Moorcroft, W.H. (2003). Understanding sleep and dreaming - r.6 Dreams, s.127-149.pdf - ćw. 01 - psychologia-UJ

Chapter 6

Dreams 17

In this chapter, we will focus on the characteristics and content of dreams as gleaned

from the study of what people recall of their dreams, but first I have to clarify the

focus of this endeavor.

DREAMING IN NREMS?

Much of the controversy over whether dreams occur in NREMS is over what

should be included as a dream and what should not be included. Part of the problem

is, as discussed in the introduction to this section, there is no universally agreed upon

definition of a dream . If any kind of mental activity is accepted as a dream, then

around 60% of NREMS awakenings yield dream reports. However, as the criteria for

a dream becomes more stringent, the percent of awakenings from NREMS that yield

dream reports drops. Using the strictest definition of a dream, which is the one I

prefer—a holistic mental experience (some would say hallucination) while asleep con-

sisting of characters interacting over a period of time in a succession of several organ-

ized and apparently real, although often bizarre, vivid images or scenes—then reports

of dreams following NREMS awakenings occur less than 10% of the time.

There is no doubt that some mental processes are occurring during much of

NREMS, but using the stricter criteria, the experiences cannot be called dreaming.

While a small percent of NREMS mentation fits these dream criteria, most of the rest

are shorter, not as dramatic, not as vivid, not as emotional, not as elaborated, not pro-

gressive, and contain less activity. Most of what is recalled from NREMS is more like a

photograph, often not clearly in focus, compared to a clear movie such as experienced

in REMS. It has also been described as more thought-like. Such mental activity during

NREMS should be called NREMS MENTATION to distinguish it from dreaming.

If REMS dreaming and NREMS mentation are truly different but mixed

together, then our research and understanding of dreaming and other mental

processes becomes muddled, just as if we were to say that apples and bananas are

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really the same and mixed them in a bowl to study their attributes. On the other

hand, if we treat REMS dreams and NREMS mentation as separate, but later discover

that, as some now maintain (c.f. Foulkes, 1978), they really are results of the same

mental processes, it would be easy to combine our knowledge and understanding of

them into a unified theory. So, for the rest of this book, we will consider them as sep-

arate. (For a more complete analysis of the data leading to the strong conclusion that

REMS dreams are indeed different from NREMS mentation, see Hobson, Pace-

Schott, & Stickgold, 2000). Furthermore, we will assume that when we are in REMS,

we are dreaming, and the memory of the dream is “lost” during the 10 to 20% of the

time that there is no dream recall when awakened from REMS. In contrast, there may

be mentation occurring only in a portion of our NREMS.

Reinforcing this view are studies of brain activity during sleep (see Chapter 4).

They suggest that much of the cerebral cortex during REMS shows activity levels

comparable to that of waking. During NREMS, however, the activity patterns in

much of the brain, including the cerebral cortex, is much less than that of waking.

Assuming that the cortex needs to be active to engage in the mental processes neces-

sary to put dreams together, we can conclude that, while some mentation can occur

during NREMS, it is not of sufficient quality to be called dreaming.

Some studies have looked at the EEG response to meaningful sensory stimuli.

They find indicators of cognitive processing during REMS that are diminished or

absent in NREMS. Tore Nielsen, a Canadian brain and sleep researcher in Montreal,

maintains that those recalls from NREMS that meet the definition of a dream may

occur because the brain processes that produce dreams in REMS are partially acti-

vated (Nielsen, 2000). He finds some support for this hypothesis in the facts that

(1) computer analysis shows the EEG during NREMS from which dreams are

reported is different from other NREMS EEG, and (2) more NREMS dreaming is

reported when NREMS occurs close to a REMS period. In contrast, New York cog-

nitive psychologist John Antrobus (1983) maintains that the generation of REMS

dreams and NREMS mentation is identical, but retrieval of the content is more dif-

ficult from NREMS than from REMS because of the state of the cortex.

About one-third to three-fourths of awakenings shortly after sleep onset result

in reports of NREMS mentation. These reports are short, but otherwise have all the

elements of REMS dreams (Strauch & Meier, 1996). However, they lack a narrative

structure, and the occurrences of the dreamer being an active character is unusually

low. Additionally, the content of these “sleep onset dreams” does not relate to what

the sleeper was thinking about prior to sleep.

There are differences in the nature of recalls from different kinds and times of sleep.

There is more episodic memory present in sleep onset dream recalls and more thinking

than in REMS recalls, with NREMS recalls intermediate between them. There is con-

siderably more hallucinative content in REMS recalls than in sleep onset dream recalls,

with NREMS recalls intermediate between these two (Stickgold et al., 2001).

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Sleep onset recalled mentation is more related to the dreamer’s immediate and recent

past and more resembles waking fantasy than does REMS dream recall.

I should note that it has become standard to ask subjects, “What was going

through your mind?” rather than “What were you dreaming about?” Some people

may not consider NREMS mentation or fragments of REMS dreams to be dreaming

and fail to report them when asked to recall a dream. A loss of valuable data is less

likely to occur when asking the more general question about what was going through

the person’s mind when asleep.

WHO DREAMS AND HOW OFTEN

Everybody dreams every night. We know this fact because of being able to

awaken people in the sleep lab and immediately asking them what was going

through their mind just before being awakened. Typically, when any of the 6% of

people who adamantly profess they never dream were awakened during REMS, they

frequently, in a groggy manner, would begin describing the dream they were just

experiencing. Then they would suddenly pause with this look of surprise on their

face, when they realized that they do dream. So we conclude that everybody dreams

every night, but some people do not remember doing so.

