Spontaneous Task Structure Formation Results in a Cost to Incidental Memory of Task Stimuli.

Christina Bejjani,Tobias Egner

doi:10.3389/fpsyg.2019.02833

Abstract

Humans are characterized by their ability to leverage rules for classifying and linking stimuli to context-appropriate actions. Previous studies have shown that when humans learn stimulus-response associations for two-dimensional stimuli, they implicitly form and generalize hierarchical rule structures (task-sets). However, the cognitive processes underlying structure formation are poorly understood. Across four experiments, we manipulated how trial-unique images mapped onto responses to bias spontaneous task-set formation and investigated structure learning through the lens of incidental stimulus encoding. Participants performed a learning task designed to either promote task-set formation (by “motor-clustering” possible stimulus-action rules), or to discourage it (by using arbitrary category-response mappings). We adjudicated between two hypotheses: Structure learning may promote attention to task stimuli, thus resulting in better subsequent memory. Alternatively, building task-sets might impose cognitive demands (for instance, on working memory) that divert attention away from stimulus encoding. While the clustering manipulation affected task-set formation, there were also substantial individual differences. Importantly, structure learning incurred a cost: spontaneous task-set formation was associated with diminished stimulus encoding. Thus, spontaneous hierarchical task-set formation appears to involve cognitive demands that divert attention away from encoding of task stimuli during structure learning.

Highlights

Humans are characterized by a remarkable degree of cognitive flexibility, allowing us to respond to an identical stimulus in a variety of ways, as a function of context
Spontaneous Task-Set Learning Affects Memory been paid to the process of task structure building in terms of its immediate cognitive demands and consequences. Connecting these distinct but related literatures, we here ask the question: How does learning task structure affect the processing of the stimuli that form the input of the learning process? One potent way to answer this question is through the lens of incidental stimulus encoding, since on-task fluctuations in attention ramify in subsequent memory for task stimuli
Collins and Frank, 2013, 2016a,b; Collins et al, 2014), which did not allow for tests of recognition memory and may suggest that structure formation is prone to large individual differences or results from feature priming effects across trials

Summary

Introduction

Humans are characterized by a remarkable degree of cognitive flexibility, allowing us to respond to an identical stimulus in a variety of ways, as a function of context. While a parallel learning literature has examined how individuals infer and identify causal structure (e.g., Gershman and Niv, 2010; Wilson and Niv, 2012; Schapiro et al, 2013), not much attention has Spontaneous Task-Set Learning Affects Memory been paid to the process of task structure building in terms of its immediate cognitive demands and consequences. Connecting these distinct but related literatures, we here ask the question: How does learning task structure affect the processing of the stimuli that form the input of the learning process? An improved understanding of implicit structure formation via incidental encoding adds further insight into interactions between attention and memory in everyday scenarios

Objectives

Methods

Results

Discussion

Conclusion