The book manages to be difficult and engaging at the same time. The topic is fascinating and the author is consistently honest about the limits of his work, the debate that he is contributing to and the criticisms that others have leveled against the ‘enactive model’ of perception. On the other hand, the book is written in the style of natural philosophy, though it is underpinned by empirical research. The debates that are expressed in the book are difficult and expressed with a language-framework that is occasionally bewildering, for someone encountering it for the first time (as I am). Nonetheless, the model (if accurate) provides a valuable insight into the relationship between sensory stimulation, bodily action, cognition (in a broad sense) and perception.
At the core of the book is a fairly simple idea – the conventional way of understanding perception is flawed. “Perception is not something that happens to us, or in us. It is something we do.” Exploration of the world by touch, through time “by skilful probing and movement” […] “ought to be our paradigm of what perceiving is. The world makes itself available to the perceiver through physical movement and interaction.” Noë argues that all perception is touch-like in this way: “Perceptual experience gains content thanks to our possession of bodily skills.” (p1)
The image to have in mind is not one of a stationary observer, looking at and understanding the world but rather someone who is moving through the world. Even when we’re stationary, our eyes are moving around constantly.
“To be a perceiver, then, you must understand, implicitly, that your perceptual content varies as things around you change and that it varies in different ways as you move in relation to things around you.” (p169)
This statement needs breaking down somewhat:
Firstly, there is a distinction between raw, sensory stimulation and ‘world-presenting perceptual content’. “[To] perceive you must have sensory stimulation that you understand. (p183)
Secondly then, there is an act of cognition which translates this stimulation into perception. This act of cognition is based on an implicit understanding of the way the world works. This is why I’ve used the word ‘cognition’ and not thought (‘thought’ implies something explicit and conscious). Noë proposes that this understanding is based on a set of skills that are “themselves conceptual or ‘protoconceptual skills’”. He also proposes that they are “cognitively basic”. That is they are natural and at the basis of our “normative, concept-using practices.” (p183-184) This allows me to reconcile Noë’s position with the position, developed from Heller-Roazen, that perception precedes conscious thought.
This invocation of an implicit understanding of the world seems to relate nicely to some of the work on developmental object cognition in early infancy, which likewise suggests that an intuitive framework of expectations about object behaviour develops around 2½ months (which I’ve written about in an earlier blog entry).
He clarifies this idea of ‘conceptual skills’ when he writes that “we hold to an oversimplified conception […] of what it is to make use of a concept in thought and experience. We think of concepts as brought into play only in the context of what we might call explicit deliberative judgement. But conceptual skills can also enter thought as background conditions on the possession of further skills of one sort or another.” […] “This way of thinking about concept possession suggests that concepts can enter into an experience not so much because they are judged, by the possessor of the concept, to apply, but because their possession is a condition on the having of that experience.” (p189)
Thirdly, your implicit understanding is that although the appearance of, say, an object changes as you interact with the world, you understand that the object is actually unchanging. So, for example, we know that a plate is circular but we also know that, when viewed from a particular angle, it appears elliptical without ever ceasing to be the same plate. Thus we hold, in our heads a range of possibilities for given shapes, colours etc. “To be a perceiver is to understand, implicitly, the effects of movement on sensory stimulation. […] The central claim of what [Noë calls] the enactive approach is that out ability to perceive not only depends on, but is constituted by, our possession of this sort of sensori-motor knowledge.” (p1-2)
“Philosophers have tended to deploy a somewhat too narrow conception of perceptual (that is to say, representational) content. [Noë considered one instance of this earlier], namely, the assumption that perceptual qualities such as perspectival shapes, sizes and colours must be though of as properties not of the experienced world, but rather as properties of the experience. Against this [Noë proposes] that these are genuine properties capable of being captured in experience. [Noë seeks to] make explicit what this more inclusive conception of perceptual content requires: It requires the recognition that perception is a way of encountering not only how things are, but how things are in relation to the perceiver. Perceptual experience is intrinsically perceiver-centred.” (p169)
A couple of other implications are worth noting:
One implication of this approach “is that only a creature with certain bodily skills […] could be a perceiver.”
The second implication is that the idea that “perception is a process in the brain whereby the perceptual system constructs an internal representation of the world” ought to be rejected. Instead this approach argues that “perception is a kind of skilful activity on the part of the animal as a whole.” (p2) In exploring whether experience is in the head or in the interaction between the world and the person, Noë makes an interesting point about memory. Other authors have commented that in reality we only remember fragments of past events and then during recall we re-imagine the past event by filling in the gaps between the fragments with realistic elements. Similarly, Noë argues that we do not need a complete internal representation of the world because the world is there around us and we are in it and we have “the skills to enact our perceptual experience.” This may also represent part of the solution to the ‘binding problem’.
Noë argues that the senses should not be understood in isolation but we should consider perception as a more integrated activity. An example of how our bodies enter into our perceptual experience comes from air travel… Suppose you are in an airplane during take-off. At that moment, “it will look to you as if the front of the plane, the nose, rises or lifts up in your field of vision. In fact, it does not. Because you move with the plane the nose of the plane does not lift relative to you.” Instead, “when the plane rises, your vestibular system detects your movement relative to the direction of gravity. This causes it to look as if the nose is rising” […] “How things are experienced visually depend on more than merely optical processes.” It also “depends on our embodiment, that is, on idiosyncratic aspects of our sensory implementation.” (p26) There’s also a nice illustration, drawn from the work of Adrian Cussins (2003) where Cussins explores how a motor-cyclist experiences the speed they are moving at. [As] “an element in a skilled interaction with the world, as felt rotational pressure in my right hand as it held the throttle grip, a tension in my fingers and foot in contact with the brake pedals or levers, a felt vibration of the road and a rush of wind, a visual rush of surfaces, a sense of how the immediate environment would afford certain motions and others.” (p203) Clearly Noë disagrees with the way that Cussins deals with this experience but the integration of the different sensory modalities ties in neatly with the idea of the supra-modality of thought developed by Struiksma.
I should, finally, add that although this idea was new to me, it is clearly not an entirely new idea. I recently came across an essay, ‘Illusion and Visual Deadlock’, originally written by E.H. Gombrich in 1961 where he posits the same idea. I suspect however, that Noë has worked out the implications of the idea in greater detail.