Pack 1 Flashcards
(84 cards)
1
Q
What is the aim biological psychology ?
A
To explain behaviour through its physical causes, it seeks to use biology as a means of understanding human behaviour.
2
Q
What are the key assumptions of biological psychology ?
A
1) Our biological make up determines our behaviour
2) The central nervous system has a major influence on human behaviour
3) Biological and psychological development is assumed to be based upon the changes in the brain and our biology in general.
4) the process of evolution can explain the existence of many human behaviours. Behaviour has evolved to help our survival and pass on our genetics to our offspring
5) Genes influence behaviour.
6) there is behavioural continuity between species, therefore it makes sense to study animals and generalise to humans.
3
Q
Why is it difficult to research links between biology and behaviour ?
A
One reason is ethical constraints. due to ethical consideration biological psychologists can’t manipulate the independent variable of someones biological makeup to see how it impacts their behaviour.
Another reason is practical difficulties as psychologists are limited by technology as to how well we can observe the functioning of the body when a behaviour is taking place.
4
Q
What is the central nervous system ?
A
The central nervous system is made up of the brain and the spinal cord. The central nervous system is a infomation processing and control centre for the information we receive and responses we make to environmental stimuli.
a
5
Q
What is the brains role in the central nervous system ?
A
The brain draws together information from all over the body and sends information out to the body in response.
6
Q
What is the spinal cords role in the central nervous system ?
A
The spinal cord contains the nerves that carry messages between the brain and the body.
7
Q
What is the peripheral nervous system ?
A
The peripheral nervous system (PNS) beaches out from the spinal cord. it is a web of nerves carrying information to and from the CNS to the rest of the body.
8
Q
What is the process which allows the body respond to information it receives ?
A
The body receives information from our environment which is detected by our senses, the web of nerves which from the PNS receive this information and send it to the spinal cord which is part of the CNS which carries the message to the brain. The brain processes the information and send out a response to the spinal cord then to the PNS and required muscles to perform the response.
9
Q
What is the youngest part of the brain ?
A
The outer part of the brain known as the cerebrum or cortex is the youngest part of the brain in terms of evolution. It is made up of four lobes which are responsible for sophisticated cognitive functions like memory, vision and planning.
10
Q
What are the four lobes of the brain ?
A
1) Frontal
2) Parietal
3) Occipital
4) Temporal
11
Q
What is the function of the frontal lobe ?
A
The frontal lobe carries out higher mental processes such as decision making, planning and problem solving. The frontal lobe also inhibits inappropriate behaviour.
12
Q
What is the function of the parietal lobe ?
A
The parietal lobe is responsible for the reception and processing of sensory information.
13
Q
What is the function of the occipital lobe ?
A
The occipital lobe is responsible for processing visual information detected from our eyes without it we would be blind.
14
Q
What is the function of the temporal lobe ?
A
The temporal lobe is responsible for processing auditory information. Additionally the temporal lobe is linked to memory and language.
15
Q
What is the prefrontal cortex ?
A
The prefrontal cortex (PFC) is part of the frontal lobe and sits right behind the forehead. It is relatively late to fully develop and is fully functioning only in our twenties. The prefrontal cortex has several executive functions such as inhibiting inappropriate response, decision making and motivational behaviour.
16
Q
What are the two halves of the brain called ?
A
The brain is divided into two halves known as hemispheres.
17
Q
What are the functions related to the right hemisphere ?
A
The right hemisphere is concerned with creativity, intuition and the movement of the left had side of the body.
18
Q
What are the functions related to the left hemisphere ?
A
The left hemisphere is concerned with language, logic and the movement of the right had side of the body.
19
Q
What is contra-lateral control ?
A
Contra-lateral control is the term used to describe the fact that the left hand side of the brain controls the right hand side of the body and the right hand side of the brain controls the left hand side of the body.
20
Q
What is the corpus callosum ?
A
The two hemispheres of the brain are joined together by a massive bundle of neurone called the corpus callosum. The main function of the corpus callosum is to ensure the two hemispheres are able to communicate with each other.
21
Q
What are ventricles ?
A
The Ventricles are a linked system of cavities (spaces) that are filled with cerebrospinal fluid. They produce cerebrospinal fluid and ensure that it circulates around the brain. Cerebrospinal fluid baths and cushions the brain. it also ensures chemical stability of the brain and provides nutrients.
22
Q
What is the limbic system ?
