NCT04714879

Modulation of Memory Consolidation in Humans

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 54 (actual)
• Sponsor: University Medicine Greifswald · Academic / Other
• Sex: All
• Age: 50 Years – 80 Years
• Healthy volunteers: Accepted

Summary

The goal of the present study is to optimize effects of slow oscillatory transcranial direct current stimulation (so-tDCS) on sleep physiology and memory consolidation in humans by combining computational and experimental human models in an iterative process. The investigator therefore works in cooperation with Prof. Dr. Klaus Obermayer (TU Berlin), who contributes computation models with the aim to mechanistically understand the impact of different perturbations on sleep-related electrophysiological features, and to subsequently optimize so-tDCS parameters for inducing SO and spindle activity.

Detailed description

Sleep plays an active role in long-term consolidation of memories. Specifically, slow oscillations (SO, large amplitude waves \<1 Hz) and sleep spindles (8-15 Hz), that can be measured by electroencephalography (EEG), appear to be critical for declarative memories. According to the "active system consolidation" account, newly encoded memories are reactivated during sleep, accompanied by sharp-wave ripple events (80-100 Hz) in the hippocampus, and redistributed to cortical long-term storage networks through a coordinated dialog between the hippocampus and neocortex. This dialog is supposedly mediated by a particular coupling between cortical SO and thalamo-cortical fast spindles (12-15 Hz), with spindles preferably occurring during SO up-phases, and hippocampal ripples grouped at the troughs of fast spindles. Slow spindles (8-12 Hz) are a separate kind of sleep spindle activity whose function in memory consolidation is less well understood. Interventions targeting sleep parameters may not only make it possible to beneficially modulate a vital aspect of memory consolidation, i. e., sleep-dependent memory consolidation, but may also help to delineate which specific elements of the neural dynamics during sleep are crucial for successful consolidation.

Conditions

• Sleep

Interventions

Type	Name	Description
OTHER	Device: anodal tDCS	anodal current modulated by an oscillatory component including a fixed (0,75 Hz) versus individually adapted so-tDCS frequency with three different stimulation durations (5 min, 2 min, 30 sec)
OTHER	Device: no stimulation	sham stimulation

Timeline

• Start date: 2018-12-01
• Primary completion: 2021-01-05
• Completion: 2021-01-31
• First posted: 2021-01-19
• Last updated: 2024-06-11

Locations

1 site across 1 country: Germany