Late Adulthood & Aging

brain and nervous system

• Decrease in gray matter between middle and late adulthood

• The most extensive decreases in gray matter density occur over dorsal, frontal,and parietal lobes

• Loss of neurons, a factor in age-related cognitive decline

• Cognitive decline is related to loss of neuronal elements though, not necessarily loss of neurons

• As we age, there is an associated shift in the timing or level of transmission through neuronal structures

• Compensatory processing?

• Normally aging brain has lower blood flow and gets less efficient at recruiting different areas into operation

• Declines in verbal fluency, may have to work harder at executive functions, and difficulty recovering from physical and emotional stress

Loss of Purkinje Fibers from the Cerebellum

Influence control of posture, balance, locomotion, movement sequencing, repetitive and alternating movements, and smooth eye movements

cortical white matter and myelin

DECREASES

REMEMBER: Myelin is important for the rapid, accurate, and effective

transmission of neural signals



Leads to the slowing of psychomotor speed

which increases processing time

required for complex info



Increased processing time

for transmission of motor responses via the

corticospinal and peripheral neural pathways

cogntive functions 

• Global mental functions tend to remainintact

• Consciousness functions, orientationfunction, intellectual functions, global psychosocial functions, temperamentand personality functions, energy and drive functions, and sleep functions

• One study found that 92% of normalelderly adults had perfect or near perfectorientation

• The area with the most change is withspecific mental functions

• Attention, memory, and psychomotor

attention

• Functional Attention requires both good working memory and inhibitory control

• Suggests that older adults are engaging other executive resources to support these tasks

activation differences

specifically in the prefrontal cortex, have been found when comparing older adults with younger adults when completing working memory tasks

inhibitory control 

• Older adults are more susceptible to distraction during tasks that require attention

• However, studies show that sustained attention shows no decline with age

post error slowing

• When older adults detect they have made an error, they slow their response speed much more than younger adults

• May be related to the process of redirecting attention to the primary task after an error is detected

• Research shows that older adults have a decreased ability to reengage the task set after the set has been lost, leading to the error

processing speed

_ deficits are associated with diminished white matter volume and white matter integrity

• Research shows consistently that the abilities to manipulate and retain acquired information steadily declines over the life span

memory functions 

• Not a general decline of memory functions, specific memory functions tend to decline first

• Weaker activation in regions of the medial temporal lobe but increased activation in the prefrontal regions compared with younger adults

• Interference (distractions) blocks encoding and slowed processing can make retrieval of information more difficult

• This can improve through specific practice

episodic memory

what did I eat for lunch?

source memory

where did I hear that from?

flashbub memory 

where were you on Sept. 11?

age-associated memory

• Clinical state that involves complaints of memory impairment with everyday activities

• Modest loss of memory function in healthy people aged 50 and older

benign senescent forgetfulness (BSF)

• A term associated with healthy individuals who experience brief transitory episodes of cognitive decline

• Attributed more to inattentiveness and forgetfulness than to theactual aging process

• KEY POINT: BSF is not severe enough to interfere with daily activities

psychomotor functions 

• Pronounced slowing in psychomotor processing speedwith aging

• Healthy elderly adults are slower to initiate and produce speech

• Differences in bimanual tasks

• Slower reaction times and balance

sensory functions

Examination Survey found the following:

• 1/6 people in late adulthood have impaired vision

• 1/4 people have impaired hearing

• 1/4 people have loss of feeling in the feet

• 3/4 have abnormal posture balance testing

Presbyopia

not a disease state, part of normal aging

dynamic visual acuity 

ability to accurately identify a moving target (can also be identifying objects while moving the head)

Ex. Reading a street sign while driving can be a significant problem for older people whodrive a car

vision

• Among people age 65 and older, 21% report some form of vision impairment

• Physical changes in the eye result in greater difficulty with visual acuity when there is low contrast and glare

useful field of view (UFOV)

• The visual area over which information can be extracted at a brief glance without eye or head movements

• With age, people notice the size of UFOV decreases

• Less attentional resources and increases distractions

• Correlated with many important real-world functions, suchas risk of a car crash

• THE GOOD NEWS: Driving safety can be assessed andimproved with clinic and computer-based simulations and cognitive training programs

color vision

• Yellowing of the lens of the eye and cells on the retina that are responsible for normal color vision decline in sensitivity

• Colors become less bright and the contrast between colors is less noticeable

peripheral vision

• The size of our visual field loss is about 20-30 degrees

• Increases the risk for automobile accidents

hearing loss 

very common in older adults

• Functional limitations caused by hearing loss include difficulty participating in conversations, hearing the telephone, hearing verbal instructions, and hearing traffic noises

The factors that determine the person’s quality of life

• the degree of loss

• pattern of loss across different frequencies,

• one or both ears affected,

• hx of exposure to loud noises,

• environmental or drug-related toxins that are harmful to hearing

• age

hearing aids

Types

1. Behind the ear (BTE)

2. In the ear (ITE)

3. In the canal (ITC)

4. Intracanal (CIC)

Levels of Technology

1. Conventional/analog

2. Improved (analog and programmable instruments)

3. Advanced (fully digital programmable)

taste and smell

• Become less acute with age

• Saliva flow decreases

• May make food less appealing and lead to poor nutrition

• Risk for failing to recognize spoiled food or toxic gases during cooking

hyposmia

decreased sensitivity to smell

hypogeuia 

the decreased sensitivity to taste

somesthesia

• The faculty of bodily perception, including information from all of the sensory systems associated with the body

• Sensitivity to touch, vibration, temperature, kinesthesia, proprioception, and pain

• Aging people experience decline in each of these senses thanks to _

functional change in touch

• Decline in fine touch and in pressure/vibration sensation

• Individuals will rely on other systems, such as vision

• Delay in muscle response to perturbations results in delayed equilibrium and protective responses

cardiovascular system 

• Atherosclerosis continues to be a problem

• The aorta becomes thicker, stiffer, and less flexible

• Makes the blood pressure higher and makes theheart work harder, which can lead to thickening of the heart muscle

• About 65% of Americans aged 60 or olderhave high blood pressure

• Less able to tolerate increased aerobic demands

orthostatic hypotension

a condition where blood pressure falls when you go from lying down or sitting to standing

• Causes dizziness due to less blood flow to thebrain

• More frequently seen in the elderly

• Can increase risk for falls

baroreceptors

pressure receptors in the blood vessels that initiate changes in blood volume to help maintain a fairly constant blood pressure during activities

• These receptors become less sensitive with age

integumentary systems

• Loss of collagen and loss of tissue support for remaining capillaries (increased bruising)

• Lentigos (flat age spots) increase

• Older skin does not stay hydrated well, may need extra care during hygiene

epidermis 

thins and flattens as we age, making it more susceptible to hearing stresses, skin tears, and blisters

dermis

atrophies and has decreased vascularity

oil and sweat glands

decrease in number and size, less sweat production

chronic health conditions

• High Blood Pressure - 58.4%

• High Cholesterol - 48.6%

• Diabetes - 22.6%

• Cancer - 19.2%

• Depression - 15.7%

depression 

• Older people with depression report unusual fatigue, low energy level, and a feeling of being slowed down (along with the typical symptoms)

• The National Institute of Mental Health consider depression in people aged 65 and older a major public health crisis

• Doubles the risk of cardiac diseases and increases their risk of death from illness

• Reduces their ability to rehabilitate from an injury