Can non-conscious knowledge support instrumental conditioning?

Instrumental conditioning (IC) consists in actively learning to approach rewarding stimuli and to avoid punishing stimuli. This central process for adaptation requires a relatively high computational capacity, because it entails the integration of knowledge regarding stimuli, behaviours and outcomes. Some current theories of consciousness postulate that this high level of integration could only be achieved based on conscious knowledge. Indeed, recent studies using subliminal exposure show that IC occurs only for consciously perceived stimuli. Here, we investigate whether IC can occur when implicit processing is stimulated not by subliminal exposure, but by employing predictive regularities that are complex and difficult to detect consciously. In a novel IC task based on the artificial grammar learning task, participants will first undergo an incidental learning phase, in which they will be exposed to strings from two artificial grammars. In a subsequent phase, they will have to give approach (Go) or avoid responses (No-Go) to strings from the two grammars. Unbeknown to them, one of the grammars is reward-predictive and the other is punishment-predictive. Go responses to stimuli from the reward-predictive grammar bring rewards, but Go responses to stimuli from the punishment-predictive grammar bring punishments (hence No-Go responses are adaptive in this latter case). Trial-by-trial measures will assess participants’ awareness of the grammar structures and of their judgments regarding the predictive value of the strings, both in the conditioning task, and in a delayed instrumental responding phase performed after two weeks. The delay aims to reduce even further participants’ reliance on conscious knowledge.