Research Methods Flashcards
Correlational research
What is the purpose of correlational research
Measures a relationship between 2 co-variables and determines the strength of that relationship
Correlational research
What are the 2 types of correlation
Positive correlation = as 1 variable goes up, the other one also goes up
Negative correlation = as 1 variable goes up, the other goes down
Correlational research
Advantage of using this method
Method of looking at relationships between continuous variables and determening the significance of the relationship.
Correlational research
Weakness of this method
Cannot show cause and affect as there is no IV that has been altered.
Correlational research
What graph is used in correlation to show relationship
Scatter diagram - the data must be have a linear order
Brain scanning techniques
What are the 3 brain scanning techniques in the biological approach
CAT scan
PET scan
fMRI scan
Brain scanning techniques: CAT scan
How does a CAT scan work
X-rays and a computer are used to create detailed images of the inside of the brain.
Each image is a cross section of the persons brain, all slices are put together to make the final image
Brain scanning techniques: CAT scan
Advantages of CAT scan
Useful in revealing abnormal structures in the brain with high quality images.
Brain scanning techniques: CAT scan
Disadvanatges of CAT scan
Only give structural information and do not provide information about the activity of the brain
Brain scanning techniques: PET scan
How does it work
Measures metabolic activity in the brain using a glucose tracer that is injected in the participants which is detected by scanner.
Brain scanning techniques: PET scan
Advantages
Provide evidence about which location of the brain is responsible for what function
example: parts of the brain used in solving a puzzle can be identified
Brain scanning techniques: PET scan
Disadvantages
Sometimes the results are dificult to interpret as different brain activity can be shown in diffenrent people doing the same task
Brain scanning techniques: fMRI scan
How does it work
Uses radio waves to measure blood oxygen levels in the brain, areas of the brain most active have the highest levels of oxygen
Brain scanning techniques: fMRI scan
Advantages
fMRI scans do not use radiation and so it is completely safe method to study the brain
Brain scanning techniques: fMRI scan
Disadvantage
Only works if the brain stays perfectly still, this can cause problems in some people. Limits use of fMRI to some kind of research
Twin and Adoption studies
Describe twin studies
Twins are compared on a specific behaviour to see how similar they are
If behaviour is entirely genetic, concordance rates = 100%
If behaviour is more environmental than genetic, MZ twins would show higher concordance rates than DZ twins
Twin and Adoption studies
Advantages of twin studies
Enables researchers to investigate the influence of genes on a behaviour because it’s assumed MZ and DZ twins share sma environment
Information for twin studies are taken from twin registries. These hold data on thousands of twins and contain information about many variables
Twin and Adoption studies
Disadvanatges of twin studies
Twin studies may overestimate genetic influence. MZ twins usually have more similar environments than DZ twins as they are treated more similarly and spend more time with eachother
Twin and Adoption studies
Describe adoption studies
Genetic factors are implicated if child is more like biological parent (share gene) than adoptive parent (share environment).
Environmental factors are implicated if reverse is true.
Twin and Adoption studies
Advantages of adoption studies
Adoption studies have the advantage of removing the extraneous variable of the environment. If MZ twins are similar, it could be to do with the environment or genetics. In adoption studies it’s either the genetics or environment
Twin and Adoption studies
Disadvantages of adoption studies
Families who adopt tend to be better educated and have lower rates of mental illness. So any conclusion drawn on the affect of genes on these factors aren’t representative
Twin and Adoption studies
Example of twin study
Gottesman and Shields (1966) looked at 57 pairs of twins where atleast 1 had a diagnosis of schizophrenia
Twin and Adoption studies
Twin study: Gottesman and Shield (1966), how did they determine Zygosity
Looking at blood samples from both twins, so they could identify MZ and DZ twin pars
Twin and Adoption studies
Twin study: Gottesman and Shields (1966), sampling technique
Opportunity sampling
Twin and Adoption studies
Twin study: Gottesman and Shield (1966), what did they find
Where atleast 1 twin in MZ twins had been diagnosed with schizophrenia, the other twin was 42x more likely to develop schizophrenia
In same sex DZ twins, the other twin was 9x more likely
Twin and Adoption studies
Example of an adoption study
Tienari et al (1994) - Finnish Adoptive Family study also looking at schizophrenia
Twin and Adoption studies
Tienari et al (1994) findings
Adopted children whos biological mothers had schizophrenia had 9.4% risk of developing it
Corresponding figure for adopted away children of unaffected biological parents was 1.2%
Twin and Adoption studies
Adoption study: Tienari et al (1994), what did the findings show
Strongly suggests that genetic influneces have an important role in schizophrenia
