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CHAPTER SIXTEEN. PHYSICAL AND COGNITIVE DEVELOPMENT IN LATE ADULTHOOD. I. VARIABILITY IN LATE ADULTHOOD. The scientific study of aging is known as gerontology Late adulthood is now thought of as a period of tremendous individual variability rather than one of universal decline.
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CHAPTER SIXTEEN PHYSICAL AND COGNITIVE DEVELOPMENT IN LATE ADULTHOOD
I. VARIABILITY IN LATE ADULTHOOD • The scientific study of aging is known as gerontology • Late adulthood is now thought of as a period of tremendous individual variability rather than one of universal decline Copyright © 2006 Pearson Education Canada
A. Characteristics of the Elderly Population • Life expectancy increases as adults get older • In Canada, the average 65-year-old man lives to just over age 82, but once a man reaches his early 80s, he is likely to live to be 90 • The average 65-year-old woman lives to the age of 87, and those who live to their mid 80’s can expect to live to over 92 • There are more elderly women than men, but the gender gap has been narrowing in Canada since 1981 (continued) Copyright © 2006 Pearson Education Canada
Characteristics of the Elderly Population (continued) • Subgroups: • Young-old (60 to 75) • Old-old (75 to 85) • Oldest-old (85 and up) • The oldest-old are the fastest growing segment of the population in Canada • From 1981 to 2000, the over-65 population in Canada increased by about two-thirds, to 13% of the total population, and the over-85 population almost tripled • Frail elderly: older adults whose physical and/or mental impairments are so extensive that they cannot care for themselves • The majority of older Canadian adults across all three age subgroups regard their health as good or excellent • Health is the single largest factor determining the trajectory of an adult's physical or mental status over the years beyond 65 (continued) Copyright © 2006 Pearson Education Canada
Characteristics of the Elderly Population (continued) • As the prevalence of dementia increases in Canadian elderly, so does the rate of cognitive impairment • Alzheimer’s disease, an irreversible degenerative condition, is the most common cause of dementia • Other sources of mental confusion include intercurrent illnesses, infections, metabolic disturbances and drug intoxications • Little of the cognitive impairment is reversible • Some enhancement or better maintenance of intellectual skills results from an "engaged" and intellectually active lifestyle (continued) Copyright © 2006 Pearson Education Canada
Characteristics of the Elderly Population (continued) • Functional status: a measure of an individual’s ability to perform certain roles and tasks, particularly self-help tasks and other chores of daily living • Activities of Daily Living (ADLs): self-help tasks such as bathing, dressing, and using the toilet • Instrumental Activities of Daily Living (IADLs): more complex daily living tasks such as doing housework, cooking, and managing money • The proportion of older adults with disabilities increases with age • The physical problems or diseases that are most likely to contribute to some functional disability in late adulthood are arthritis and hypertension Copyright © 2006 Pearson Education Canada
No Easy Answers: The Coming Demographic Crisis in Canada • There will be fewer young and middle-aged adult workers for every retired person • At present, Old Age Security (OAS) program and Canada and Quebec Pension Plans (C/QPP) make up half of the income for seniors • The other half of seniors’ income came from private sources, including retirement pensions and RRSP investments, investments other than RRSPs, and employment income • As for long-term pension security: • the federal Chief Actuary has projected that CPP contributions will exceed benefits until 2021 • after that, contributions plus investment income will pay benefits • this is important in helping to pay the pensions of younger workers who are decades away from retirement Copyright © 2006 Pearson Education Canada
B. Longevity • Longevity appears to result from interactions among heredity, environment, and behavioural choices • The maximum human life span seems to be about 110 or 120 years • Hayflick limit: the theoretical proposal that each species is subject to a genetically programmed time limit after which cells no longer have any capacity to replicate themselves accurately • Telomere: string of repetitive DNA at the tip of each chromosome in the body that appears to serve as a kind of timekeeping mechanism (continued) Copyright © 2006 Pearson Education Canada
Longevity(continued) • There is a large range of individual differences in how long people live • Some general tendency toward longevity is clearly inherited • identical twins are more similar in length of life than are fraternal twins • adults whose parents and grandparents were long-lived are also more likely to live longer (continued) Copyright © 2006 Pearson Education Canada
