Summary: A new study finds that stimulating alpha brain waves using sound could improve sleep in people with dementia. The technique, known as closed-loop alpha auditory stimulation (aCLAS), can speed up or slow down alpha rhythms depending on the timing of the sound. This non-invasive approach could offer a new therapeutic avenue for sleep disorders linked to dementia.
Highlights:
- Sound stimulation can modify alpha brain waves, which are linked to memory and perception.
- The aCLAS technique can speed up or slow down alpha rhythms depending on the timing of the sound.
- This approach could potentially improve sleep in people with dementia.
Source: University of Surrey
Using sound to stimulate certain brain waves could potentially help people with dementia or cognitive decline sleep better, a new study reveals. Sleep disturbances are a common feature of dementia and can affect up to half of people with the condition.
During the study, the research team from the University of Surrey and the Center for Care Research & Technology at the UK Dementia Research Institute at Imperial College London, used sound stimulation to target alpha rhythms, a type of brain wave, at specific times during the wave to study how the brain responds.
Alpha rhythms have been associated with memory and perception, and changes in the rhythms have been observed in people with cognitive decline and dementia.
Lead author Dr Ines Violante, senior lecturer in psychological neuroscience at the University of Surrey, said:
“Alpha oscillations are a defining feature of our brain’s electrical activity, but we do not yet fully understand their role in shaping fundamental brain functions.
“Using sound is a powerful, non-invasive approach to stimulating certain oscillations in the brain. It’s important that we find ways to manipulate these oscillations to create tools for therapeutic applications, because we know that brain oscillations are slower in diseases such as Alzheimer’s.
In a series of experiments, researchers used an innovative brain modulation technique known as Alpha Closed-Loop Auditory Stimulation (aCLAS)., in which sounds are timed to the precise phase of alpha rhythms. To monitor the effect of stimulation, measurements of the brain’s electrical activity were read continuously and in real time, and when a brain The wave reached a particular phase, a sound (a burst of pink noise) was played over the participant.
The researchers observed that depending on the phase at which the sound was played, the alpha rhythm became faster or slower. The effect also depended on where the alpha oscillations were coming from in the brain.
Mr Henry Hebron, former PhD student at the University of Surrey and first author of the publication, said:
“What we discovered is that alpha oscillations can be manipulated via sound when we approach this rhythm on its own terms, using a closed-loop approach. Surprisingly, when we performed our aCLAS experiment while participants were falling asleep, we observed that sounds from a particular phase prevented them from reaching deeper sleep stages (without waking them), whereas the same sounds from a different phase were not disruptive.
“There is still much to explore regarding behaviors dependent on neuronal oscillations, and we believe that closed-loop approaches, like the one we implemented here, could be essential. »
According to the researchers, now that they have shown that they are able to influence alpha waves with sound, the next steps will be to explore whether they can modify the waves in ways that improve cognition and sleep, which could ultimately benefit patients with dementia.
Professor Derk-Jan Dijk, Director of the Surrey Sleep Research Center and Group Leader at the UK Dementia Research Institute Center for Care Research & Technology Centre, said:
“There is much to discover about the role of the alpha rhythm in sleep and cognition. This technique could help improve our understanding and improve sleep functions in people with dementia. We are currently studying the effects of this closed-loop auditory stimulation approach in REM sleep, where alpha rhythms are present but their role is still unknown.
The research contributes to the United Nations Sustainable Development Goal 3 – Good health and well-being.
About this news on auditory neuroscience and sleep research
Author: Natasha Meredith
Source: University of Surrey
Contact: Natasha Meredith – University of Surrey
Picture: Image is credited to Neuroscience News
Original research: Free access.
“A closed-loop auditory stimulation approach selectively modulates alpha oscillations and sleep onset dynamics in humans” by Ines Violante et al. Biology PLOS
Abstract
A closed-loop auditory stimulation approach selectively modulates alpha oscillations and sleep onset dynamics in humans
Alpha oscillations play a critical role in managing brain resources, inhibiting neuronal activity based on their phase and amplitude, and are altered in many brain disorders.
Developing minimally invasive tools to modulate alpha activity and identify the parameters that determine its response to exogenous modulators is essential for the implementation of targeted interventions.
We introduce alpha closed-loop auditory stimulation (αCLAS) as an EEG-based method to modulate and study these brain rhythms in humans with specificity and selectivity, using targeted auditory stimulation.
Through a series of independent experiments, we demonstrate that αCLAS modifies alpha power, frequency, and connectivity as a function of phase, amplitude, and topography.
Using single-pulse αCLAS, we show that the effects of auditory stimuli on alpha oscillations can be explained within the theoretical framework of oscillator theory and a phase reset mechanism.
Finally, we demonstrate the functional relevance of our approach by showing that αCLAS can interfere with sleep onset dynamics in a phase-dependent manner.