The Aging Brain Flashcards
1
Q
Frontal Lobe
A
- Executive functioning
2
Q
Motor Cortex
A
- movement
3
Q
Somatosensory cortex
A
- Sensory information
4
Q
Parietal lobe
A
- Goal orientated movement
5
Q
Temporal lobe
A
- Hearing, language, and music
6
Q
Occipital libe
A
- Visual processing
7
Q
Viewpoints of the brain
A
- Anterior: front of the brain
- Posterior: back of the brain
- Lateral: sides of the brain
- Medial: middle of the brain
8
Q
White matter
A
- Made up of nerve fibres
- Forms tracts that send information through the brain
9
Q
Gray matter
A
- Made up of cell bodies
- Where processing of information occurs
10
Q
Ventricles
A
- Filled with cerebrospinal fluid (CSF)
- Cushions the brain and spinal cord
- People with dementia have more CSF and less white and grey matter which is a sign of atrophy
11
Q
How much of the brain is white matter and how much is gray matter
A
- 40% is is gray
- 60% is white
12
Q
names of the two halves of the brain
A
- Left cerebral hemisphere
- Right cerebral hemisphere
13
Q
What are the four lobes of the brain called
A
- Frontal
- Parietal
- Occipital
- Temporal
14
Q
What is a sulcus and which sulcus separates the frontal and parietal lobe
A
- A sulcus is a shallow groove in the cerebral cortex
- The central sulcus separate the frontal and parietal lobe
15
Q
Why is white matter white
A
- Because of the myelin, an insulating layer around nerves, and axons
16
Q
Why is gray matter grey
A
- Because of the cell bodies, dendrites, and/or axons
17
Q
How does the brain change with age
A
- Decreased white and gray matter volume
- Alteration in functional connectivity
- Increases in vascular lesions
- Changes in protein composition
- Reductions in neural activity and blood flow
18
Q
Functional brain changes
A
- Changes in functional connectivity
- Reductions of tract within lobes
- Reduction between lobes
- Reduction between hemispheres
19
Q
How does white matter change with age
A
- Associated with myelin degeneration, axonal loss, and reduced WM integrity
- Most changes are often observed in areas with complex functions
- WM reductions are quite variable within and between people
- WM loss is linked to widespread cognitive loss
20
Q
Gray matter changes in aging
A
- GM volume reduction is attributed to reduce synaptic dendrites
- Reductions don’t occur at the same rate in all areas
- GM reductions don’t occur in everyone or at the same rate in everyone
- GM loss is associated with cognitive deficits, but the deficits are specific to the area
21
Q
What happens to brain volume throughout the lifespan
A
- Ventricle volume steadily increases after 40
- This coincides with maximum loss of gray and white matter starting around 40
- Total cerebrum volume peaked just before the onset of puberty
- GM and WM growth peaks in infancy and early childhood
22
Q
Brain lesions
A
- Appearance of vascular lesions due to risk factors such as smoking, high blood pressure, and drinking
- If the lesions are the result of vascular risk factors they often appear in the frontal lobe
- If the lesions are associated with early dementia, they are often more widespread
- These changes are also associated with future cognitive decline
23
Q
Types of brain lesions
A
- Brain lesionss are areas of the brain that show damage from injury or disease
- White matter lesions
- Large cortical infarction
- Microbleed
- Multiple lacunar infracts
24
Q
Changes in protein composition
A
- Many changes in proteins and enzymes influence brain health and function
- Common increases in amyloid beta and tay proteins occur with age
- May have specific directionality of accumulation in the brain
- Starting at the temporal lobe and then spreading out
- Can lead to dementia and other severe deficits
25
Neural activity changes
- Reductions in how the neurons fire results in changes in brain activation patterns during cognitive tasks and at rest
- Changes observed can be decreases or increases in activity while some areas see no change
- Neural changes are influenced by individual variability
- Associated with cognitive deficits
26
Blood flow in the brain
- Alterations and reductions in cerebral blood flow are observed during cognitive tasks and at rest
- Like neural activity, there can be increases (compensation) or decreases in blood flow
- Changes in blood flow are largely influenced by arterial stiffness and vascular risk factors
- Reductions in blood flow are typically associated with poorer cognitive performance
- Older adults showed decrease activity in the hippocampus compared to younger adults
- Older adults showed increases in left prefrontal cortex activity compared to younger
27
Commonalities across all brain changes
