Lecture 4: Theories of cognitive aging

Question 1

What are the four theories of cognitive aging?

Answer 1

1. processing speed
2. cognitive resource
3. inhibitory function
4. sensory function

Question 2

Reduced processing leads to decline in cognitive performance through which two mechanisms?

Answer 2

Limited time mechanism: The time to perform later operation is greatly restricted when a large proportion of the available time is occupied by the execution of earlier operations
simultaneity mechanisms; the products of earlier processing may be lost by the time later processing is completed
This means: Older adults are slow to perform early steps in complex cognitive task
May never reach later stages because the products of earlier operations

Question 3

What is the cognitive resources theory?

Answer 3

Older adults have fewer cognitive (processing) resources than younger adults
Processing resource is best measured by working memory

Question 4

What is the decline inhibitory function theory?

Answer 4

Older adults find it difficult to focus on target information and inhibiting attention to irrelevant information
Thus “age-related decline in cognition is actually caused by older adults ability to stay focused on primary information
Often tend to diffuse their attention between irrelevant and relevant info

Question 5

What is sensory function theory?

Answer 5

that there is a strong link between perceptual abilities and cognitive performance esp in OA

Question 6

What are the proposed hypotheses for the link between perceptual and cognitive decline in old age?

Answer 6

common cause, cognitive load on perception, information degradation and sensory deprivation

Question 7

What is the scaffolding theory of aging and cognition?

Answer 7

Incorporates the effects of a broad range of adverse biological and neurophysiological factors
Delineates their dynamic interaction with:
Protective factors
Newly Emerging compensatory processes deemed to be at work in the oder brain

Question 8

What are neural challenge in STAC?

Answer 8

Regional atrophy
Loss of White matter
Cortical thinning
Dopamine depletion

Question 9

What are functional deterioration?

Answer 9

dedifferentiation (decreased specificity) of ventral visual area and motor areas
Decreased recruitment of Medial temporal lobe region
Dysregulation of the default mode network

Question 10

What is compensatory scaffolding?

Answer 10

Greater activation/ additional recruitment of prefrontal and parietal brain regions
Bilateral recruitment (using both sides of brain)
(speculatively) neurogenesis may contribute to compensatory scaffolding to compensatory scaffolding
Frontal recruitment
Neurogenesis
Distributed processing
Bilaterality

Question 11

What is scaffolding enhancement?

Answer 11

New learning
Engagement
Exercise
Cognitive training

Question 12

What is a SuperAger?

Answer 12

An older adult with cognitive abilities like someone decades younger
Different studies use different exact definitions
Superagers do not differ from controls in 1Q or education

Question 13

What does a neuroimaging of a superager’s brain look like?

Answer 13

Neuroimaging showed selective cortical [reservation in anterior cingulate and hippocampal regions
No difference amyloid deposition between superagers and control
Functional connectivity patterns looked like young adults

Question 14

Does being a SuperAger protect against decline? Effects of beta-amyloid (I may ask you what the figures in slides 15 and 16 illustrate)

Answer 14

No it does not
In the graph, we see the sugeragers displayed resilience against clinical progression to MCI/dementia compared to CNFA despite equivalent risk for alzheimer’s disease; however superagers had no greater protection from amyloid deposition, the effects of amyloid beta on cognition persist regardless of baseline cognitive ability