Newcomer et al (1999)

• Newcomer et al (1999)

  
• This study can be used for...

  1. Hormones influence on behaviour

  (Relationship between stress levels and memory)
• Aim


  To investigate whether high levels of cortisol interfere with verbal declarative memory.
• Research Method


  Double blind. Lab experiment. The participants were matched for age and gender to one of three conditions.
• Participants


  18 - 30 year olds
• Procedure


  Participants were matched for age and gender to on of three conditions.

  Condition 1 - high level of cortisol: the participants were given a tablet containing 160 mg of cortisol on each day of the four day experiment - similar to cortisol levels in people experiencing a major stress event.

  Condition 2 - love level of cortisol: the participants were given a tablet containing 40 mg of cortisol per day - similar to cortisol levels in people experiencing a low level stressor.

  Condition 3 - placebo group. The participants in this condition were given placebo tablets - that is, a tablet that looked like the other tablets but with no active ingredient. All participants were asked to listen to and recall parts of a prose paragraph. This tested their verbal declarative memory over a period of four days.
• Findings


  The results indicated that high cortisol levels impaired performance in the memory task since the participants who received the highest level of cortisol also showed the worst performance in verbal declarative memory. However, the effect was not permanent. The performance of participants in the high cortisol condition returned to normal after they stopped taking the hormone tablet.
• Conclusions


  According to the researchers, these results demonstrate a clear line b/w levels of cortisol and remembering. It appears that high levels of cortisol interfered with the recall of the prose passage, whereas moderate levels of cortisol may have actually assisted in the recall of the passage. This makes sense as there are cortisol receptor sites in the hippocampus, which is responsible for the transfer of info from STM to LTM and vice versa.
• Implications


  High levels of stress effect memory
• Evaluation: Strength


  - Double blind

  - Clear variables

  - No invasive procedures
• Evaluation: Weaknesses


  - Deception

  - Stressful lab environment