A
The limbic system is a complex system of structures and nerve networks deep inside the brain. the limbic system has been linked to instincts and mood as well as controlling basic emotions such as fear, pleasure and anger and drives such as hunger, sex and care of offspring. The limbic system is one of the oldest parts of the brain in terms of evolution and has an important role in survival of an organism.
23
Q
What structures four the limbic system ?
A
1) Thalamus
2) Hippocampus
3) Amygdala
4) Hypothalamus
24
Q
What is the role of the Thalamus ?
A
The thalamus relays information from the five sense to the relevant parts of the cortex. the senses play an important role in our emotions as we react to stimuli around us including stimuli we perceive as threatening.
25
What is the role of the Amygdala ?
Emotions such as anger and fear are linked to the amygdala, for example if our sense perceive a threat this region is stimulate. The flight or fight response is also linked to this area.
26
What is the role of the Hippocampus ?
We know form case studies of brain damaged patients that the hippocampus plays a key role in memory formation for example converting from short term memory to long term memory. Therefore this area can also be linked to emotions as in evolutionary terms it would make sense to remember things that frighten us to ensure we avoid them in the future.
27
What is the role of the Hypothalamus ?
the hypothalamus regulates bodily functions via stimulating the release of hormones. This structure is also linked to the flight or fight response- this requires lots of energy so it involves the release of a hormone called adrenaline. adrenaline diverts oxygen to our muscles, speeds up heart rate and lowers pain thresholds. this will enable us to act aggressive and protect ourselves or run away.
28
What are neurons ?
A neuron is a specialised cell within the nervous system. The human brain is made up of 85 billion neurons.
29
What is the function of neurons ?
The functions of neurons is to communicate with 1000s of other cells at a time in huge networks (pathways). These networks adapt as we have new experiences. New networks are formed when we learn something new.
30
What components is the of the neuron ?
1) Nucleus
2) Cell body
3) Axon hillock
4) Dendrites
5) Node of Ranvier
6) Axon
7) Synaptic terminal
8) Myelin Sheath
9) Synapse
31
What is the function of the Axon of a neuron?
The axon is long branch from cell body that passes electrical impulses down to the end of the neuron to allow it to communicate with other neuron.
32
What is the function of Dendrites of a neuron ?
Dendrites are branches at the top end of a neuron that receive messages from other neurons in order to trigger an electrical impulse within the cell.
33
What is the function of the Cell Body of a neuron ?
The cell body is the main part of the cell where the nucleus sits, it connects the dendrites and the axon. The cell body contains materials that allow the cell to function, such as mitochondria which provide the cell with energy.
34
What is the function of the Nucleus of a neuron ?
The nucleus is the control centre of the cell. it houses the genetic material (DNA) for the neuron.
35
What is the function of the Axon Hillock of a neuron ?
The axon hillock is the area that connects the cell body to the the axon. The axon hillock is where electrical impulses are triggered from.
36
What is the function of the Myelin Sheath of a neuron ?
Myelin Sheath is a fatty deposit that provides electrical insulation for an axon which speeds up the rate of message transmission.
37
What is the function of Nodes of Ranvier of a neuron ?
Nodes of Ranvier are gaps between adjacent Myelin Sheaths these allow the electrical impulses to travel quickly through the axon.
38
What is the function of the Synapse of a neuron ?
The synapse is where the communication between one neuron and the next takes place. It has three main elements. The presynaptic neuron where the action potential starts, the postsynaptic neuron where the message travels to and the tiny space between the two which is known as the synaptic cleft, Neurotransmitters new realised into this gap and travel across it.
39
Whats the Role of Nuerons in human behaviour ?
Neurons play a fundamental role in human behaviour - they are the basis of all behaviour in that any time we think, feel or do something thousands of neurons are communicating with one another. Neurons make a chain with each other forming a sort of passage-way that allows messages to be sent from one part of the brain to another keeping the brain and the body working correctly. They form new connections or change existing connections every time we learn something new. The terminal of the presynaptic neuron from a connection with the receptor sites in the dendrites of the post synaptic neuron. The connections do not actually make contact; instead presynaptic neutron fires neurotransmitters across a the gap called a synapse.
40
What are the functions of Neurotransmitters ?
Neurotransmitters are chemical messengers that take information around the brain. They are released from the pre-synaptic neuron to the synaptic cleft after an action potential. They then stimulate the post-synaptic neuron and assist that that neuron to create its own action potential. Therefore the function of neurotransmitters is to allow neurons to communicate with one another. This communication between neuroses is important in behaviour as it allows our brains to think, feel and our bodies to do things. So everything we think or do can be reduced down to a specific combination of neurotransmitters sent around our brain. More than 100 of these chemicals messengers have been identified so far. It has also been possible to say certain neurotransmitters are likely to a range of behaviours.
