L2 - Methods to study Diversity

Question 1

Experience sampling method

Answer 1

• Ppts report thoughts, feelings and behaviours repeatedly over period of time
• Act of self-monitoring can influence what is being measured

Question 2

Observational measures

Answer 2

• Can be used in naturalistic settings and when impossible to give instructions to a ppt
• Can only measure overt behaviours
• Scoring may be influenced by observer biases. Can be minimised by computerised scoring (eye tracking)

Question 3

Performance measures

Answer 3

• Differences across tasks reflect differences in info processing mechanisms
• Objective
• Relationship with real-world behaviours not always clear

Question 4

Measuring the unconscious mind

Answer 4

• Cognitive tasks and priming used to measure unconscious cognitive processing
• In a priming paradigm, ppts exposed to stimulus then response to subsequent stimulus measured
• Prime activates mental representations which could affect processing of SS
• In masked priming, prime presented followed by junk visual material, prevents prime from entering conscious processing

Question 5

Factor analysis

Answer 5

• Reduces large number of variables into fewer factors
• Analyse pattern in which variables vary together. Variables indicating same underlying construct expected to covary

Question 6

Exploratory factor analysis

Answer 6

• Does not assume particular factor structure

Uses the data to determine:

• Number of factors
• Correlations between a variable and a factor (factor loadings) are computed and examined
• Higher factor loading = higher importance of the variable to the factor

Question 7

Confirmatory factor analysis

Answer 7

• Hypothesise factor structure and test how well it fits actual data
• Factor loadings, factor correlation and some fit indexes are estimated

Question 8

Structural brain imaging

Answer 8

• Measure anatomical details of the brain
• White matter consists primarily of myelinated axons
• Gray matter consists primarily of neuronal cell bodies

Question 9

MRI

Answer 9

• Used to measure brain, grey matter and white matter volume
• Strong magnetic field causes hydrogen atoms to align in same orientation
• Radio wave passed through head, atoms emit electromagnetic energy as they relax, detected by scanner
• Different types of tissue produce different signals
• Computer reconstructs image

Question 10

PET (position emission tomography)

Answer 10

• Radioactive tracer injected into bloodstream
• Amount of each radioactivity in each voxel of the brain measured

Question 11

fMRI

Answer 11

• Measures dynamic physiological changes in brain and associate them with different patterns of mental processes/behaviour
• Measures downstream consequence of neural activation
• Lot of brain areas activated how to tell what activation related to specific process:
  • Subtraction method (diff in activation for tasks
  • Conjunction method (joint activation for tasks)

Question 12

fMRI - process

Answer 12

• BOLD signal measured. Its affected by amount of deoxyhaemoglobin
• When neurons consume O2 they convert oxy to deoxy which has strong paramagnetic properties and distorts local magnetic field
• Therefore BOLD signals indicate oxygen consumed
  (implying neural activities) in the voxel of the brain
• 1mm Spatial resolution, several seconds temporal resolution