Socio Cultural Flashcards
Concerns about generalizing from animal studies
Martinez and Kesner
Rosenzweig, Bennet & Diamond (1972)
Meaney (1988)
what was the aim of Martinez and Kresner
the aim was to investigate the role of acetylcholine in memory
what was the procedure of Martinez and Kresner
rats were trained to go through a maze at the end of which they received food. Once the rats were able to do this, they injected one group of rats with an antagonist substance (scopolamine) that blocks ACh receptor sites, thus decreasing available ACh. They then injected the second group of rats with an agonist (physostigmine) that led to the increase of ACh and stopped the synapse returning to its ‘resting state’. A third group, the control group, were not given any injections. THerefore, the researchers either boosted or blocked levels of Ach in two groups of rats. The DV was memory and was measured by how fast the rats could run a maze.
what were the results of Martinez and kresner
The rats had their Ach levels boosted, were better at running the maze and found food more quickly.
The researchers concluded that the ACh played an important role in creating a memory of the maze.
what was the aim of Rosenzweig, Bennet & Diamond (1972)
The aim of the study was to investigate whether environmental factors such as a rich or an impoverished (empty) environment would affect the development of neurons in the cerebral cortex.
what was the procedure of Rosenzweig, Bennet & Diamond (1972)
Three male rats from a common litter were randomly allocated to one of three environments. In the control condition [CC] there were three rats in the cage. For the enriched condition [EC], the researchers placed 10 - 12 rats in a cage containing different stimulus objects to explore and play with. In the impoverished condition [IC], the researchers placed each rat in individual cages. The individual cages lacked toys and the maze which were in the enriched environment. All groups had free and adequate access to food and water.
The rats typically spent 30 to 60 days in their respective environments before they were euthanised in order for the researchers to study changes in the brain’s anatomy.
what were the results of Rosenzweig, Bennet & Diamond (1972)
The anatomy of the brain was different in the EC and the IC. There was an increased thickness and higher weight of the cortex in EC rats compared to that of IC rats. The researchers also noted that rats in the EC condition had developed significantly greater activity in the neurons in the cerebral cortex associated with transmission of acetylcholine, which is an important neurotransmitter for learning and memory.
what was the aim of Meaney (1988)
to find out what the effect of glucocorticoids is
on memory.
what was the procedure of Meaney (1988)
He and his team used an independent samples
design. One set of rats were taken away from their
mother and did not experience the normal
grooming that baby rats experienced. These rats
were labeled the “non-handled” rats. The second
set of rats were not taken away from their
mothers. These rats served as a control group.
Rats that were not handled secreted more glucocorticoids in response to stress than did handled rats. At later ages, non-handled rats also showed elevated basal glucocorticoid levels, with the result that there was a greater cumulative exposure to glucocorticoids in non-handled rats. Increased exposure to adrenal glucocorticoids can accelerate hippocampal neuron loss and cognitive impairments in aging. To test the effect, aged rats were put into a pool of milky water. In the pool was a platform. Meaney and his team tracked the route of the rats as they sought out the platform based on the rats’ memories of previous attempts to escape the water. The paths that he traced can be seen in the image below.
what were the results of Meany (1988)
You can see that the non-handled rats took a much more circuitous route to get to the platform. Hippocampal cell loss and pronounced spatial memory deficits emerged with age in the non handled rats, but were almost absent in the handled rats. He found that high levels of
glucocorticoids - stress hormones - in the early life
of a rat resulted in changes that affected the rats in
old age.