41
What are the functions of the neurotransmitter Serotonin ?
Serotonin is a chemical messenger responsible for maintaining mood balance, contributing to wellbeing and happiness as well as lifting moods. Serotonin deficiency can lead to to depression. It is also responsible for inhibiting violent tendencies.
42
What are the functions of the neurotransmitter Dopamine ?
Dopamine provides the feeling of please and can boost peoples motivation, concentration and focus. Dopamine helps use to plan ahead and resist impulses to ensure we achieve our goals.
43
What are the functions of the neurotransmitter Noradrenaline ?
Noradrenaline is responsible for the bodies section to stressful situations. It can cause many changes in the body to allow for the flight or flight response to take place for example it can increase heart rate and breathing rate and lower metabolic processes.
44
Describe the step by step process of synaptic transmission ?
Step 1) An action potential moves down the the pre-synaptic neutron and causes vesicles filled with neurotransmitters to move close the the terminal membrane
Step 2) the vesicles fuse with the terminal membrane in a process called exocytosis. this causes the neurotransmitter to be erased into the synaptic cleft.
Step 3) The neurotransmitter binds with protein receptors in the post-synaptic neutron and causes the post synaptic neuron to increase the probability of the action potential. the neurotransmitters also bind with protein receptors on the pre-static neuron, activation of these auto receptors causes the presynaptic neuron to stop releasing the neurotransmitter.
Step 4) once the neurotransmitter is released into the synaptic cleft, it is removed by one of the three processes Diffusion, Degraded, Reuptake. Diffusion is when the neurotransmitters desired away from the synaptic cleft.
Degraded is when the the neurotransmitters are broken down and destroyed by enzymes in the synaptic cleft. Reuptake is when the presynaptic neuron absorbs the neurotransmitters. This is a very important part of the process- if there is a neurotransmitter left in the synaptic cleft it will keep stimulating the post synaptic neuron.
45
What are the strengths of the synaptic transmission as an explanation of how messages move around the brain ?
Much of the research on the processes of synaptic transmission is from research using brain scanning such as PET scans which provide objective, reliable evidence of brain functioning increasing scientific credibility of the the research. For example studies using PET scans have found differences in the synaptic receptor sites related to serotonin pathways in women with pre_menstrual dysphoric disorder (PMDD) suggesting that th correct synaptic transmission of serotonin is important in the brain. However PET scans do not give microscopic detail on synaptic transmission.
46
What are the weaknesses of the synaptic transmission as an explanation of how messages move around the brain ?
A disadvantage of the research on synaptic transmission is that much evidence in this felid has also come from studying animals. But to generalise from rats ad cat brains to human brains may not be valid as there are differences in animal and human brains such as size, sensory and cognitive ability.
In addition individual differences are not always taken into account as it is assumed everyone's brain uses systematic transmission in the same way. However, some people have different levels of certain neurotransmitters, so although the processes may be the same, the messages are influenced.
47
Define the recreational drugs ?
recreational drugs are those used in the absence of medical grounds, but are taken for personal enjoyment e.g. cocaine, caffeine, alcohol etc.
48
What are reward pathways of the brain ?
Many users of recreational drugs report experiences of intense of well-being known as euphoria. This is probably because these drugs target what are known as the 'reward pathways' in the brain. Reward pathways are circuits of structures and nerves that linked to the activities of specific neurotransmitters.
49
What are dopamine pathways ?
Dopamine pathways are activated by natural reading behaviours such as having sex or eating food. these behaviours stimulate the release of normal levels of dopamine in certain areas of the brain including the nucleus accumbens and the ventral tegmental area in the limbic system. messages are sent from the frontal cortex and we experience pleasurable feelings. These feelings are rewarding and make us more likely to repeat the behaviour. It is likely that reward systems in our Brian excise because they ave adaptive purpose- that is to encourage behaviours that enable us to survive.
50
How do recreational drugs effect the dopamine pathways ?
The majority of recreational drugs work by altering neurotransmission in the dopamine system. They share the ability to increase the levels of dopamine in the nucleus accumbens and the ventral tegmental area (VTA). This almost certainly accounts for the rewarding (pleasurable) effects of abused drugs as these structures, in the limbic system are associated with pleasurable experiences and are considered to be part of the reward systems in the brain. for example both heroin and cocaine target the dopamine system.
