Aging

Question 1

Invariant aging hypothesis
Which cognition improves w/ age? (reasoning, spatial visualization, memory, speed, vocabulary knowledge)
- When do they peak + when do they decline significantly
- Which has largest decline

Answer 1

Aging is an inevitable biological reality

Vocab knowledge
- Peak at 20, decline at 60
- Speed (reaction time)

Question 2

Younger vs older adults reaction time and accuracy
Low education vs high education in cognitive decline

Answer 2

Rxn time decreases but accuracy doesnt
Educated people show less cognitive decline

Question 3

Brain regions most vulnerable to cortical thinning (4)
Accelerated thinning in temporal cortex associated with w/?
Brain reserve theory

Answer 3

• Superior, middle, inferior frontal gyri
• Superior, middle temporal gyri
• Precuneus, inferior, superior parietal cortices
• Temporo-parietal junction
  —
  Future cognitive impairment + higher risk of disease
  —
  We have more cells than we need; Wr receive impairment when reserve of cells go under required to function normally

Question 4

Meditators show less age-related atrophy in which areas (5)
Study shows brain of long term meditators was how many years younger
In controls but not meditators, aging is associated w/? (3)

Answer 4

• Hippocampus/Amygdala
• Posterior cingulate
• Orbital gyrus
• Anterior cingulate gyrus
• Mid cingulate gyrus
  —
  7.5 years
  —
• Reduced GM
• Impaired attention
• Increased RT

Question 5

Raven’s progressive matrices
- Typically used in what assessments
- Performance in controls vs meditators and yogi

Answer 5

Nonverbal test of fluid intelligence (reasoning of abstract concepts)
- Used in IQ assessments
- Performance declines w/ age, but less in meditators and yogi

Question 6

What tracts (white matter) maintain integrity w/ age
Glucose metabolism (effects strongest where? 3)

Answer 6

Regions associated with meditation (insula, hippocampus, amygdala, ACC)
—
Declines w/ age but less significant in meditators
- vmPFC, pCC, insula

Question 7

Mechanisms of meditation on aging/cortical thinning (4)

Answer 7

• Reduced anxiety and depression, improves stress regulation (less cortisol, less hippocampal atrophy)
• Improved sleep amount and quality
• Cardiovascular effects (blood pressure, heart rate variability)
• Neuroplasticity (Lower cortical atrophy, increased thickness)

Question 8

PTSD highest cortical thinning where?
Depression causes more cortical thinning where?

Answer 8

• Frontal cortex, temporal lobe
• Hippocampus

Question 9

Controversies w/ meditation and brain changes:
- Gray matter
- Mechanism for cortex changes unclear
- Functional effects of cortex changes
- Study design
- Sample size
- Bias

Age-well randomized clinical trial (RCT)

Answer 9

• Not all studies show increased gray matter volumes w/ meditation, some go down
• Reduced gray matter changes may reflect a number of changes in brain other than neuronal loss
• Often untested; usually measure either brain changes or cortical changes, not both
• Usually cross-sectional and observational, no causal relationship
• Small sample size
• Usually high risk of bias
  —
• Large sample, controlled, experimental, low attrition
• Shows no fx on brain structure/perfusion, but higher global composite score (reflects multiple abilities)

Question 10

Hayflick limit
- Telomeres
- Telomerase
- Effect of meditation, effect greatest in who

Answer 10

Cells can only divide a finite number of tines
- Imperfect copy/mitosis process bcuz entire DNA strand can’t be copied every time

Telomeres usually cut instead of DNA but shorten w/ cell division
- Telomerase maintains telomere length and prevents shortening, but activity reduced by chronic stress
- Activity enhanced by meditation (ppl w/ personality traits high in neuroticism and low agreeableness)

Question 11

Caveats of telomere studies:
- Effects measured where
- Mechanism
- Length
- Sample size

Answer 11

• White blood cells (leukocytes) but not neurons
• No known mechanism by which telomeres may affect neuronal function
• Some studies report increased length (controversial)
• Sample size small

Question 12

More DNA methylation = ___ gene expression
- As we age, there is increases/decreased methylation in DNA sequence
- Epigenetic clock

Meditators vs controls in methylation (30-60 years old)
Older meditators (>52 years), relationship between epigenetic clock and meditation practice (years)

Problems w/ studies (4)

Answer 12

• Less
• Increased
• Methylation can be used to predict age; More methylation = faster aging
  —
• No evidence of slowed aging w/ meditation
• Meditators show downward trajectory (lower methylation patterns) w/ age
  —
• Epigenetic effects rarely examined
• Implications of Epigenetic modifications unclear (specific patterns of gene methylation and protein expression)
• Might not be feasible to investigate (requires older participants, observed over years)
• Aging-related changes may be distinct from short-term changes

Question 13

Alzheimer’s disease
- Features (4)
- Risk factors + modulated by what
- What’s most sensitive to meditation in elderly ppl + major difficulties sensitive to meditation in AD
- Problems w/ studies (5)

Answer 13

• Neuronal loss
• Neurofibrillary tangles
• Amyloid plaques
• Reduced acetylcholine transmission
  —
• Hypertension, blood perfusion, stress
• Meditation may slow progression + rescue lost cognitive function
  —
• Attention
• Disrupted mood + sleep
  —
• Few studies
• Designs lack control groups
• Biomarkers related to AD not reported
• Hyperfixation in cognition in AD
• Narrow examination; only focuses on AD patients