Developmental psychology.pdf

50 Background and Methods
RESEARCH IN PERSPECTIVE
In concluding this overview of research methods, we return to the original research
question: "What happens when we dream?" As the reader now understands, dreaming
is a complex activity and this research question is indeed a broad one. Given the limitations
of time, space, and energy, it must be studied in parts, each in its own detail.
One might ask instead: "What happens physiologically when we dream?" But
here again there are too many possibilities; innumerable changes could be occurring
throughout the body. One might ask: "What changes take place in the brain during
dreaming?" To be still more specific, and to develop a highly appropriate topic for
research, one might ask: "What changes, if any, occur in electrical brain activity during
sleep?" In short, most investigators concern themselves with very specific questions
and use very specific research methods, singly or in various combinations.
Through use of the electroencephalograph, which provides a record of some
brain activities, we now know that certain types of brain waves, those of low voltage
and high frequency, characterize dreaming. These waves are more like those of a person
who is awake rather than asleep, but because it is difficult to awaken a sleeper
showing this brain-wave pattern, the REM or dream state is also known as paradoxical
sleep. Further research, probing beneath the brain's surface, has suggested that the
neural bases for these activities originate in part in the brain area known as the reticular
formation (Hobson & McCarley, 1977).
Inference and Theory
Through naturalistic observation we have learned that behavioral dimensions of
dreaming exist, evident not only in the rapid eye movements but also in the changes
of the facial muscles. Using these behavioral and physiological measures, and waking
people at specified moments, we now know that nearly everyone dreams, that there are
predictable topics for most of our dreams, that dreams sometimes occur in non-REM
sleep, and that we have several dreams per night. Babies are in REM sleep almost onethird
of their lives, whereas adults spend one-twelfth of their lives dreaming (Figure
2.12).
Are babies actually dreaming during REM sleep? Do they experience the visual-auditory
images that adults call dreaming, even in the early weeks of life? It seems
possible that babies undergo some rudimentary form of dreaming for, in addition to
the REMs, they show the other physiological and behavioral accompaniments of
dreaming. We cannot be certain, and therefore the study of dreams, just as other topics
in psychology, often requires that the investigator go beyond the demonstrated facts.
Figure 2.12.
Age and Dreaming. As people grow
older they spend less time sleeping
and a decreasing proportion of their
sleep time in the RBM state. Hence,
they presumably do much less
dreaming (Hartmann, 1967).
Role of Inference Suppose that the young woman who reported the dreams at the
beginning of this chapter is observed in bed. She might be sleeping, feigning sleep,
resting, unconscious, dreaming, or even dead. The only evidence immediately available
is that she is in bed, and on this basis alone we cannot be sure of her condition or what
she is doing.
But we can make an inference. An inference, as we saw earlier, is an idea or
judgment drawn from some observable events. It concerns something not directly evident
but is based on available data. As we approach the woman, we notice that her
chest is rising and falling. These events are not consistent with being dead. Accordingly,
the inference that the woman has died is no longer tenable.
We see that her breathing is deep, not shallow, so we make another inference.
She is not unconscious. The woman's eyes are closed, and occasionally she mumbles
or seems to be talking to someone who is not in the room. Hence we tentatively discard
the inference that she is resting. Our observations have led instead to the inference
that the woman is sleeping and perhaps dreaming.