Most recreational drugs change the way that the neurotransmitter dopamine works in the communication of the brain - they alter the synapse between neurons that is enabled by dopamine. Drugs act to prolong and intensify the activity in the reward systems by ensuring that an increase in dopamine levels continually excites the post synaptic neurons within the system so they keep firing. there are a variety of ways in which drugs may effect synaptic transmission such as:
1) Increasing the amount of dopamine released into the synaptic cleft. e.g. heroine directly leads to excitation of the dopamine neurones in the ventral tegmental area so that more dopamine is related into the synapse.
2) Blocking the pre-synaptic transporters so that reuptake of the neurotransmitters is stopped and more remains I they synaptic cleft.
3) stopping the action of enzymes that would normally breakdown the neurotransmitter so more dopamine is left the synaptic cleft e.g. nicotine does this.
All result I more dopamine in the synaptic cleft leading to more activity in the post synaptic neurones.
51
How does cocaine impact the dopamine pathways ?
Cocaine is a highly addictive CNS stimulant extracted from the leaves of the coco plant. It disrupts the normal functioning of the dopamine reward pathways in the brain. Cocaine works by blocking the transporter receptor on the presynaptic dopamine neurons in the Ventral tegmental area (VTA) in the midbrain. as a result the pre-synaptic neurons so not re-uptake dopamine, therefore dopamine remains in the synaptic cleft for longer. This prolonged and intensifies the stimulation of the post synaptic neuron. Because the VTA activates another area of the brain that are associated with euphoric feeling, the nucleus accumbens, the user experiences euphoria.
52
How does drug addition occur ?
The effect of drugs are not limited to the reward pathways in the brain. Drugs can act in various regions of the brain. Drugs can act in various regions of the brain to exert their effects, but their ability to alter dopamine neurotransmission in the ventral tegmental area (VTA) and the nucleus accumbens is the initial and one of the most important factors driving continued drug use and addiction.
A we have seen cocaine, heroin etc. increase the amount of dopamine in the reward pathways of the brain. However the brain is a self regulating system and reacts to this over production of dopamine by reducing how much dopamine it naturally produces. This plasticity of the brain allows it to adapt to changes imposed on it by the use of drugs. But it also means the brain will no longer operate properly without the drug. So when the heroin or cocaine 'high' subsides the brain has less dopamine than it needs for normal functioning causing the feeling of dysphoria. This then leads to the motivation to self-administer such a drug to be overpowering as the person is driven to reduce the feeling of dysphoria and re-experience the euphoria if the drug induced high. this leads to repeated use of the drug which causes the brain to further down-regulate the production of dopamine. So a tolerance is built up for the drug - the natural baseline of dopamine in the brain has become so low that the user must take ever greater doses of the drug to get a 'high'. This causes the person to be physically dependent on the drug in order to avoid the experience of withdrawal. Overtime the person cannot do without the drugs and so they are addicted.
53
What are the strengths of the explanation of how drugs effect brain functioning and synaptic transmission ?
There is a great deal of well controlled, scientific evidence, often using animals to support conclusion erased on how drugs effect the brain. such research would not be possible to conduct on humans due to ethical constraints. E.g. Van Den Oever et al (2012) found changes in the synapse of the medial pre-frontal cortex in rats that were heir addicts.
Furthermore Brain scanning techniques have been used to provide important data on hoe the brain works whilst using drugs. for example Li et al used FMRI scanning to shoe that heroin had changed the functioning and connections in the brain of his human participants so that addictive thinking, craving and drug seeking behaviour became associated with rewards. The use of brain scans provides an objective and scientific approach to studying the effect of relational drugs on brain functioning and synaptic transmission giving the theory hight internal validity.
Additionally this explanation has many real world applications as the discovery of how drugs influence the brain and synaptic transmission in the dopamine system may enable scientist to develop medications to help addicts give up using drugs.
54
What are the weaknesses of the explanation of how drugs effect brain functioning and synaptic transmission ?
However the used of scanning techniques does have some limitations as these techniques are not sophisticated enough to show everything that happens I the brain when drugs have been taken, particularly the tiny changes in the synapses therefore they cannot provide a holistic explanation of all the changes in brain functioning and synaptic transmission.
Also much of the evidence on there of synaptic transmission in drug use comes from research with animals and so findings may not be straightforwardly generalised to humans. There are also serious ethical issues raised in such research.
55
What is the title of the contemporary study in Biological psychology and who conducted it ?
Van den Oever et al conducted the contemporary study in 2008 titled Prefrontal cortex AMPA receptors plasticity is crucial for cue-induced relapse to heroin seeking.
