Abnormal Psychology

Understanding Psychological Disorders: The Neuropsychosocial Approach 37

Thelimbic system plays a key role in emotions; among its most important com-

ponents are the hypothalamus, the hippocampus, and the amygdala:

• Thehypothalamus governs bodily functions associated with eating, drinking, and

controlling temperature, and it plays a key role in many aspects of our emotions

and in our experience of pleasure (Swaab, 2003).

• Theamygdala is central to producing and perceiving strong emotions, especially

fear (LeDoux, 2000).

• Thehippocampus works to store new information in memory of the sort that

later can be voluntarily recalled; (Squire, 2002).

In addition to components of the limbic system, other important subcortical ar-

eas are the thalamus, the nucleus accumbens, the basal ganglia, and the cerebellum:

• Thethalamus is critical for controlling sleep and maintaining attention (and parts

of it are closely involved with the limbic system; Lambert & Kinsley, 2005). Some

people with schizophrenia have abnormalities in the structure and function of the

thalamus, a fi nding that is consistent with their diffi culties in focusing attention

(Andreasen et al., 1994; Andrews et al., 2006).

The• nucleus accumbens plays a major role in registering reward and learning from

experience (Breiter & Rosen, 1999). The functioning of the nucleus accumbens is

involved in substance abuse (Leone, Pocock, & Wise, 1991).

• Thebasal ganglia are involved in automatic responses. Some psychological dis-

orders disrupt the basal ganglia and can cause repetitive thoughts or behavior.

For example, the basal ganglia operate abnormally in people who have obsessive-

compulsive disorder, which is characterized by preoccupying thoughts and repeti-

tive behaviors that the person feels compelled to do (Rauch et al., 2006).

The• cerebellum helps to manage physical coordination, attention, and many auto-

matic motions (Ivry et al., 2002).

Both physical abnormalities and abnormal levels of activity in these subcortical

brain areas can contribute to psychological disorders.

Figure 2.3

2.3 • 23 Key Subcortical Brain AreasKSb tilBiA

Hypothalamus

Cerebral

cortex

Spinal Cerebellum

cord

Thalamus

Hypothalamus

Amygdala

Hippocampus