Week 11 Long Comprehensive Study Notes on Ageing: Biological, Cognitive, and Psychosocial Perspectives

Ageing: Theory and Background

Inevitability of Ageing - There is a fundamental distinction between "life expectancy" and "lifespan." - Maintenance Function: This involves biological processes where damaged tissue is repaired and the immune system destroys potential cancers. - This critical system begins to diminish noticeably between the ages of $50$ and $100$ . - Senescence: This is defined as the degenerative phase of ageing, characterized by being universal, progressive, and eventually leading to the failure of the organism.
Theories of Ageing - It is likely that both of the following processes contribute to senescence: 1. Cellular Theories: These suggest that continuous exposure to toxins, pollutants, and free radicals leads to genetic errors in replicating cells. Over time, an individual accumulates more cells with multiple errors, resulting in cell inefficiency, cell death, and eventually the death of the entire organism. 2. Programming Theories: These suggest that the maximum lifespan is preset by specific genetic factors. While an individual can shorten their life through various choices, the absolute maximum is fundamentally predetermined.

Major Experimental Designs for Studying Ageing

General Approach: Studying change in older age uses the same fundamental methodologies as studying change across younger age groups.
Cross-Sectional Studies - These involve comparing the performance of different-aged groups of adults on the same set of tests simultaneously. - Assumption: It assumes older adults will perform at the same level as younger adults. - Presumption of Decline: If older adults perform more poorly, it is presumed their skills have declined with age. - Constraint: A major drawback is that "cohort differences" (differences in the era people were raised) may be confounded with age, potentially leading to an overestimation of age-related decline.
Longitudinal Studies - These involve testing the same group of participants at different times as they age over an extended time period. - Advantages: This design controls for cohort differences and minimizes the risk of overestimating age decline. - Potential Problem: Individuals in poor physical or mental health may not return for subsequent testing (attrition). This can lead to an overestimation of skills in the surviving older adult population, though this is usually corrected using statistical methods.

Ageing and Physical Functioning

General Declines - There is a general slowing of motor, sensory, and intellectual functioning. - Physical changes occur in the skin, bones, and muscles. - Significant declines are noted in cardiovascular and respiratory systems.
Physical Changes in the Brain - Brain weight and mass decrease throughout adulthood. - This decrease accelerates considerably after the age of $60$ . - Neuronal loss occurs (alternatively characterized as shrinkage). - Decreased blood flow to the brain is observed, which can lead to neuronal death.

Changes in Sensation and Perception

Processing Sensory Information - Older adults face increasing difficulties in processing and interpreting sensory data. - This decline is gradual across adulthood, and individuals typically develop ways to compensate for deficits. - Forms of Loss: Losses manifest as increased sensory thresholds and decreased sensitivity to low-level stimulation.
Declines in Vision - Changes occur in all components of the visual system, specifically the pupils and the lens. - Visual acuity declines steadily in old age. - Gender Differences: Specific differences between genders exist in vision decline. - Current Statistics: Despite declines, $75\%$ of adults aged $75$ years and older have good corrected vision. Non-corrected poor visual acuity is linked to a reduced quality of life.
Attention and Visual Search - Older adults show a decreased ability to divide attention. - They encounter problems with selective attention, specifically difficulty ignoring distractors while attending to stimuli. - Difficulties in processing visual information are greatest when the situation is either novel or complex.
Declines in Hearing - Age-related hearing impairments are $3$ times more likely to occur than vision impairments. - Most problems originate in the inner ear. - There is an increase in the thresholds required to hear sounds. - Gender Differences: Men tend to lose hearing sensitivity earlier and at a faster rate than women.
Speech Perception - Understanding conversation depends on both hearing and cognitive processes. - Listening conditions are vital; increased attentional demands are problematic for older adults. - Auditory perception becomes more difficult when the task is novel or complex, or when listening conditions are poor.
Taste and Smell - There is a general decline in taste sensitivity, with men experiencing a sharper decline than women, though individual variability is high. - Perception of odor generally declines and can be worsened by disease, specific medications, and smoking.
Touch, Temperature, and Pain - Touch: Sensitivity is gradually lost starting from middle childhood. - Temperature: Sensitivity to temperature changes declines in later adulthood. - Pain: Sensitivity decreases for weaker pain stimuli, but remains relatively stable for strong pain stimuli. Chronic pain is more likely in older adults, and while effective relief is not always obtained, it is crucial for daily functioning and mental wellbeing.
Perceptual Declines in Perspective - Declines in sensation and perception (S&P) are real and universal during older adulthood. - Having $2$ or more sensory impairments is often associated with difficulties in performing basic tasks. - Despite these impairments, most older adults remain engaged in diverse activities and live full lives.

Ageing and Cognitive Functioning

Intelligence and Competence - While youth is often admired for learning from new situations, competence in older age depends heavily on experience. - Older adults may perform poorly on standardized tests for reasons unrelated to actual intelligence.
Categories of Memory and Ability - Cognitive Mechanics: Involves basic memory processes. These abilities decline, and while mnemonics help, their utility is limited. - Episodic Memory: This is the retention of "where" and "when" information regarding happenings; it declines in older adulthood. - Semantic Memory: Knowledge about the world. Older adults take longer to retrieve this information but are usually eventually successful. - Working Memory and Perceptual Speed: Experience significant declines. - Explicit Memory: Conscious recollection of facts and experiences. - Implicit Memory: Memory without conscious recollection. - Executive Functioning: The management of thoughts to engage in goal-directed behavior and self-control.
Non-Cognitive Factors - Performance on memory tasks is influenced by health, education, and socioeconomic status (SES). - "Use it or Lose it": The hypothesis that mental activity maintains cognitive skills is controversial; some research shows benefits, while others find no effect.
Practical Intelligence and Expertise - Performance on experimental problem-solving tasks decreases with age. - Conversely, skill in solving real-world problems actually increases across adult years. - Standard intelligence tests, developed for children and young adults, often fail to measure qualities important for real-world functioning.
The Importance of Experience - Older adults perform better when tests are practical and based on familiar situations. - Experience is highly relevant to real-world competence but less relevant to abstract cognitive assessments. - Expert Performance: Involves the accumulation of knowledge, refined through experience, and the acquisition of complex skills and physiological adaptations.

