Newcomer et al (1999)

Aim

• Explore impact of high cortisol levels on verbal declarative memory.

Procedure

• Participants from Washington University Medical Center.

• Exclusion criteria: pregnant, history of mental illness, head trauma, corticosteroid treatment.

• Double-blind experiment with three conditions:

  • Condition 1 (High cortisol): 160 mg cortisol/day.

  • Condition 2 (Low cortisol): 40 mg cortisol/day.

  • Condition 3 (Placebo): Control group.

• Participants listened to and recalled prose paragraphs over four days.

• Baseline test before cortisol administration.

• Follow-up tests conducted one day, four days, and six days after treatment cessation.

Results

• High cortisol group showed impaired verbal declarative memory compared to low cortisol and placebo groups.

• Impairment was temporary; memory performance returned to normal after stopping cortisol.

Conclusion

• High cortisol levels interfere with verbal declarative memory.

• Temporary effect observed, highlighting cortisol's impact on memory recall.

Strengths

• Experimental design establishes cause-and-effect relationship.

• Baseline testing controls for individual differences at start.

• Follow-up tests capture short-term and recovery effects of cortisol.

Limitations

• Limited control over extraneous variables (e.g., individual stressors).

• Use of prose paragraphs may limit generalizability to other memory tasks.

• Ethical considerations regarding cortisol's impact on participants' memory, albeit temporary and reversible.