A new study looks into the mechanism behind sleep-dependent
neuroplasticity within the process of
assimilating new visual information. An important a part of how
we relate to the planet is perceptual
learning, which refers to our ability to “make sense” of varied stimuli – visual, auditory, or associated with taste, smell, and touch – through
repeated exposure to them.
Perceptual learning improves the way during which we relate to stimuli, helping us to unpick ambiguous ones. Research had already shown that for consolidating perceptual learning, immersion in slow-wave – or non-rapid eye movement (NREM) – sleep is required.
A previous study concluded that “perceptual memory consolidation requires top-down cortico-cortical input during orthodox sleep ,” which suggests that the route of data transmitted from one cortical region to a different is crucial to completely assimilating perceptual learning undergone throughout the day.
Now, new research from the University of Michigan in Ann Arbor is observing how new visual experiences are consolidated as memories during NREM slow-wave sleep.
Led by PI Dr. Sara Aton, scientists used mouse models to know the neural mechanism that underlies this process of consolidation. Their findings were published within the Proceedings of the National Academy of Sciences.
Deep sleep consolidates visual learning
Dr. Aton explains that new visual stimuli are transmitted via the retina to a neighborhood of the brain called the thalamus, which then relays that information to the cerebral mantle , which is understood to play a task in memory formation.
During wakefulness, the neurons that communicate that visual information between the thalamus and therefore the cerebral mantle ensure a gentle flow of electrical impulses. During NREM deep sleep, on the opposite hand, the neurons “burst,” meaning that spikes of activity are registered.
Dr. Aton explains that after bursting, the neurons pause during a rhythmic then during a synchronized pattern. The team also noted that the cortex fires information back at the thalamus, in order that the knowledge is fed back and forth during a circular fashion.
In a previous study by Dr. Aton and team, they experimented with the impact of sleep on the brain mechanism behind processing and consolidating new visual information.
Working with mice, they exposed the animals to novel visual stimuli then allowed them to sleep. After sleep, the scientists noted, the neurons within the cerebral mantle became more active when exposed to an equivalent visual stimuli.
At an equivalent time, if the rodents experienced sleep deprivation, the cortical neurons were unable to make new connections and consolidate the new information.
But within the new study, Dr. Aton explains that she and her team were curious about checking out what would happen if they performed a reverse experiment. She explains, “We wondered what would happen if we just disrupted that pattern of [brain] activity without awakening these animals at all?”
Sleep-dependent plasticity mechanism
In the recent study, the researchers inhibited neurons from the visual area – that’s , the a part of the cerebral mantle directly implicated in processing visual stimuli – so as to disrupt the feedback pattern between the thalamus and therefore the cortex.