56
What do heroin uses experience why taking this drug ?
Heroin is used as a recreational drug for the euphoria it induces. Users report an sudden rush of pleasure that lasts for a minute or two while the heroin bathes the brain. soon the heroine is distributed by the bloodstream and becomes a more usable form of morphine. After the rush, the high lasts four to five hours and is caused by the morphine diffusing from the bloodstream into the brain. Addicts report a profound sense of satisfaction, mild dizziness and a sense of distancing or lack of interest to their surroundings. Heroin is highly addictive with a relapse rate for opiates being 91%. Tolerance for heroin develops quickly and increased doses are needed in order to achieve the same effects.
57
What are the Risks of taking heroin ?
Taking heroin includes a number of risks like:
1) Overdoses can lead to a coma or even death as it can cause respiratory failure.
2) there is also risk of death through inhaling vomit because heroin stops you from coughing properly and so vomit can realm in your airways and stop you from breathing.
3) injecting heroin can damage your veins and arteries, and has also been known to leas to gangrene.
4) Sharing needles, syringes and other equipment used to inject heroin lead to serious infections like hepatitis B, hepatitis C and HIV/AIDS.
58
Define relapse ?
Relapse, in relation to drug abuse, is resuming the use of drugs after a period of abstinence.
59
How are drug seeking behaviours related to relapse for heroin users ?
People initially take heroin to because of the euphoria experienced. However, it soon turns into an absolute compulsion to take the drug even when the euphoric feeling isn't as strong as it was initially. This compulsion to get the next hit is referred to drug seeking- behaviour. During periods of abstinence, people don't experience this compulsion for drug seeking- behaviour. However something in the environment can trigger this compulsion and lead a person to relapse and drug-seek and eventually take heroin again; entering the addiction cycle one more.
60
What is the cause of relapse Van Den Oever studies in his contemporary study ?
One key cause for relapse is when people experience stimuli their environment that are associated with when they used to take heroin. These stimuli are referred to as drug-associated cues.
61
How can rats be used to investigate drug addition ?
One way to investigate heroin addition in humans into allow rats to give themselves doses of heroin. This is achieved by using skinner like boxes where the rat can poke their nose through a hole to receive a dose of heroin automatically given to them. This trained behaviour is referred to as self-admisitration as the rats are administering the rugs themselves. The rats are trained so that when a light appears and a tone is heard, the rat will receive a dose of heroin if it pokes its nose through the hole. When the rat pokes its nose through the hole it breaks a laser bean and will automatically release some heroin into the catheter that has been surgically inserted into the rats bloodstream. In this sensation the light and auditory tone act as drug associated cues that are always present during heroin self-administarion., Thus allowing researchers to look at how these cues influence drug seeking behaviour and the biology of the brain.
62
What is the the aim of Van Den Oever's contemporary study ?
To investigate acute changes in the molecular composition and functioning of synapse on the medial prefrontal cortex upon re-exposure to heroin cues after long-term abstinence from self administration.
63
What was the sample of Van Den Oever's contemporary study ?
Numerous white male Wistar rats were used in this study. They were separated into two groups the experimental group and the control group
64
What was the procedure of Van Den Oever's contemporary study ?
Stage 1 self administration of Heroin.
the experimental group, were trained to self administer heroin every time an audio-visual cue was presented (lights flashed and the sound of a tine was played) they rats would poke their nose in a hole and heroin would be released into their surgically implanted catheters.
The control group were a separate group of rats who were trained to self administer a sucrose solution 9 a sweet drink) the same way as the experimental group. This was to ensure any neurobiological changes were due to heroin not just any reward. All the later stages were conducted on both the experimental and control group,
Stage 2 Abstinence and Extinction.
After becoming addicted to there heroin or sucrose solution, the rats were split into two:
Some rats were kept in a separate cage for 21 days with no access to heroin, thus providing a forced abstinence.
Other rats were put into the self-admisitration box for 21 days but did not receive any heroin when nose poking behaviour was displayed.
Step 3 Re-exposure to drug associated cues.
After 21 days of abstinence or extinction, these two groups were both split into two:
Half of the abstinence and half the extinction rats were re-exposed to the drug-associated cues for 60 minutes in the original self-administration boxes, they didn't receive any heroin.
The other half of the rats were placed in the self-administration boxes but were not exposed to any drug associated cues. they also didn't receive any heroin. This was a control in order to confirm that any synaptic changes were due to drug associated cues. The drug associated cues were recored as how many times they nose-poked attempting to get the heroin as a measure of relapse.
