Noise with a deeper meaning
The nerve cells in the brain are almost never still. However, much of the electrical impulse is considered irrelevant noise. Do they have an important meaning?
Since neuroscientists first measured the voltage changes in the membranes of individual nerve cells around 60 years ago, we have known that brain activity fluctuates constantly. Even to the same sensory stimulus presented at different times, a sensory nerve cell rarely responds with exactly the same count rate. Even without any stimulation, she keeps erupting. Yet only a small fraction of this activity seems to actually matter to our behavior or cognition. The rest of the ebb and flow of brain activity is commonly considered noise with no informational value.
New findings from animal experiments show that there is more to neuronal noise than previously thought. Throughout the brain, even in the early stages of processing in the visual cortex, nerve cells encode information unrelated to their traditional job-such as processing visual stimuli. They will respond to any behavior the animal happens to exhibit, even a quiver of whiskers or a twitch of a hind leg.
The reason why this finding is so new: Until about ten years ago…
