Understanding Psychology (10th Ed)

 hemispheres 
,
control motion in—and receive sensation 
Neuroscience in Your Life:
The Plastic Brain
FIGURE 7
The brain is incredibly plastic, meaning that it can change structurally (through 
changing connections between neurons) and chemically (through changing levels of 
neurotransmitters and hormones) throughout our lifetime. This plasticity can also be used to 
adapt to new situations. For example, it can reorganize how it represents the motor system 
when limbs are lost. (a) Here we see how the brain learns to respond and control a new 
artifi cial robotic hand. In the brain scans in (b) and (c), we see the areas responsible for hand 
movement. They appear in red and yellow. The fi rst scan (b) shows the activation in the 
motor and parietal cortex before the person has used the robotic hand. The second scan (c) 
shows greater activation after the person has used it for a month, demonstrating the brain’s 
ability to alter its functioning to better utilize the new prosthetic hand. 
(Source: Kato et al., 2009.)
(a)
(b)
(c)
hemispheres 
Symmetrical left and 
right halves of the brain that control 
the side of the body opposite to their 
location.
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90 Chapter 
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Neuroscience and Behavior
from—the side of the body opposite their location. The left hemisphere of the brain, 
then, generally controls the right side of the body, and the right hemisphere controls 
the left side of the body. Thus, damage to the right side of the brain is typically 
indicated by functional diffi culties in the left side of the body.
Despite the appearance of similarity between the two hemispheres of the brain, 
they are somewhat different in the functions they control and in the ways they con-
trol them. Certain behaviors are more likely to refl ect activity in one hemisphere than 
in the other, or are