The Twenty-Four Hour Mind: The Role of Sleep and Dreaming in Our Emotional Lives
My reading list these days is erratic and wide. I am picking up things that pique my interest without any plan, without any connection to what I previously had been reading. But that’s okay for these summer days.
A colleague had forwarded an article from Maria Popova’s brain pickings blog. It was a review of Rosalind D. Cartwright’s book on the role of sleeping and dreaming in our lives. The review (like nearly everything on “brain pickings”) was intriguing and interesting. So of course, I had to find it in our library.
Cartwright is one of the preeminent scientists studying sleep–a relatively new area in scientific research. Her thesis is that sleep is essential to our health, particularly to our emotional health, and that the modern penchant (and desire) for sleeping less is damaging both physically and psychically.
Indeed, the mind does not sleep when we sleep–it goes into over-drive, cataloging memories, cementing new knowledge, mapping neural pathways. Cartwright states:
We can now begin to answer the question, “Where do we go when we got to sleep?” Clearly we do not sink into a void, but instead into a mental workshop where emotionally important information is kept active until it is saved in neural networks. When the highly activated REM sleep comes along, perceptual dreams reveal the matching of new information to old… . Through the night, from REM to REM, new information is integrated, drawing together more and more remote associations.
She continues that there is short-term functionality to these rhythms– “down-regulation of negative mood” –and long-term functionality. The long-term benefits, she lists as “continuously test[ing] and modify[ing] those non-conscious habitual schemas that make up our self-system and influence our behavior choices, based on our emotional evaluation of whether the new experience supports or challenges our present self-definition.”
This is a lot of responsibility thrown onto a good night sleep, and Cartwright’s argument is that we, as modern human beings, are sabotaging that essential need.
Aside from emotional turmoil–and Cartwright’s expertise is on sleep disorders, particular sleepwalking–Cartwright points out physical dangers as well. Those with long-term insomnia are more prone to obesity and diabetes. A famous study by the American Cancer Society was done over a 10-year period and found a puzzling pattern. Those who slept less than six hours a night AND those who slept more than nine hours a night had a higher mortality rate for their age. The conclusion is that we humans are built to sleep about 1/3 of our 24 hour cycles, that magic 7 to 9 hour range.
“We speak prose while awake and poetry when asleep.”
Yet, for Cartwright’s thesis, it is not merely sleep that is essential to human health, but dreaming as well. In her profession, Cartwright is known as “the Queen of Dreams,” and dream-research is what she is interested in and battles for. Here is how Cartwright explains the symbiotic functioning of the waking and dreaming life.
“…[T]he mind is continuously active, although in different modes of expression, during the two major alterating states of waking and sleep. … In waking, there is a wider lens open to receive and respond more to the external world, while in sleep we are mostly confined to a narrower base of internal information both new and old.”
It is this “internal” information that sets us dreaming, that allows us to fit old information with new information, to anticipate new situations and reconcile old. Cartwright firmly believes that our emotions are greatly tied to the functioning of our dreaming, and of our sleeping.
While Cartwright acknowledges the contributions of Freud to dream-analysis and the understanding of the unconscious, she moves decidedly apart from him. (The technological abilities for brain-image mapping, sleep studies, etc. give her a great advantage.) The Freudian concept of the preconscious, unconscious and conscious mind is much too simplistic for what Cartwright sees happening. Here is her take on dreaming:
“So in good sleepers, the mind is continuously active, reviewing experience from yesterday, sorting which new information is relevant and important to save due to its emotional saliency. Dreams are not without sense, nor are they best understood to be expressions of infantile wishes. They are the result of the interconnectedness of new experience with that already stored in memory networks. But memory is never a precise duplicate of the original; instead, it is a contining act of creation. Dream images are the product of that creation. They are formed by pattern recognition between some current emotionally valued experience matching the condensed representation of similarly toned memories. Networks of these become our familiar style of thinking, which gives our behavior continuity and us a coherent sense of who we are. Thus, dream dimensions are elements of the schemas, and both represent accumulated experience and serve to filter and evaluate the new day’s input.”
It all is a lot to digest. But it is something to sleep upon.