- Influenced by individual variability
- Associations with cognition are dependent on the area affected
- Compensation method can result in increased blood flow and neural activity despite changes in GM
28
Compensation
- Process which the brain recruits additional brain regions or strengthens existing neural networks to compensate for age related cognitive decline
29
Crystallized abilities
- Cumulative abilities built up overtime
- Ex: General knowledge, vocabulary
- Remains stable with age
30
Fluid Abilities
- Require flexibility of cognitive processing at the time of test
- Ex: Processing speed, attention, task switching
- Declines with age
31
Processing speed with age
- Declines steeply
- You can still process, just slower than before
32
Sustained attention and aging
- Sustaining attention throughout long periods of time
- Preserved in aging
33
Selective attention and aging
- Focusing on a particular unique stimulus for a certain period of time
- Declines in aging
34
Divided attention and aging
- Paying attention to a lot of things at once, like when you're driving
- Declines with age
35
Long term episodic memory
- Memory with the conscious recollection of information from a specific event or point of time
- Ex: your first kiss
- Stable until about 55-60
- Declines around age 65
36
Long term semantic memory
- Meaning of words and concepts not specific events or times
- Increases from 35-55 followed by a plateau
- Slight decline after 65
37
Working memory
- Holding information in mind and manipulating it declines with age
- Declines with age
38
Short term memory
- Holding information in mind for short times
- Relatively preserved in normal aging
39
Language and aging
- Vocabulary is stable or improves
- Visual confronting naming is stable and declines at 70
- Verbal fluency also declines with age
40
Physical activity and aging
- Exercise aids executive functioning
- Reduces declines in tissue density in frontal, parietal, and temporal cortex
- Might have global effects on the brain
41
Intellectual Stimulation
- Protects against age related declines and progression of AD
- Mental activity also increases our baseline cognitive function
- Rats show neurogenisis in enriched environments indicating possible benefits for cognition
42
Minimizing chronic stress
- Associated with higher risk of AD and faster rate of cognitive decline
- Damages hippocampal neurons
- Reduces glucose metabolism in the hippocampus of older adults
43
Brain healthy diet
- Unsaturated fatty acids
- Polyphenols
- Antioxidant
- These can slow cognitive decline and prevent AD progression
44
Dementia prevention
- 45% of risk factors are modifiable
- Early life: Education
- Mid life: Hearing loss, high LDL cholesterol, Depression, TBI, physical inactivity, diabetes, smoking, hypertension, obesity, excessive alcohol
- Late life: Social isolation, air pollution, vision loss
45
Cognitive reserve
- Individual differences in how people process tasks which allows some to deal with pathology better than others
- The brain tries to cope with pathology by using this pre-existing cognitive processing
- Explains how people with similar brains may or may not get dementia
- Measured through things like education level
46
Factors to improve cognitive reserve
- Mental stimulation
- Active lifestyles
- Social time
- Cognitive remediation
- Physical activity
47
Negative factors for cognitive reserve
- Poor education
- Mood disturbances
- Poor nutrition
- Alcohol/drug abuse
- Poor health
48
Brain reserve
- Often measured in terms of neurobiological capital, like number of neurons
- Is fixed where cognitive reserve is malleable
- Deficits only occur after a threshold has been hit
49
Scaffolding theory of aging and cognition
- Captures how life style and brain factors interact
- Compensatory scaffolding is when the brain changes to compensate for these changes using various methods like neurogenesis and biological recruitment
50
What factors influence compensatory scaffolding
- Cognitive reserve factors such as education
- Brain reserve factors such as head trauma
51
Posterior to anterior shift in aging (PASA)
- Memory declines are associated with atrophy in parietal regions
- Additional frontal regions are often recruited to help maintain high function
- This additional recruitment in considered a method of compensatory scaffolding
52
STAC-R and bilateral recruitment
- Left frontal activity is increased in high-performing older adults vs younger adults
- Low performing older adults do not show this additional recruitment
53
What cognitive domains are affected by exercise and which brain regions
- Memory, attention, and decision making
- Frontal cortex, temporal lobe, hippocampus
