Invitation to Psychology

ChapTER 5 Body Rhythms and Mental States 159

In sum, the body only provides the clay for

our symptoms and feelings. Learning and culture

mold that clay by teaching us which symptoms

are important or worrisome, and which are not.

Whether we are male or female, the impact of

most of the changes associated with our bio-

logical rhythms depends on how we interpret and

respond to them.

problem solving, college exam scores, creativity, or
any other behavior that matters in real life (Earl-
Novell & Jessop, 2005; Golub, 1992; Richardson,
1992). In the workplace, men and women report
similar levels of stress, well-being, and ability to do
the work required of them—and it doesn’t matter
whether the women are premenstrual, menstrual,
postmenstrual, or nonmenstrual (Hardie, 1997).

Recite & Review

Recite: It’s time to say out loud everything you can about biological rhythms, endogenous

rhythms, circadian rhythms, desynchronization, seasonal affective disorder, and PMS.

Review: Next, go back and read this section again.

You have no hormonal excuse for avoiding this Quick Quiz:

1. The functioning of the biological clock governing circadian rhythms is affected by the hormone
   __.


2. Jet lag occurs because of __.


3. For most women, the days before menstruation are reliably associated with (a) depression, (b)
   irritability, (c) elation, (d) creativity, (e) none of these, (f) a and b.


4. A researcher tells male subjects that testosterone usually peaks in the morning and that it
   probably causes hostility. She then asks them to fill out a “HyperTestosterone Syndrome Hos-
   tility Survey” in the morning and again at night. Based on your knowledge of menstrual-cycle
   findings, what do you think her study will reveal? How could she improve her study?
   Answers:

Study and Review at MyPsychLab

Because of the expectations that the men now have about testosterone, 4. e3. internal desynchronization2. melatonin1.

they may be biased to report more hostility in the morning. It would be better to keep them in the dark about the hypothesis and

to measure their actual hormone levels at different points in the day, because individuals vary in their biological rhythms. Also, a

control group of women could be added to see whether their hostility levels vary in the same way that men’s do. Finally, the title

on that questionnaire is pretty biased. A more neutral one, such as “Health and Mood Checklist,” would be better.

The Realms of Sleep LO 5.5

Let’s start with some of the changes that occur

in the brain during sleep. Until the early 1950s,

little was known about these changes. Then

a breakthrough occurred in the laboratory of

physiologist Nathaniel Kleitman, who at the

time was the only person in the world who

had spent his entire career studying sleep.

Kleitman had given one of his graduate stu-

dents, Eugene Aserinsky, the tedious task of

finding out whether the slow, rolling eye move-

ments that characterize the onset of sleep con-

tinue throughout the night. To both men’s

surprise, eye movements did occur but they

were rapid, not slow (Aserinsky & Kleitman,

1955). Using the electroencephalograph

(EEG) to measure the brain’s electrical activ-

ity (see Chapter  4), these researchers, along

with another of Kleitman’s students, William

Dement, were able to correlate the rapid eye

You are about to learn...

• the stages of sleep.

• what happens when we go too long without
enough sleep.

• how sleep disorders disrupt normal sleep.

• the mental benefits of sleep.

The Rhythms of Sleep

Perhaps the most perplexing of all our biological
rhythms is the one governing sleep and wakeful-
ness. Sleep, after all, puts us at risk: Muscles that
are usually ready to respond to danger relax,
and senses grow dull. As the British psycholo-
gist Christopher Evans (1984) once noted, “The
behavior patterns involved in sleep are glaringly,
almost insanely, at odds with common sense.”
Then why is sleep such a profound necessity?