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

Not Applicable

Completed

• Conditions: Memory Consolidation
• Interventions: Behavioral: Congruent vs. Incongruent; Behavioral: Immediate vs. Awake vs. Asleep; Behavioral: Targeted memory reactivation (TMR)

• Registration Number: NCT05746299
• Lead Sponsor: University of Pennsylvania

Brief 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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2023-02-14
• Study First Submitted QC: 2023-02-14
• Study First Posted: 2023-02-27
• Study Start: 2023-03-29
• Primary Completion: 2024-06-30
• Study Completion: 2024-06-30
• Status Verified: 2024-07
• Last Update Submitted: 2024-07-30
• Last Update Posted: 2024-07-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 300

Inclusion Criteria

• Ages between 18 and 35

Exclusion Criteria

• No medical or neurological illness that would impact experimental performance
• Not a member of a vulnerable population

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Awake Congruent	Immediate vs. Awake vs. Asleep	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2.5-hour break, they will learn and be tested on a novel semantic category with a Modular structure.
Sleep Incongruent	Congruent vs. Incongruent	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2-hour nap opportunity, during which TMR will be used to reactivate the non-Modular category, participants will take a 30-minute break. After the break, they will learn and be tested on a novel semantic category with a Modular structure.
Immediate Congruent	Congruent vs. Incongruent	Participants will learn and be tested on two different semantic categories with the same structure that dictates the co-occurrence of different features.
Immediate Congruent	Immediate vs. Awake vs. Asleep	Participants will learn and be tested on two different semantic categories with the same structure that dictates the co-occurrence of different features.
Immediate Incongruent	Immediate vs. Awake vs. Asleep	Participants will learn and be tested on two different semantic categories with different structures that dictate the co-occurrence of different features.
Sleep Incongruent	Targeted memory reactivation (TMR)	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2-hour nap opportunity, during which TMR will be used to reactivate the non-Modular category, participants will take a 30-minute break. After the break, they will learn and be tested on a novel semantic category with a Modular structure.
Immediate Incongruent	Congruent vs. Incongruent	Participants will learn and be tested on two different semantic categories with different structures that dictate the co-occurrence of different features.
Awake Incongruent	Congruent vs. Incongruent	Participants will learn two different semantic categories, neither of which has a Modular structure. After a 2.5-hour break, they will learn and be tested on a novel semantic category with a Modular structure.
Awake Incongruent	Immediate vs. Awake vs. Asleep	Participants will learn two different semantic categories, neither of which has a Modular structure. After a 2.5-hour break, they will learn and be tested on a novel semantic category with a Modular structure.
Sleep Congruent (REM)	Congruent vs. Incongruent	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2-hour nap opportunity, during which TMR will be used to reactivate the Modular category during rapid eye movement (REM) sleep, participants will take a 30-minute break. After the break, they will learn and be tested on a novel semantic category with a Modular structure.
Sleep Congruent (REM)	Immediate vs. Awake vs. Asleep	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2-hour nap opportunity, during which TMR will be used to reactivate the Modular category during rapid eye movement (REM) sleep, participants will take a 30-minute break. After the break, they will learn and be tested on a novel semantic category with a Modular structure.
Sleep Congruent (REM)	Targeted memory reactivation (TMR)	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2-hour nap opportunity, during which TMR will be used to reactivate the Modular category during rapid eye movement (REM) sleep, participants will take a 30-minute break. After the break, they will learn and be tested on a novel semantic category with a Modular structure.
Awake Congruent	Congruent vs. Incongruent	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2.5-hour break, they will learn and be tested on a novel semantic category with a Modular structure.
Sleep Incongruent	Immediate vs. Awake vs. Asleep	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2-hour nap opportunity, during which TMR will be used to reactivate the non-Modular category, participants will take a 30-minute break. After the break, they will learn and be tested on a novel semantic category with a Modular structure.
Sleep Congruent (SWS)	Congruent vs. Incongruent	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2-hour nap opportunity, during which TMR will be used to reactivate the Modular category during slow wave sleep (SWS), participants will take a 30-minute break. After the break, they will learn and be tested on a novel semantic category with a Modular structure.
Sleep Congruent (SWS)	Immediate vs. Awake vs. Asleep	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2-hour nap opportunity, during which TMR will be used to reactivate the Modular category during slow wave sleep (SWS), participants will take a 30-minute break. After the break, they will learn and be tested on a novel semantic category with a Modular structure.
Sleep Congruent (SWS)	Targeted memory reactivation (TMR)	Participants will learn two different semantic categories, one of which has a Modular structure. After a 2-hour nap opportunity, during which TMR will be used to reactivate the Modular category during slow wave sleep (SWS), participants will take a 30-minute break. After the break, they will learn and be tested on a novel semantic category with a Modular structure.

Primary Outcome Measures

Name	Time	Method
Structure knowledge for a new Modular category in Stage 2	In Aim 1, accuracy is collected in a missing feature task 25 min. into the experiment, taking 25 min. In Aim 2, accuracy is collected in a missing feature task over 25 min in Stage 2	Accuracy (0-100%) on the missing feature task in Stage 2

Trial Locations

Locations (1)

University of Pennsylvania; 🇺🇸 Philadelphia, Pennsylvania, United States