Is the Ecological Approach Radical Enough?

Radical enactivists do not just want to get representations out of their explanations for our mental life. They also want to get rid of the notion of content. Hutto & Myin (2013) is the strong version of this claim. 

Mental states or processes have content if there are specified conditions of satisfaction and if it can be evaluated for things like truth (i.e. does the thing conveying content doing so accurately or not?). Part of the concern is that ecological psychology is committed to content and thus can’t play with the other radical theories. The evidence is that we talk about things like ‘information about affordances’; that ‘about’ implies content. 

van Dijk, Withagen & Bongers (2015) took a swing at defending a content-less ecological psychology. I admire the attempt to get the radical camps on the same page, but at the end of the day I think a) the defence is grounded on the wrong notion of affordances (as relations, instead of dispositions) which means b) I don’t think it works but that c) I don’t think I care. I am as yet unfazed by critiques of content, although I’m happy to hear more on this; frankly Hutto & Myin’s book is a real struggle to read and any clarity people can add, I’ll take. 

Visual illusions and direct perception

A while back I reviewed a bunch of papers by Rob Withagen who is currently arguing that while perception is not typically based in specifying variables, it can and should still be ecological in nature. While we are also developing an account of information that goes beyond specification I still have some reservations about the details of Rob's work. That said, I do think there is a lot of overlap and I'm still interested in figuring out what that is. 

Rob's latest paper (de Wit, van der Kamp & Withagen, 2015) is about visual illusions, and how to talk about them ecologically. There is a lot of very useful stuff in here, not least the review of the many things Gibson said about illusions. After this review, the paper tries to put all of this into Rob's and Tony Chemero's evolutionary framework and uses this to formalise and tidy up what Gibson was up to. I'm adding this paper to the set I've covered from Withagen as I continue to think through these issues.

Evolution vs.Specification (Specification V)

One of Gibson's key contributions was to reveal that it was possible for the optic array to specify a meaningful property of the world. Gibson insisted that specification existed between the world and optics (each property produced one unambiguous pattern, and thus the mapping is 1:1). Specification, said Gibson, meant direct perception was possible, because picking up that one variable meant perceiving the one property that caused it. 

Turvey, Shaw, Reed & Mace (1981) formalised this idea by describing how ecological laws governed which properties of the world could be specified and identifying that these laws allowed affordances into this set. Turvey et al (hence TSM, because Reed changed his mind later on) then insisted that, in order for perception to be direct, specification also had to exist between the optics and the perceiver; an organism should only use one variable per property, and thus the mapping from world to perceiver is 1:1:1. This is a very high bar, and was put in place to defend ecological psychology from the Establishment attack (Fodor & Pylyshyn, 1981).

Withagen & Chemero (2009) think that the 1:1:1 account is incompatible with evolutionary thinking, and they aren't hot on the 1:1 account either. Specifically, they think that any given species will show individual variation in it's members ability to use information, and that in many cases species will end up using sub-optimal solutions (two important elements of evolutionary thinking). The1:1:1 bar, they say, is implausibly high and a naturalised theory of perception (one that is compatible with evolution) will instead predict the common use of non-specifying information. They also claim that this does not stop perception from being direct, so long as you allow 'directness' to live along a continuum.

I think there are some important issues here, but I think this paper's presentation is problematic. It contains no analysis of any particular information or task, and instead is full of sentences such as 'it seems more plausible to us that' and 'it is possible that'. This comes off as the kind of woolly evolutionary thinking psychology is rightly scolded for. Gibson and TSM spent a lot of time trying to make us pay less attention to what might be and more to what is.My concerns are mostly along these lines, and once I get them off my chest I want to turn in future posts to some ideas for a research programme to pursue this all in more detail.

Individual Variation in the Use of Perceptual Information (Specification IV)

If it is the case that perception requires the use of specifying variables, then there should be no individual variation in what information variables people use. However, as we've already seen, such variation exists: the dynamics of a collision event produces multiple kinematic patterns in the optic array, and people judging the mass ratio of colliding balls use all of these, only one of which actually specifies which ball is heavier. Even with training, people do not always find the specifying variable. 

