Active or haptic touch typically involves externally directed experiences of things in the world. We experience through touch tables, chairs, breezes, cups, dogs, microwaves, even other people. Such experiences are directed at ordinary material objects and their properties, just like vision is typically directed at external objects and their features (note that sometimes these ordinary objects are also parts of our own bodies). Touch also possesses another character, one directed not at external objects but at the body itself. This “body-directed” character seems to involve an awareness from the inside of the present state of our bodies (cf. Ratcliff, 2008). Press your hand against the table or some other object in front of you. Move your hand around. You will feel the table and its various features. But it seems, if you pay just the right kind of attention, that you can also feel the deformations and movements of your fingers as the table presses back against them. Or imagine the feeling of walking along the beach. You can feel the warm surf and soft, pliant sand as you walk along. But you can also feel the changes and alterations occurring to your feet at the same time.
Question 1: is this duality unique to touch?
This is a difficult question that requires a somewhat nuanced answer. First, I think there is a legitimate sense in which all sensory modalities involve bodily awareness. This is because we sense with our bodies, and so any sensory awareness will reveal features of our present bodily state. Even in vision there is a kind of duality; in revealing to us features of the external world our visual system also reveals something about the present state of our own bodies.
Still, there seems to me to be something special about the form of bodily awareness found in touch. Consider this example I use in the book (Fulkerson 2014, pp. 100-1):
Cross Moving Hands: Place your hands one above the other, palms facing each other. First move the top hand slowly back and forth across the bottom hand (keeping the bottom hand still). Then stop the top hand, and move the bottom hand back and forth across the top hand, using the same surfaces of the skin. Notice that when moving the top hand, the experience tends to be one of touching the bottom hand, while when moving the bottom hand, the experience tends to be one of touching the top hand. As you switch moving hands, the object of the experience switches. Notice also that, despite the switch, there is also always a feeling in the passive hand, a feeling of being touched, a subjective experience of the present state of the passive sensory surface on the target hand.
When we switch moving hands, the experience shifts from one hand to the other, but the passive, inactive hand does not become numb or fall outside of awareness. It doesn’t disappear. Instead, it recedes into a more bodily form of awareness, a feeling of being touched rather than of touching. I have a hard time thinking of a similar shift that we can do in vision or audition (though see below). Olfaction is an interesting intermediate case.
Question 2: What is the relation between the object-directed and body-directed forms of tactual experience?
When you place your finger in the water and (initially) feel both the warmth of the water and your finger warming, are there two separate, independent experiences? One body-directed and another externally directed? If there are two experiences, how are they related? Could we capture the distinction by appeal to the classical distinction between sensation and perception? Could we capture it in some other way?
In the book I survey and reject a number of possible answers to these questions. My own positive view is that there are two forms of awareness involved, and the externally directed form informationally depends on bodily awareness, in the sense that our external awareness depends on representations that are computed or extracted from more local bodily information. The bodily information is just another node in the channel connecting us to the world, but it is special because it is a node that is available to experience. In touch we can attend to both representations, and this explains its unique relation to bodily awareness (note: vision and the other modalities also seem to have this kind of distal-proximal duality (Schellenberg 2007; Cohen 2010); the crucial difference is that only in touch is the proximal information explicitly bodily). When we’re not touching anything in the world, we can simply attend to the present state of our sensory surfaces. This is a graded distinction, since we can and often do have both forms of awareness at the same time. Bodily awareness is often recessive and implicit, especially while our focus is directed on external objects and their properties. But how recessive depends on a number of factors, including whether there is exploratory movement, whether we are in control of those movements, and whether we are using our hands or some less-used part of our body.
On my view, then, we have two things that it’s really nice to have: direct awareness of external objects through touch, and genuine experiential duality that explains how we are able to shift our attention from external objects to bodily awareness.
References
Cohen, J. (2010). Perception and Computation. Philosophical Issues, 20(1), 96–124.
Ratcliffe, M. (2008). Touch and Situatedness. International Journal of Philosophical Studies, 16(3), 299–322. doi:10.1080/09672550802110827
Schellenberg, S. (2007). Action and Self-Location in Perception. Mind, 116(463), 603–632. doi:10.1093/mind/fzm603
Thanks for an interesting post, Matthew!
