have a doctrine that constantly explains failure on the same terms, both a priori and a posteriori, there is good reason to examine it even closer. Observable behaviour is supposed to be the basis of assumption, indication and generalisation. I propose that traditional psychology does not. I propose it solely deals with antecedent assumptions and consequential rationalisation. Behaviour is only a means to the end of perpetuating the doubtful conclusions already postulated in the assumptions. There is a strong need for reinvention, to say the least.

Non-(?)necessary discrimination between actualisation and realisation

In Gibson’s perspective, are they not really the same thing? Perception in Gibson’s terms seem to imply that “acting on” is implied by perception. I am confused with how this unfolds in practice. Take the definition I outlined in a previous post, that realisation is the perception of a possible interaction as opposed to actualisation which is the instantiation of an interaction. Perception is interaction?!

I think of studies on mirror neurons (if they exist, if it is assumed they do not do what trad. cog. sci. say they do and instead are simple sensory modality + movement overlap/association -happenstancily, not predeterminally- neurons/cluster of neurons/areas) in that, ‘visual perception of’ and ‘engaging in’ is the same thing physiologically -since, as I suppose Gibson would have it, perception (regardless of which kind) includes oneself always. If one is not separated from the environment, then one perceives what others and oneself do as the same thing (obviously, humans distinguish between self and others, but, even then, not innately -which in itself doesn’t have to decide in the matter, but may inform). Maybe this could be seen as the process behind empathy or sympathy for example. I feel disgust if I perceive rotting meat, because perception is that of systems and parallel modalities and not separate “input pathways”.

They may however have a practical, communicationally, significant aspect to them since it makes it easier to explain perspective or experience of a situation in those terms. Though I also get the feeling that they refer to the false dichotomy of conscious/unconscious perception. Something superfluous to the ecological model. Indeed, it perpetuates the false assumption of consciousness per se. Note here however that “how we consciously experience” situations, is central to psychiatry, for example, and can be useful to navigate within in therapy. Experimental psychology however, should refrain from allowing this massive source of frame-of-reference error to guide theory too heavily.

Temporary conclusion on subjective/objective perspective and affordances (3/3)

I should stop writing “Temporary” in front of my titles. It should be presupposed that all theory is always temporary.

I may have gained an understanding leading on from the previous posts on subjective and objective perspectives, on the definition of affordances and perception, relating Gibsons ecological view with traditional philosophy and cognitive psychology.

As Gibson defines perception of the environment and oneself as the same thing at the same point in time, neither a subjective nor objective perspective discriminates between what is perceived and not. Both are perceived, always, for any point of location of observation. This is true for both an objective perspective and a subjective perspective. Since both are perceived, any concept related to perception will necessarily imply this conclusion. If one assumes a non-static observation point (as we almost never have a static one, we move), then the experience of perceiving affordances are of both environment and self always coupled, non-separable, always pointing in both directions. This conclusion is then perpetuated by direct perception.

The only issue I am facing with this is that when one wants to begin defining from a philosophical perspective, one immediately wants to ground theory in realism, inviting subjective and objective perspectives, mind-dependence and independence, since, it is a way in which we can discriminate between dualism and monism for one. Coming from a strictly ecological perspective, or perhaps, Gibsonian ecological perspective, and grounding theory from ecology, one does not need these perspectives since they do not discriminate between anything, they do not show any difference when either perspective is subsumed. It should then be for this reason that Gibson confuses me when he speaks of nothing being subjective nor objective or both, because the meaning of those perspectives do not have a bearing on experience or theory, i.e. change the perspective per se. They are presumably brought in because of tradition and norm, because they are words used widely in the classic literature -and are most fitting in philosophically (Hegelian argumentally) founded perspectives like traditional cognitive psychology.

Are affordances retained? 42.

You see, it doesn’t really matter. We are not in the area of discussing the physical world. We are not concerned with matter in the ontological sense at this point (although we, as written about in several previous posts, obviously take a realist stance if forced to define things in traditional linguistics and perspectives). The reason the answer is 42, then, is because we perceive and act in the “coupled” perspective (self & environment) always. We assume affordances are retained, that the ground affords walking if we should want to walk tomorrow on that surface. But the question is misleading, because it forces upon the answerer to provide an explanation from a physical perspective. It forces one to deal with terms in a traditional cognitive language. It forces discussion on words like realism, objective, subjective, memory (for past) and imagination (for future). When I am lead to believe Gibson would rather speak of perception, movement, senses and affordances.

On subjectivity/objectivity of affordances… (2/3)

Building on the previous post.. Reading Gibson.. I think, unfortunately, that there is good use of communicating an objective and subjective perspective to clarify what there is and isn’t. This is an objective perspective in itself. Besides that, consider the point of which misperception of affordances comes into play, just by the word “misperception” there is an implication that -in a subjective perspective we may perceive an affordance, that in actual fact, is not there. Then, it has to have not been there in an objective sense to begin with.

I appreciate the fact that Gibson tries intently to explain and visualise the non-subjective/objective nature of affordances themselves -I am on board here. It’s only that, the dichotomous relationship of subj.-obj. bears on the information communicated and is entrenched in the linguistics. I do not think we can escape them unless we resort to dualism in some sense. Each time an affordance exists and not exists it must be said in a subjective sense. Unless, we wish to abandon that specific set of philosophical underpinnings.. is that possible?

[Edit, 12:17, 3/4-2013]
[Gibson also seems to confuse me at times in this area, he speaks of affordances very strictly as relationships in an initial definitional sense, but goes on saying that objects always afford their affordances to actors in a .. behavioral sense? But this is not entirely true, it is not only in a behavioural sense that he speaks of them as retained. He doesn’t speak of them differently in separate philosophical terms either (ontologically/epistemologically).. Could it be the distinction between realisation and actualisation that separates Koffka’s and Gibson’s view here? That Gibson picks up on but doesn’t mention explicitly?]