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quickly, for instance, but a more experienced chess player has more knowledge to draw on.
Older adults are also more effective at understanding the nuances of social interactions than
younger adults are, in part because they have more experience in relationships (Blanchard-Fields,
Mienaltowski, & Seay, 2007).[13]
Dementia and Alzheimer’s Disease
Some older adults suffer from biologically based cognitive impairments in which the brain is so
adversely affected by aging that it becomes very difficult for the person to continue to function
effectively. Dementia is defined as a progressive neurological disease that includes loss of
cognitive abilities significant enough to interfere with everyday behaviors, and
Alzheimer’s disease is a form of dementia that, over a period of years, leads to a loss of
emotions, cognitions, and physical functioning, and which is ultimately fatal. Dementia and
Alzheimer’s disease are most likely to be observed in individuals who are 65 and older, and the
likelihood of developing Alzheimer’s doubles about every 5 years after age 65. After age 85, the
risk reaches nearly 8% per year (Hebert et al., 1995). [14] Dementia and Alzheimer’s disease both
produce a gradual decline in functioning of the brain cells that produce the neurotransmitter
acetylcholine. Without this neurotransmitter, the neurons are unable to communicate, leaving the
brain less and less functional.
Figure 6.14 A Healthy Brain (Left) Versus a Brain With Advanced Alzheimer’s Disease (Right)
Dementia and Alzheimer’s are in part heritable, but there is increasing evidence that the
environment also plays a role. And current research is helping us understand the things that older