And study led by Valentine Dragoprofessor at Rice University and co-author with an interdisciplinary team from Houston Methodist University and Weill Cornell Medical College, revealed a key mechanism that explains how sleep improves cognitive and behavioral performance.
The authors spoke of dream NREM (non-rapid eye movement sleep) and explained that it is recognized as the lightest stage of sleep. rest. This phase encourages brain synchronization and optimizes information encodingwhat could open the door to new treatments for sleep disorders and cognitive improvement techniquesaccording to the job.
The team analyzed Neural activity of macaques during visual discrimination tasks (NdeR: distinguish differences and similarities in visual stimuli) before and after a period of NREM sleep of 30 minutes. Brain activity was recorded in three areas: the primary and middle visual cortices and the dorsolateral prefrontal cortex. These regions are associated with visual processing and executive functions of the brain, according to the study. To ensure that the animals were in NREM sleep, brain and muscle activity monitoring was used, in addition to confirming body relaxation through video analysis.
The results published in Science indicated a significant improvement in performance of macaques after sleep. Animals that slept achieved greater accuracy in discriminating rotated images, unlike those that remained awake in a state of quiet wakefulness. This finding, for experts, highlights The direct influence of sleep on behavioral performance.
“During sleep, we observed an increase in low-frequency delta wave activity and synchronized activation between neurons in different cortical regions,” he noted. Natasha Kharasfirst author of the study and former researcher in Dragoi’s laboratory. According to the specialist, after sleep, neurons acquired greater independence in their activation due to neuronal desynchronization. This change improved accuracy in information processing and visual performance.
The research also included methods to artificially replicate the effects of sleep. The scientists applied low-frequency electrical stimulation to the visual cortex, with the aim of mimicking the delta waves of NREM sleep. This procedure, performed while the macaques remained awake, reproduced neuronal desynchronization and improved their performance on the tasks. “This finding is significant because it suggests that some of the restorative and performance-enhancing effects of sleep could be achieved without the need for actual sleep,” Dragoi explained.
The team also developed a large-scale neural network model to further explore their findings. During sleep, they identified an asymmetric weakening of the brain’s excitatory and inhibitory connections; The former presented a greater weakening, which generated a general increase in neuronal excitation. According to Dragoi, This mechanism allows the brain to reduce its level of synchrony after sleep, optimizing neural activity for specific tasks.
“The ability to reproduce sleep-like neural desynchronization in a waking state opens new possibilities for improving cognitive and perceptual performance in situations where sleep is not possible, such as in the case of people with sleep disorders or in circumstances mitigating factors such as space exploration,” said Dragoi.
The study suggests a promising future for the development of therapeutic brain stimulation techniqueswith potential applications to improve cognitive function and memory in people with sleeping difficulties, always according to scientists.
“Our study not only deepens our mechanistic understanding of the role of sleep in cognitive function, but also breaks new ground by showing that specific patterns of brain stimulation could substitute for some benefits of sleep, pointing toward a future in which we could enhance brain function independently of sleep itself,” Dragoi concluded.
