Theory:
Animal model: The use of a non-human animal to animal to study a psychological or psychopathological; process that is similar to a human condition
Why are animals used:
* They are similar to us both genetically and physiologically - and hence are good for drug testing.
* Mices have 99% of the same DNA responsible for brain construction
* They breed faster than humans, so several generations can be observed over a shorter period
* Mice have an average life span of 2 years and reach sexual maturity within 3 weeks of birth
* They age faster, so the effects of childhood stress- for example- can be observed in ageing rats
* They can be used for procedures that would be considered unethical for humans
* Post-mortem, brain lesions and early termination for procedures
Brain and behaviour studies
1. Rosenzweig
2. Merzenich https://quizlet.com/fr/414693650/merzenich-et-al-1984-flash-cards/
Links:
1. Rozenwieg’s study showed how animal models and studies can be used to investigate human phenomena i.e. neuroplasticity. The study found that when the rats were in a deprived impoverished environment their brains were anatomically different from those in the enrichment environment. Those in the enrichment environment showed increased activity is certain areas of the brain compared to the rats in the impoverished condition. This has valuable applications to explain how an unhealthy environment may influence our brains and in turn our behaviour. It can be applied to explain behavioural differences of individuals in environments abundant in or lacking resources which cannot be ethically tested on humans. Therefore, animal studies were critical in investigating how environments can affect our brains and influence our behaviour.
2. Merzenich’s study showed us how our neural networks can be adapted and developed in order for us to cope with physical bodily handicaps. It gave us important insight as to how neuroplasticity allows us to cope and adjust our behaviour in response to physical obstacles. This study requires the use of monkey animals as not only their physiology but also their brain structures are similar to that of humans, which allows for the results to be generalizable to humans and their adaptive behaviour.Furthermore, the amputation of a finger on a human would be deemed morally unethical and therefore the use of animals allowed us to ethically research neuroplasticity and how it can translate into real-life applications such as rehabilitation.
Evaluation of the studies (if there is time)
Rosenzweig (additional to the previous eval)
1. The use of a standardised procedure and clinical methodology to study the rats’ brains means that this study has good reliability
2. The findings of this study have some applications to therapeutic settings for example with dementia patients(providing stimulation may help to offset or prevent further loss of brain function)
3. It is difficult to generalise the findings and rats’ brains are simplistic in nature compared to human brains, so some caution is necessary when applying the results to humans.
4. There are ethical concerns not only due to the fact that the animals were killed after the procedure, but the use of the impoverished’ deprived environment may have caused some deterioration in the rats who were exposed to such a negative environment.
Merzenich
1, the research effectively illustrates the concept of neuroplasticity by showing that extensive training in tactile discrimination tasks lead to significant reorganisation in the somatosensory cortex in owl monkeys . This supports the idea that the brian can adapt structurally and functionally in response to learning and experience, which is crucial for understanding how behaviours can shape brian functions.
2. The study provides a clear correlation between behavioural performance and cortical changes. As the monkey improved their retrieval skills without their limb , corresponding changes in their cortical maps were observed. This direct link between behaviour and brian structure enhances our understanding of how specific experiences can lead to functional adaptations in the brain
2. Findings have substantially implications for human rehabilitation and cognitive training. Furthermore consistent data has been seen through human studies.
However, while findings may be consistent, there are inherent limitations in generalizing the findings of this study to humans. Differences in brain structure and function between species may limit the application of results, necessitating caution when translating animal research to human contexts.
Hormones and pheromones
1. Romero et al ( oxytocin)
2. Berthold et al (1849) (https://quizlet.com/gb/597012711/berthold-1849-flash-cards/)
1. Romero et al used oxytocin administration on dogs to test how the hormone would influence displays of affection and bonding. By using animals, there were clearly coded behaviours of the species that allowed the researchers to be able to gather quantitative and qualitative data regarding their show of affection. This would have been difficult to test on humans, as the display of affectionate behaviour is variable across individuals. From this clearer conclusions were drawn, and these could be more accurately applied to human behaviour. Another point to consider is that humans like all other animals are sociable meaning that we tend to create stronger social bonds, making the findings even more applicable to humans and their behaviour.
