Consciousness, the Brain, and Behavior
253
Chapter 8 Answers to Physiological Inquiries
near the edge of a high cliff. Our tendency to be disgusted by
the smell of rotting food and fecal matter may have evolved as
a protection against infection by potentially harmful bacteria
or pathogens. Anger and rage could contribute to both survival
and reproduction by facilitating our ability to fi ght for mates or
territory, or for self-defense. Emotions like happiness and love
may have evolved to encourage the safety of kinships and pair-
bonding with mates.
Figure 8–13
An increase in serotonin concentrations is associated
with the waking state (refer back to Figure 8–6), so sleep is
inhibited by DMT and other drugs that simulate serotonin
action. For this same reason, sleeplessness is also a common
side effect of antidepressant medications discussed earlier in the
text (e.g., serotonin-specifi c reuptake inhibitors) because they
increase serotonin levels in the brain.
Chapter 8 Quantitative and Thought Questions
(Answers appear in Appendix A.)
1. Explain why patients given drugs to treat Parkinson’s disease
(Chapters 6 and 10) sometimes develop symptoms similar to
those of schizophrenia.
2. Explain how clinical observations of individuals with various
aphasias help physiologists understand the neural basis of
language.
Figure 8–6
Among the drugs used to treat allergic reactions are
antihistamines. They are prescribed because of their ability to
block histamine’s contributions to the infl
ammatory response,
which include vasodilation and leakiness of small blood vessels
(see Table 18–12). Because a decrease in histamine is associated
with the induction of NREM sleep, drowsiness is a common
side effect of antihistamines. Fortunately, antihistamines have
been developed that do not cross the blood-brain barrier, and
thus do not have this side effect, (e.g., loratadine [Claritin
®
,
Alavert
®
]).
Figure 8–11
There are many ways in which emotions could
potentially contribute to survival and reproduction. The
perception of fear aids survival by stimulating avoidance or
caution in potentially dangerous situations, like coming into
contact with potentially venomous spiders or snakes, or walking
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