2 - Research methods

Question 1

What are cohort effects?

Answer 1

• Differences caused by experiences and circumstances unique to a generation which one belongs
  → people born at a very particular time
  → p.ex: baby boomers

Question 2

What are time of measurement effects?

Answer 2

• Differences from sociocultural, environmental, historical,
  or other events at the time from which the participants are tested
  → p.ex: people doing a well-being test in 2020 when covid lockdown was happening, vs. in 1990

Question 3

What are age effects?

Answer 3

• Differences caused by underlying processes such as biological psychological or sociocultural changes
  → p.ex: chronological age
  → these are effects that are very inherent within a person

Question 4

What are confounding effects?

Answer 4

• A factor or set of factors that influences the outcome and we cannot determine which of the effect is response for the behavior being observed
  → p.ex: cognitive decline in 2 groups, and one group had half males and the other had full males, there would be differences, but sexe would be a confounding factor here because the differences we find may not speak of aging, but rather of sexe differences
  → this is smt we need to control for

Question 5

What are the 4 types of research designs?

Answer 5

1) Cross-sectional design: Studies people from different groups at the same time
2) Longitudinal design: studies a single group of people at two or more points in time
3) Sequential design: studies the same individuals at two or more points but also different groups
4) Time-lag comparison design: Studies different groups of people at the same age at different times (very rare, researchers don’t typically use this)

Question 6

Elaborate on the cross-sectional design.

Answer 6

• Examines two groups of people at the same time (e.g., 18-30 yr olds vs 65+)
  → a lot of research using this design will use this age range
• This design is low cost and easy to implement
• Employed to examine age differences but NOT age changes
  → if i was looking at the same person across time, that would be age changes
  → but age differences is 2 different age groups
• Major issues is cohort effects which are factors that influence results related to the time of a person’s birth
  → p.ex: baby boomers compared to millennials
  → if comparing baby boomers and millennials while using computers for the test, performance may be affected in the baby boomers because millennials are more comfortable with computers; this is a confounding effect that needs to be taken into consideration

Question 7

Elaborate on the longitudinal design.

Answer 7

• Examines the same people over time (e.g., following 60-year-olds annually for 20 years)
• This design is expensive and difficult to manage
• Employed to study age changes
  → huge benefit because we can study people over time and look at age change
• Main issues are:
  → Practice effects, participants may improve over time simply because people are tested multiple times with the same measures
  → if you give someone the same test year after year, it might not be an improvement in cognitive faculties, it might just be the practice effect
  → Limited generalizability, only one cohort is followed therefore the results may be associated with time of measurement

Question 8

Elaborate on the sequential design.

Answer 8

• Examines the same groups of people over time (e.g., following 60-year-olds annually for 20 years starting at two timepoints)
• Combines both longitudinal and cross-sectional
  → consists of 2 cross-sectional studies at 2 or more times of measurements
  → taking the best of both worlds essentially
• Examines age-changes AND age-differences
• Can study cohort effects
• sequential is very optimal
• Main issues: however can be expensive, and practice effects, as well as people dropping out of the study over time

Question 9

What is an experimental design?

Answer 9

• The specific structure of a scientific experiment allowing researchers to investigate the influence of independent variables on a dependent variable

Question 10

What is a correlational study?

Answer 10

• Investigation into the relationships between different variables
  → changes in one variable are associated with changes in another variable
  → p.ex: people who show up to 100% of the classes tend to have a higher grade average
  → BUT correlation is not causation

Question 11

What is a case study?

Answer 11

• An in-depth study of a single individual, group, or community
  → useful when wanting to investigate the occurrence of a very uncommon disease

Question 12

What is a meta-analysis?

Answer 12

• A combination of results from many studies to estimate relations between variables

Question 13

Cognition is a term referring to…

Answer 13

The mental processes involved in gaining knowledge and comprehension
→ It includes attention, thinking, knowing, remembering, judging, making decisions, and problem-solving

Question 14

How is cognition studied?

Answer 14

• Studied using standardized tests (e.g., Montreal Cognitive Assessment) and often in conjunction with neuroimaging methods (e.g., Magnetic Resonance Imaging or functional Magnetic Resonance Imaging)
  → integrating not just behavioral responses, but also your brain, which is super important
  → it’s crucial to look at brain scans after doing paper and pen tests

Question 15

What is the Montreal cognitive assessment (MoCa)?

Answer 15

• A screen for early dementia that tests multiple cognitive domains
• Provides an overall assessment of global cognitive functioning

Question 16

What is the stroop test?

Answer 16

• Measures inhibition
• Name the colour of a word, colour of ‘x’ and colour of word that says another colour

Question 17

What is the Boston naming test (BNT)?

Answer 17

• Measures language function
• Name 60, line drawings of increasing difficulty
  → naming an item

Question 18

What is the California verbal learning test (CVLT)?

