Understanding Brain Mechanisms Involved in Autobiographical Memory

NCT05710549 | Recruiting

• 1 other identifier: 2021-01388
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

The overall objective of this project is to characterize the spatiotemporal dynamics of brain oscillations underpinning autobiographical memory (ABM) and the modulation of the memory network using non-invasive brain stimulation.

Conditions

Mild Cognitive Impairment; Alzheimer Disease; Memory Loss

Keywords

autobiographical memory (ABM); high-density electroencephalography (EEG); magnetic resonance imaging (MRI); non-invasive brain stimulation (NIBS); transcranial alternating current stimulation (tACS)

Outcome Measures

Primary Outcomes (2)

• Spatiotemporal dynamic changes measured with electroencephalography (hdEEG)

  Changes in spatiotemporal dynamics in different frequency bands (theta, alpha, beta, gamma) will be assessed with hdEEG

  up to 30 minutes

• Cognitive Assessment

  The Montreal Cognitive Assessment (MOCA) will be administered to characterize the cognitive status

  baseline

Study Arms (2)

neurophysiological measurements

EXPERIMENTAL

40 cognitively-unimpaired healthy young adults (age 18-35 years old), 40 cognitively-unimpaired healthy older adults (age 55+ years old), and 40 age-matched patients with mild cognitive impairment (MCI) (age 55+ years old) will be assessed using high-density electroencephalography (hdEEG) to characterize the spatiotemporal dynamics of brain oscillations during personalized, autobiographical memory (ABM) tasks.

Device: high-density electroencephalography (hdEEG)

neuropsychological examination

EXPERIMENTAL

40 MCI patients (age 55+ years old) will undergo 20min multi-channel protocols of transcranial alternating current stimulation; tACS (either gamma, beta, or ActiSham stimulation randomized across the three laboratory sessions) to modify cognitive functioning (MoCA score), and oscillatory brain activity during performing personalized, autobiographical memory (ABM) tasks and resting-state EEG.

Device: Transcranial alternating current stimulation (tACS)

Interventions

high-density electroencephalography (hdEEG) DEVICE

EEG will be recorded with a 257-channel EEG system (Geodesic Sensor Net, MegStim). An EEG net is applied at once on the head with evenly spaced sensors that provide full scalp coverage, including the cheek, Ag/Ag-Cl electrodes that are interconnected by thin rubber bands and contain small sponges soaked with saline water that touches the participant's scalp surface directly. Net application takes about 10 min to derive impedances to \<30 kOhms. EEG is recorded with 1 kHz and band-pass filtered between 0.1-200 Hz. Vertex electrode Cz is used as an acquisition reference.

neurophysiological measurements

Transcranial alternating current stimulation (tACS) DEVICE

tACS will be delivered by a battery-driven current stimulator Starstim SS32 (Neuroelectrics) through surface Ag/AgCl electrodes placed into holes of a neoprene cap corresponding to the international 10/20 EEG system. Gel (Parker Lab, Inc.) will be applied to optimize signal conductivity and lower impedance.

neuropsychological examination

Eligibility Criteria

• Age: 18 Years - 85 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Cognitively-Unimpaired Younger and Older Adults
• Age 18 to 35 years old (younger adults)
• Age 55+ years old (older adults)
• without any cognitive impairment (based on the Montreal Cognitive Assessment: MoCA)
• willing and capable to give informed consent for participation in the study after it has been thoroughly explained able
• willing to comply with all study requirements informed consent form was signed
• Mild Cognitive Impairment (MCI) patients
• Age 55+ years old
• Clinical Diagnosis of MCI
• Confirmation of diagnosis will be made by the study MD based on a holistic consideration of the participant's cognitive evaluation and history
• Mini-Mental State Examination (MMSE) ≥ 18 (Mild AD ≥ 21)
• CDR ≥ .5
• Demonstration or history of autobiographical memory impairments
• On a stable dose of medications for memory loss including cholinesterase inhibitors (e.g. donepezil, rivastigmine) or memantine as defined as 6 consecutive weeks of treatment at an unchanging dose
• Minimum of completed 8th-grade education

