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Completed

NCT Number: NCT04277104

Does Acoustic Stimulation During Sleep Boost Slow Wave Sleep and Memory Performance?

With aging the amount of slow wave sleep decreases drastically and this disruption is markedly exaggerated in older adults suffering from mild cognitive impairment and Alzheimer's disease. Critically, the disruption of slow wave sleep and cognitive decline seem bidirectionally linked forming a vicious cycle. In the long run, improving slow wave sleep might be a useful intervention tool to delay the onset of cognitive decline. The present study aims at improving slow wave sleep and memory functions through a closed-loop acoustic stimulation approach. A closed-loop algorithm is used that detects slow waves in the electroencephalogram and is programmed to present short tones (50 ms) in the rhythm of these waves. This procedure has shown to boost both slow wave sleep as well as memory performance, mainly in young adults and when applied for one night. Here, the investigators apply tones via multiple consecutive nights and assess memory performance during this 3-night intervention.

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Key information

Conditions

Healthy Alzheimer Disease Brain Diseases Central Nervous System Diseases Cognition Disorders Cognitive Dysfunction Dementia Mental Disorders Mild Cognitive Impairment Nervous System Diseases Neurocognitive Disorders Neurodegenerative Diseases Tauopathies

Age range

60 year–85 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University Hospital of Old Age Psychiatry and Psychotherapy

Bern, 3000 60, Switzerland

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Written informed consent
  • Fluent in German
  • Normal or corrected to normal vision
  • Unimpaired hearing
  • For healthy group: Montreal Cognitive Assessment Score ≥ 26
  • For MCI group: Montreal Cognitive Assessment Score < 26
  • For at risk group: smoker, high cholesterol, high blood pressure and high fasting plasma glucose OR smoker, high BMI, physically inactive, unhealthy dietary habits

Exclusion criteria

  • Known sleep problems such as Insomnia, restless leg syndrome, apnea
  • Irregular sleep pattern
  • Symptoms of depression
  • History of untreated severe neurological and psychiatric diseases
  • Alcohol or substance abuse
  • Use of medication acting on the central nervous system

Treatment and study plan

Closed loop acoustic stimulation

Other

The intervention consists of three consecutive nights of closed loop acoustic stimulation during slow wave sleep. An established closed-loop algorithm is utilized that detects slow oscillations in the electroencephalogram and is programmed to present short tones (50 ms) into their up-states. Tones will be presented via a headband with integrated speakers. The procedure does not wake participants

Sham acoustic stimulation

Other

Sham acoustic stimulation: participants wear the headband but no stimuli are delivered during slow wave sleep. This ensures that in both the control and the intervention group the conscious experiences are the same.

Primary outcomes

  1. Change from baseline episodic memory performance after three nights of intervention

    Time frame: The change in memory performance will be assessed between the baseline measurement (evening before the first intervention night) and on the morning of the last intervention night (1 hour after waking), 3 days after initial encoding

    Face-occupation associative memory task: encoding of 40 faces coupled with 40 occupations takes place on the evening of the first intervention night followed by a retrieval session (BASELINE). Feedback-based retrieval sessions take place on the following mornings and evenings of three consecutive intervention nights (4 feedback-based encoding sessions). After the last intervention night a retrieval session without feedback is performed upon waking (ASSESSMENT OF CHANGE)

  2. Change from baseline performance in computer-based verbal new learning task (episodic memory) after three nights of intervention

    Time frame: The change in new learning performance will be assessed between the baseline measurement (morning before the first intervention night) and on the morning of the last intervention night (1.5 hour after waking), 3 days after.

    Verbal associative memory task: a list of 30 moderately associated word pairs (e.g. balloon-air) are presented on a screen. The respective word pairs are displayed for five seconds each and participants are asked to memorize them. After a one-minute break, a cued recall follows in which one word of each pair is randomly shown and participants are prompted to name the matching second word (BASELINE). After the last intervention night a different list of 30 word pairs is used for another session of encoding and retrieval (ASSESSMENT OF CHANGE)

Secondary outcomes

  1. Improvements in sleep physiology

    Time frame: Three consecutive nights of EEG measurement/polysomnography

    EEG-data: Quality of slow wave sleep, number of slow oscillations, number of sleep spindles can all be measured by the data provided by the electroencephalographic recordings. A high densitiy electrode cap with 128 channels is used for this purpose.

  2. Improvement in episodic memory performance at follow-ups

    Time frame: One week as well as 3 months after intervention

    Face-occupation associative memory task

  3. Improvement in new learning of episodic memory at follow-ups

    Time frame: One week as well as 3 months after intervention

    Verbal associative memory task

  4. Decreases in plasma amyloid-beta

    Time frame: Blood samples will be taken twice: on the morning before the first intervention night, on the morning after the last intervention night (3 days apart)

Other outcomes

  1. General cognitive functions: working memory

    Time frame: Assessed four times: on the morning before the first intervention night, on the morning after the last intervention night, one week after and 3 months after the intervention

    A computer based visual n-back task is performed (established task for working memory)

  2. General cognitive functions: cognitive flexibility

    Time frame: Assessed four times: on the morning before the first intervention night, on the morning after the last intervention night, one week after and 3 months after the intervention

    A computer based task switch task is performed (established task for cognitive flexibility)

  3. General cognitive functions: cognitive inhibition

    Time frame: Assessed four times: on the morning before the first intervention night, on the morning after the last intervention night, one week after and 3 months after the intervention

    A computer based go/no go task is performed (established task for cognitive inhibition)

Sponsors and collaborators

Lead sponsor

University of Bern

Other

Registry information

Official study title

Improving Slow Wave Sleep by Auditory Stimulation to Enhance Memory Consolidation and New Learning in Healthy Older Adults and Older Individuals at Risk for Dementia

Important dates

Study start
2019
Primary completion
2023
Study completion
2023
First posted
Feb 20, 2020
Registry last updated
Dec 15, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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