In 2015, as part of an experiment conducted on adult mice, researchers discovered that complete absence of sound stimuli activates neurogenesis processes in the hippocampus — the area of the brain responsible for learning and memory.
The mice were subjected to various auditory conditions, including standard background noise, white noise, sounds that are significant for their species (such as the cries of pups), structured music, and finally, silence.
One day after the exposure, increased proliferation (division) of neural progenitors was recorded for all sound stimuli. However, after a week, a sustained increase in the number of new neurons was observed only in those mice that were in silence, unlike those exposed to white noise or background acoustic environments. This suggests that complete silence activates neurogenesis more effectively.
At first glance, it may seem surprising that the absence of sound triggers such a reaction. Nevertheless, a study published in the summer of 2023 in the journal PNAS showed that silence is processed by the brain similarly to sound, thus we actually "hear" the absence of sound.
Moreover, silence can act as a powerful stimulus, as it is unusual for the natural environment and is perceived by the organism as a signal to increase attention and adaptation. Perhaps this need to adapt to "meaningful silence" explains the brain's response. However, despite the growing amount of indirect evidence of neurogenesis in adult humans, caution should be exercised when extrapolating results obtained from rodents to the human brain.
The record "Silence Generates New Neurons in the Brain of Adult Rodents" first appeared in K-News.
