Author:

Abstract:

Contemporary, propositional theories of learning assume that fear learning relies on conscious, declarative memory processes. According to such theories, it is the acquisition of propositional knowledge about CS-US contingencies that drives conditioned responding. Psychological and neurobiological evidence would suggest that this is even more true for extinction learning and other forms of fear inhibition, as they appear to involve working memory resources and effortful prefrontal control. The strong dependence of extinction learning on effortful prefrontal inhibition may in fact help to explain why conditioned fear is so prone to recovery (reinstatement, renewal, spontaneous recovery). I will first review evidence that illustrates the important role of declarative knowledge in fear reduction and extinction in humans and shows how modifying people’s conscious knowledge or expectations can be a very powerful way to affect conditioned fear responding. I will then go on to point out evidence that human conditioned fear responses do not always track conscious contingency knowledge quite so closely. In particular, I will argue that conditioned fear responses can be demonstrated even in the complete absence of US expectancy (and, perhaps, US expectancy can also go hand in hand with the absence of conditioned fear responses). This poses a challenge to propositional theories of learning and simple prefrontal theories of extinction learning.