Animal Model
A living organism used in research to investigate human-like behaviours or processes. The goal is to generalize findings to human behaviour.
Biological Similarity
Many animal brain structures are similar to human brains, supporting the use of animals in studying psychological processes.
Animal research plays a critical role in understanding human behaviour by allowing controlled experiments on brain processes, hormones, genetics, and behaviour.
Although animals provide valuable insights, generalizing results to humans can be limited due to differences in brain function and psychology.
Advantages of Animal Research
- Controlled Environments: Animal studies enable researchers to control variables more strictly than in human studies.
- Generational Studies: Short lifespans of animals (e.g., mice) allow for intergenerational research.
- Genetic Manipulations: Techniques like gene "knockouts" are more feasible with animals.
- Accessibility: Animals are easier to handle and house in laboratories.
Disadvantages of Animal Research
- Generalizability Issues: Findings in animals may not always apply to humans.
- Ecological Validity: Laboratory conditions may alter animal behaviour, reducing applicability to natural or more realistic settings.
- Ethical Concerns: Studies involving invasive procedures can cause pain or distress to animals.
Ethical Considerations
- Three Rs Principle from the British Psychological Society:
- Replacement: Use animals only when no alternatives exist.
- Reduction: Minimize the number of animals used.
- Refinement: Ensure minimal distress during experiments.
- Justified Purpose: Research must benefit humans or other animals.
- Ethics Approval: All studies must be approved by an Ethics Committee.
- An example of establishing the ethics animal research is is Bateson's Cube, where 3 important aspects were outlined.
- degree of suffering of the animal
- quality of proposed study
- Overall, the British Psychological Society and the American Psychological Association are constantly updating their guidelines for animal research, so it is important for researchers to look into the most recent guidelines.
Key Animal Research Studies
Localization of Brain Function
Lashley (1929)
Aim: To identify specific brain areas responsible for memory in maze navigation.
Method: Rats were trained to navigate a maze; various cortical areas were then removed.
Results: Memory loss depended on the amount of cortex removed rather than the location, suggesting distributed brain function.
Insights: While invasive, the study contributed to understanding how memory is stored and distributed in the brain.
Ethical Considerations: Rats underwent harmful surgeries, emphasizing the need for strong ethical justification.
Neuroplasticity
Merzenich et al. (1984)
Aim: To investigate how the adult brain reorganizes after structural damage.
Method: Adult owl monkeys had fingers surgically amputated; cortical representations were measured using electrodes.
Results: Adjacent cortical areas compensated for the missing fingers, demonstrating neuroplasticity.
Insights: Provides a model for understanding human brain injury recovery.
Ethical Considerations: Invasive procedures caused irreversible harm, highlighting the importance of anesthesia and post-study care.
Epigenetics and Stress
Weaver et al. (2004)
Aim: To examine how maternal behaviour affects stress responses in rats through epigenetics.
Method: Rats were divided into high-licking and low-licking maternal groups; stress and brain samples were analyzed.
Results: High-licking mothers led to lower stress hormone levels in offspring, linked to changes in gene expression.
Insights: Suggests that early-life nurturing influences stress resilience in humans.
Ethical Considerations: Procedures involved genetic manipulation and stress induction, requiring careful ethical oversight.
Oxytocin and Social Memory
Ferguson et al. (2000)
Aim: To explore the role of oxytocin in social memory using genetically modified mice.
Method: Oxytocin gene knockout mice were compared with normal mice in recognizing familiar individuals.
Results: Knockout mice showed impaired social memory, emphasizing oxytocin’s role in social behaviour.
Insights: Provides insights into disorders like autism.
Ethical Considerations: Genetically altered mice were bred and studied, raising concerns about long-term welfare.
Critical Thinking
Are Animals Biologically Similar to Humans?
- Structural Similarities: Many animal brains share key structural components with humans, such as the amygdala, hippocampus, and cerebral cortex, supporting the use of animal models to study behavior and brain function.
- Functional Differences: Despite structural similarities, humans possess unique cognitive abilities, such as abstract thinking, language, and chunking, which are not fully replicated in animal models.
- These differences highlight the limitations in generalizing findings from animals to humans, especially in studies of complex cognitive processes or social behavior.
- Evolutionary Continuity: Shared evolutionary ancestry between humans and animals explains many similarities in brain structure and function, but it also necessitates caution when inferring human behavior from animals.
- While certain traits are conserved, others have evolved in response to unique environmental and social pressures, making a direct comparison challenging.
- Life Span: When considering research on rodents, they have a short life cycle compared to humans, so they can be observed at an accelerated rate.
