Aging and Sensory and Physical Changes Lecture 4 – PS277

Darwin in Youth and Later Life

Lecture Outline  Overview of aging and physical changes  Sensory system changes  Cardio-vascular systems and disorders  Changes in the brain and nervous system

I. Overview of Some Primary Changes Across Adulthood Function:Age of Change:Nature of Change VisionMid-40’sLens thickens, poorer near vision HearingMid-50’sLoss of high and low tones SmellAbout 40Poorer detection and discrimination Heart & Lungs35-40Aerobic capacity during work Height40Compression of disks in spine Skin40Wrinkling, oil secretion poorer Bones35Loss of calcium, osteoporosis – increased porosity

Some General Points on Physical Aging- Nuland (2007)  Individual variability is great  Systems generally maintain competence despite some losses at maximums  Several factors: biological changes, disease, environment, personal attitudes all interact in predicting and explaining aging process  These changes themselves are not diseases, but they predispose some people to certain diseases  Physical changes have important implications for psychological functioning

II. Sensory Predictors of Cognitive Functioning – Lindenberger & Baltes (1994)

III. Cardiovascular Changes with Age  Circulation of blood, heart, arteries, carries oxygen from lungs  Deposits of fat in arteries of heart, stiffening of arteries with age (atherosclerosis)  Heart must work harder with age, highest output declines  Blood pressure gradually rises with age – hypertension can result  None of these are diseases in themselves, just changes with age, but make disease more likely

Chronic Conditions in Later Life Percentages Suffering From Each Type

Canadian Adult Death Rates by Disease Type

Types of Cardiovascular Disease  Heart problems – congestive heart failure, angina pectoris, myocardial infarction (heart attack)  Atherosclerosis – restriction of blood flow in arteries due to fatty deposits  Strokes (CVAs, TIAs) – blood flow interruptions to brain, paralysis, speech problems, risk factor for dementia  Psychological consequences: Role of circulatory system in brain and cognitive function – quite a direct impact: jogging is good for health and for mind…

IV. Changes in Brain - Major Components at Cellular Level  Neurons: axons plus cell bodies – electrical pathways  Synapses = 1,000,000,000,000,000 in brain  Dendrites = connect to next neurons at synapses  Neurotransmitters: chemical pathways that cross synapses

Changes in Brain with Age  Overall weight loss = 5%  Some loss of neurons, but new ones can grow and new synapses can form too  Substantial loss of dendrites leads to some slowing at synapses – one of the key markers of aging  Changes in some neurotransmitters – loss in dopamine and acetylcholine, but some increases too  Most of these changes more marked with disease!

Some Modest Increases in Alzheimer- Like Problems – Brain Sections  Tangles: tadpoles, axon fibres twisted together  Plaques: blobs, dying neurons coalesce around protein core  If these are common enough, they can be used to indicate 6 stages of Alzheimer’s disease

Psychological Implications of Changes: The Nun Study – Snowdon, 2001  Followed large sample of 700 nuns from convent in US Midwest into late adulthood  Tested every year on cognitive function, brains were donated and studied after death  Observed physiological levels of plaques and tangles don’t fully predict memory loss, decline into Alzheimer’s symptoms  Some people resist expressing this behaviorally  Patterns of stroke seem to interact with these biological markers, magnify problems

Pictures of Centenarian Nuns