Stage 4 Analysis of composition and function of synapses in the medial prefrontal cortex.
Straight after stage 3 all rats 9including the control group) were decapitated and the brains were frozen and later analysed using mass spectrometry technique. This allowed detection of subtle changes in the crept protein in the synapses of the medial prefrontal cortex. Mass Spectrometry is an analytical technique to identify the amount of types of chemicals present in a microscopic sample
65
What was the first results and conclusion made from Van Den Oever's Contemporary study ?
Results: After a period of abstinence and extinction for heroin, rat that were exposed to the drug-associated cues demonstrated a significantly greater amount of drug seeking behaviour (nose-poking) compared to the rats thats also self-administered heroin but were not exposed to drug associated cues.
Conclusions: After a period of abstinence exposure to drug-associated cues can trigger a relapse neck into drug seeking behaviour. Therefore removing drug addicts need to avoid their drug associated cues.
66
What was the second results and conclusion made from Van Den Oever's Contemporary study ?
Results: the researchers used mass spectrometry to study the the post synaptic receptor called AMPA receptor in the medial prefrontal cortex which is a target for the neurotransmitter glutamate. After a period of abstinence?extinction from heroin, rats that were exposed to the drug-associated cues had significantly lower levels than normal of AMPA receptors in the medial prefrontal cortex. whereas, rats that were self-administering heroin but were not exposed to drug associated cues and rats that were trained to self administer sucrose had normal levels of AMPA receptors.
Conclusion: re-exposure to drug associated cues related to herion after a b period of abstinence or extinction is linked to a lower number of AMPA receptors in the medial prefrontal cortex of post synaptic neurones. The molecular composition and functioning of the synapse changed.
67
How do Neurones lose receptors ?
The brain has plasticity and can adapt to drug use in many ways. Neurons can reduce the number of receptors by a process called endocytosis. This is where the receptors are engulfed in a membrane and taken into the neutron. Endocytosis of receptors results in a reduced amount of activity for that neuron.
68
What was the follow up procedure to Van Den Oever's study and what did it find ?
The researchers used a new set of rats that went through a similar procedure as the initial study. Except both groups self-administered heroin and both were exposed to drug associated cues in the period of abstinence or extinction. However one grope was injected with a drug that prevented endocytosis in the medial prefrontal cortex.
They results showed that rats that had not been injected with the drug to prevent endocytosis showed significantly greater amount of drug seeking behaviour (relapse) compared to the rats that were given the drug to prevent endocytosis. The researchers say the lack of synaptic activity in the glutamate system after exposure to drug associated cues leads to loss of inhibitory control over drug seeking behaviour.
This concludes that the reduction in AMPA receptors of the post synaptic neurones in the medial prefrontal cortex, as a result of being r-exposed to drug associated cues, is causing relapse back to drug associated behaviour. Therefore, the synapses in the medial pre-frontal cortex could be a potential target for therapeutic drugs in order to tear peoples addition to heroin. This would help prevent reaps in the presence of drug associated cues.
69
How generalisable is Van Den Oever's contemporary study ?
One weakness of this study is the sample which consisted of white male whistar rats. This is a weakness because rats brains are very different to humans so the results with regards to drug addition in rats is less generalisable to drug addition in humans, the target population. for example the medial prefrontal cortex in rats is much smaller compared to humans, which could influence the way synapses change when re-exposed to the drug associated cues. however the crucial areas of the brain for drug addition are similar in rats and humans for example reward pathways between the midbrain and prefrontal cortex exist in humans and rats alike.
70
How reliable is Van Den Oever's contemporary study ?
One strength of Van Den Oever's contemporary study is the use of standardised procedures. this is strength because standardised procedures within the studies step by step methodology allows for the study to be replicated for each participant and in future research increasing the reliability. for example the standardised procedures used include the same environment of skinner like boxes being used for every rat.
71
How applicable is Van Den Oever's contemporary study ?
The study is deemed useful as it has practical applications for preventing drug addicts from relapse. This is a straight as heroin has a very high relapse rate of 91% with relapse causing serious negative consequences for both the individual and society. For example the follow up procedure to Van Den Never's study showed the use of drugs to prevent endocytosis prevent relapse in the rats when exposed to drug associated cues. this information could be used to develop therapeutic drugs to prevent relapse. Furthermore Van Den Oever's original study showed that those who were exposed to drug associated cues after 21 days of abstinence or extinction showed significantly grater amount of drug seeking behaviour than those who weren't exposed to these cues, therefore covering drug addicts should avoid their own drug associated cues to reduce chances of relapse.