Longevity(continued) Health Habits affecting Longevity: Smoking and Exercise • Smoking limits longevity:65-year-old male smoker can expect to live six years less than a non-smoker and a female smoker will live 8.5 years less. • Smokers are also more likely to suffer disease related disabilities—by age 65 more than half of all smokers will have a disability (compared to one-third of non-smokers) • Physical exercise has been clearly linked to: • greater longevity • lower rates of diseases such as heart disease, cancer, osteoporosis, diabetes, gastrointestinal problems, and arthritis • helping maintain higher levels of cognitive performance among the elderly • Just over half of Canadians over the age of 65 engaged in a minimum of 15 minutes of vigorous activity, three or more times a week • Only 27% of older adults in Canada are active enough to achieve the desired health benefits associated with exercise • Canada’s Physical Activity Guide to Healthy Active Living for Older Adults is a practical handbook for overcoming misconceptions and excuses for inactivity Copyright © 2006 Pearson Education Canada
II. PHYSICAL CHANGES • Despite variability in health and functioning among the elderly, there are several changes in physical functioning that characterize the late adult years for almost everyone Copyright © 2006 Pearson Education Canada
A. The Brain & Nervous System • Four main changes in the brain: • a reduction of brain weight • a loss of grey matter • a loss of density in the dendrites • slower synaptic speed • Synaptic plasticity: the redundancy in the nervous system that ensures that it is nearly always possible for a nerve impulse to move from one neuron to another or from a neuron to another type of cell (e.g., a muscle cell) • There is a loss of neurons themselves, but the number of cells lost is so insignificant and there are so many redundancies in the nervous system that there is little impact • When significant interconnectivity is lost, which occurs as dendrites shrink in number, "computational power" declines and symptoms of old age appear Copyright © 2006 Pearson Education Canada
B. The Senses & Other Body Systems Vision changes: • Presbyopia (farsightedness) • An enlarged "blind spot" on the retina and a reduced field of vision • The pupil does not widen or narrow as much or as quickly resulting in more difficulty seeing at night and responding to rapid changes in brightness • Diseases of the eye, such as cataracts or glaucoma, that further diminish visual acuity and adaptability (continued) Copyright © 2006 Pearson Education Canada
The Senses & Other Body Systems (continued) Hearing changes: • Presbycusis, major hearing loss • Loss of ability to hear high-frequency sounds • Difficulties in word discrimination • Problems hearing under noise conditions • Tinnitus, a persistent ringing in the ears (continued) Copyright © 2006 Pearson Education Canada
The Senses & Other Body Systems (continued) Changes in Taste, Smell, and Touch: • The ability to taste the four basic flavours (salty, bitter, sweet, and sour) does not seem to decline over the years of adulthood • Other changes in the taste system: • less saliva • flavours seem blander, but this may be a result of a loss of the sense of smell • The sense of smell clearly deteriorates in old age • A loss of sensitivity to touch • Less responsive to cold and heat Copyright © 2006 Pearson Education Canada
C. Theories of Biological Aging • Senescence: physical changes and declines associated with aging • Programmed senescence theory: the view that age-related declines are the result of species-specific genes for aging • Cross-linking: the formation of undesirable bonds between proteins or fats • Free radicals: molecules or atoms that possess an unpaired electron • Terminal drop hypothesis: the hypothesis that mental and physical functioning decline drastically only in the few years immediately preceding death Copyright © 2006 Pearson Education Canada
D. Behavioural Effects of Physical Changes • A general sense of slowing down • Sleep changes: • wake up more frequently in the night • show decreases in rapid eye movement (REM) sleep • more likely to wake early in the morning and go to bed early at night • nap more during the day • Satiety seems to be impaired and the result may be a feeling of hunger all the time that may cause overeating • Satiety: the feeling of fullness that follows a meal (continued) Copyright © 2006 Pearson Education Canada
Behavioural Effects of Physical Changes (Continued) • Reduction in stamina, dexterity, and balance • Older adults fall more often, and because of osteoporosis, such falls more often result in fractures • Problems with fine-motor movements • Sexual activity declines from middle adulthood to late adulthood • More than 70% of adults continue to be sexually active in old age Copyright © 2006 Pearson Education Canada
III. MENTAL HEALTH • Dementia: a neurological disorder involving problems with memory and thinking that affect an individual’s emotional, social, and physical functioning • Dementia is the leading cause of institutionalization of the elderly in Canada, especially women in Canada • Depression is also a concern in the late adult years Copyright © 2006 Pearson Education Canada