This information brings up a related question. Why is there no recall following

10 to 20% of REMS awakenings? One possibility is that there was no dreaming

going on then. While there is no direct evidence to refute this statement, there are

some indirect indicators. Dreams are not always easy to recall. Most of us have had

the experience of being able to recall only a fragment of a dream or of knowing that

we dreamed but were unable to recall anything about it. On other occasions, some-

thing we experience later in the day may trigger recall of a recent dream previously

unrecalled. From these common experiences, it can be inferred that it is likely that

we all dream during every REMS period, but sometimes recall of the dream is lost in

the transition to waking.

Box 16

Dreams of People who are Blind

I am often asked about the dreams of people who are blind. Since dreams are so

visual, do blind people have dreams? If so, what do they dream about? The answers to

these questions, as so often happens, are not simple but in this case very understandable.

They are summarized by Hurovitz, Dunn, Domhoff, and Fiss (1999).

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Blind people dream. Their dream reports are as complex as those of the sighted.

Whether or not there is a visual aspect to their recalled dreams depends on when they

became blind. If totally blind since birth, they never report visual images in their

dreams. If they became totally blind before the age of five, they seldom report visual

images in their dreams. Those people who lost their sight after the age of seven con-

tinue to report visual aspects to their dreams, but often the clarity and frequency of

them diminish with time. Those who lost their sight between the ages of 5 and 7 may

or may not report some visual imagery in their dreams. When visual images are absent

in the dream recalls of people who are blind, they are replaced by more taste, smell,

touch, and sound.

In other respects, with a few exceptions, their dream report content is much like

that of sighted persons. Two notable exceptions involve aggression and moving from

one place to another. People who are blind report having more dreams with at least one

incidence of aggression. They also have higher numbers of dream recalls involving

moving about, either under their own power or by some means of transportation. These

transportation dreams are often linked to misfortune for the dreamer. Uniquely, two

women who were blind had an unusually high number of dogs in their dream recalls,

mostly their guide dogs.

CHARACTERISTICS OF DREAMS

How Much are Dreams Like Waking Experiences?

How do dreams compare to our waking visual experiences? In a clever experi-

ment, Rechtschaffen and Buchignani (1983) prepared 129 variations of a single

photograph. They varied the degree of fuzziness in the foreground and in the back-

ground, the brightness, the color intensity, and so forth. They then awaked 22 sub-

jects from REMS and asked them to choose the photograph that best matched the

visual quality of their dream. Four out of 10 times, they selected the photo that was

most like typical waking visual experience. The rest of the time, there was less

intense color and/or fuzzy background. Early in the night, the selected photos were

least like that of typical waking perception.

Antrobus and colleagues (1987) did a similar experiment but found that images

experienced in dreams were at best three-fourths as bright as those experienced dur-

ing waking, while the clarity was close to that of waking. Yet, some dreams were

experienced as having little color and poor clarity. Interestingly, they also found that

the clearer the details perceived in a dream, the more likely that they were strange in

some way, such as being too large.

When looked at from a waking perspective, dreams are often bizarre (Hobson,

Pace-Schott, & Stickgold, 2000). The most common kind of bizarreness in dreams is

sudden discontinuities between sequences. These perceptions are often marked by the

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dreamer’s words, “All of a sudden …” But dreams often contain otherkinds of

bizarreness, such as characters in our dream may be a composite of two or more real

people, have something about them that is highly irregular, or may physically change

during the course of the dream. The same things can happen with settings, objects,

and even time.

Yet, just as it does when awake, our mind attempts to explain and integrate all

the experienced elements of our dreams. However, unlike when we are awake, dream-

ing accomplishes this task by creating a story line attempting to meld everything

into a single confabulatory narrative from which self-reflection and critical evaluation

are missing. Dreams have been called “single minded” by Alan Rechtschaffen, a

research psychologist and long-time sleep and dream researcher at the University of

Chicago (Rechtschaffen, 1978). By this term, he meant that while dreaming, the

mind is wholly focused on the dream and less interrupted by other thoughts and

images. It does not reflect on the fact that it is dreaming, what it is dreaming about,

or that it is actually lying in bed. Likewise, it is little influenced by external and

internal stimuli. This experience contrasts greatly from waking where our attention

easily shifts from our thoughts to salient internal or external stimuli and back again,

we reflect on our mental processes and current state, and we evaluate our experiences.

What People Typically Dream About

Leaving interpretations aside, just what kinds of things do people describe

dreaming about? Common folklore and Freud’s writings leave the impression that

dreams are full of sex and violence, but this assumption only appears to be the case,

because people remember and tell others more of these types of dreams. It turns out

that simply asking or surveying people about what they typically dream about does

not provide very accurate data when compared to the content of actual dream reports

from REMS awakenings, dream diaries, or having people write out their most recent

dream.

The best research with such dream reports often uses what is called content

analysis developed by two psychologists, Calvin Hall and Robert Van de Castle.

Essentially, this method first categorizes things like the characters, settings, objects,

activities, social interactions, and so forth that are found in a dream and then count-

ing the number of instances in each category. For example, characters might be

grouped according to sex and age (such as male adult, female child, or indeterminate

elderly). The categories are carefully developed so that different researchers working

with the same dreams will produce nearly the same results. An excellent resource

to learn more about the technique of content analysis and how to use it is

dreamresearch.net.

Results from such objective studies of the content of dream recall show that

rather than being filled with sex and aggression with lots of emotion, recalled dreams

are mostly mundane and ordinary but with some bizarre elements or happenings.

Moorcroft, W.H. (2003). Understanding sleep and dreaming - r.6 Dreams, s.127-149.pdf

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