Case Study: Phineas Gage
What: Got an iron pole up through the base of his head, through the front brain and exited the top.
So What: He was awake and showed no signs of brain damage. He only lost his left-eye vision. There was no paralysis or language problems. Though, his behavior changed drastically. He could not follow though with plans, became much more agitated and could not maintain social relationships due to impaired social abilities (pornographic language etc.).
Shows that: The balance between his intellectual and emotional abilities had been damaged. The study showed that the frontal lobe affects personal and social behavior.
Neurotransmitters in Learning and Memory,
Martinez and Kesner (1991)
Aim: To determine the role of Acetylcholine in memory.
Participants: Rats in three groups.
Method: Rats were trained to go through a maze in order to get food. When this was done, group one was injected with a acetylcholine blocker (scopolamine), group two with a neurotransmitter that blocks the “cleaning” chemical of the receptors (physostigmine), and the third one was kept a control group. Then the rats were let back into the maze.
Results: The group with scopolamine was slower at getting through the maze, the group with physostigmine was faster then both group one and the control group.
Conclusion: Acetylcholine plays an important role in memory.
Cause and effect.
It has been seen that acetylcholine producing cells are damaged in the early stages of Alzheimer; could be the reason for memory loss. Multiple groups, including a control.
Is it applicable to humans?
It is assumed memory works the same way in all animals.
Serotonin and Risky Male Behavior in Monkeys,
Higley et al. (1996)
Aim: To investigate the correlation between serotonin and risky behavior in male monkeys.
Participants: 49 male monkeys who migrated to new social groups.
Method: Field study. The monkeys’ serotonin levels were measured from spinal fluids, and the monkeys were divided into three groups depending on their serotonin levels (high, mid, and low). The monkeys’ behavior was observed and recorded, and their risk taking was based on the number of scars they had, their aggressiveness and death.
Results: 11/49 monkeys who died had low serotonin.
Conclusion: Serotonin may affect risk taking behavior in male monkeys.
High ecological validity.
Can we generalize and say it is true for humans too?
It may only be true for male monkeys.
Lacked lab control;
Serotonin might not have affected risk taking but slowed them down, made them more receptive to new diseases etc.
Serotonin and Female Risky Behavior in Monkeys,
Westergaard et al. (1999)
Aim: Is serotonin related in female risk taking in monkeys?
Method: Two different species of monkeys in captivity were studied. One specie was known for being friendly, one for being aggressive. Their serotonin levels were measured from spinal fluid. They then observed the aggressiveness of the monkeys’ behavior in groups of other female monkeys and the amount of wounds they acquired.
Result: The supposedly aggressive monkeys acted more aggressively and had lower serotonin levels than the friendly monkeys.
Conclusion: Serotonin affects aggressive behavior in females too.
High ecological validity.
Excluded death because of virus or sickness.
Does it apply to humans?
Testosterone and Criminal Males,
Aim: To investigate if testosterone can be related to the type of crime male criminals do.
Participants: 692 male prisoners.
Method: The saliva of the participants was analyzed for levels of testosterone, and compared to their criminal record.
Results: Prisoners with higher levels of testosterone had done more serious crimes such as rape and and homicide.
Conclusion: Testosterone levels might influence the type of crimes male criminals commit....
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