2. Berthold’s experiment demonstrated the importance of testicular secretions (later identified as testosterone) in controlling male sexual characteristics and behaviour. This was done through castrations which would have been unethical. He discovered that reintroducing testicular tissue restored typical male behaviours and traits, suggesting that hormones play a crucial role in regulating behaviour. This hormone is dominant in human males, which allows for the findings to be generalized. These results have a strong application for boys undergoing puberty as often this hormone becomes more dominant, and therefore the findings of the study may be used to understand the behaviours displayed by them during this period of development.
Evaluation (if there is time)
Romero
The study analyzed the affiliation of dogs with their owners through specific behaviours that could be observed. This allowed the researchers to find the relationship between oxytocin and social bonding. The animals were found to stay closer to the owners and there was an increase in licking and pawing in the dogs. These behaviours were shown =in dogs which were given oxytocin, highlighting how oxytocin is related to social bonding and love/ affiliation towards others.
The study used dogs, which may mean that due to physiological and behavioural differences between dogs and humans, it may not apply to humans. This can be highlighted by behaviours, as many individuals have varying observable behaviours which may or may not indicate increased affiliation. Furthermore, we lack an understanding of the extent to which oxytocin affects our need to bond and be affectionate to others around us therefore oxytocin may not have the same effects on humans and may not be as significant in producing observable behaviours of social bonding in humans.
By the intranasal administration of oxytocin, they were able to mimic the natural secretion of oxytocin, this means that the findings more accurately showed how oxytocin release in real life would produce similar if not the same results of behaviours. This helps showcase the link between oxytocin the hormone and social bonding and affiliation and how hormones can influence our behaviour.
The study did not look at the short and long-term effects of oxytocin on the dogs. Hormones are known to have long-lasting effects on our body and behaviour so by having a short study it limits our understanding of whether or not the hormone oxytocin does in fact have long-lasting effects. From the experiment, we can only be sure that oxytocin has a positive short-term effect on social bonding and affiliation., which is in contrast with our understanding of hormones and their effects on our behaviours.
Berthold
low repeatability
low reliability - 1849
low generalisability- roosters
ethics-protection from harm
Genetics and behaviour
1. Weaver et al (2004)
2. Lassi and Tucci (2017)
https://www.savemyexams.com/dp/psychology/hl/17/revision-notes/the-biological-approach/genetics-and-behaviour---animals/two-key-studies-genetics-and-behaviour-animals/
1. Do this later
Evaluation (if there is time)
Weaver
1. Demonstrates a clear link between epigenetics and nurture, providing insight into gene-environment interactions across a lifespan i.e. that maternal responses to stress become ‘programmed’ within the offspring
2. The use of a standardised procedure in lab conditions means that the findings of the study could be tested via multiple replications
3. Results cannot explain why the epigenetic changes occurred: they could have been due to an array of variables which had nothing to do with LG-ABN: this decreases the internal validity of the study
4. The sample of rats used was taken from a laboratory facility so the experience of nurture and stress is likely to be different to animals in the wild who will have fart more threats and danger to contend with i.e it lack ecological validity and This weakens the theoretical generalizability to human behaviour
Lassi and Tucci
1. The results of this study agree with previous research (e.g guinea pigs seek proximity to their mother; maternal presence lowers stress in offspring) so it can be said to have concurrent validity
2. The findings have good application to parenting generally(i.e positive nurturing can be seen in a secure attachment style) which could be used in human settings
3. Measuring maternal mouse behaviour is often open to interpretation e.g the researchers cannot know with any real confidence that what they are observing is positive behaviour, as not being mice themselves, means that they can only infer the type of behaviour on display
4. The strange situation is an artificial procedure- even when applied to mice- and it may not reflect how mice behave in non-experimental attachment scenarios
Theory evaluation
Arguments against the use of animals:
* Similarities may be insufficient to generalise to human beings
* Procedures that are deemed unethical for humans may cause similar suffering in non-human animals
* Animals cannot communicate their stress, cannot withdraw from the experiment and cannot give consent. Some feel that this is human arrogance
Animal studies need to be justified through the value of the testing - what impact will it have for humans
Furthermore, the following conditions must be taken into account:
* The moral value of human vs animal testing
* Number of humans that will benefit from the study
* The effect on humans if the study is not conducted
* The number of animals suffering in the experiment
* The harm done to the animals
Due to these considerations laws and protection laws for animals have been put in place to reduce the suffering of the animals and provide a safe and comfortable environment for them to be tested in.
*Animal study evaluations are not necessary add the basic not applicable points