Biological approach - study book notes

What form do genes carry information in?

DNA

what does DNA contain?

instructions for characteristics eg eye colour , height

What is a genotype?

a person’s genetic makeup which is fixed at birth - can’t change

What is a phenotype ?

the expression of genes which leads to the observable characteristics of a person

what is the phenotype influenced by ?

• genetic inheritance

• interactions with environment

Geneticists using the approach, have found what about the similarities between physical and psychological characteristics ?

• both can be inherited

What group of people has been used in this research field the most?

twins

What are mono-zygotic twins?

identical twins that share 100% of the same DNA

What are di-zygotic twins?

non identical twins that share 50% of the same genes

What type of twins have a higher concordance rate of schizophrenia?

monozygotic twins

What did McGuffin 1996 find?

if one identical twin (MZ) has depression - there is 46% chance that the other twin does too

what does research into twins and behaviour/psychology show about psychological illnesses?

there is a genetic component to psychological illnesses like depression

What process did Darwin propose?

natural selection

What is natural selection?

characteristics that provide evolutionary advantage eg survival or advanced reproductive chances , are passed down generations whilst others don't mate and die out

What was Buss’s 1994 study of evolutionary research ?

a survey of heterosexual mate selection

• 37 countries studied

• men preferred good-looks , youth and chastity

• women preferred good financial prospects , industriousness and dependability

• traits and behaviours have evolved in males and females to promote better chances of passing on genes

What do biological psychologist believe determine our behaviour?

the structure of organs such as the brain - CNS , PNS , endocrine systems

What does the nervous system do ?

transmits messages through neurons

What examples of behaviour being due to neuronal activity are there?

• eating - feeling of hunger/satiation

• breathing

Different lobes of the brain relate to different functions - what does the occipital lobe perform ?

visual perception

What does the parietal lobe do ?

linked to processing sensory information

What case study demonstrated the effect of brain damage ?

Phineas Gage

What happened to Phineas Gage ?

• working on trainline - price of iron went through his skull

• survived but experienced a drastic change in personality such as increase in anger

What did Phineas Gage’s case study establish ?

evidence for the influence of brain structures on behaviours

What else other than neurons do biological psychologists believe influences behaviour ?

chemicals

What happens at the synapse?

• signals sent between neurons

What chemical sends signals to neurones ?

neurotransmitter

What is atypical behaviour associated with? Give 2 examples

an imbalances of neurotransmitters

• little serotonin linked with depression

• too much dopamine linked with schizophrenia

What neurotransmitter is responsible for regulating behaviour and impulse control?

serotonin

What other type of chemical influences behaviour ?

hormones

Where do hormones travel ?

through the blood - to target cells

What hormone did Carre 2006 say was linked with high aggression and defensiveness ?

testosterone

What does cognitive neuroscience study ?

the influence of brain structures on mental processes

What allowed an emergency of cognitive neuroscience ?

advances in brain imaging techniques such as MRI and PET scans

Where , When and who pioneered cognitive neuroscience ?

• MIT

• 1956

• term ‘cognitive neuroscience ‘ came from Miller and Gazzaniga in the 70s

How has cognitive neuroscience had a positive influence on mental illness?

• Kallis 2005

• studies involving the imaging of the amygdala and hippocampus now show how atypical functioning of these areas relate to depression

• brain imaging has high levels of validity

How has cognitive neuroscience contributed to the nature vs nurture debate ?

• brain imaging can show directly the effects that learning has on the brain

• behaviour can’t be explained by nature or nurture alone - it is a relative contribution of both

What is a limitation of the approach in terms of causation ?

• causation strongly implied in explanations that focus on brain structures

• eg - an explanation of schizophrenia suggests a lack of activity in the ventral striatum is linked o negative symptoms of avolition

• research only tells us that there i an association between brain structure sand behaviour - can’t differentiate the initiator and the outcome eg could be the behaviour causes the lower activity in the area

• biological explanations based on correlational research - doesn’t mean one event causes the other

What is another weakness of the approach ?

• view of human behaviour is deterministic (external to the will)

• assumptions like behaviour is as a result of evolution - to maximise chances of survival etc

• evolutionary claims provide explanation for gender differences like stress or aggression

• suggests humans have little control over actions - not influence by past experience , free will or the environment .

• problematic for those who don't follow typical or expected behaviours - overemphasises role of nature

• unfalsifiable so has no scientific validation

What is a strength of the approach ?

• uses objective methods of research

• MRIs , PET and EEGs

• provides accuracy and objective measures of internal processes that were previously inaccessible

• makes biological approach much less susceptible to misinterpretation or experimenter bias

What is a strength of the approach in terms of applications ?

• real world applications

• drug therapies for mental illnesses base Don research into neurotransmitters - antidepressants reduce serotonin

• understanding imbalances of neurochemical activity allows patients to have explanations that their illness is not their fault