292 CHAPTER 7
People also can have a natural disinclination to allow some particu-
lar conditioned stimuli to elicit certain conditioned responses, which is
calledcontrapreparedness. For example, Marks (1969) describes a 43-
year-old patient who, at the age of 10, saw a snake in a ditch just as a car
door was accidentally slammed on her hand. Thirty years later, she still
felt extremely afraid of snakes (preparedness), but she had no fear of car
doors (contrapreparedness), despite a car door’s having been the actual
source of her pain.
Although Howard Hughes was worried about developing a fear of fl y-
ing (specifi c phobia, situational type), the phobia didn’t materialize. Because
of his concern about becoming afraid of fl ying and the passion he had had
for the activity, he pushed himself to get back in the cockpit as soon as
he was physically able (Barlett & Steele, 1979), and then he fl ew repeat-
edly, successfully undergoing a self-imposed exposure treatment. However,
Hughes may well have had a phobia of contracting an illness—his concerns
were excessive and unreasonable, and his avoidance behaviors extreme.Specifi cs About Specifi c Phobias
Let’s consider neurological, psychological, and social factors that contribute to spe-
cifi c phobias, as well as their feedback loops. For this disorder, neurological and
psychological factors appear to weigh more heavily than social factors.Neurological Factors
Researchers are making good headway in understanding the brain systems that un-
derlie specifi c phobias, and there is evidence that an unusually reactive amygdala
may predispose some people to develop these disorders. In addition, abnormal
functioning of several neurotransmitters has been shown to contribute to specifi c
phobias. Finally, researchers have provided solid evidence that genes play a role
in specifi c phobias, and have also documented the role of environmental factors in
triggering these genetic predispositions.Brain Systems
Perhaps not surprisingly, our old friend the amygdala is again implicated in an anxi-
ety disorder. In fact, the amygdala appears to have a hair-trigger in patients with
specifi c phobia. For example, in one fMRI study, patients who were phobic of spi-
ders and control participants were asked to match geometric fi gures. In this study,
the trick was that in the background behind each fi gure—which was completely
irrelevant to the task of matching the fi gures—was a picture of either a spider or
a mushroom (because no one in the study was afraid of mushrooms). Even in this
task, where the participants were not paying attention to the background pictures,
the amygdala of the patients with the phobia was more strongly activated in re-
sponse to the spiders than the mushrooms; this was not true for the control partici-
pants (Straube, Mentzel, & Miltner, 2006).
But the amygdala is not the only brain structure associated with the disorder. For
example, in one PET study, people who had phobias of animals were shown pictures
of those animals (e.g., snakes) while their brains were scanned (Rauch et al., 1995).
The photos of animals not only activated various parts of the limbic system (includ-
ing the amygdala), but also activated the part of the cortex (known as somatosen-
sory cortex) that registers sensations on the body. One interpretation of this fi nding
is that the pictures triggered mental imagery of bodily sensations (such as the feeling
of a bug crawling on the skin); in fact, when interviewed afterward, all participants
reported having both tactile sensations and visual imagery during the study.Neural Communication
The sort of anxiety evoked by specifi c phobias is associated with too little of the in-
hibitory neurotransmitter substance GABA (File, Gonzalez, & Gallant, 1999). When a
benzodiazepine (such as diazepam, or Valium) binds to the appropriate receptors, it facil-
itates the functioning of GABA. The drug thereby ultimately produces a calming effect.Although many people fear some kind of animal,
such as spiders or snakes, the fear and avoidance
of that type of animal do not constitute a specifi c
phobia unless they signifi cantly interfere with
normal functioning.New Line Cinema/courtesy Everett Collection