I would like to understand how far the resemblance between the dual nature of touch and the proximal-distal distinction in vision goes, on your view. In vision, the proximal-distal distinction is strongly linked to the phenomenon of perceptual constancy, e.g., shape constancy: One can see the same distal shape (e.g., the circularity of a rotating coin) despite different proximal shape (e.g., various ellipses and a circle). Is there something analogous in the case of touch? For example, is it possible to experience the same distal warmth (e.g., of the water), despite differences in proximal warmth (e.g., of the hand)? My intuitions are not clear here. I would love to hear your opinion.
I think the similarities are quite strong. In the book I also appeal to the notion of constancy (among other notions) to make this connection clear. When we feel a textured surface, for instance, there is typically a lot of proximal bodily variation while the external texture feels constant. This seems to be the case with many tactual qualities. On the other hand, thermal awareness is a more interesting and difficult case. We adapt so quickly to thermal stimuli, and our externally directed awareness seems so closely tied to our current bodily thermal state, that it seems less likely that there will be wide proximal variation with constant distal awareness. Still, I think the basic picture is right. (There is in hindsight rather limited discussion of thermal awareness in the book, especially as it relates to bodily awareness and externalization. This topic deserves a more extended treatment).
Very cool stuff, thanks a lot for posting. I find the examples with hands touching each other very confusing when I try to carry them out. I end up in a kind of recursive loop in my mind, ending up experiencing a fairly low-level relatively confused sensation that is very hard to categorize. To me I don’t get “the experience tends to be one of touching the bottom hand.”
This is in pretty sharp contrast to my more ‘world directed’ experiences, as when rubbing my fingers against two swatches of sandpaper to determine which feels more smooth.
That said, I do appreciate the point that we can shift between more world-focused and more bodily focused awareness of touch (the latter, as you said, is usually more implicit and background, but at least in humans trained to look for it, it doesn’t have to be). I wonder which (if any) other species can have such bodily-focused somatosensory awareness?
It is often noted that tools and such take on this implicit background role, almost like an extension of our bodies (a really fun book ‘The Absent Body’ is basically an extended meditation on this from a phenomenological perspective). I’m curious whether you plan to discuss this putative phenomenon of external artifacts becoming extensions of our body, and the degree to which this is a uniquely somatosensory phenomenon.
A follow up: I’ve been thinking about the familiar experience of getting into a swimming pool, gradually adjusting to the temperature of the water. When I enter the pool, the water (or the body) initially feels quite cold, so I enter slowly, legs first, torso and head at the end. After some time, the water (the body?) no longer feels cold. At the same time, I have no tendency to judge that the temperature of the water has changed. This has a structure somewhat similar to shape constancy in vision (but of course it is possible to deny that the judgment of constancy reflects an experience of constancy. But some people say the same about vision). I wonder what you make of this.
Continuing with the swimming pool case: at some point, because I entered into the pool slowly, legs first, and only later torso, one body part does not feel cold (the legs) but another (the torso) does , yet I have no tendency to judge that the water surrounding the torso are colder than those surrounding the legs. Another form of constancy, perhaps?
Eric Thomson: My next post will be on this exact topic, with a discussion of tool use and haptic exploration. I can see how the example can generate a kind of loop. I think active exploration tends to externalize our awareness, but there is also a role for attention (and other factors). The artificial nature of the example can cause some interference that is (as you say) not found in more natural examples.
Assaf Weksler: those are really good examples! I discuss a couple similar ones in the book. For instance, when we’re sitting in the sun we can feel our skin being warmed and also feel a cool breeze flowing by. We feel the breeze as “cool” despite feeling our skin as “warm.” The issue of adaptation is important here, as a sustained cool breeze might actually start making our skin feel cool too.
I like your second swimming pool example. It reminds me of the classic at home experiment where you warm one handin hot water, cool another in an ice bath, and then place them both in neutral water. This sort of case is often used to show that we don’t really experience external thermal properties, only changes in our current bodily state. The feeling that the water temperature stays the same is, on such views, more like an inference than something actually perceived. A really good paper on this is Gray, R. (2012). What do our experiences of heat and cold represent? Philosophical Studies, 166(S1), 131–151. doi:10.1007/s11098-012-0083-5.
I think that we do represent external thermal features, but that these values are derived from more local variations (as outlined above). When our bodies adapt and there are no longer any local variations, we become unable to accurately extract external features (so maybe thermal awareness is a bit–though just a bit–like the vestibular system, which also functions to detect changes rather than static properties, and depends a lot on the prior state of adaptation). Of course, these alternatives are notoriously difficult to pry apart experimentally.