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Friday, March 1, 2019

Skilled bodily capacities


When philosophers think of action they generally have in mind a combination of intentionality and simple motor movements. "John flips the switch to turn on the lights." But a great deal of human action is substantially more complex than this. Skilled bodily performance -- playing the piano, returning a tennis serve, fabricating a guitar -- seems to require a sustained treatment from within cognitive science. Bodily action is a cognitive activity. It is enlightening to learn that there is in fact such a field. It turns out that the cognitive science of skilled bodily action is creating a great deal of highly interesting work. Some of that research is happening at Ruhr University-Bochum, and my exposure to this group of researchers last month was very rewarding. (Thanks, Albert Newen, for your warm introduction to the work your group is doing.)

Elisabeth Pacherie has made major contributions to this field, bridging philosophy and cognitive science in her effort to contribute to a richer understanding of skilled bodily action. Her perspective has been to argue that bodily action is intentional and cognitive all the way down, and is dependent on mental representations of the field of action. She emphasizes that skilled action involves situated awareness and flexible control, at a granular level of bodily action. She and collaborator Myrto Mylopoulos provide a recent statement of their views in "Intentions and motor representations: the interface challenge" (link).  Here is the abstract to their article:
Abstract A full account of purposive action must appeal not only to propositional attitude states like beliefs, desires, and intentions, but also to motor representations, i.e., non-propositional states that are thought to represent, among other things, action outcomes as well as detailed kinematic features of bodily movements. This raises the puzzle of how it is that these two distinct types of state successfully coordinate. We examine this so-called "Interface Problem". First, we clarify and expand on the nature and role of motor representations in explaining intentional action. Next, we characterize the respective functions of intentions and motor representations, the differences in representational format and content that these imply, and the interface challenge these differences in turn raise. We then evaluate Butterfill and Sinigaglia’s (2014) recent answer to this interface challenge, according to which intentions refer to action outcomes by way of demonstrative deference to motor representations. We present some worries for this proposal, arguing that, among other things, it implicitly presupposes a solution to the problem, and so cannot help to resolve it. Finally, we suggest that we may make some progress on this puzzle by positing a "content-preserving causal process" taking place between intentions and motor representations, and we offer a proposal for how this might work.
Another useful presentation of their work is offered in "Intentions: The dynamic hierarchical model revisited"; link.

Another key contributor to this field is Ellen Fridland. Her article, "Skill and motor control: intelligence all the way down" provides a compelling framework for analyzing skilled bodily action (link). Her fundamental insight is that we are not justified in analyzing bodily activity into higher processes (thought and decision) and lower processes (habits of motor control, learned reflexes). Intelligence comes into skilled action only at the higher level, the "propositional" level. What this fails to see, however, is that intelligence pervades skilled action all the way down, with fine-grained motor movements being affected by perception and opportunity at a very granular level. "In short, for [Stanley and Krakauer (link), Papineau (link), and Stanley and Williamson (link)], skill combines intelligent guidance by propositional knowledge with the noncognitive, basic, subpersonal, low-level motor and perceptual abilities. The propositional bit of skill is knowledge-involving while the motor acuity bit is not" (1543). She quotes an interesting passage from Papineau 2013:
At any stage of an inning, a competent batsman will have assessed the situation and formed a view about how to bat—a conscious intention to adopt a certain strategy. As with any intention, this will then set the parameters of the basic action-control system. It will direct that system to bat aggressively, say. It will take one raft of conditional dispositions from the batsman’s repertoire, and reconfigure that basic control system so that it embodies just those dispositions...Having been so reset, the basic action-control system will then respond accordingly, without any further intrusion of conscious thought’’ Emphasis in original, (2013, p. 191). (1544)
In this paper Fridland goes through a careful examination of the assumptions underlying the strong distinction made by S&K between propositional (intellectual) knowledge and motor acuity (habit or reflex), and shows that these assumptions are not well grounded. She makes use of "optimal control theory" to make her point (Todorov and Jordan 2002; link). Here is the Todorov-Jordan abstract describing this approach:
A central problem in motor control is understanding how the many biomechanical degrees of freedom are coordinated to achieve a common goal. An especially puzzling aspect of coordination is that behavioral goals are achieved reliably and repeatedly with movements rarely reproducible in their detail. Existing theoretical frameworks emphasize either goal achievement or the richness of motor variability, but fail to reconcile the two. Here we propose an alternative theory based on stochastic optimal feedback control. We show that the optimal strategy in the face of uncertainty is to allow variability in redundant (task-irrelevant) dimensions. This strategy does not enforce a desired trajectory, but uses feedback more intelligently, correcting only those deviations that interfere with task goals. From this framework, task-constrained variability, goal-directed corrections, motor synergies, controlled parameters, simplifying rules and discrete coordination modes emerge naturally. We present experimental results from a range of motor tasks to support this theory. (Todorov and Jordon 2002)
One important issue that emerges is the question of where learning occurs as a subject improves his or her skill level. Is it at the reflexive level of motor acuity, or is it at the intellectual and "model-building" level of intention? Here again, Fridland gives reasons to believe that the motor level improves effectiveness through the construction of models of the actions being performed -- or in other words, that there is flexible cognition in play at the motor-acuity level as well as at the strategic, intentional level. Here is the conclusion to her paper:
I hope that it has become clear that a hybrid view of skilled bodily action where the intelligence of skill is cashed out in propositional, intentional terms and motor control is characterized in bottom-up, brute-causal, unintelligent ways is unsustainable. Instead of thinking of independent intentional states and automatic reflex-like basic actions or of independent action trajectories and the execution of those trajectories by processes of motor acuity, it seems that we must revise our view of skill in order to reflect findings which show that even those processes responsible for the automatic, low-level, fine-grained sensorimotor executions of motor skills are sensitive to high-level goals.
This is a place where cognitive science, neuroscience, and philosophy meet and shed very important new light on the nature of intentionality, action, and bodily skill. It is a very exciting field of research. Joshua Shepherd captures the intellectual challenges of the field very aptly in a recent paper, "Intelligent action guidance and the use of mixed representational formats"; link. Here is the abstract to this paper:
My topic is the intelligent guidance of action. In this paper I offer an empirically grounded case for four ideas: that [a] cognitive processes of practical reasoning play a key role in the intelligent guidance of action, [b] these processes could not do so without significant enabling work done by both perception and the motor system, [c] the work done by perceptual and motor systems can be characterized as the generation of information (often conceptually structured information) specialized for action guidance, which in turn suggests that [d] the cognitive processes of practical reasoning that play a key role in the guidance of intelligent action are not the abstract, syllogistic ones philosophers often treat as the paradigm of practical reasoning. Rather, these cognitive processes are constrained by, and work well with, the specialized concepts outputted by perception and the feedback outputted by sensorimotor processes.
One immediate thought that I had in listening to Elisabeth Pacherie present some of her work at a symposium in Bochum earlier this month is that this approach has the potential of solving the problem Norbert Elias was wrestling with in his own account of action. (Here is an earlier post on figurational sociology; link.) Elias used the example of skilled soccer play and proposed that we need to consider the unit to be the configuration (several players) rather than the individual player. But the real-time cognitive adaptiveness in skilled behavior described in this field of research provides a different and perhaps simpler way of understanding the rapid, intelligent adaptiveness of the players on the soccer field. Their bodily motions are indeed intelligent and adaptive, and their motions and reactions are responsive to the small clues available to them about the motions and intentions of the other players on the field. But at the other end of the research spectrum, it seems evident that research in this area is very relevant to work in robotics and artificial intelligence.

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