On the surface, sleep appears to serve some very basic, and very logical, functions.
For example, scientists have noted for some time now that a significant portion of growth and repair occur on a cellular level during sleep.
And it makes perfect sense that we expend energy, get tired, and need to rest and recuperate in order to be able to do it all over again the next day.
But researchers are now saying we sleep in order to “forget” certain portions of our day so we can remove interference.
As a sort of street-sweep of extraneous but immediately non-useful information, our brains backtrack and delete connections of synapses made during the day, the research says.
According to interpreters of the two studies, in a way, the process is like deleting memory from our hard drives, or at least relegating it to folders that may not be revisited in the short term, if ever.
Data Collection…and Surprising Results
To prove the hypothesis, researchers gave neurons in dishes a drug that overstimulated them into new growth. After this spur of growth, the neurons actually snipped back some of this growth, the researchers have revealed.
Supporting tests paired a slowing of brain waves, as during sleep, with a paring back of neurons.
The tissue for the petri dish experiments was obtained from mice.
Not All Are Pared; Some Are Spared
Interestingly, however, during this “paring down” process, some specific neurons appeared to not be touched but rather, left intact.
The researchers theorize that these specific synapse connections could relate in some way to memory or general data that the brain has, through its life experience, found useful, and therefore elects to keep, at least for now.
It has not yet been determined whether the human brain reacts in exactly the same way as the mouse brain tissue and EEGs (which measured brain waves) found.
Why Forgetting is Important
Not all of the brain’s function has yet been accounted for, and estimates run a wide and surprising gamut from 65-90% of the brain potentially “empty” of current usage. This concept is far from certain to date, as there could be functions in the brain not yet accounted for or measurable, or “empty space,” so to speak, could be based on the potential for further growth as humans, like all creatures, are still evolving biologically.
However, it’s well-known that competing information in the immediate consciousness of any given individual can be confusing and reads as “white noise” to the person, potentially drowning out data that’s important in the here-and-now.
Too much of this type of confusion could have negative consequences such as less safe driving, inability to perform work or school functions, agitation or other negative conditions that harm rather than help the person.
An ability to compartmentalize what isn’t immediately necessary and delete what is perceived by the brain to be useless both short- and long-term is critical for thought organization, calmness and balance, experts say.
Not So Fast: Opposing Interpretations
In the wake of the fascinating reports, some experts are saying more research is needed, citing correlation v. causation: in other words, just because two events happen at roughly the same time does not mean one has directly caused the other.
It’s possible, for example, that the “dumping” of unnecessary information could be based on a biorhythm or lack of a light source, as would happen in nature during nighttime, were no electronic lighting available.
Or they could be based on an individual’s body clock independent of a sleep/wake schedule, could be different from mice than in humans, or may not happen in humans at all.
However, the information IS intriguing, and given similar mechanisms in mammalian brains in some respects, the papers could lead to a better understanding of the brain, sleep, and exactly what the brain is capable of doing.