Projects

As we age, our sleep quality decreases. This is part of normal aging, but if this decrease becomes severe, it can be a warning sign of imminent dementia. At the same time, dementia leads to even more decreased sleep quality, leading to faster progression of dementia. This vicious cycle must be broken, and one way to do it could be by increasing sleep quality. In this project, we use phase-locked acoustic stimulation (PLAS) to present quiet sounds to sleeping individuals to boost their sleep quality across three nights in the sleep laboratory. First results show that PLAS induces physiological responses during sleep, and the magnitude of these induced responses correlate with memory gains across the intervention in a dose-dependent way. Additionally, these effects were associated with beneficial changes in plasma amyloid beta 42/40 ratios. We now explore this dynamic in individuals with mild cognitive impairment or subjective cognitive decline to find the optimal way of using sound treatment during sleep as a tool to delay the onset of dementia.

Our laboratory-based results show that the magnitude of the physiological response to phase-locked acoustic stimulation (PLAS) predicts improvement of memory functions and improvements of metabolic clearance. However, true long-term studies in an ecologically valid setting in a large sample are needed to assess the efficacy of PLAS for the improvement of sleep, memory, and metabolic clearance with the goal of preventing cognitive decline. Laboratory-based studies quickly become economically and logistically unfeasible to achieve this goal. In this project, we aim to utilize home-use devices to study the effect of PLAS on memory functions in the comfort of one’s own home. Treatment spans a 12-week period, and we assess cognitive performance using tablet-based, engaging “serious games” that can also be played at home. We sample dementia-related blood-biomarkers (amyloid beta, pTau181 and 217, GFAP and NfL) and their response to treatment. We expect PLAS to enhance sleep, which will lead to down-stream effects on memory performance and metabolic clearance. Using a novel approach allowing brain-age estimation from sleep-electrophysiology, we hypothesize to see a “rejuvenating” effect of PLAS, restoring an electrophysiological profile typically seen in younger brains. This study could pave the way for PLAS-capable home-use devices as an affordable, non-invasive tool to combat cognitive decline, and could lead to novel preventative applications for memory clinics, relieving their clinical burden and improving public health.