Hormones

Question 1

Define hormones

Answer 1

Hormones are chemical messengers that effect behaviour

• secreted by glands in endocrine system into the bloodstream
• take longer to produce behavioural changes then neurotransmitters, but effects last longer
• can only produce reactions in specific target cells that have receptor sites for a hormone
• hormone either increases or decreases function of a cell

Question 2

Define adrenaline

Answer 2

Secreted by adrenal glands, responsible for arousal and fight or flight response, plays a role in emotional memory formation

Question 3

Define cortisol

Answer 3

Secreted by adrenal glands, regulates blood sugar levels, metabolism, reduces inflammation and assists in memory formation

Question 4

Cahill and Mcgaugh

Answer 4

Aim: to investigate the role of adrenaline and amygdala on emotional memory
- lab experiment

Procedure:

1. Participants were divided into 2 groups
2. First set of participants were shown a 12 slide boring story about a woman and her son visiting a hospital where they witnessed the staff in disaster preparation drill of a simulated victim
3. Second set of a participants were shown a 12 slide emotionally arousing story where the boy was in a car accident and both of his feet were severed, brought to the hospital where doctors reattached limbs
4. 2 weeks after participating, participants were called back to answer a set of multiple choice questions about the story in their condition
   
   • recognition task
5. In a follow up study, the above procedure was repeated, but the participants in the emotionally arousing story were injected with propranolol (beta blocker), interfering with the release of adrenaline

Results:
Participants who were shown the emotionally arousing story in the original study demonstrated better recall of specific detail. In the follow-up study, it was found the participants who also witnessed the traumatic story but were injected with propranolol did no better then the boring story group

Conclusions:
Therefore, it can be concluded that adrenaline and the activation of the amygdala plays an important role in emotional memory formation

Question 5

Meaney et al

Answer 5

Aim: Determining the effect of glucocorticoids (stress hormones) on learning and memory

• true lab experiment
• independent measures

Context:
how the brain is effected by glucocorticoids:
- secreted in stressful situations
- extensive exposure - destroy glucocorticoid receptors in hippocampus
- brain becomes less capable to process information, deficits in learning and memory

Procedure:

• Rats are randomly allocated to one of two conditions, being handled or not handled at birth, leading to higher extensive exposure to glucocorticoids in non handled rats
• newborn rats were either handled daily for 3 weeks by researchers or taken away for 15 minutes into a plastic container with paper towel, groomed by researchers
• control group were taken away from their mothers but not groomed by researchers
  - repeatedly exposed to stressful events
• Rats were placed in a shallow pool of milky water with a platform inside
• How long the rats took to find the platform and the distance they swam before was measured
• Repeated for a number of trials - measuring learning

Results
Non handled rats swam further and took longer to find the platform, taking a much more circuitious route then the groomed rats, and little improvement and learning across repeated trials

Conclusion
Therefore the relationship between glucocorticoid levels and learning and memory can be understood, where higher levels lead to lower level of learning and memory due to the degeneration of hippocampal cells from higher levels of calcium uptake and over-stimulation.

Evaluation

• minimal confounding variables
• significant applications to human research
• use of animal model to overcome ethical concerns in human study
• very repeatable, strengthening reliability
• controlled environment impacts the level of external validity greatly
• inability to generalise to humans