Dr. Robert E. Hampson
The dream sequence, an all-too-clichéd way to begin a scene or impart background information the author wants the reader to have. But dreams are real, and they do have a purpose. How can an author use them with more scientific accuracy rather than as an info-dump shortcut?
Anyone who has the tendency to repeatedly hit the snooze button on your alarm clock has probably experienced the seven-minute dream. The alarm goes off, you barely rouse yourself—just enough to reach out and hit the snooze button, then settle back into the pillows. You have a vivid dream, from which you are awakened by the alarm clock . . . again . . . your seven-minute snooze is over.
How can you have such a vivid dream in just seven minutes? And what is a dream, really?
To answer the first, we will need to talk about the sense of time in dreams, and that's probably best to save for after a discussion of the second question. Some understanding of the nature of dreams will also give some insight into the question of time in dreams.
What are Dreams?
Dreams are memories. Our memories. They needn't be personal. Snips of movies, commercials, descriptions by a friend, all are fodder for dreams. Sleep consists of many stages, typical scientific terms refer to four stages, from stage one, light drowsiness in which you are vaguely aware of surroundings, to stage four, in which the body is so deeply unconscious that most muscles in the body are shut down. A person spends most of the night progressing from stage two to stage four sleep and back again. Persons with sleep apnea, asthma or who wake frequently in the night frequently oscillate all the way from stage one to four and back again, often without spending sufficient time in deep, stage four sleep to feel fully rested. Dreams typically occur during stages two and three in what is called REM (rapid-eye-movement) or "paradoxical" sleep—so called because the brain (and eyes) are as active as during wakefulness even while the body stays completely asleep (even paralyzed). At least, that's what scientists have told us up until very recently. We now know that dreams can also occur in stage two and three Non-REM (or NREM) sleep and that's fairly important for those seven-minute dreams in between pressing the snooze button and the next time the alarm goes off.
A full sleep cycle can take as little as forty-five minutes, or as much as two hours. During a cycle, the amount of time spent dreaming is quite short, about ten minutes per cycle, although it is possible to cycle between REM and non-REM sleep, and in and out of the dream state, multiple times per cycle.
The recent movie Inception got a lot of things right regarding dreams, dream settings, and time within dreams, but sorry, this part they got wrong—people do not typically dream the entire time they are asleep, nor when they are sedated—at least not at the sedation level that would keep a person asleep for seven to ten hours. Sedation suppresses brain and body activity, similar to stage four, and usually also suppresses REM sleep. Sure, there are drugs that promote sleep and dreaming, but they result in a very light sedation and have their effects mainly through pain relief and muscle relaxation. Doctors in the neurosciences who specialize in sleep and dreams often hear reports that people taking melatonin and certain opiate based pain relievers (such as hydrocodone and oxycodone) have vivid, strange dreams. To the researcher who learned that dreams only occur in the REM state, this seems counterintuitive, since melatonin and the pain relief drugs reduce the amount of REM, and increase the time spent in NREM sleep per sleep period. However, studies of patients who get their sleep only in ten to fifteen-minute naps show that people report that they remember having dreamed even when there was no REM sleep during the nap. Whether these dreams are actually more unusual, or simply more easily remembered is not clear, but it is likely that such dreams are the ones reported by patients taking these drugs.
But back to those seven-to-ten minutes of dreaming. How can a dream seem so complete, so detailed, and so long and yet occur within orders of magnitude of less time than the events portrayed? Several reasons: first, dreams are strung together from memories. These are memories of events during the day, the past, personal experience, stories read from books, movies, TV. Even if only vague impressions, the mind can make a dream from it.
Memories are stored in the brain as associations. Ever struggle to name a song? Remember part of a tune or a verse, but can't think of the title until you sing the verse through to the end and rewind to the beginning? That's association. Each verse, each phrase, is associated in memory, and you have to run through the chain of associations to get to the title. There are other types of associations: cooking smells may help recall a vivid memory of childhood, a sound can trigger a traumatic memory, a touch or color may bring back memories of a first date . . . first love . . . first kiss. Once a memory is recalled, it can lead in turn to another memory, and another, and another. Such associations are nearly instantaneous. A series of memories spanning minutes, days, months or years can be recalled in seconds.