Dementia and Alzheimer’s Disease

Dementia Overview - Dementia is a collective term for a syndrome associated with neurodegenerative diseases that cause the deterioration of brain function. - It is progressive, irreversible, and usually terminal. "Early onset" is defined as occurring before the age of $65$ .
Alzheimer’s Disease (AD) - AD is the most common cause of dementia. - Risk Factors: No clear cause identified, but includes unmodifiable (genetic) and modifiable factors (toxin exposure, excessive alcohol use, poor nutrition, pollution, head injury). - Treatment: No cure currently exists, and there is little effective treatment, though drug treatments can slow progression. - Stages of AD: - Early stages: Problems remembering recent information. - Middle stages: Personality changes, including irritability. - Later stages: Significant difficulties with motor movement. - After several years: Speech problems emerge.
Global and National Impacts - Dementia is a major global public health challenge. Estimates suggest $57 \times 10^6$ (million) people worldwide by $2026$ and $145 \times 10^6$ (million) by $2050$ . - There is a shift from acute/communicable diseases to chronic/degenerative illnesses. - Australia Statistics: Dementia was the $12^{th}$ leading cause of disease burden in $2003$ ; it became the $5^{th}$ leading cause in Australia and is the leading cause of death as of $2025$ .

Caregiving for Dementia

Informal Care - Individuals with dementia living in the community rely heavily on others: $91\%$ have informal, unpaid assistance, and $22\%$ rely solely on such assistance. - Carers are most commonly family members, such as a spouse or adult offspring (often female). - High-quality family care predicts a longer duration before the transition to an institution, contributing to better health and wellbeing.
The Cost and Burden of Caring - Economic impact: The annual value of care is approximately $US\$1.3 \times 10^{12}$ (trillion) worldwide and $AU\$4.7 \times 10^9$ (billion) in Australia (Feinberg et al., 2011). - Institutional care can be up to twice as expensive as home care (W63ubker et al., 2014). - Carer Wellbeing: While many find the role rewarding, it often goes unrecognized (Zarit & Femia, 2008). - Deficits reported by carers: Declines in health, quality of life, and economic security (Robinson et al., 2009; 2012). - Psychological impact: At least $30\%$ of carers experience depression (Brodaty & Donkin, 2009; Cuijpers, 2005). They also face stress, social isolation, financial burden, and sleep issues (Peacock & Forbes, 2003).
Caring for Carers - Supporting carers helps promote their wellbeing, delays institutionalization of patients, and reduces burdens on health systems. - Meta-analysis indicates that Cognitive Behavioral Therapy (CBT) is efficacious for improving carer mood (Spijker et al., 2008). - While face-to-face CBT is validated, it is expensive; group CBT and telehealth are viable alternatives.

Psychosocial Functioning and Identity

Mental Health - Depression: The most common mental health problem in older people, affecting up to $7\%$ (WHO). - Dementia and depression are the primary mental health issues for the elderly, followed by anxiety disorders. - Gender Differences: Higher prevalence in women due to greater susceptibility and more persistent depression, coupled with a lower probability of death (Barry et al., 2008).
The Role of Work - Work identity provides financial input, self-concept, structure, and a social context for relating to others. - Lifespan Work Roles: - Adolescence: Transition into part-time work. - Early adulthood: Establishment of career. - Mid-late adulthood: "Job for life" is no longer the standard; job satisfaction may dip in middle adulthood. - Older adulthood: The challenge of defining the self outside of work.
Adjustment to Retirement - Older workers often have lower absenteeism, fewer accidents, and higher job satisfaction than younger workers. - Retirement is a major status transition into later adulthood, involving both objective and subjective transformations. - Factors for Successful Adjustment: Being healthy and active, having adequate income, being educated, having an extended social network, and being satisfied with life prior to retirement.
Effects of Bereavement - Widow(er)s generally score lower on psychological wellbeing and experience both short- and medium-term depression. - Coping is aided by social relationships and better general health. - Gender Differences in Bereavement: - While women generally have higher depression levels, this effect often reverses in widowhood (Bennett Smith & Hughes, 2005). - Resources matter: Widowers face financial stress that may impede emotional coping (Baarsen & van Groenou, 2001). - Women generally adapt better in the long term (Lee, De Maris, Bavin & Sullivan, 2001). - Why Gender Differences?: - Starting Points: Married men are less depressed than married women, meaning they have "further to fall" into depression after the loss (Lee et al., 2001). - Social Factors: Widowers are less common and may lose contact with still-married friends. Widowed women tend to interact more with family (Antonucci, 1990; Peters & Liefbroer, 1997; Stroebe & Stroebe, 1987). - Health and Domesticity: Widowhood lead to stronger health declines in men, potentially due to poor nutrition or the sudden need to assume domestic tasks (Lee et al., 1998).
Psychosocial Wellbeing Trends - Life satisfaction typically follows a U-shaped curve: it dips in early-to-mid adulthood and rises again as individuals approach retirement age.