Online research in philosophy

In her commentary of Field (1999), Hammerl (1999) has drawn attention to several interesting points concerning the issue of contingency awareness in evaluative conditioning. First, she comments on several contentious issues arising from Field's review of the evaluative conditioning literature, second she critiques the data from his pilot study and finally she argues the case that EC is a distinct form of conditioning that can occur in the absence of contingency awareness. With reference to these criticisms, this reply attempts to address Hammerl's comments by exploring the issues of how awareness is defined, how it is best measured, and whether it is reasonable to believe that EC uniformly occurs in the absence of contingency awareness. The article concludes that the available evidence supports Field's proposition that EC is, in fact, Pavlovian learning.

We argue that the effects of evaluative learning may occur (a) without conscious perception of the affective stimuli, (b) without awareness of the stimulus contingencies, and (c) without any awareness that learning has occurred at all. Whether the three experiments reported in our target article provide conclusive evidence for either or any of these assertions is discussed in the commentaries of De Houwer and Field. We respond with the argument that when considered alongside other studies carried out over the past few decades, our experiments provide compelling evidence for a theory that posits a dissociation between evaluative learning and contingency awareness.

There is good evidence that, in general, autonomic conditioning in humans occurs only when subjects can verbalize the contingencies of conditioning. However, one form of conditioning, evaluative conditioning (EC), seems exceptional in that a growing body of evidence suggests that it can occur without conscious contingency awareness. As such, EC offers a unique insight into what role contingency awareness might play in associative learning. Despite this evidence, there are reasons to doubt that evaluative conditioning can occur without conscious awareness. This paper aims to critically review the EC literature and to draw some parallels to what is known about autonomic conditioning. In doing so, some important general issues about measuring contingency awareness are raised. These issues are illustrated with a brief report of an experiment in which a sensitive measure of contingency awareness is compared against a commonly used measure.

Behavioral momentum theory has evolved within the realm of operant conditioning. The thought-provoking momentum metaphor equates the strength of an operant response with its resistance to change and preference (i.e., choice) for that response over other available responses. Whereas baseline response rate (velocity in the metaphor) is assumed to be largely influenced by the response-reinforcer contingency, resistance to change and preference are assumed to reflect an intervening variable called behavioral mass, which is determined primarily by the stimulus-reinforcer relationship. This invites the question of how well the momentum metaphor applies to the stimulus-reinforcer relationships of traditional Pavlovian paradigms. Presumably, a correspondence exists between behavioral mass and the notion of associative strength in the associative learning literature. Although response rate has little meaning in the trialwise structure of classical (i.e., Pavlovian) conditioning, response probability or magnitude might be regarded metaphorically as velocity. Momentum theory suggests that resistance to change (e.g., extinction) is a better indicator of associative strength than is response probability or magnitude. Therefore, variables that strengthen Pavlovian learning should influence resistance to extinction of conditioned responding in a similar manner. Moreover, it is important to assess momentum theory outside of strictly operant paradigms, particularly because in clinical settings many common disorders (e.g., phobias) and their therapies (e.g., cue exposure) are thought to be classically conditioned.

Fulcher and Hammerl's (2001) important exploration of the role of contingency awareness in evaluative conditioning (EC) raises a lot of issues for discussion: (1) what boundaries, if any, exist between EC and affective learning paradigms?; (2) if EC does occur without awareness does this mean it is nonpropositional learning?; (3) is EC driven by stimulus-response (S-R), rather than stimulus-stimulus (S-S), associations and if so should it then surprise us that contingency awareness is not important?; and (4) if S-R associations are at the heart of EC, should we automatically assume EC is part of a different learning mechanism to autonomic Pavlovian conditioning (Field, 2000a, 2000b)? This article, after a critical review of Fulcher and Hammerl's work, discusses these issues with reference to what can be realistically inferred about the mechanisms underlying EC.