+ Brain Aging Review

Question 1

Types of cognitive abilities that decline with age

Answer 1

• Fluid abilities (require real time cognitive processing); shown to linearly decrease with age from 20 to 80 (e.g. processing speed)
• Decline in ability to take on new information

Question 2

Types of cognitive abilities that do no decline with age:

Answer 2

• Crystallised abilities (acquired knowledge etc) are shown to improve from 20 to 60 then plateu until 80)
• Procedural memories (skills based) are preserved with age
• Speech and language appear to remain intact with age

Question 3

Structural and functional changes in the aging brain phenotype:

Answer 3

• Size of brain decreases with age; both grey and white matter, varying slightly by region
• Substantial number of neurons change in structure -> lower number/length of dendrites, loss of dendritic spines, fewer axons, significant loss of synapses

Question 4

Age-associated conditions that result in increased neurodegeneration

Answer 4

• AD
• Vascular dementia
• Dementia with Lewy bodies
• Often hard to study (distinguishing healthy from early onset of disease)

Question 5

Lifestyle factors that may contribute to loss of neuroplasticity:

Answer 5

• Alcoholism
• Certain mental illnesses
• Obesity
• Hypoxic brain injury
• Diabetes
• Brain injury

Question 6

Biggest sources of bias in aging research:

Answer 6

• Participation bias: More advanced cases make it more difficult for individual to participate in the trials -> underestimate of degeneration
• Misclassification bias: Assuming someone is normal when they are in fact showing early signs of disease

Question 7

Threshold for symptomatic dementia (synapses):

What might effect baseline and rate of decline?

Answer 7

• 40% loss of neocortical synapses as compared with normal adults
• Depends on rate of loss and baseline (often affected by neonatal hypoxic brain injury)
• Rate may be mediated by healthy lifestyle choices
• Rate would be greatly accelerated by ND diseases like AD

Question 8

Factors to prevent loss of neuroplasticity:

Answer 8

• Healthy diet
• Avoiding excessive alcohol consumption
• Exercising regularly
• Brain exercises
• Managing emotional stress
• Managing symptoms of certain diseases