Biological psychology Flashcards
Describe the role of the central nervous system in human behaviour.
- Composed of the brain and spinal cord
- Spinal cord- recieves information from the skin, joints and muscles
- Brain- processes and interprets the sensory information from the spinal cord and then sends it to the muscles
- Neurons- motor, inter and sensory that all pass messages using electrical impulses
Describe the parts of a neuron and how neurotransmitters have a role in human behaviour
- Dendrites- collects information from other cells and recieves messages in order to trigger an action potential
- Nucleus- site of aerobic respiration
- Axon Hillock- where the impulses are triggered from
- Myelin Sheath- layers of fatty deposit that provide an insulating layer and help to speed up the rate of message transmission
- Axon- transmits information away from the cell body towards other neurons
- Schwann’s cells- the cells that make up the long cell chain
- Terminal buttons- contains the vesicles that store neurotransmitters ready for the next stage of neurotransmission
- Axon terminals- transmitters
- Action potential- inside is negatively charged, when stimulated positive particles enter, some of these then get pushed out and the neurone goes back to negative
- Chemical transmission accross a synapse
Describe the effect of recreational drugs on the central nervous system.
Nicotine- a toxic, colourless liquid that is found in tobacco and is highly addictive. The short term effects of the drug include increased blood pressure, increased pulse and a release of dopamine. Nicotine imitates the action of acetylcholine and binds to the acetylcholine receptors. An action potential is triggered and it stimulates the release of dopamine. Once tolerance is built up, it is required to maintain normal levels of dopamine.
Alcohol- short term effects include aggression, slowed reflexes and thought processes and personality changes. Alcohol affects GABA which increases serotonin and dopamine. It lowers the frequenc of action potentials which causes slowed reactions. Withdrawal symptoms include agitation, fever and hallucinations.
Heroin- gets broken down in to morphine in the body which binds to receptors causing a reduction in neurological activity and releases dopamine. The effect of the drug include slowed breathing, drowsiness, dry mouth and vomiting. If a high level of tolerance is built up and then the drug is stopped, there could be serious side effects.
Evaluate the effect of drugs on the central nervous system in terms of generalisability.
Lots of the research is done on animals as it would be too unethical to complete on humans. To an extent, animals have a very similar brain structure to humans however humans are far more complex and capable of higher order thinking and reasoning. Therefore, the research can be seen to lack generalisability.
Evaluate the effect of drugs on the central nervous system in terms of reliability.
High in reliability as most research is carried out in the laboratory using highly scientific medical testing or scans. This means that high levels of control can be obtained and so the research will follow a standardised procedure. This means that the research is replicable and so supports findings.
Evaluate the effect of drugs on the central nervous system in terms of validity.
High level of validity due to the highly scientific and objective measures used. PET scans are a scientific and objective way to study the brain. This allows for high control over extraneous variables and so a cause and effect relationship can be established.
Evaluate the effect of drugs on the central nervous system in terms of supporting studies.
Support comes from withdrawral symptoms. They demonstrate the fact that the brain relies on the drugs once youve started to take it. Everytime the drug is taken, tolerance to it is built up and failing to take it results in the physical symptoms.
Further support can be seen by Li et al who looked at heroin addicts.
Describe the role of evolution and natural selection to explain human behaviour.
- Males produce thousands of sperm at relatively little physiological cost; as such, their best strategy is to mate with as many females as possible as this will result in the maximum number of offspring to perpetuate their genetic line
- Female investment in her offspring is greater than male investment partly as a result of the physical and emotional efforts of pregnancy. Therefore females might be more discriminatory in their choice of partner.
- The purpose of relationships and attraction is to reproduce and ensure our genes are passed on. Men and Women should seek partners who will produce healthy offspring who can be cared for. This explains why men prefer young women and women prefer wealthy men.
- Women can only bear a limited number of children and they can invest in each very heavily during pregnancy and the years after. Therefore this explains why women are picky about who they mate with.
- Females might be attracted to males with features that have survived as it makes it more likely that her offspring will survive.
Describe the role of evolution and natural selection to explain aggression.
- ‘Aggression is an innate response’ suggests that humans are aggressive because of the process of natural selection. It is suggesed that our ancestors passed on their aggressive traits to their offspring through their genes.
- Aggression is often associated with males. Males are motivated to acquire status as this allows them to have access to mates and resources for survival. Not engaging in conflict with other males may therefore be costly as they will not be able to reproduce.
- Females are generally seen as less aggressive since for them, the costs of such behaviour outweighs the benefits. It is more important for the mother to survive as she helps the offspring to survive
Describe how different brain areas can be an explanation for aggression
- The prefrontal cortex is involved in planning, control and organisation. It regulates the amygdala and so also regulates the aggressive thoughts and actions. It plays a part in assessing any potential threats and helps to determine a rational response.
- The amygdala has a functional role in memory, emotion and fear. Damage to the amygdala causes a reduction in automatic arousal which leads to reduced emotional responses and fearlessness. Strong links with the fight or flight response.
- The hypothalamus releases seratonin in order to communicate with the pituitory glands. It does this to stop too much testosterone from being released.
- The hippocampus is associated with aggression and plays a role in forming episodic memories. This suggests that whilst we are able to make and learn from our memoies ordinarily, if this part of the brain is damaged we still can make new memories but are no longer able to learn from them.
Evaluate the role of brain areas in aggression in terms of supporting research.
- Prefrontal cortex- Phineas Gage suffered from damage to this area. He suffered personality changes and went from being a calm and kind person to someone who was aggressive and short tempered. This demonstrates the importance of this area
- Amygdala- Raine et al found that murderers who pleaded not guilty by reason of insanity had lower glucose metabolism in the left side of the amygdala and higher metabolism in the right which deals with emmotions. This suggests a higher emotional response which is shown as aggression.
- A study by Alpars found that an individual who had a tumour growing on this part of the brain had a personality change to become aggressive
Evaluate the role of brain areas in aggression in terms of criticisms of the supporting research.
- Research in to brain structure and functioning happens in the laboratory. This is a highly objective research method and the use of scans is highly scientific. Therefore it is possible to gain control over extraneous variables and maintain a cause and effect relationship.
Evaluate the role of brain areas in aggression in terms of criticisms of the research method.
- Lots of the research is animal research as this allows us to overcome ethical and practical issues. It can be argued that the limbic system in animals functions similarly to humans. Therefore it can be argued to have some generalisability. On the other hand, humans are much more complex and have more complex brain structures, this may limit the generalisability and usefulness of the research.
Evaluate the role of brain areas in aggression in terms of other points.
- Can be seen to be reductionist as it fails to take in to consideration social factors that could impact upon aggression such as the specific situation that an individual finds themself in. Therefore the theory lacks validity.
Describe the role of the psychodynamic approach on aggression.
- id- the part of the subconscious that is concerned with things that ensures the survival of a person and with the things that gives us pleasure. These demands need to be satisfied by all instincts immediately and at all costs.
- superego- develops to help us to know what is right from wrong and what we should/shouldn’t do to help us to fit in to society. A weak superego may develop if you have low expectations of yourself as a child.
- ego- aims to satify the demands of the id without conflicting the superego.
- In aggression, the id is the most dominant and it makes selfish demands that are hard to please.
- A harsh superego can lead to strong feelings of guilt and obsession whenever the id attempts any kind of satisfaction. Dealing with the overiding feelings of guilt can lead to aggression. If the urges are overwhelming aggressive behaviour may be displaced on to others.
- Catharsis- an emotional release of unconscious conflict