The Effects of Direct Context Reactivation During Sleep on Memory

NCT04702152 | Completed

• 1 other identifier: STU00213443-A
• Study Type: interventional
• Target: 38
• Locations: 1 country
• Sites: 1

Brief Summary

The context in which memories are encoded is a major factor influencing how memories are organized. Individual memories are bound to the context (e.g., the location, time and state of mind in which they are encoded) and this context is later reinstated to recall the details related to the memory. Although the role of context has been explored with regard to memory encoding and retrieval, its role during sleep-related memory consolidation has not been explored. Memories are thought to be reactivated during sleep, subsequently benefitting from the process. This study will use encephalography (EEG) in humans to consider several competing hypotheses regarding context's role in sleep reactivation, thereby enhancing the current understanding of how reactivation of memory over sleep relates to models of context and memory. Participants will learn to associate pictures of scenes to different sounds and to smaller images of items and animals, and then learn the spatial locations of these smaller images on a grid. Crucially, for half of these scenes, the sounds themselves will then also be linked directly to some of images during training. The associated sounds will then be unobtrusively presented during sleep, in a manner that has been shown to improve associated memories. The subsequent memory benefits will reveal whether (1) all images associated with the cued scene will benefit from cuing, demonstrating a context-reactivation effect; (2) only the images directly associated with presented sound will benefit from the cuing, demonstrating a item-reactivation effect; or (3) some composite of these two models. Regardless of which hypothesis is correct, the results will expand our current understanding regarding the role context plays in sleep consolidation.

Conditions

Sleep; Consolidation

Outcome Measures

Primary Outcomes (2)

• Change in error rates between pre- and post-sleep for the different conditions

  The correct location of an image is compared with the position in which the participant has placed it. Measured in pixels on a computer screen.

  Approximately 15 minutes before sleep onset and approximately 15 minutes after sleep offset within the same experimental session

• Modulation of EEG spectral power following sound/odor presentation

  Power modulations within the sigma (12-16 Hz), theta (4-8 Hz) and delta (0.5-4 Hz) ranges immediately following sound onset. Measured across different EEG channels.

  During sleep within the experimental session, assessed up to 1.5 hours

Study Arms (1)

Experimental group

EXPERIMENTAL

This is a within-subject study with a single group of participants

Behavioral: Targeted memory reactivation (sounds)

Interventions

Targeted memory reactivation (sounds) BEHAVIORAL

I will unobtrusively and repeatedly present learning-related sounds during sleep using speakers. This method was shown to improve memory in various tasks. The sounds will be presented several seconds apart and the volume will be so adjusted as not to disturb the participant's sleep. The sounds will be presented during non-rapid eye movement sleep (sleep stage 2 and slow wave sleep). The sounds presented will be non-congruently related to the scenes in the previous learning task. This manipulation is within-subject - all participants will get it, but different specific sounds will be presented for each individual participant.

Experimental group

Eligibility Criteria

• Age: 18 Years - 35 Years
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

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You may not qualify if:

• Participants with a history of neurological disorders or of sleep disorders will be excluded.
• Participants who do not believe they would be able to fall asleep in the lab will be excluded.

Sponsors & Collaborators

• Northwestern University: lead

Study Sites (1)

Cognitive Neuroscience Lab - Northwestern University

Evanston, Illinois, 60208, United States

Location

MeSH Terms

Interventions

Sound

Intervention Hierarchy (Ancestors)

Radiation, Nonionizing; Radiation; Physical Phenomena

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Postdoctoral Fellow at the Cognitive Neuroscience Lab

Study Record Dates

• First Submitted: January 6, 2021
• First Posted: January 8, 2021
• Study Start: September 15, 2020
• Primary Completion: November 30, 2021
• Study Completion: November 30, 2021
• Last Updated: January 12, 2022

Record last verified: 2022-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)