This is an example of how the mapping between a property in the world (mass ratio) and the optic array can be one-to-many, with consequences for perception. Figure 1 on this post shows us that there is another mapping to investigate, namely the one from a perceptual array to the organism. Can this mapping also be one-to-many?  Withagen & van Wermeskerken (2009) suggest that it can, and that again training does not necessarily help.

How Information Gets Its Meaning (Specification II)

Gibson proposed that specification was required in order for perceptual information to have meaning that was tied to the world in a manner an organism could use. The concept of specification has been placed back under the microscope by recent theoretical and empirical work. Here I want to briefly summarise the theoretical argument put forth by Withagen & van der Kamp (2010), who worry that specification places too strong a constraint on what a perceiving-acting organism might find informative. They suggest that (visual) perception can still be direct with non-specifying patterns, if you stop thinking information is in the relation between the environment and the optic array but rather, in the relation between the optic array and the organism. They propose this because recent empirical work suggests that organisms can happily get around using non-specifying variables; they want to keep directness, however and they don't think Chemero's solution to the problem does the trick. I'll review the studies they cite over the next few posts; first, let's lay out the solutions they propose.

Again, I want to emphasise that this is very much a work in progress for me. I'm using these posts to come to grips with the arguments, and I don't yet endorse any of these various critiques. My goal is simply to have a clear understanding of what everyone says, so that we can evaluate those claims later on when I review some data.

Specification: What It Is, and Why We Need It (Specification I)

The first thing I need to do in a discussion of specification is explain what it is and why it's important to ecological psychology. I've tried to maintain a clear logical progression in this post, building towards the need for specification. In my next post, I'll take a first swing at explaining what specification gives us, namely a reason why information means one thing and not another.

The issue of specification comes from Gibson's (1966, 1979) analysis of visual perception, so that's where I'll start too. Most descriptions of visual perception begin with the anatomy of the eye; people note that the eye resembles a camera, and that the lens seems to focus a messy, upside down image onto the retina. The retina then pixelates that image into neural activity, and this pixelated structure then shows up in primary visual cortex (this is topographic mapping). If vision does indeed begin this way, then a huge amount of work seems to be required to take this impoverished stimulus and use it as the basis for the rich, 3D visual world we experience.

Gibson's ecological theory begins with a re-evaluation of the stimulus for vision. The first three chapters of the 1979 book are about the world and what it contains, while chapter 4 is about how this world can interact with light to produce information. Only once he lays out the information available to the organism does he begin to talk about the act of perception itself; this re-evaluation of the 'job description' for a visual system is one of his most important contributions to psychology. Gibson's reanalysis leads him to conclude that action relevant properties of the world (specifically, affordances) can be specified in the optic array, and this concept underpins the directness of his theory of perception.

The issue of specification is assumed to be critical for the success of a direct theory of perception. The traditional views propose a 'many-to-one' mapping; a given pattern of stimulation on the retina is ambiguous because it could be caused by many possible states in the world. Specification is the hypothesis that there is a 'one-to-one' mapping - a given pattern in the optic array comes from one and only one state of the world. This can happen, according to Turvey, Shaw, Reed & Mace (1981) if (and only if) the creation of information about the world is a lawful process. If the projection of world into optics is underwritten by a law and thus one-to-one, then detecting the optical pattern is equivalent to detecting the property of the world: detecting the information is perceiving the world, with no additional processing work required. Perception can be direct.

A theory of direct perception will require several elements: there must be invariant structure within the endless flow across the retina that relates 1:1 to some property of the world. To be invariant, this structure must be relational, and therefore higher order. If perception is to be direct, these higher-order invariants must be detectable as a piece, and not built out of their elements in some post-perceptual process. Only if you have all this do you have the possibility of a one-to-one mapping between the world and vision, i.e. the possibility of specification.This post lays out what this all means, and  how these pieces come together in ecological psychology.

Specification & Its Discontents

A topic that has been flying under the radar a little in Sabrina's language posts is the issue of specification. Sabrina's ecological analysis of language discusses information and what it means, but is not committed to the kind of law based account that is typically invoked in the perception-action literature. It can't - language can be used to talk about things in their absence, and it's not clear what kind of ecological laws might govern the connection between the speech event and it's meaning. Breaking specification has consequences, however, and has been a topic of some debate lately; the next few posts from me will be an in-depth look at the theoretical and empirical contributions to the debate as I try to come to terms with the idea and whether it can still support a direct theory of perception.