A. Alzheimer's Disease & Other Dementia • Alzheimer’s disease: a very severe form of dementia, the cause of which is unknown • Genetic factors seem to be important to some, but not to all cases of Alzheimer’s • Problems with three genes have been identified as causative factors • Breakdown of the myelin tissue during the fifth decade (due to the release of toxins, related to cholesterol levels) may eventually lead to Alzheimer’s • Preventive measures include cholesterol and iron reduction through changes in diet and exercise, or with medications, a regime of anti-inflammatory medications, and for women, hormone replacement therapy. • The time to prevent this destructive chain of neurological events is in middle adulthood—by the time the symptoms are obvious in older adults, the damage has been done and is probably not reversible. (continued) Copyright © 2006 Pearson Education Canada
Alzheimer's Disease & Other Dementia (continued) • Multi-infarct dementia: a form of dementia caused by one or more strokes • 2 to 8% of all adults over age 65 show significant symptoms of dementia • 2 to 5% have Alzheimer's disease • The rate of dementia rises rapidly among people in their 70s and 80s Copyright © 2006 Pearson Education Canada
The Real World/Caregiving: Institutionalization among the Canadian Elderly • The average older adult will spend at least a few years with some kind of disability or chronic disease • About the same amount of older Canadian women and men between 65 and 74 (approx. 2% each) require institutional care in any given year, but far more women in the old-old group are institutionalized • Factors most closely associated with institutionalization: • the odds of living in an institution increase directly with age • seniors with a serious cognitive impairment • those with uncorrected visual impairment • seniors with low or lower-middle household income • those seniors who perceived themselves as having only fair or poor health were 2.6 times higher than for seniors who had good to excellent self-perceived health status • In Canada there is a growing need to create alternatives to institutionalization such as community support and home care Copyright © 2006 Pearson Education Canada
B. Depression • Signs of depression in older adults may be dismissed as old-age "grumpiness“ • Depression can be mistaken for dementia because both share symptoms of confusion and memory loss • Older adults are more likely to report physical symptoms related to depression no matter what their emotional state • Geriatric dysthymia: a chronic depressed mood in older adults (continued) Copyright © 2006 Pearson Education Canada
Depression(continued) Risk factors for depression and dysthymia among the elderly: • inadequate social support • inadequate income • emotional loss • nagging health problems • health status (the strongest predictor)—the more disabling conditions older adults have, the more depressive symptoms they have • gender: Among the elderly, • four times as many Canadian men than women commit suicide • two times as many women are depressed • poverty • education—poorly educated older adults are more likely to be depressed (continued) Copyright © 2006 Pearson Education Canada
Depression(continued) • The suicide rate for the elderly has declined to a level slightly below the national average • Although women in Canada have higher rates of depression, elderly men are more than 5 times as likely to commit suicide • Psychotherapy for depression is often recommended, especially interventions that help sufferers develop optimistic thought patterns • Therapy also appears to be very effective when combined with antidepressant medications Ways to prevent depression in the elderly: • Help older adults improve their health • Provide opportunities for social involvement, especially participation in activities with children • Support for the spiritual needs of the elderly Copyright © 2006 Pearson Education Canada
IV. COGNITIVE CHANGES • Among the young old (aged 65-75), cognitive changes are still fairly small • But the old old and the oldest old show average declines on virtually all measures of intellectual skill, with the largest declines evident on any measures that involve speed or unexercised abilities Copyright © 2006 Pearson Education Canada
A. Memory • The more any given cognitive task makes demands on working memory, the larger the decline with age • Older adults outperform younger adults on prospective memory tasks in a natural setting, such as their home, but under-perform on such tasks when in a controlled laboratory setting where there are no external memory cues, such as a calendar or reminder note • The learning process takes longer for older adults; however, when allowed more time, older adults' performance was more similar to that of younger participants • On virtually all "everyday" tasksolder adults recall less well than younger adults • Task-specific prior knowledge gives the elderly some recall advantage • Older adults take longer to register some new piece of information, encode it, and retrieve it Copyright © 2006 Pearson Education Canada
B. Wisdom & Creativity • Wisdom: a hypothesized cognitive characteristic of older adults that includes accumulated knowledge and the ability to apply that knowledge to practical problems of living • Performance on wisdom tasks does not decline with age • The speed of accessing wisdom-related knowledge remains constant across adulthood • Gene Cohen’s four-stage theory of mid- to late-life creativity: • re-evaluation phase • liberation phase • summing-up phase • encore phase Copyright © 2006 Pearson Education Canada