72
How valid is Van Den Oever's contemporary study ?
A strength of this study was the strict controls for extraneous variables, this is important because it allows for isolation of the independent variable (exposure to drug associated cues after abstinence) and dependent variable (number of AMPA receptors on post synaptic neuron in the medial prefrontal cortex and the about of drug seeking behaviour displayed) to be isolated to ensure clear cause and effect links can be measured increasing the internal validity. For example the use of a control group of rats addicted to a sucrose solution allowed for researchers to be certain and changes in synaptic structure and functioning was due to being addicted to heroin not just an addiction.
Furthermore the study could be deemed to have high validity as the study used objective and scientific measurement of the dependent variable, meaning the results accurately measure what they intend to. As the used of Mass spectrometry to analyse the number of AMPA receptors on the post synaptic neuron in the medial prefrontal cortex. However the study could be seen to be reductionist as it only consider one biological aspect that could cause relapse, the number of AMPA receptors in the post synaptic neuron in the medial prefrontal cortex, therefore not providing a holistic explanation as to why relapse occurs as it doesn't consider other biological causes and any social or cognitive factors reducing the explanations validity.
Alternatively the study lacks ecological validity as it takes place in a laboratory study which is unrepresentative of real life events reducing the mandate realism of the experiment. This can be seen the process of the rats becoming addicted to heroin as this is strictly controlled and take place in a simple environment with no other variables than the drug associated cues affecting their behaviour however in real life drug users may take drugs in complex environments with many factors impacting this behaviour including other people.
73
How ethical is Van Den Never's contemporary study ?
Van Den Never's study prefrontal cortex AMPA receptors plasticity is crucial or cue-induced relapse to heroin -seeking behaviour doesn't follow ethical guidelines as participants are not protect from harm during any stage of the procedure in the study, this is a weakness of the study as it may damage the integrity of psychological research within society and may impact future research application for grants. For example rats were restricted to living in skinner like boxes whilst they were forced to become addicted to heroin which entered their blood stream through a catheter surgically implanted into their backs, they were then forced to undergo 21 days of abstinence before they were decapitated. However when conducting this research cost and befits must be considered as although the study isn't very ethical the implications form the research could prevent relapse into drug seeking behaviour.
74
What are hormones and how do hormones work ?
Hormones are chemical substances which act as messengers and are produced by specialised glads and transported through the bloodstream, to stimulate specific target cell or organs into action. They are secreted by glands which are collectively known as the endocrine system. The command centre of the endocrine system is located in the brain, the hypothalamus within the limbic system. The hypothalamus has direct control of the pituitary gland which secretes many different hormones as well as ensuring messages are sent through the nervous system. Once hormones have been secreted by a glad, they are passed through the bloodstream until they reach a particular destination in the body. Hormones work by binding with the receptor on the target cells specific to the hormone. The cell then responds according the its function. There are many different types of hormones and they operate all over the body regulating numerous physical processes such as growth, sexual development and metabolism. Unlike neurotransmitters, hormones operate all around the body so they usually take longer to work.
75
How do hormones impact human behaviour ?
In the biological psychology, human behaviour can be made up of three interacting processes,
1) Sensory input - by the senses
2) Intergation - by the central nervous system
3) Motor out put - by muscles
Hormones influence all three processes. Hormones do not cause immediate behaviour changes rather influence the systems of the body and brain in a gradual way. Hormones change the probability that a particular behaviour will happen in certain situations. They can also change the intensity of a behaviour. Hormones can change behaviours but behaviours can impact the levels f hormones produced for example hugging can stimulate the release of oxytocin, so the relationship is reciprocal.
The sensory input is impacted by hormones as they change the way we perceive our enviroment e.g. oxytocin is teased after child birth to reduce the mother perception of pain.
Hormones influence the central nervous system within the integration stage by making neurons more or less sensitive. This makes the neurons fire action potentials more or less frequently which influences behaviour,
Hormones effect the motor output as they impact hoe the way the body develops and grows.
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How does the role of hormones influence human development ?
Differences in hormone levels can affect development an behaviour throughout life. for example
1) In the womb
In the womb the development of the brain is influenced by reproductive hormones. The female hormones are oestrogen and progesterone the male hormones are androgens such as testosterone. These reproductive hormones impact on sex different causes female and male brains to develop slightly differently.
2) During early childhood.
