In a step toward combating dementia, Western researchers have received a $1.1 million grant from the Weston Family Foundation to explore the potential of gentle brain-synched sounds to improve sleep and memory performance in older adults. The method, which involves playing those gentle sounds during sleep, is called phase-locked auditory stimulation.
This research, led by psychology professor Laura Batterink, aims to advance brain health and sleep science among older adults with amnestic mild cognitive impairment (AMCI). The condition is characterized by noticeable memory problems that are greater than expected for a person's age, but not severe enough to interfere significantly with daily life.
"Our goal with this grant is to use phase-locked auditory stimulation to enhance slow-wave sleep in older adults, particularly those at high risk for Alzheimer's disease," said Batterink, a member of the Western Institute for Neuroscience (WIN). "Poor sleep can create a vicious cycle of declining brain health, which further worsens sleep. By intervening with this method, we hope to break this cycle and improve overall brain health."
Understanding phase-locked auditory stimulation
Phase-locked auditory stimulation involves playing gentle sounds at specific times during sleep to sync with the brain's naturally slowed waves. By using real-time technology to monitor brain activity, researchers can send these sounds at just the right moment to strengthen the brain waves that help with memory consolidation and cognitive functions.
"This method involves reading people's electroencephalography (EEG) results while they sleep and using real-time algorithms to predict slow oscillations. By emitting a quiet auditory pulse at the right moment, we can increase the amplitude of these slow oscillations, which has been shown to improve memory consolidation and other aspects of cognition," said Batterink.
Her research focuses on sleep-dependent memory consolidation, which is crucial for retaining information learned during the day. The new project is particularly significant given the world's aging population and the increasing prevalence of dementia.
"If we can demonstrate this method is effective, it could potentially be used as a widespread biofeedback system to improve sleep and, consequently, brain health," Batterink said.
Lyle Muller
Lyle Muller, a mathematics professor, is co-principal investigator on the project.
"My lab is developing algorithms to process neural signals in real-time and play sounds at specific points during sleep rhythms. By reducing the time between signal processing and sensory stimulation, we hope to see significant improvements in memory," he said.
Muller highlighted the potential of those algorithms to detect slow-wave amplitudes - a sign of deep sleep - in older adults, which tend to be smaller and harder to detect.
The collaborative study brings together experts in psychology, neuroscience and computational science. The research team, which also includes Adrian Owen, Stefan Kohler, Stephen Pasternak and Jaspreet Bhangu, will conduct the study in two phases. In the first phase, participants will undergo sleep studies in a controlled laboratory setting.
"They will spend three nights receiving auditory stimulation and three nights with sham stimulation to serve as a control. This allows us to directly compare the effects," Batterink said. The second phase will involve using portable EEG systems to test the method in participants' homes, making it more accessible and scalable.
"This research could be directly translatable to real-world applications, potentially helping a large number of aging individuals," she said.
Combating poor sleep and brain health decline
Recruitment for the study will target individuals aged 60 and older, including those with a clinical diagnosis of AMCI and healthy older adults. The team will assess the impact of the sound stimulation on sleep quality and memory performance.
The team is excited about the potential real-world applications of their research.
"If successful, this method could be a game-changer for brain health in aging populations. It's exciting to work on something that could have a direct, positive impact on people's lives." – Laura Batterink, psychology professor and study lead