The second reason why dreams seem complete and detailed is that filling in the gaps with details is what the brain does. Any student of music can tell you that they can hear instruments when reading music. In fact, there is a fascinating study in which brain imaging proves just that point: a conductor reading a score shows the same brain activity he or she displays if he or she is hearing (or even playing) the music. Optical illusions work this way, too. The eyes see only lines, shapes and shadows. The brain fills in—even when there are no details in the original image. Mathematical models that mimic the connections of neurons (brain cells) have demonstrated the ability to restore information even when up to half of the information becomes missing or garbled.
Finally, dreams allow the brain to disconnect from the body. There is a location in the brain called the "red nucleus" that acts like a cut-off switch. During dreams, the nerve impulses to the muscles are stopped, and many signals from the rest of the body do not reach the brain (consciously). The brain acts as if all of the connections are intact, but the normal feedback delay is not present, and the whole process runs faster. Note that this can account for the helpless feeling we experience in some dreams—running in slow motion, say, or sitting in the back seat of a runaway car, unable to defend against an attacker. During these events, the red nucleus block of nerve signals is not complete. Commands to muscles are blocked, but the information that those muscles are not moving is getting to the brain.
Again, the relatively new findings of non-REM dreams, and the effects of certain drugs on sleep and dreaming are important here. A particular sleep disorder results when the red nucleus does not completely shut off the signals to muscles. Patients with behavioral sleep disorder act out their dreams, and have awoken to find themselves out in public, or in the middle of attempting to walk, drive, cook, etc.
The disorder is treated with sedative drugs that reduce REM sleep and dreaming, and result in a restoration of the "off switch," and deeper sleep stages. More recently, doctors are treating the disorder with melatonin, which reduces REM sleep, but retains some dreaming in the NREM state. During both REM and NREM dreaming, there is an increase in our awake-type of brain activity, however, it is much weaker in NREM dreaming, and there are more of the slow, rhythmic patterns associated with deep sleep stages. Thus, while the brain is clearly asleep (based on the slow rhythms), during dreaming, there is activity associated with the recall and association of memories.
Thus, dreams are memories. Memories can trigger recall of other memories at widely separate times. The brain (and mind) are good at taking incomplete information and filling in details—often with familiar situations, and other memories. The brain does not have the normal feedback from the body to signal what is a real experience and what is not. Hence, the seven-minute dream. In reality, the dream may have only lasted for about two minutes, but that is enough time to trigger a sequence of stored memory patterns in the brain, and for the mind to make up a script to go along with the sequences. It is the ultimate moviemaker's storyboard.
Dreams—the Story in the Brain
What is the purpose of dreaming?
Simply stated, dreams are a necessary function of making temporary memories permanent. It's long been known that dreams are composed of memories, and that memories can be triggered by specific electrical activity within the brain.
Dr. Wilder Penfield was a Canadian neurosurgeon noted for mapping most of what we know as the "topography" of the brain. Penfield noted that, in the course of brain surgery to treat epilepsy, when applying electrical stimulation to various brain areas to locate damaged brain cells with the patient awake, the patient was able to tell the surgeon what they saw, felt, tasted, etc. Modern neuroscientists have built enormously on this discovery, and by studying which functions are lost due to brain damage.
Neuroscientists now know which brain areas are responsible for movement, sensation and various memories. In the 90s, Professors Matt Wilson and Bruce McNaughton at the University of Arizona determined that brain cells activated in the rat brain while running a maze were activated in the exact same sequence and relationship while the animal slept immediately following the behavior. From studies since that time, we know that the reactivation of electrical patterns during sleep is essential to consolidation of memory from short term storage (essentially what you do when you repeat a phone number to remember it long enough to place a call) to long term storage. In fact, this is where Non-REM dreams may be important: Neuroscientists have found that the reactivation of patterns primarily occurs during NREM sleep, and not during REM sleep.
