I guess I have been living under a rock, but I never heard of this before. I am a right-brain type of person, but really, using only one-half of your brain so you can sleep and be awake at the same time? Terrestrial mammals do NOT have this capacity, however whales, dolphins, ducks, etc. do have this.
As I understand this, through evolution’s time, us humans might have had the ability to do the same. That basically is, the ability to sleep with one eye open and one-half of our brain awake so as to ward of predators. For example ducks sleep in a group, perhaps four ducks on a log in the stream, sitting side-by-side. The two center ducks will sleep with both eyes closed while the two ducks on the end will sleep with one eye open. The eye that is facing the end of the log, assuming they are perpendicular to the log. After so much time has passed, they will get up and rotate 180 degrees and let the other side of the brain and that open eye, get (as they say), “Shut Eye.” Maybe this is where the term comes from. Then, after more time has passed, the two center sleeping ducks will get up and replace the two ducks on the end. Fascinating! This is all based on no fox or predator coming to interrupt their sleep, but if the foxy-fox does come along, they will know because of the two ducks keeping guard.
Mammals in the water do this as they are mammals and must breathe air to survive, so they do Unihemispheric sleeping to stay awake, yet not awake while ‘logging’ on the surface.
The way I see it, Americans or the Japanese will figure out a way to do this or evolve back to this. Think of it, the average American who works int he corporate world may work 50-60 hours, every dangling their electronic device off their fingers, checking work emails, returning calls, etc. This same worker then has to come home to be the spouse, feed the kids, play with them, etc. Where has the time gone?
If this worker could capture rest and sleep on the train, while watching their briefcase or purse, they get more sleep and perhaps more productivity so the top Fortune 100 or 500 companies will require them to work more hours based on this newly acquired way of sleeping.
After all, doesn’t if feel if we are all just mutated hamsters running on the treadmill of life, made to go faster, faster and faster? Did you ever wonder if we are not the Barbie and Ken dolls of the extra-terrestrial beings from afar? We are all in one big science lab experiment and they are playing with us.
Sorry God, this is all based on evolution. There is so much more on this topic and if you are like me I found it quite interesting. Okay, must run, time for the treadmill of life. As one of my really smart friends would say, “Intergalactical.”
Some information on this can be found at: http://www.sciencedirect.com/science/article/pii/S0149763400000397
The Rattenborg review is only guessing, but I think its clear that there is a cost to unihemispheric sleep, even if we don’t know what it is. Cetaceans and birds and perhaps reptiles having unihemispheric sleep are all cases where there are perpetual and strong selection forces that maintain the ability in these animals. Without constant predation experienced by tasty ducks or the vagaries of being an air-breathing underwater mammal, animals quickly lose their ability to sleep with one half their brain, one assumes because the ability to maintain it is particular and easily lost with variation. Modelling work of the hemispheres in sleep indicates that the connections between the hemispheres are modulated between the two modes of sleep – there may be advantages to such brain structures for instance.