A rat has been given food contingent on its pressing a level. When it presses the lever, is its action habitual or instrumental? By the end of this section you should understand why this question is puzzling and also how to resolve the puzzle. You should also understand devaluation, and be able to understand an experiment that provides some of the foundational evidence for the dual-process theory of instrumental action.
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I struggled to find a good order for this section and Goal-Directed and Habitual: Some Evidence. In the end, I put this section first because is most important and much harder. But if already know you are going to study Goal-Directed and Habitual: Some Evidence as well as this section, it will probably be easier to do that section first and then return to this one.
You see a rat and a lever. The rat presses the lever occasionally. Now you start rewarding the rat: when it presses the lever it is rewarded with a particular kind of food. As a consequence, the rat presses the lever more often. This indicates that the rat’s lever pressing is an instrumental action, for manipulating the outcome of the action has changed its frequency. But is this lever pressing a habitual action?
In thinking about this question, consider how we characterised habitual and goal-directed processes (in Instrumental Actions: Goal-Directed and Habitual). What does the hypothesis that the rat’s lever pressing is dominated by habitual processes predict? And what does the alternative hypothesis that the rat’s lever pressing is dominated by goal-directed processes predict?
Because the aim of this section is to get you thinking about the questions, these notes do not answer them. The recording will take you through some considerations.
Dickinson (1985) found that when a rat has learned to perform an instrumental action to obtain a food and when the food is devalued, the frequency with which the rat performs the action is reduced but the rat does nevertheless continue to perform the action
If the action is habitual, why is it influenced by devaulation at all?
If the action not habitual but controlled by goal-directed processes, why does it still occur (albeit less frequently) after devaluation?
As the term ‘habitual’ is used on this course, actions are the wrong kind of thing to be described as habitual. It is the processes that trigger and guide actions that can be habitual, not the actions themselves.
This matters because on the dual-process theory of instrumental action, one action may be simultaneously guided by two or more distinct kinds of process, one goal-directed and the other habitual.
The Minor Puzzle is telling us that, in the case of the rat’s action, both kinds of processes are influential. The frequency with which the rat performs the action is reduced, indicating that it is influenced by goal-directed processes but the rat does nevertheless continue to perform the action, indicating that it is influenced by habitual processes.
Actions are controlled by two or more distinct kinds of process, one goal-directed and the other habitual. If an action were very strongly dominated by habitual processes, we might informally label the action ‘habitual’. But, as we will further explore in Goal-Directed and Habitual: Some Evidence, the actions of humans, like rats, are often significantly influenced by both kinds of process.
Your question will normally be answered in the question session associated with this lecture.
You may variations on this definition of instrumental in the literature. Dickinson (2016, p. 177) characterises instrumental actions differently: in place of the teleological ‘in order to bring about an outcome’, he stipulates that an instrumental action is one that is ‘controlled by the contingency between’ the action and an outcome. And de Wit & Dickinson (2009, p. 464) stipulate that ‘instrumental actions are learned’.