Understanding Psychology (10th Ed)

 neuroplasticity 
.
Although for many years conventional wisdom 
held that no new brain cells are created after childhood, new research fi nds other-
wise. Not only do the interconnections between neurons become more complex 
throughout life, but it now appears that new neurons are also created in certain areas 
of the brain during adulthood—a process called
 neurogenesis 
.
Each day, thousands 
of new neurons are created, especially in areas of the brain related to learning and 
memory (Jang, You, & Ahn, 2007; Poo & Isaacson, 2007; Shors, 2009).
The ability of neurons to renew themselves during adulthood has signifi cant impli-
cations for the potential treatment of disorders of the nervous system (see Figure 7). 
For example, drugs that trigger the development of new neurons might be used to 
counter such diseases as Alzheimer’s, which are produced when neurons die (Tsai, 
Tsai, & Shen, 2007; Eisch et al., 2008; Waddell & Shors, 2008). 
Furthermore, specifi c experiences can modify the way in which information is 
processed. For example, if you learn to read Braille, the amount of tissue in your 
cortex related to sensation in the fi ngertips will expand. Similarly, if you take up the 
violin, the area of the brain that receives messages from your fi ngers will grow—but 
only relating to the fi ngers that actually move across the violin’s strings (Kolb, Gibb, 
& Robinson, 2003; Schwartz & Begley, 2002). 
The future also holds promise for people who suffer from the tremors and loss 
of motor control produced by Parkinson’s disease, although the research is mired in 
controversy. Because Parkinson’s disease is caused by a gradual loss of cells that 
stimulate the production of dopamine in the brain, many investigators have reasoned 
that a procedure that would increase the supply of dopamine might be effective. 
They seem to be on the right track. When stem cells—immature cells from human 
fetuses that have the potential to develop into a variety of specialized cell types, 
depending on where they are implanted—are injected directly into the brains of 
Parkinson’s sufferers, they take root and stimulate dopamine production. Preliminary