Discuss the value of animal models in research to provide insight into human behavior. Flashcards
Discuss the value of animal models in research to provide insight into human behavior.
INTRO
Animal research has significantly contributed to our understanding of human behavior, particularly at the biological level of analysis. The physiological similarities shared among mammals make animals valuable subjects for studying psychological processes related to the human condition. Animal models, which involve the use of nonhuman animals to study behaviors and processes relevant to humans, have been instrumental in providing valuable insights into human behavior. However, it is important to acknowledge that animal models also have limitations that must be considered. This essay will explore the value of animal models in research by examining two different studies and discussing their contributions to understanding human behavior, while also addressing the limitations associated with using animal models.
Study 1: Rosenzweig, Bennet & Diamond
Aim: In this classic study, Rosenzweig, Bennet & Diamond wanted to see if changing the level of stimuli in the environment would result in physical changes in the brain. Neuroplasticity refers to the ability of the brain to change as a result of one’s experience. Before this research was done, scientists believed that the brain changed up until a critical period in childhood. After that, no changes in the brain were believed possible.
Procedure: he researchers established three conditions: control, impoverished, and enriched environments. Rats were randomly assigned to each condition. In the enriched environment, rats were placed in cages containing various stimulus objects, while in the impoverished environment, rats were individually housed without such enriching stimuli. The control condition involved rats housed together without specific environmental manipulations. All groups had access to food and water.
Findings: The study revealed significant differences between the enriched and impoverished conditions. Rats in the enriched environment exhibited a thicker cortex and higher brain weight compared to those in the impoverished environment. Furthermore, the enriched rats showed increased neuronal activity associated with the transmission of acetylcholine, a neurotransmitter critical for learning and memory.
Evaluation of study 1:
Strengths:
Highly controlled laboratory experiment: The study’s experimental design allowed for rigorous control over variables, ensuring that changes in the brain’s anatomy could be attributed to the enriched environment. This strengthens the validity of the study and increases confidence in the causal relationship between environmental stimulation and neuroplasticity.
Replication of results: The fact that the research findings have been replicated multiple times adds to the strength of the study. Replication enhances the reliability of the results and suggests that the observed effects are consistent and not simply due to chance or specific experimental conditions.
Limitations
Ambiguity regarding the specific variable responsible for the effects: While the study demonstrated that an enriched environment led to changes in the brain’s anatomy, it remains unclear whether it was the environment itself (the presence of toys) or the social interaction that drove these effects. This lack of clarity hinders a precise understanding of the mechanisms underlying neuroplasticity in response to environmental stimuli.
Limited generalizability to humans: Although the study provides valuable insights into the impact of environmental factors on neuroplasticity, generalizing the findings to humans requires caution. Animals and humans differ in various aspects, including cognitive abilities and social complexities. Therefore, additional research involving human participants is necessary to determine if similar effects occur in humans.
Ethical considerations: The study involved isolating rats and placing them in an impoverished environment, which may have caused stress and potentially harmed the animals. Additionally, the rats were euthanized at the end of the study for further analysis. These ethical concerns raise questions about the ethical trade-offs involved in conducting animal research and necessitate a careful evaluation of the benefits and potential harm inflicted on the animals.
Another use of animal models is the study of neurotransmitters. Rogers and Kenser wanted to derrmine the role of acetylcholine neurotransmitter.
Aim:
To investigate the role of acetylcholine in the formation of spatial memory.
Method:
Sample: 30 rats were acclimated to a Hebb-Williams maze.
Two conditions: Scopolamine injection and saline solution injection (placebo).
Injections administered directly into the hippocampus.
Encoding assessment: Comparison of errors made on the first five trials of Day 1 and the last five trials of Day 1.
Retrieval assessment: Comparison of errors made on the first five trials of Day 2 and the last five trials of Day 1.
Results:
The scopolamine group took longer and made more mistakes in learning the maze compared to the placebo group.
The scopolamine group had a higher average number of mistakes on the last five trials of Day 1.
However, there was no significant effect of scopolamine on the retrieval of already formed memories.
Acetylcholine appears to play a role in the consolidation of spatial memories.
The results of the study suggest that acetylcholine plays a significant role in the formation and consolidation of spatial memories. The administration of scopolamine, which blocks the acetylcholine receptor sites, resulted in longer learning times and more mistakes during the maze task, indicating impaired memory formation. However, scopolamine did not affect the retrieval of already formed memories. This implies that acetylcholine is specifically involved in the initial encoding and consolidation of spatial memories rather than their retrieval.
Evaluation of study 2
Evaluation of the study
Strengths:
Rigorously controlled experiment with a placebo condition to minimize confounding variables.
Establishes a cause-and-effect relationship regarding the role of acetylcholine in memory formation.
Potential implications for the development of treatments for dementia and Alzheimer’s disease.
Limitations:
Reductionist approach may overlook the complexity of different memory processes.
Findings based on animal models may not fully generalize to humans.
Possible limitations in fully capturing the intricacies of human memory consolidation.
How does study 2 Rogers is important for animal models
The study highlights the role of acetylcholine in the formation and consolidation of spatial memories, providing insights into the neural mechanisms of memory in humans.
Understanding the impact of acetylcholine on memory can aid in the development of interventions and treatments for memory-related disorders, such as Alzheimer’s disease.
The findings suggest that optimizing acetylcholine levels through educational practices or pharmacological approaches may enhance learning and memory retention in educational settings, benefiting human cognition and performance.
General Advantages of animal model research
Genetic and structural similarities: Animals share genetic and brain structure similarities with humans, allowing findings from animal studies to be applied to human behavior and understanding biological processes.
Ethical experimentation: Animal models enable experimentation that would be unethical in humans, such as brain lesioning or premature termination, providing valuable insights into specific physiological processes
Accelerated lifespan: Certain animals, like mice, have shorter lifespans, allowing researchers to study developmental processes in a shorter time frame.
Lifespan research: Animal models facilitate the study of behavior and physiological changes throughout an entire lifespan, providing insights into long-term effects and disease progression.
Experimental control: Animal models offer a high level of experimental control, enabling researchers to manipulate variables and isolate specific factors to investigate causal relationships.
Cost-effective and accessible: Animal models are generally more cost-effective and accessible, allowing for a wider range of research studies and experiments.
Disadvantages of animal research
Lack of exact similarity: Animals and humans are not identical, and findings from animal studies may not directly translate to humans. Replication of research findings in humans is necessary to ensure validity.
Biological-psychological differences: While animals may share biological similarities, there are psychological differences that limit the direct application of biomedical treatments for psychological conditions to humans. Further testing in larger animals and humans is often required.
Limited generalization: Animal models serve as a starting point for research, but the findings cannot always be directly generalized to humans. The pyramid of generalization requires additional studies in humans for reliable translation.
Strict laboratory environments: Animals used in research are often subjected to strictly controlled laboratory conditions, which may induce stress and affect their behavior, potentially impacting the generalizability of the results.
Genetic and environmental variations: Despite genetic similarities, human genetic codes differ from animal species. Additionally, the diverse environmental inputs between animals and humans pose confounding variables that limit generalization.
