Biological Psychology Flashcards
What are the assumptions of the biological approach
Human genes have evolved over millions of years to best adapt us to our environment.
Influence of the brain on behaviour.
Nervous system is seen to be responsible for human behaviour.
Genetic factors like genes determine our brain.
What is a concordance rate
The degree of similarity in characteristics beteeen pairs of people as a percentage. 48% concordance rate=0.48 correlation
What was the aim of Brendgens study?
To investigate if social aggression could be caused by genes or the environment.
See if social aggression and physical aggression have the same cause and if one type leads to another.
What was brendgens sample.
Opportunity sample of 234 twin pairs recruited from the Quebec New-born twin study and all born between November 1995 and July 1998
What was the procedure of Brendgens study for teachers.
Teacher ratings scored each statement like ‘to what extent does the child get into fights’ on a 3 point scale 0-2 taken from the preschool social behaviour scale and the direct and indirect aggression scale.
What was the procedure of Brendgens study for the students.
Peer ratings were done by each child circling pictures of their peers who matched the behaviour descriptions like ‘gets into fights’.
What were Brendgens findings.
Teachers foung boys more likely to be physically aggressive and girls more socially.
Peers found boys more physically and socially aggressive.
MZ correlation almost twice as high as same sex DZ correlation for physical and were similar for social.
Brendgens conclusion.
Strong genetic component to physical aggression but not social.
Children who are physically aggressive were also more likely to display social aggression due to an interaction of genes and environment.
What were the aims of Leves study.
Look at specific environmental issues related to parenting and family processes that interact with genetic factors on a child.
Look at adoptive parents and adopted child to see how and why genes and environment interactions occur.
What was the sample for Leves study.
360 sets of adoptive triads recruited by means of ‘opt out’ between 2003 and 2006 via adoption agencies
What was the procedure for leves study.
The adopted parents and biological parents took questionnaires and interviews testing intelligence, conduct disorder and questions on functioning. Children took part in frustration tasks and researchers observed the behaviour. Saliva was collected from the participants 6 times 30 mins pre going to sleep and post waking up. Nursery teachers took questionnaires about the kids.
Leves findings.
If the biological mother had emotional issues the child was more likely to show frustration.
If the adoptive mother had emotional issues the child was unlikely to shift their frustration.
Leves conclusion
Genetic factors in an adopted child can interact with environmental influences.
Explain action potential.
Nerve impulse travels down the dendrite of the pre synaptic neuron. If it builds up enough energy it will depolarise the synaptic knob. This means the vesicles will release neurotransmitters into the synapse. They will lock on to receptors and when enough are stimulated the message will pass on. Any spare neurotransmitters will be sucked up the reuptake pump and stored away.
What happens in action potential if the nerve impulse doesn’t build up enough energy
It will polarise the synaptic knob and the vesicles won’t be stimulated so the message won’t be sent.
Effect of recreational drugs on the transmission process in the CNS.
Block reuptake pumps e.g Heroin which means a build up of neurotransmitters in the synapse causing the post synaptic message to fire more frequently.
Mimic neurotransmitters e.g Alcohol so they fit into receptors meaning less receptors free for actual neurotransmitters so less firing of neurons.
What is the reward pathway.
The dopamine system that causes a pleasurable and rewarding feeling in the body that drugs hack into causing euphoria.
How do people become addicted to drugs
After the drug wears off The person has less dopamine than they should for their brain to function normally so causes dysphoria and motivated the person to take more drugs to make them happy. This repeated causes them to become dependent- leading to addiction
How do FMRI scans work to show a detailed Image of the brain structure.
A strong magnetic field is used which affects protons in the brain as they move when subject to a magnetic field. The fewer hydrogen atoms the darker the brain appears and the more the darker it appears on the image(denser).
How do FMRI scans work to show brain activity.
Blood flow in certain areas of the brain increase in active areas to keep up with demand for oxygen. When carrying oxygen haemoglobin repels the magnetic field and these changes create the image. The redder the more active the bluer the less active.
How do PET scans work to show brain activity and structure.
A tracer of harmless radioactive material is injected into the blood and bonds to glucose. P’pant completes a task and the area of brain which are most active will absorb the glucose. Glucose is broken down but the radioactive material remains. Measure areas with more gamma rays to see which part was most active. Red=active Blue=not active.
How do CAT scans show the structure of the brain.
Multiple X rays from different angles pass through the brain of the p’pant. Scanner scans for a few minutes getting multiple images. The paler the image the x rays haven’t passed through so is solid mass(denser)
What was the aim of Raines study(classic)
Whether there was brain differences between violent murderers who had pleaded NGRI compared to a married control group of non murderers using PET scans. Specifically brain dysfunction in their PFC.
What was the sample of Raines study.
41 p’pants 39 males 2 females who had pleaded NGRI but were charged with murder or manslaughter. 6 diagnosed with schizophrenia. This was exactly matched by a group of non murderers on a 1to1 basis.
What was the procedure of Raines study.
Murderers and p’pants were injected with a radioactive glucose tracer and then did a ‘continuous performance task’ - a visual task that increases activity in the frontal lobes of normal p’pants for 32 mins. Afterwards took a PET scan to see activity.
What were the findings of Raines study.
Murderers had less activity in PFC
Murderers had more activity on right side of the thalamus
Murderers had less activity on less side of amygdala
Murderers had more activity on right side of amygdala.
Less=left more= right 2+2
What is Raines conclusion
Violent behaviour is controlled by certain areas of the brain. Link between abnormal brain activity and a predisposition towards violence in this specific group.
What is in the limbic system and what does it do.
Hippocampus, amygdala and hypothalamus. Linked to our automatic systems which responds automatically to danger rather than in a planned way.
What is The role of the hypothalamus and how can it cause increased level of aggression.
Maintain homeostasis through regulation of hormones. It problems with more activity higher levels of testosterone are released.
