Research Methods Flashcards
Correlational Analysis
What is a correlation coefficient? (3)
Statistical measurement of strength of a linear relationship between variables -1 and +1
Perfect positive rel. = +1
Perfect negative rel. = -1
Correlational Analysis
Strengths (3)
Continuous covariables
Preliminary analysis
Can be repeated
Correlational Analysis
Weaknesses (4)
Can’t show cause and effect
Impossible to know direction of any casual rel.
Intervening variables
May lack reliability/ validity
Biological Research Methods
CAT scans- METHOD (2)
Pass X-ray through head from different angles w. multiple x-rays
Creates cross- sectional images of brain showing structure
Biological Research Methods
CAT scans- STRENGTHS (3)
Painless, non-invasive, accurate
Image bone, soft tissue, blood vessels
Shows structure
Biological Research Methods
CAT scans- WEAKNESSES (3)
No info about how brain works
Risk of radiation
Only used if intrusive surgery not needed
Biological Research Methods
PET scans- METHOD (4)
Radioactive material injected and as it travels around body, glucose accumulates
Where metabolism is active, radioactive material breaks down and releases neutron and proton
When n hits p, both destroyed and gamma rays released
Gamma rays picked up by scanner
Biological Research Methods
PET scan- STRENGTHS (3)
Reasonably non-invasive
Ethical, valid, reliable
Conditions e.g. epilepsy, strokes can be studied
Biological Research Methods
PET scans- WEAKNESSES (4)
Radioactive tracer is invasive
Scan is claustrophobic
Difficult to isolate different brain functions presicely
Expensive
Biological Research Methods
fMRI scan- Method (2)
Detects changes in blood oxygenation and flow that occurs in response to neural activity
When brain is active, consumes more oxygen so increases blood flow
Biological Research Methods
fMRI scans- STRENGTHS (4)
Non invasive, high spatial resolution
Records signal from all regions of brain
Standard and widely used
Produces compelling images of brain
Biological Research Methods
fMRI scan- WEAKNESSES
Debate over whether it measures what it claims to
Very noisy
Must be interpreted carefully
Can produce false positives
Biological Research Methods
MRI scan- METHOD (2)
Dye can be injected into body to help show body organs and relevant areas
Shows blood flow in a person using magnets
Biological Research Methods
MRI scan- STRENGTHS (3)
Can be noninvasive
Valid
Reliability
Biological Research Methods
MRI scans- WEAKNESSES (4)
Can be invasive
Needs interpretation
Can’t scan brain activity
Is noisy and claustrophobic
