Awhile back I read two things that jostled something loose in my brain and I am working to get a handle on what and where it is. The first item was a PLOS article asking if infant sleep were a precursor to adult sleep, linked here.
This is an odd question to me, because all things infant (except those neurons marked for apoptosis or cell death) are the precursors of most adult things. Ask William Wordsworth and he will tell you:
My heart leaps up when I behold
A rainbow in the sky:
So was it when my life began;
So is it now I am a man;
So be it when I shall grow old,
Or let me die!
The Child is father of the Man;
Anyway the researchers found infant sleep to have similar components to adult sleep, so we also have it scientifically. The specifics here are interesting. The researchers identified cells in the pons (of mice) that turn off the body’s motor output, resulting in atonia, the limp, relaxed body state of sleep. Other cells turned on the twitching movements characteristic of dream states. Both of these are critical components of REM sleep, so that infant sleep is indeed a precursor to adult sleep, i.e., there is continuity of function through development. Of course we knew that but just hadn’t found it right here.
Reading further these researchers are following up on some work by Howard Roffwarg, a preeminent sleep researcher since the 1960s. He presented the notion in 1966 that dreaming, aka REM sleep, plays a role in our neurological development. In this he focused on the fact that for all mammals, REM sleep is more frequent during infancy than during adulthood, and that for adults, sleep and dream deprivation has serious negative results. This is great work. Here is his picture and a good bio: http://www.cumc.columbia.edu/psjournal/archive/archives/jour_v19no2/profile.html
Now while reading about this research, I also read in Joseph’s Neuroscience text that infants, who we know spend much time asleep and much of that time in REM sleep, also show REM during wakefulness. Dr. Roffwarg, it turns out, was probably one source for this information. He found that infants engage in more REM sleep, go directly from awake to REM unlike adults who have to have some period of deep sleep before REMing, and that the eye flutters and gurgles of satisfaction after nursing are really the manifestation of REM, the pons instigating the movements and relaxation.
I like this. If you have followed this train in my posts, you may remember that 1) I think consciousness is the autogenic (following Langer) control of sentience and 2) that sentience and consciousness, being two different things, can be on and off at different times. Sentience is a basic life function: find the nutrients out there and move on to more. Consciousness evolves as the CNS cephalizes and autogenic impulses, the vital energy the animal produces autonomously not in response to any impact from outside, take control of sentient functions. From a past post, then, I thought that adults can be both sentient and conscious (as I assume you are now), not sentient but conscious (as in REM dream sleep), unconscious but sentient (as in highway hypnosis), and unconscious and insentient (as in deep sleep). Infants in their sleep patterns develop some control over these 4 states, thereby creating more discrete and adaptive functioning modes.
Now Dr. Roffwarg has studied the complexities involved in REM sleep as it prepares the developing mind for learning and then helps to maintain the mature mind’s capacity. From my perspective, early REM helps the developing self and MEMBRAIN exert control over sentient functions, the ones dedicated to perceiving the external environment and moving on to life sustaining activities. With this control comes the ability to be conscious, i.e., mindful, of non-sentient information such as memory and symbols. Thus, ‘priming’ for learning means the integration of perceptual information with intentional formation (and its displaced information), and ‘maintenance’ means the rhythmic resurgence of autogenic impulses over sentience while the sentient flow is much reduced. This would be another essential part of sleep: quieting the soma and its need for sentient processing of the welter out there, so that the information rising into the more mindful layers is self-generated. Which brings up the subject of meditation, but enough for now.