Autonomic Nervous System
Do you feel hot or cold right now? Do your palms sweat when you get nervous? These and other regulation functions in your body are controlled by the autonomic nervous system. Fortunately, few changes occur in the autonomic nervous system as we age, but two changes do tend to get people’s attention: body temperature control and sleep. Jorge, whom we met in the vignette, is experiencing both of these changes.
Regulating Body Temperature. Every year, newscasts around the world report that during cold or hot spells more older adults die than people in other age groups. Why does this happen? We considered evidence earlier in this chapter that cold and warm temperature thresholds may change little. If older people can feel cold and warm stimuli placed against them about as well as people of other age groups, what accounts for these deaths?
It turns out that older adults have difficulty telling that their core body temperature is low (Van Someren, 2007). In other words, older people are much less likely to notice that they are cold. To make matters worse, older adults also have slower vasoconstrictor response, which is the ability to raise core body temperature when the body’s peripheral temperature drops (DeGroot & Kenney, 2007; Van Someren, 2007). Similarly, older adults have trouble responding to high heat, because they do not sweat as much (Kenney & Munce, 2003). Even when they are hot, older adults are less likely to drink water, because they have lower thirst sensitivity (Phillips et al., 1991).
Taken together, the difficulties older adults have in regulating body temperature in extreme cold and heat are the primary reason why older adults are much more susceptible to hypothermia (body temperature below 95°F over a long period) and hyperthermia (body temperature above 98.6°F that cannot be relieved by sweating) (Kenney & Munce, 2003). This is why social service agencies are especially mindful of older adults during major weather events.
Sleep and Aging. How did you sleep last night? If you are older, chances are that you had some trouble. In fact, sleep complaints and problems are common in older adults (Wolkove et al., 2007a). These complaints most often concern difficulty in falling asleep, frequent or prolonged awakenings during the night, early morning awakenings, and a feeling of not sleeping very well. Effects of poor sleep are experienced the next day; moodiness, poorer performance on tasks involving sustained concentration, fatigue, and lack of motivation are some of the telltale signs.
Nearly every aspect of sleep undergoes age-related changes (Wolkove et al., 2007a). It takes older adults longer to fall asleep, they are awake more at night, they are more easily awakened, and they experience major shifts in their sleep-wake cycles, called circadian rhythms. Across adulthood, circadian rhythms move from a two-phase pattern of sleep (awake during the day and asleep at night for most people) to a multiphase rhythm reminiscent of that of infants (daytime napping and shorter sleep cycles at night). These changes are related to the changes in regulating core body temperature discussed earlier. Other major causes of sleep disturbance include sleep apnea (stopping breathing for 5 to 10 seconds), periodic leg jerks, heartburn, frequent need to urinate, poor physical health, and depression.
Older adults try lots of things to help themselves, such as taking daytime naps, without success (Wolkove et al., 2007b). As a result, many older adults are prescribed sleeping pills or hypnotic sedatives. But these medications must be used with great caution with older adults, and often do not help alleviate the problem in any case. Among the most effective treatments of sleep problems are increasing physical exercise, reducing caffeine intake, avoiding daytime naps, and making sure that the sleeping environment is as quiet and dark as possible (Passarella & Duong, 2008; Wolkove et al., 2007b).
As we now know, Jorge’s difficulty with heat and sleep reflect normative changes that occur with age. Olivia should be informed of these changes and encouraged to make sure Jorge drinks plenty of water and adopts good sleep habits.
Chapter 6). But the term senility has no valid medical or psychological meaning, and its continued use simply perpetuates the myth that drastic mental decline is a product of normal aging (Qualls, 1999; Woodruff-Pak & Papka, 1999). It is not. The diseases involving loss of memory, emotional response, and bodily functions are dementias, which are discussed in Chapter 4. Dementia is not a part of normal aging; roughly 6 to 8% of people over age 65 have dementia, with the risk doubling about every 5 years (see Chapter 4). People who develop dementia may show severe and progressive impairments of memory, judgment, comprehension, and motor functions. It is often the fear of developing dementia that makes people interpret the slightest mental or physical mistake as symptomatic.
Nevertheless, several aspects of psychological functioning are affected by normal brain aging, which may, in turn, affect adults’ adaptation to the environment (Whitbourne, 1996a). For example, age-related declines in recent memory may be caused by neuronal losses. These changes make it more difficult for older adults to complete daily routines that demand remembering information over time, and older adults become less efficient at learning new facts and skills. In contrast, continued dendritic growth may be one reason why there is little evidence of age-related changes in experience-based problem solving, reasoning, and judgment until late in life (Schaie & Zanjani,
Probably the worst stereotype about aging is that older adults “get senile" Older adults may even consider an insignificant memory lapse as evidence of impending senility, even though memory lapses normally occur throughout life (see
1. What structural changes occur in the neurons?
2. What changes occur with age in neurotransmitters?
3. What changes occur with age in the autonomic nervous system?
4. What is the most damaging stereotype about the psychological effects of brain aging?
100 CHAPTER 3