Click to edit table header
3 Key Features:
Scanning is used in order to study the brain and discover which areas control which functions.
PET scan: colours, to show the flow of blood (simplified)
MRI scans: black and white, an x-ray of the skull (very similar to) – more detailed and precise.
PET: Positron Emission Tomography
It is used to look at functions and studies brain activity levels
It involves injecting a radioactive tracer in to the blood stream to see where most of the blood is flowing
Greater levels of brain activity appear in different colours
Participants are scanned twice (when inactive and active)
Uses are to look at schizophrenia and/or epilepsy
MRI: Magnetic Resonance Imaging
Used to look at structure
It studies the tissues, which looks at abnormalities and can measure the blood flow
It involves injecting a dye into the body to help show organs and relevant areas
A strong magnetic field is passed over the body to pick up radio waves from hydrogen atoms in water molecules to build up a detailed image of the brain
Uses are to compare ‘normal’ and ‘abnormal’ brains, ‘old’ and ‘young’, ‘men’ and ‘women’, and assessing damage following a stroke, tumours (abnormalities)
The central nervous system is made up of the brain and spinal cord
The brain within the skull and spinal cord is within the vertebrae
The biological approach focuses on the brain, as it controls our behaviour
A synapse is a gap between two neurons so that they never meet.
We have 100 billion neurons.
Describe and evaluate two studies relating to the Biological Approach. One must be Money J (1975) Ablatio penis: normal male infant sex-reassigned as a girl, and David Reimer’s subsequent testimony and one other.
The other study chosen was:
16 years’ consecutive admissions to a psychiatric hospital
Schizophrenia in twins Gottesman and Shields
A study researching schizophrenia using twins.
Concordance rate: shared characteristics, both twins having schizophrenia
Disconcordance: only one twin has schizophrenia.
Twins of the same sex, born between 1893 and 1945 and had survived to 15. 24 twin pairs.
The research method was a twin study, which incorporated the use of a range of methods to collect data including:
The researchers in the study looked at the concordance rate of MZ and DZ twins with schizophrenia.
Concordance was assessed in four ways:
A concordance rate for schizophrenia:
MZ twins between 35% and 58%
DZ twins: between 9% and 26%
Genes play an important role in development of schizophrenia
Environmental factors must be important
+ The results agree with those of previous studies, meaning it’s seen to be reliable.
+ Sampling issues are dealt with coherently, as there are many subcategories within the sample
- Although the results suggests a genetic link, it doesn’t explain the relationship further
- It only measures if schizophrenia occurs, doesn’t develop in to why schizophrenia occurs. The study contains more description rather than detail
A gene is a set of instructions and carries information.
Each individual has a genotype – which is his or her own genetic composition.
The phenotype is what the individual becomes after their genes interact with the environment they grow up in.
A gene consists of a long strand of DNA.
A chromosome is a double strand of DNA.
Some diseases are ‘sex triggered’ e.g. most colour-blind people are men
If one parent gives two copies of chromosome 21, the child will have Downs Syndrome.
Disease PKU: (brief)
After birth they are tested from their heels, PKU can lead to brain damage but if carefully controlled via their diet it can be diverted.
Hormones and Brain Lateralisation in gender development:
Hormones carry messages through the blood stream, affecting growth, development, mood and metabolism.
Most common illness in men: alcoholism
Most common illness in women: depression