A crude theory of perception: thoughts on affordances, information, and the explanatory role of representations

Perception is the reaction to meaningful information, inside or outside the body. The most basic information is information specific to affordances. An affordance is a part of reality which, in virtue of its objective structure, offers itself as affording the possibility of some reaction (usually fitness-enhancing, but not necessarily so). A reaction can be understood at multiple levels of complexity and mechanism. Sucrose, in virtue of its objective structure, affords the possibility of maintaining metabolic equilibrium to a bacteria cell. Water, in virtue of its objective structure, affords the possibility of stable ground for the water strider. Water, in virtue of its objective structure, does not afford the possibility of a stable ground for a human being unless it is frozen. An affordance then is, as J.J. Gibson said, both subjective and objective at the same time. Objective, because what something affords is directly related to its objective structure; subjective, because what something affords depends on how the organism reacts to it (e.g. human vs. water strider)

The objective structure of a proximal stimulus can only be considered informationally meaningful if that stimulus is structured so as to be specific to an affordance property. If a human is walking on the beach towards the ocean, the ocean will have the affordance property it has regardless of whether the human is there to perceive information specific to it. The “success” or meaningfulness of the human’s perception of the ocean is determined by whether the proximal stimulus contains information specific to that affordance property. A possible affordance property might be “getting you wet”, which is usually not useful, but can be extremely useful if you are suddenly caught on fire. Under normal viewing conditions, the objective structure of the ambient array of light in front of the human contains information specific to the ocean’s affordance properties in virtue of its reflective spectra off the water and through the airspace. But if the beach was shrouded in a very thick fog, the ambient optic array would stimulate the human’s senses, but the stimulus wouldn’t be meaningful because it only conveys useless information about the ocean, even though that information is potentially there for the taking if the fog was cleared. An extreme version of “meaningless stimulus without perception” is the Ganzfeld effect. On these grounds, we can recreate, without appealing to any kind of representational theory, the famous distinction between primary and secondary qualities i.e. the distinction between mere sensory transduction of meaningless stimuli and meaningful perception.

Note too how perception is most basically “looking ahead” to the future since the affordance property specifies the possibility of a future reaction. This can be seen in how higher animals can “scan” the environment for information specific to affordances, but restrain themselves from acting on that information until the moment is right. This requires inhibition of basic action schemas either learned or hardwired genetically as instinctual. In humans, the “range” of futural cognition is uniquely enhanced by our technology of symbols and linguistic metaphor. For instance, a human can look at a flat sheet of colored paper stuck to a refrigerator and meaningfully think about a wedding to attend one year in the future. A scientist can start a project and think about consequences ten years down the road. Humans can use metaphors like “down the road” because we have advanced spatial analogs which allow us to consciously link disparate bits of neural information specific to sensorimotor pathways into a more cohesive, narratological whole so as to assert “top-down” control by a globally distributed executive function sensitive to social-cultural information.

This is the function which enables humans to effortlessly “time travel” by inserting distant events into the present thought stream or simulating future scenarios through conscious imagination. We can study the book in our heads of what we have done and what we will do, rehearse speech acts for a future occasion, think in our heads what we should have said to that one person, and use external symbolic graphs to radically extend our cognitive powers. Reading and writing, for example, has utterly changed the cognitive powers of humans. Math, scientific methodology, and computer theory have also catapulted humans into the next level of technological sophistication. In the last few decades, we have seen how the rise of the personal computer, internet, and cellphone has radically changed how humans cope in this world. We are as Andy Clark said, natural born cyborgs. Born into a social-linguistic milieu rich in tradition and preinstalled with wonderful learning mechanisms that soak up useful information like sponges, newborn humans effortlessly adapt to the affordances of the most simple environmental elements (like the ground) to the most advanced (the affordance of a book, or a website).

So although representations are not necessary at the basic level of behavioral reaction shared by the unicellulars (bacteria reacting to sucrose by devouring it and using it metabolically), the addition of the central nervous system allows for the storage of affordance information into representational maps. A representational map is a distributed pattern of brain activity which allows for the storage of informational patterns which can be utilized independently of the stimulus event which first brought you into contact with that information. For example, when a bird is looking right at a food cache, it does not need its representational memory to be able to get at the food; it simply looks at the cache and then reacts by means of a motor program for getting at the food sparked by a recognition sequence. However, when the cache is not in sight and the bird is hungry, how does the bird get itself to the location of the cache? By means of a re-presentation of the cache’s spatial location which was originally stored in the brain’s memory upon first caching the food. By accessing stored memory-based information about a place even when not actually at that place, the bird is utilizing representations to boost the cognitive prowess of its nonrepresentational affordance-reaction programs. Representations are thus a form of brain-based cognitive enhancement which allow for the reaction to information which is stored within the brain itself, rather than just contained in the external proximal stimulus data. By developing the capacity to react to information stored within itself, the brain gains the capacity to organize reactions into more complicated sequence of steps, delaying and modifying reactions and allowing for the storage of information for later retrieval and the capacity to better predict events farther into the future (like the bird predicting food will be at its cache even though it is miles away).

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7 Comments

Filed under Consciousness, Philosophy

7 responses to “A crude theory of perception: thoughts on affordances, information, and the explanatory role of representations

  1. I’m still not convinced the concept of representation buys us anything at all. You mention a classic representationally-hungry skill, episodic memory, and while I admit we don’t yet have a good, non-representational account, I am very aware the apparent necessity of representations in this case is rooted firmly in a cognitivist set of assumptions I think are deeply flawed. I’ve been thinking about the brain a bit recently, and what it might be up to if not representing, and I’m trying to take very seriously what Gibson did: went back to the start and worked his way back up via a different path. This means there’s not a lot of representational thinking I can use because a) it suffers from numerous problems (http://psychsciencenotes.blogspot.com/2011/07/selection-of-problems-with.html) and b) it’s not part of the resulting theoretical tool kit made by Gibson’s move anyway.

