This lecture is about motor representation. We will explore what it is, and how, if at all, discoveries about motor representation might feature in objections to standard philosophical attempts to solve The Problem of Action and, separately, The Problem of Joint Action.
In this lecture we shift from thinking about
the triggers of action to thinking about action guidance.
When we thought about the rat pressing a lever (in The Minor Puzzle about Habitual Action),
we were thinking about triggers.
The triggers included a desire for sugar (in the case of a goal-directed process)
or a stimulus--action link (in the case of a habitual process).
Discussion about habitual and goal-directed processes is discussion about triggers.
We focussed on triggers because we were mainly concerned with how an action is selected.
Our question was why one action (lever pressing) should occur rather than
no action or another action (nose scratching, say).
This is all mainly about what happens before the action.
But what about the action itself?
Pressing a lever requires the precise, temporally extended coordination of limbs, torso, effectors and fingers.
Although many of us are too skilled to notice the difficulty,
(who require many months of practice to be able to use individual fingers)
makes the difficulty of pressing a lever obvious.
As we will see, many choices are involved in the period between initiating movement
and successfully having pressed a lever. The same is true of many other simple actions
like opening a draw or grasping a mug and drinking from it:
successful execution in a continuously changing environment involves making choices throughout the action.
Our challenge is to discover why people act, individually and jointly.
In attempting to meet the challenge, we need to think not only about triggers (as we have been doing) but also about guidance (the topic of this lecture).
And the key to understanding guidance is something called motor representation.
Prerequisites and What to Skip
This lecture depends on you having studied a section from a previous lecture:
For the minimum course of study, consider only this section:
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: A process which involves ‘a
representation of the causal relationship between the action and outcome
and a representation of the current incentive value, or utility, of the
outcome’ and which influences an action ‘in a way that rationalizes
the action as instrumental for attaining the goal’ (Dickinson, 2016, p. 177).
: A process underpinning some instrumental actions which obeys
Thorndyke’s Law of Effect:
‘The presentation of an effective [=rewarding] outcome following an action [...] reinforces
a connection between the stimuli present when the action is performed and the action itself
so that subsequent presentations of these stimuli elicit the [...] action as a response’
(Dickinson, 1994, p. 48).
(Interesting complication which you can safely ignore: there is probably much more to say about
under what conditions the stimulus–action connection is strengthened; e.g. Thrailkill, Trask, Vidal, Alcalá, & Bouton, 2018.)
: The kind of representation characteristically involved in preparing, performing and monitoring sequences of small-scale actions such as grasping, transporting and placing an object.
They represent actual, possible, imagined or observed actions and their effects.
The Problem of Action
: What distinguishes your actions from things that merely happen to you?
(According to Frankfurt (1978, p. 157), ‘The problem of action
is to explicate the contrast between what an agent does and what merely happens to him.’)
The Problem of Joint Action
: What distinguishes doing something jointly with another person from acting in
parallel with them but merely side by side?
Bratman, M. E. (2014). Shared agency: A planning theory of acting together
. Oxford: Oxford University Press. Retrieved from http://0-dx.doi.org.pugwash.lib.warwick.ac.uk/10.1093/acprof:oso/9780199897933.001.0001
Dickinson, A. (1994). Instrumental conditioning. In N. Mackintosh (Ed.), Animal learning and cognition
. London: Academic Press.
Dickinson, A. (2016). Instrumental conditioning revisited: Updating dual-process theory. In J. B. Trobalon & V. D. Chamizo (Eds.), Associative learning and cognition
(Vol. 51, pp. 177–195). Edicions Universitat Barcelona.
Frankfurt, H. G. (1978). The problem of action. American Philosophical Quarterly
Hyman, J. (2015). Action, knowledge, and will
(First edition). Oxford: Oxford University Press.
Jusczyk, P. W. (1997). The discovery of spoken language
. Cambridge, Mass.: MIT.
Shepherd, J. (2021). The Shape of Agency: Control, Action, Skill, Knowledge
. The Shape of Agency
. Oxford: Oxford University Press.
Thrailkill, E. A., Trask, S., Vidal, P., Alcalá, J. A., & Bouton, M. E. (2018). Stimulus control of actions and habits: A role for reinforcer predictability and attention in the development of habitual behavior. Journal of Experimental Psychology: Animal Learning and Cognition
, 370–384. https://doi.org/10.1037/xan0000188