Why is consolidation necessary?
Memory comes in two forms: short term (also known as "working") and long-term memory. Short term/working memory is temporary. It will eventually be forgotten, and in fact, it is best if it is forgotten! The perfect example of short-term memory is recalling a parking spot at work, school or while shopping. It is necessary to remember the detail of the location for a short time-span, but if remembered for longer terms, it can interfere with itself (we call this "proactive interference"). The memory of where I parked yesterday, or last week, would interfere with finding my car today! Thus, short-term memory should be forgotten once its usefulness is over.
So how do we humans move information from short-term to long-term memory? Two ways: repetition, or strong associations. Repetition is the familiar one. Rote learning. Memorization. "Repeat after me . . . My car is on level four, second row. . . . " Strong emotion is one of the key features to association—whether love, hate or fear, association in memory is a powerful motivator.
The key feature of consolidation is that repeating information strengthens the connections between brain cells that form the basis of the information code for memory. However, such strengthening requires time, and metabolic processes in the brain cells. This is one reason why an accident victim may not remember details of an accident (or up to hours before). There may not have been enough time to consolidate the memory before the brain received a trauma that caused it to stop processing information.
What's more important, though, and relevant to the discussion of dreams, is that sleep provides the time, the low body activity frees up the metabolic processes, and dreams provide the repetition to enable memory to be stored most efficiently. With consolidated memory, the mind can build a sense of time with respect to events in the outside world.
Ask Me for Anything But Time . . .
Now that we know that dreams are constructed of our own memories, what about time in dreams? How can so much apparent elapsed time be condensed into a few minutes of dreaming? A popular phrase in psychology from about ten or more years ago is "time-binding." The label refers to that ability of humans to place memories of events in sequence and judge the amount of time that passes. Time-binding is less known by its presence, but by its absence.
One of the tests given to children suspected of depression or attention deficit disorder is to have them place pieces of a story into sequential order and tell how much time they think elapses during the story. Failure to do so is a pretty good indicator that the child has a deficit in time-binding, and such deficits indicate an abnormal interaction with the outside world.
However, problems with time-binding are neither unusual, nor crippling. So why is time-binding an issue? Do humans really need to know that only two minutes has elapsed while we wait at a traffic light? Or that James Garfield was president before Chester Arthur and after Rutherford B. Hayes?
As a memory scientist and a writer, the answer is an enthusiastic yes! In fact, a proper sense of time is important to real life, dreams and enjoyable reading. In the real world, everything is a sequence of events, and the consequences of those events only have a finite duration. Event A: A burner is lit on the stove; Event B: a hand is placed over the burner. If B precedes A, no problem—unless the hand remains after the burner is lit. If A precedes B, well, that could be a problem—it depends on how much time has elapsed. Time-binding is difficult for persons on mind-altering drugs, in clinical depression, schizophrenia, and many other disorders.
Dreams and Memory in Fiction
Finally, what does this have to do with writing (and reading) fiction, notably science fiction?
Quite a bit, actually. Aside from the obvious usage of time-binding as a plot point, I suggest examining the story for its time-binding. For examples I'm going to pull out two novels I read in college: Titan by John Varley, and Lord Valentine's Castle by Robert Silverberg. In Titan, the protagonist, Captain Cirocco Jones, and her companion Gaby spend months climbing the support cables trying to reach the hub and speak to the controlling intelligence Gaia. In Lord Valentine's Castle, Valentine, the juggler, travels to the Coronal's festival on Castle Mount, recovering from amnesia and learning about himself and his place in the world. Again, the story action takes place over many months as the travelers cross the continent or climb the Mount to reach the festival.
I chose these two examples because even thirty years after a single reading, both novels left me with a profound unease. It took a while to realize what bothered me, and it was many years later that I realized all of the implications.