    I’m a big fan of killing representational talk entirely, because I think it’s empty and forcing ourselves to not rely on this crutch is the only way we’ll make decent progress.

    • Gary Williams

      Andrew,

      I don’t see what’s so computationally or biologically mysterious about memory-based representations. They don’t have to be anything spooky. Instead, they could be something as basic as a topographic or isomorphic representation. The existence of topographically based cortical wiring patterns in the brain suggests the very real existence of “maps” in the brain. They know the patterns are topographically because, for example, the finger areas in the cortex are next to other finger areas, and not randomly distributed. Now, I suppose it’s possible that the dynamicists could come up with a nonrepresentational story about how these maps function, but it seems to me to be perfectly reasonable to talk about these cortical maps as representational maps, since they represent information by means of firing patterns and I don’t think the concept of representation information in terms of some kind of spatial-topographic manner is all that mysterious or based on “cognitivist” assumptions that are deeply flawed. The assumption is simply that the birds are operating on mental content that has in some way been stored in the brain, rather than accessing information available in the environment. And the storage of information in spatial maps just screams “representation” to me, and is consistent with the work of many respected researchers. Antonio Damasio, for example, spent a lot of time talking about the importance of “mapping” in his latest book, and this is a form of topographical representationalism. This kind of representation talk is very different from the first-wave cognitive scientists who talked about discrete symbolic representations based on a kind of “language of thought”. The LOT is classic representationalism and cognitivism, but that’s not what I am really talking about with memory-based representations.

      • Well first, you buy yourself a lot of history with the word ‘representation’, and unless you want to spend the rest of your career saying ‘that’s not what *I* mean by representation’ you might want to worry about that history.

        Second, what you’re describing here sounds a lot more like good old fashioned representation and less like, say, Ed Reed’s description you shot across Ken’s bow a while back (http://psychsciencenotes.blogspot.com/2010/09/brief-note-tools-and-brains-and.html?showComment=1283989270368#c2935518154495373083). It stuck out to me as being surprisingly non-ecological, I guess.

        Plus this is on my mind as Sabrina and I blog about trying to reconceive what the brain is doing, if not representing, in a way that doesn’t keep you stimulus bound. I’m becoming convinced that the way neuroscience interprets its findings right now (eg on topographical mapping, etc) may not survive such a reconception, and so I’m currently not all that convinced by arguments that rest on those results.

      • Gary, Andrew,
        Shameless plug: Francois Tonneau, in the my edited volume, takes on the problem of memory from a Radical Behaviorist perspective. He provides a convincing argument that it is possible to treat ‘memory’ as a direct response to an object far away in time… exactly as we treat my perception of my front door as direct response to an object far away in space. Thomas Natsoulas has made similar arguments, using his term retrowareness, and has argued that a Radical Ecological Psychology must go that direction (i.e., my ‘memory’ is nothing more than my extended resonance with the stimulus information). I’m agnostic as to whether either of these tracks provides the right way to go, but they certainly provide a representation-free alternatives.

        Eric

        P.S. ebook available soon, but until then… http://www.transactionpub.com/title/A-New-Look-at-New-Realism-978-1-4128-4242-6.html#edreviews

        P.P.S. Gary, I like your separation of the basic Ecological insights from the extensions of them. It is something I’m constantly striving for.

  2. Caroline Astell-Burt

    Hi there, good blog. I am interested in what you are saying about representation and memory. I am a puppeteer completing an MRes on the body of the puppeteer and form generation in puppetry. Recently became interested in Gibson and Kant. As a performer I work in the following way I assign all the movement I do with the puppet to the kinaesthetic memory through a process of repetition. In performance I have an inner sense of the character represented in my brain(I think). I am free to work on the projection of that moving form to the audience responding to the instant and immediate demands of the spectator. Much of what goes on in the performance is instinctive and not under any form of cognitive control. I am not sure what I think about the phenomenologists, but they keep coming up and crowding me so do the animists on the puppetry side.

  3. Gary Williams

    Hi Eric,

    Thanks for the comment. A behaviorist theory of memory is really interesting, but I am wondering how it really differs from the representational story I am trying to tell. If memory is “nothing more than my extended resonance with the stimulus information”, this seems to also emphasize the “re-sonance” in the same way representations emphasize re-presentation. Either way, it involves dealing with something stored in the brain which was originally encountered at a previous point in time, but is now “resonating” in the brain independently of the original stimulus. If memory is a response to something far away in time, then it seems like some representation or pattern of that something must be stored in the brain in order for the brain to respond to it. My definition of representation is simply based on the fact that the pattern of information is used independently of the original stimulus event which stored the information. I think this could be compatible with a behaviorist story so long as behaviorists are willing to talk about the storage of some kind of informational pattern. This seems to be what an “extended resonance” is.

  4. Well, see… but there you go bringing up all the baggage of the dualistic use of the term representation. So long as you mean that the organism is different now for having been in the presence of certain happenings before, no one will disagree with you. But if you think the way for such changes to occur is for some “information” to be encoded, stored, and retrieved, then people (with an ecological or behaviorist bent) will disagree with you. Of course, the information-story IS a possible way for an organism to be different from one moment to the next, but it is a hypothesis and one of many. So, the question is: What does the “information is stored” story imply that a more neutral “the organism is altered” story does not? What evidence do we have that those additional implications are true?

    My guess is that most psychologists have tremendous faith that the ‘information is stored’ story is true, but that if you nailed down the essential terms is said story (and especially if you kept them connected with their original meanings), you would find plenty of evidence against it.

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