Invitation to Psychology

(Barry) #1
ChapTER 5 Body Rhythms and Mental States 167

tend to be less focused and more diffuse than
our waking ones—unless we happen to be day-
dreaming. Our brains show similar patterns of
activity when we are night dreaming as when
we are daydreaming, a finding that suggests that
nighttime dreaming, like daydreaming, might
be a mechanism for envisioning events that we
think (or hope, or fear) might occur in the future
(Domhoff, 2011).
The cognitive view predicts that if a person
could be totally cut off from all external stimula-
tion while awake, mental activity would be much
like that during dreaming, with the same hallu-
cinatory quality—and this is, in fact, the case (see
Chapter 6). The cognitive approach also predicts
that as cognitive abilities and brain connections
mature during childhood, dreams should change
in nature, and they do. Toddlers may not dream at
all in the sense that adults do. And although young
children may experience visual images during
sleep, their cognitive limitations keep them from
creating true narratives until age 7 or 8 (Foulkes,
1999). Their dreams are infrequent and tend to
be bland and static, often about everyday things
(“I saw a dog; I was sitting”). But as they grow
older, their dreams gradually become more and
more intricate and story-like.

Dreams as Interpreted
Brain Activity
A third approach to dreaming, the activation–
synthesis theory, draws heavily on physiological
research, and aims to explain not why you might
dream about an upcoming exam, but why you
might dream about being a cat that turns into a
hippo that plays in a rock band. Often dreams
just don’t make sense; indeed, most are bizarre,
illogical, or both. According to the activation-
synthesis explanation, first proposed by psychia-
trist J. Allan Hobson (1988, 1990), these dreams
are not “children of an idle brain,” as Shakespeare
called them. They are largely the result of neu-
rons firing spontaneously in the pons (in the
lower part of the brain) during REM sleep. These
neurons control eye movement, gaze, balance,
and posture, and they send messages to sensory
and motor areas of the cortex responsible for
visual processing and voluntary action during
wakefulness.
In this theory, the signals originating in the
pons have no psychological meaning in them-
selves. But the cortex tries to make sense of them
by synthesizing, or integrating, them with existing
knowledge and memories to produce some sort of
coherent interpretation. This is just what the cortex
does when signals come from sense organs during

activation–synthesis
theory The theory that
dreaming results from
the cortical synthesis and
interpretation of neural
signals triggered by activ-
ity in the lower part of
the brain.

exam, or shows up for the wrong exam, or can’t find
the room where the exam is being given. (Sound
familiar?) For their part, instructors sometimes
dream that they have left their lecture notes at home
or that their PowerPoint slides are blank. Traumatic
experiences can also affect people’s dreams. In a
cross-cultural study in which children kept dream
diaries for a week, Palestinian children living in
neighborhoods under threat of violence reported
more themes of persecution and violence than did
Finnish or Palestinian children living in peaceful
environments (Punamaeki & Joustie, 1998).
Sleep researcher Rosalind Cartwright (2010)
believes that dreams not only reflect our waking
concerns but also provide us with an opportu-
nity to resolve them. In people suffering from
the grief of divorce, recovery is related to a par-
ticular pattern of dreaming: The first dream of the
night often comes sooner than it ordinarily would,
lasts longer, and is more emotional and story-
like. Depressed people’s dreams tend to become
less negative and more positive as the night
wears on, and this pattern, too, predicts recovery
(Cartwright et al., 1998). Cartwright concluded
that getting through a crisis or a rough period in
life takes “time, good friends, good genes, good
luck, and a good dream system.”


Dreams as Thinking


Like the problem-focused approach, the cognitive
approach to dreaming emphasizes current con-
cerns, but it makes no claims about problem solv-
ing during sleep. In this view, dreaming is simply
a modification of the cognitive activity that goes
on when we are awake. In dreams, we construct
reasonable simulations of the real world, draw-
ing on the same kinds of memories, knowledge,
metaphors, and assumptions that we do when we
are not sleeping (Antrobus, 1991, 2000; Domhoff,
2003; Foulkes, 1999). Thus, the content of our
dreams may include thoughts, concepts, and sce-
narios that may or may not be related to our daily
problems. We are most likely to dream about our
families, friends, studies, jobs, worries, or recre-
ational interests—topics that also occupy our wak-
ing thoughts.
In the cognitive view, the brain is doing the
same kind of work during dreams as it does when
we are awake; indeed, parts of the cerebral cortex
involved in perceptual and cognitive processing
during the waking hours are highly active dur-
ing dreaming. The difference is that when we
are asleep we are cut off from sensory input and
feedback from the world and from our bodily
movements; the only input to the brain is its
own output. Therefore, our dreaming thoughts

Free download pdf