The problem was time-binding. Essentially both authors set their protagonists off on a strenuous physical journey that would take months to years to complete, and only gave us bare glimpses of the events in between, yet both authors treated that interval as if we were watching the action the whole time. Varley's time-binding in Titan was the greater problem, considering that the action for the first third of the story was roughly continuous, then the reader was expected to suspend this sense of continuous time while Cirocco and Gaby climb the support cable. Silverberg's novel did the better job of time-binding because the story takes place in vignettes spaced over the whole duration of the journey and we do get more of a sensation of time passing. Perhaps it was the fact that the reader is expected to accept that these events are happening to same persons over extended time, or perhaps it is the uneven time flow where the author realizes that they are running out of time/space and need to fast-forward through the next time interval.
This is exactly the issue with time in dreams. Dreams do not accurately reflect the passage of time. The human brain introduces discontinuities, and we "remember" the details in between, even though no physical time has passed. It's actually part of what can makes dreams so disconcerting. In fiction, such a transition is too disconcerting, and most authors introduce a break in the story if long periods of time need to pass without much story action.
Now for two examples of successful time-binding, and again I shall call up stories that have remained with me for twenty to thirty years: In Joe Haldeman's The Forever War we follow William Mandela through four years of subjective time, and several centuries of Earth time. The discontinuities are well-written and believable because Mandela reacts to each interval and discontinuity in time via culture shock and adjustment to each new society (via the new recruits). In Walter Miller, Jr.'s A Canticle for Leibowitz, we follow different protagonists across several thousand years of post-apocalyptic landscape thereby learning an important lesson in the cyclical nature of history with respect to man and society. The novel was originally three separate stories that Miller realized was a complete novel only when writing the third. To complete the novel he extensively rewrote the novelettes to provide continuity while preserving the unique essence of each section. Despite the span of 1,800 years, there is no doubt that Canticle tells a continuous story—particularly with the bookending of Brother Francis' story with events in the closing scenes of the book. Successful time-binding.
What other kinds of issues are there with of time-binding?
Sequence.
I'm not particularly fond of novels that jump back and forth in time, or between POV characters, because the transition is often quite jarring. It is important for the writer to provide the little cues that allow time-binding by the reader, and when those cues are absent, the reader can get quite confused. Ever have that dream where you're taking an exam but never went to class, left your book in your locker and can't remember the combination, and now you can't find the classroom, but vaguely remember that you shouldn't be doing this because you graduated twenty years ago? It's a perfect example of problems with POV shifts and time-binding.
Dwight Swain in Techniques of the Selling Writer suggests that successful writers create "scenes" that unfold in real-time (or even slow-motion), separated by "sequels" with which you can fast-forward through intervening time. It's why Star Trek had warp speed and transporters. By not abusing the sense of time and sequence created for the reader, the skilled writer can reserve jarring violation of sequence and distorted sense of time for use when appropriate to the mental state of the protagonist!
"To Sleep, Perchance to Dream . . ."
Time and sequence are likewise important to both dreaming and consolidation of memory. The subconscious creates dreams by pulling events at random from memory, but those events don't stand alone, they are part of a sequence that includes other memories not incorporated in the dream. The mind tries to fill in the gaps in time-binding—sometimes failing, as in the case of the Exam Dream. In other cases, it succeeds too well. Dreams can take on a reality, complete with false history that is hard to distinguish from reality. It's because that what the brain has constructed uses our own memories and incorporates the features that make those memories seem valid—most importantly, time. Cause precedes effect, birth before death, just as a fictional character's past precedes its future.
In dreams, we don't actually have much time to build a sequence—a whole lot of memory is called up in very rapid succession, and it is up to the parts of the brain which normally deal with memory, sequence and cause-and-effect to put it all together . . .
. . . eventually creating . . .
. . . a dream.
Copyright © 2018 Dr. Robert E. Hampson
Dr. Robert Hampson is a neuroscientist with a keen interest in neural prosthetics and human health in space. He is also known to Baen readers and SF convention audiences by his penname "Tedd Roberts," with website here. Dr. Hampson and fellow Baen author and space scientist Les Johnson are the editors of upcoming Baen anthology Homo Stellaris, a look at the changes both physical and technological that will be wrought on human beings as we head for the stars.