Answer 18

• Measures short- and long-term memory
• Repeat a list of 16 words immediately and 20 minutes later

Question 19

What is the digit span?

Answer 19

• Measures short-term and working memory
• repeat words in the same order and then backwards

Question 20

What are the types of brain assessments that can be done to look at cognition?

Answer 20

• Magnetic resonance imaging (MRI)
• Functional magnetic resonance imaging (fMRI)
• Electroencephalography (EEG)
• Positron emission tomography (PET)

Question 21

What does the MRI do?

Answer 21

• Uses magnetic fields to generate detailed images of internal structures
• MRI is essential in research and clinical settings to study normal and abnormal brain structure
• used to look at things beyond the brain as well (spinal cord, organs), can also be used to monitor tumors and injuries
• the ventricles are spread out because of a build up of spinal fluid in brains of people with alzheimers (bottom image)

Question 22

What does the fMRI do?

Answer 22

• fMRI accurately measures change in magnetic properties in the blood flow when the brain becomes active
• The BOLD (blood oxygen level-dependent) contrast provides an index of the brain’s relative activity
• Done using MRI machines, but the functional aspect of it is overlapped with the structure so you get great spatial resolution
  → the areas associated with the task use more blood, which results in either an increase or decrease of oxygen within the blood, so there will be increased blood flow in that region and will activate on the scan
  → when doing a specific cognitive task, the magnetic properties in that area changes, which increases blood flow, which is what the fMRI picks up

Question 23

What does the EEG do?

Answer 23

• gives an excellent temporal resolution
• Accurately measures brain activity
• Can be combined with cognitive or sensory tasks to measure brain activity to a certain stimulus
  → to see how fast the brain is responding (fMRI can’t do that)
• records an immediate response in the neurons
• the problem though is that it doesn’t give good spatial resolution
  → i.e., we can’t say that it’s a specific part of the brain that’s active

Question 24

What does a PET scan do?

Answer 24

• Injection of a tracer which is then measured using a special machine
  → when injected, the radioactive tracer flows through the bloodstream and takes it to areas of the brain that is more active
  → the computer construct an image of the brain afterwards
• Indirect measure of metabolic activity (glucose levels within the blood cells in the brain as the person is doing cognitive activity) or protein deposition

Question 25

What are some characteristics of physical assessments?

Answer 25

• Physical functioning changes in age and is often examined to help determine independence in older adults
• Changes often measured include:
  → Grip strength: indicator of overall muscle strength and physical performance (this declines naturally with age)
  → lower grip is associated with increased risk of frailty and mortality
  → Balance tests: indicator of future falls (TimedUpGo test, or a single leg stands test)
  → measures how quickly a person can safely rise from a chair
• Activities of daily living (ADLs): basic self-care tasks essential for daily functioning, such as bathing, dressing, eating, toileting, and transferring (e.g., from bed to chair)
• Instrumental activities of daily living (IADLs): complex tasks that require higher cognitive and physical abilities, including managing finances, preparing meals, shopping, using transportation, and managing medications
  → both ADLs and IADLs provide a practical assessment of whether an older adult can live independently and live a good life

Question 26

Psychological assessments look at symptoms of…

Answer 26

depression such as mood, and social interactions

Question 27

What are some common areas of interest when doing psychological assessments of older people?

Answer 27

• Depression: indicator of mental well-being
• Subjective cognitive decline (SCD): indicator of early cognitive changes that may be related to dementia
  → This questionnaire is one of many to assess SCD (pic on slide)
  → Self-report to rate cognitive change over the last several years
  → there is a certain bias with self-report though
  → asking them if they think they have dementia, which indicates predictors of dementia
  → Very good test to look at cognitive decline, but further changes are needed
• Loneliness: indicator of overall mental well-being
  → prevalent in 20-50% of older adult population and is associated with deficits in well-being and cognitive function
  → p.ex: chronic loneliness has been linked to lower physical health outcome; weakened immune function and increased mortality
  → can also lead to unhealthy behaviours such as poor diet and lack of exercise
  → correlated with dementia

Question 28

What are some considerations / challenges in aging research?

Answer 28

1) Aging is not the same between individuals (i.e., the process is very heterogeneous)
→ Factors such as genetics, lifestyle, socioeconomic status, environmental exposures all influence how we age
→ That means two people of the same age may look very different which makes it difficult to generalize between people and studies
→ typically longitudinal studies done on older adults are done on white well-educated (PhD) males (thus not generalizable to the population)
2) Aging is not the same within an individual (i.e., someone can age quickly in one area and not another)
→ Some organs or functions may be functionally well (e.g., heart) but others (e.g., liver) may not be functioning well (this changes within the person)
→ p.ex: a person who’s 30 with the heart of a 45 year old
3) Aging is associated with multiple chronic conditions which can interact and influence studies
→ Many older adults have multiple conditions (e.g., diabetes and hypertension) which can have an interactive effect cause both lead to a risk in dementia