Animal Models & The Brain
Weiskrantz studied the function of which part of the brain?
The amygdala.
What is part of the brain does testosterone activate?
Subcortical regions (i.e. amygdala)
What is a "knockout mouse?"
A mouse that has had a specific gene "turned off" (which means it doesn't send signals from the cell.)
Animal studies might not be able to be applied to humans. This is an issue of ......bility?
Generalizability
True or False? You will definitely have an exam question about animal studies in your IB exam.
False
One, two or all three of the Paper 1, Section B questions will be based on the extensions.
For more info, check out this video... (from 6:38-> https://www.youtube.com/watch?v=0a3B5CCzPqM&t=)
Weiskrantz's study suggested that the amygdala has a function in what behaviour?
Emotion
Fear
(Either is an acceptable answer)
What were the two conditions in Sapolsky's study?
Cortisol pellet in the hippocampus
or,
Cholesterol pellet in the hippocampus
What were the two conditions in Mosienko et al.'s study?
TPH2 knockout mice were compared with normal control mice in the resident-intruder test.
What are two ethical considerations relevant to using animals in experimentation?
1) Justification
2) Animal welfare
How many essay questions will be based on the extensions in Paper 1?
One, two or all three.
Sapolsky's study shows that cortisol may affect the...
...hippocampus.
What were three findings from Albert et al.'s study?
- Castration reduced aggression in alpha males
- Replacing testosterone restored aggression
- Castrated alphas lost their alpha position
How did Van Oortmerssen and Bakker figure out which rats to selectively breed?
They measured their attack latency using the resident-intruder test.
What's it called when animals are humanely killed to put an end to their suffering?
Euthanizing
The ability to maintain and manipulate information in our conscious attention is called...
...working memory.
What were three ways the enriched cage differed from the deprived cage in Rosenzweig and Bennett's experiment?
Maze training
Other rats in the cage
Toys to play with
Sapolsky's study could provide insight into what possible finding in human studies?
Name one of those human studies.
A) People who have experienced chronic stress (e.g. people with PTSD or those growing up in poverty) have smaller hippocampi.
Luby et al. is one study.
Bremner et al. is another (pg. 227 of student's guide)
(Gilbertson's is not an example because this shows small hippocampis is genetic, not environmental).
What was the heritability of aggression found in Van Oortmerssen and Bakker's study?
0.3 (30%)
This means that 30% of the differences in aggression between the rats is attribution to genetics.
What are the two major strengths of using animal models to understand human behaviour?
1) Variables can be manipulated in a way that would be ethically or practically impossible to do on humans (e.g. brain lesioning)
2) Researchers can conduct tightly controlled experiments to draw cause-effect relationships (e.g. keeping living environments consistent in studies on the effects of brain damage).
Who is considered "the grandfather of psychology?"
(or the "father of psychology"?)
Wilhelm Wundt - he opened the Institute for Experimental Psychology at the University of Leipzig in Germany in 1879.
What were three specific findings from Rosenzweig and Bennett's experiments regarding synapses, receptors and % brain weight growth?
Synapses increased 20%
More acetylcholine receptors
Brain increased in weight 7-10%
What were the four conditions in Albert et al.'s study?
A. Castration
B. Castration followed by implanting of tubes with testosterone
C. Castration followed by implanting of empty tubes
D. A “sham” castration followed by implanting of empty tubes
What were three results in Mosienko et al.'s study?
100% of the TPH2 knockout mice attacked within five minutes of the test beginning compared to 22% of the control group.
The TPH2 knockout mice attacked six times faster than the control group.
The total number of attacks and the total time spent attacking was also seven times more than the control group of mice.
What are two reasons why findings in animal studies on aggression might not generalize to humans?
Culture: we have more sophisticated cultures that teach us values, that in turn influence our thinking and decision making in situations involving aggression.
Cognition: we have more sophisticated thought processes that allow us to inhibit our biological impulses.
Both of the above mean that a simple change in biology isn't guaranteed to change our behaviour as they can be moderators of the relationship between biology and behaviour.
What is the name of Mrs Napper's son?
George