The Impact of Reactivation During Sleep on the Consolidation of Abstract Information in Humans

Summary

In any given cognitive domain, representations of individual elements are not independent but are organized by means of structured relations. Representations of this underlying structure are powerful, allowing generalization and inference in novel environments. In the semantic domain, structure captures associations between different semantic features or concepts (e.g., green, wings, can fly) and is known to influence the development and deterioration of semantic knowledge. The investigators recently found that humans more easily learn novel categories that contain clusters of reliably co-occurring features, revealing an influence of structure on novel category formation. However, a critical unknown is whether learned representations of structure are closely tied to category-specific elements, or whether such representations become abstract to some extent, transformed away from the experienced features. Further, if abstract structural representations do emerge, prior work provides intriguing hints that these representations may require offline consolidation during awake rest or sleep. The investigators have developed a paradigm in which carefully designed graph structures govern the pattern of feature co-occurrences within individual categories. Here the investigators implement a "structure transfer" extension of this paradigm in order to determine whether learning one structured category facilitates learning of a second identically structured category defined by a new set of features. This facilitation would provide evidence that structure representations are abstract to some degree. Aim 1 will use these methods to evaluate whether abstract structural representations emerge immediately during learning. Aim 2 will determine whether these representations persist, or emerge, over a delay, and whether sleep-based consolidation in particular is needed. The role of replay of recent experience during sleep will be evaluated using electroencephalography (EEG) paired with closed-loop targeted memory reactivation (TMR), a technique that enables causal influence over the consolidation of recently learned information in humans. This work will inform and constrain theories of semantic learning as well as theories of structure learning and representation more broadly.

Conditions

• Memory Consolidation

Interventions

BEHAVIORAL

Congruent vs. Incongruent

The Congruent vs. Incongruent intervention relates to the feature-based structure of the novel categories (Modular or non-Modular) and whether there is (Congruent) or is not (Incongruent) a match between what was previously learned and the final target category.

BEHAVIORAL

Immediate vs. Awake vs. Asleep

Immediate, Awake, and Sleep refer to either no break, 2.5 hours awake, or 2 hours asleep plus a 30-minute post-nap break to account for sleep inertia between learning and target category.

BEHAVIORAL

Targeted memory reactivation (TMR)

Targeted memory reactivation (TMR) is the systematic presentation of sounds during sleep that were associated with certain stimuli during learning and will be administered either during slow wave sleep (SWS) or rapid eye movement (REM) sleep.

Sponsors & Collaborators

• National Institute of Mental Health (NIMH)

  collaborator NIH

• University of Pennsylvania

  lead OTHER

Principal Investigators

• Anna C Schapiro, PhD · University of Pennsylvania

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

35 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2023-03-29

Primary Completion

2024-06-30

Completion

2024-06-30

Countries

• United States

Study Locations