The Biological Approach Flashcards
What are twin studies?
- Identical twins share 100% of their genes,
- In theory, if the biological approach is correct, these twins should have similar behaviour and mental illness.
What are the three basic assumptions of the biological approach?
1) Human behaviour can be explained by looking at biological stuff such as hormones, genetics, evolution, and the nervous system,
2) In theory, if we can explain all behaviour using biological causes, unwanted behaviour could be modified or removed using biological treatments such as medication for mental illness,
3) Experimental research conducted using animals can inform us about human behaviour and biological influences; we share a lot fo biological similarities.
Gottesman (1991), method
- Carried out a meta-analysis of approximately 40 twin studies.
Gottesman (1991), results
- Was found that having an identical twin with schizophrenia gave you a 48% chance of developing the condition,
- Reduced to 17% in non-identical twins.
Gottesman (1991), conclusion
- Schizophrenia has a strong genetic base.
Gottesman (1991), evaluation
- Carried out on field studies; high ecological validity,
- Identical twins share 100% of their genes, might be expected that both twins would always suffer with the same conditions,
- only 48% chance; other factor must be involved,
- Identical twins tend to treated more similarly than non-identical twins; family environment might play a large role.
Heston (1966), method
- 47 adopted children whose biological mothers had schizophrenia were studied,
- Control group consisted of 50 adopted children whose biological mothers didn’t suffer from schizophrenia,
- The children were followed up as adults and were interviewed and given intelligence and personality tests.
Heston (1966), results
- Of the experimental group, 5 of the 47 became schizophrenic, compared to 0 in the control group,
- another 4 of the experimental group were classified as borderline schizophrenic by the raters.
Heston (1966), conclusion
- Study supports view that schizophrenia has a genetic basis.
Heston (1966), evaluation
- Interview data can be unreliable and affected by social desirability bias,
- Interviews = good way of getting data in a naturalistic way,
- Adopted children whose mothers didn’t suffer from any conditions might not have shown any symptoms yet; can’t be completely ruled out.
What are the 5 basic techniques used to scan the brain? what do each do?
1) PET scans, show which part of the brain are active during different tasks. By studying PET scans, can link certain areas of the brain to particular functions,
- Also show us where the brain is most active when we are thinking about certain things,
- Show average activity over a 60 second period,
2) CAT scans, detect damaged parts of the brain, tumours, and blood clots. Brain structure is shown, not function,
3) MRI scans, detect small tumours and provide detailed information about structure,
4) Functional MRI scans, provide structural and functional information,
5) SQUID magnetometry, produces accurate images of the brain activity by measuring the magnetic fields generated when neurons are activated,
- Outside sources of magnetism can affect measurements.
Maguire et al. (2000), method
- Natural experiment, MRI scans from 16 licensed male London taxi drivers compared with a control group who had never driven taxis,
- All of the participants were in good general, neurological and psychiatric health, and had an average age of 44,
- All of the taxi drivers had been working for at least 18 months.
Maguire et al. (2000), results
- Average size of the right posterior hippocampus was significantly larger in the taxi driver group compared to the control group,
- The increased sie was relative to the length of time the taxi driver had been working, the longer the larger.
Maguire et al. (2000), conclusion
- The hippocampus is responsible for storing a spatial representation of the environment,
- Seems that the specific navigational demands on the taxi drivers had resulted in physical change.
Maguire et al. (2000), evaluation
- Findings of the study could be used to help those with brain injuries as it shows that the size of structures within the brain are influenced through cognitive activity,
- means rehabilitation could be tailored to the specific needs of individuals and their injuries,
- Study has good level of control; easily replicable; increases reliability,
- Sample size = small, results can only be generalised to cabbies in London,
- Results can’t be generalised to other areas of the brain.