When a child is exposed to stressful environments, they release a stress hormone caked cortisol, which results in high level of arousal. if a child experiences constantly high levels of cortisol, this can impact the development of their brain. For example, in cases of severe chronic abuse the regions of the brain involved in fear, anxiety and impulsive responses may overproduce neural connections whilst region dedicated ti reasoning, planning and behavioural control ,ay produce fewer neural connections.
3) In adulthood
At puberty, hormones influence changes in our bodied and mood. There is also evidence that the brain is still changing in later adulthood and is influenced by hormones. For example, hormonal imbalances in adulthood can result in brain changes that make a person more susceptible to depression, anxiety, alcoholism and even drug abuse.
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what are the strengths of hormones as an explanation of human behaviour ?
Much of the research linking hormones to human behaviour has high levels of scientific credibility. This is because standardised, objective measurements for hormone levels are possible using blood tests, urine tests and saliva swabs. This gives a high level of validity to the measurements used in the research on.
Furthermore their is extensive research liking hormones to human behaviour such as aggression. This makes it highly reliable as findings have been been replicating.
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What are weakness of hormones as an explanation of human behaviour ?
A weakness of research is that it is limited by ethical issues because protection of participants from harm is very important, researchers cannot carry out experiments where they manipulate hormone levels of participants' to see what happens to certain behaviours. This often means that correlational research is used to look for a link between hormones such as PMT and aggression. This means cause and effect links cannot be inferred and scientific credibility is reduced.
In addition there are practical problems in designing and implementing research in this field. In order to see how important hormones are in causing any human behaviour, numerous other variables would need to be controlled e.g. diet, exercise, physical environment etc.
Furthermore Reductionism is seen to be a problem within research into hormones role in human behaviour. To take complex human behaviours and isolate just hormones as the main cause for that behaviour mans research may be over simplifying highly complex biological mechanisms that involve not just one hormone but also neurotransmitters and the functioning of a number of brain structures. Researchers may also over look the importance of the influence of the environment and social interactions on human behaviour.
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Define Evolution ?
Evolution is the gradual development of different kinds of of living organisms from earlier forms throughout the history of the earth. This gradual development occurs through the process of the natural selection.
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Define Natural selection ?
Natural selection is a gradual process by which hereditable traits become more or less common in an environment. The organisms that have better traits adapted to survival in their environment are healthier, live longer and reproduce more frequently - survival of the fittest. They pass on the genes that made them fit to their offspring.
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Describe Evolution by natural selection ?
Individuals in a species show a wide range of variation caused by random genetic mutations. individuals with characteristic most well suited to the environment are more likely to survive and reproduce and pass on their genes- this is known as survival of the fittest. The characteristic that allow these individuals to be successful are inherited by their offspring. individuals that are poorly adapted to their environment are less likely to survive and reproduce. This means that their genes are less likely to be passed on. Give enough time, a species will gradually evolve the best characteristics to enable survival in their environment.
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Explain evolutionary psychology ?
Evolutionary psychology is a branch of biological psychology that looks at explaining human behaviour in terms of how any particular behaviour aided survival and successful reproduction. to allow the species to survive. The assumption is that, in the same way physical features have evolved e.g. having opposable thumbs has evolved, our brains has evolved to allow behaviours to be inherited by offspring that serve an adaptive function in the environment. Evolutionary psychologist speculate on what behaviours would have allowed our distant ancestors to survive in their potentially very hostile environments. They the try to find similar behaviours that are universally seen in modern humans. When they find such matches they argue that this means the behaviour is genetically determined.
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What are the strengths of using Evolution by natural selection to explain human behaviour ?
The assumptions that the theory of evolution makes are directly observable and are therefore testable (it is falsifiable) so it has very high scientific credibility.
Further to this, there is extensive supporting evidence for the theory of evolution coming from diverse sources for example
1) direct observation, this is how Charles Darwin collected hid evidence. One of the most famous examples is the differences seen in the beak shapes of Finches on the Galapagos Islands, who only lived a few miles apart but each species of finch evolved a beak to best suite the food amiable on their part of the island.
2) DNA analysis showing how all species share at least some genes.
3) Similarities in the embryos of different species.
4) Similarities in animals anatomy showing how structures may have adapted to the environmental requirements.
5) Fossil records that show physical evidence of development of species over time.
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What are the weaknesses of using Evolution by natural selection to explain human behaviour ?
However, the evidence for the assumption of evolutionary psychology that human behaviour has evolved is limited as there is no physical evidence go the behaviour itself, researchers must infer that behaviours evolved the same way physical featured did. Furthermore this explanation is reductionist and deterministic.