You may not qualify if:

• Cognitively-Unimpaired Younger and Older Adults
• any cognitive impairment captured by the Montreal Cognitive Assessment (MoCA) - score \< 26
• major psychiatric co-morbidity including major depressive disorder, schizophrenia, or psychosis
• blindness or other disabilities that prevent task performance
• Contraindication for undergoing MRI
• Any metal in the brain or skull (excluding dental fillings) or elsewhere in the body unless cleared by the responsible covering MD (e.g. MRI compatible joint replacement)
• Mild Cognitive Impairment (MCI) patients
• Age \< 55 years old
• Any current diagnosis of a major psychiatric disorder (e.g., schizophrenia, bipolar disorder, major depressive disorder)
• Other than MCI, any history of other progressive or genetic neurologic disorder (e.g. Parkinson's disease, multiple sclerosis, tubular sclerosis) or acquired neurological disease (e.g. stroke, traumatic brain injury, tumor), including intracranial lesions
• History of head trauma resulting in prolonged loss of consciousness
• Current history of poorly controlled headaches including chronic medication for migraine prevention
• History of fainting spells of unknown or undetermined etiology that might constitute seizures
• History of seizures, diagnosis of epilepsy, or immediate (1st-degree relative) family history of epilepsy with the exception of a single seizure of benign etiology (e.g. febrile seizures) in the judgment of a board-certified neurologist
• Any unstable medical condition or chronic (particularly) uncontrolled medical conditions that may cause a medical emergency in case of a provoked seizure (cardiac malformation, cardiac dysrhythmia, asthma, etc.) or study complication

Sponsors & Collaborators

• Lucie Bréchet: lead

Study Sites (1)

University of Geneva, Campus Biotech

Geneva, Canton of Geneva, 1202, Switzerland

RECRUITING

Related Publications (3)

• Brechet L, Brunet D, Birot G, Gruetter R, Michel CM, Jorge J. Capturing the spatiotemporal dynamics of self-generated, task-initiated thoughts with EEG and fMRI. Neuroimage. 2019 Jul 1;194:82-92. doi: 10.1016/j.neuroimage.2019.03.029. Epub 2019 Mar 19.

  PMID: 30902640 BACKGROUND

• Roehri N, Brechet L, Seeber M, Pascual-Leone A, Michel CM. Phase-Amplitude Coupling and Phase Synchronization Between Medial Temporal, Frontal and Posterior Brain Regions Support Episodic Autobiographical Memory Recall. Brain Topogr. 2022 Mar;35(2):191-206. doi: 10.1007/s10548-022-00890-4. Epub 2022 Jan 26.

  PMID: 35080692 BACKGROUND

• Michel CM, He B. EEG source localization. Handb Clin Neurol. 2019;160:85-101. doi: 10.1016/B978-0-444-64032-1.00006-0.

  PMID: 31277878 BACKGROUND

MeSH Terms

Conditions

Cognitive Dysfunction; Alzheimer Disease; Memory Disorders

Interventions

Transcranial Direct Current Stimulation

Condition Hierarchy (Ancestors)

Cognition Disorders; Neurocognitive Disorders; Mental Disorders; Dementia; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Tauopathies; Neurodegenerative Diseases; Neurobehavioral Manifestations; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Convulsive Therapy; Psychiatric Somatic Therapies; Behavioral Disciplines and Activities; Electroshock; Psychological Techniques

Study Officials

• Lucie Bréchet, PhD

  University of Geneva (UNIGE)

  PRINCIPAL INVESTIGATOR

• Paul G Unschuld, Prof. MD

  Geneva University Hospitals (HUG)

  STUDY CHAIR

Central Study Contacts

Lucie Bréchet, PhD

CONTACT

+41 22 379 08 52; lucie.brechet@unige.ch

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Dr.

Study Record Dates

• First Submitted: January 12, 2023
• First Posted: February 2, 2023
• Study Start: April 25, 2022
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): August 1, 2027
• Last Updated: July 15, 2025

Record last verified: 2025-07

Locations

CH (1)