Implicitly learning when to be ready: from instances to categories

Abstract

[Manuscript submitted for review]There is growing appreciation for the role of long-term memory in guiding temporal preparation. In experiments with variable foreperiods between a warning stimulus (S1) and a target stimulus (S2), preparation is affected by foreperiod distributions experienced in the past, long after the distribution has changed. Such memory-guided preparation shapes preparation largely implicitly and outside of a participants’ control. Recent studies have demonstrated the associative nature of such memory-guided preparation. When distinct S1s predict different foreperiods, they can trigger dissociative preparation accordingly. Here, we demonstrate that memory-guided preparation allows for another key feature of learning: the ability to generalize across acquired associations and apply them to novel situations. Participants completed a foreperiod task where S1 was a unique image of either a face or a scene on each trial. Images of either category were paired with different distributions with predominantly shorter versus predominantly longer foreperiods. Participants displayed dissociative preparation to never-before seen images of either category, without being aware of the predictive nature of these categories. They continued doing so in a subsequent transfer phase, after they had been informed that these contingencies no longer held. A novel rolling regression analysis revealed at a fine timescale how category-guided preparation gradually developed throughout the task, and illustrated how instructions at the start of the transfer phase interacted with these influences from long-term memory. These results offer new insights into temporal preparation as the product of a largely implicit process governed by associative learning from past experiences.