Flashcards in Newcomer et al. 1999 Deck (18):
to investigate whether high levels of the stress hormone cortisol interfere with verbal declarative memory
participants and what were they given?
when were they excluded from the sample(5)?
participants were employees or students at the Washington University Medical Center.
All participants were given a clinical interview with a physician.
They were excluded from the sample if they were pregnant, had a history of mental illness, had suffered head trauma, or had suffered from an illness that had been treated with corticosteroids.
participants not routinely sleeping during the night hours were excluded to standardize circadian rhythms.
What were the 3 experimental conditions
Condition 1 – high level of cortisol: The participants in the high-level cortisol group were given a tablet containing 160 mg of cortisol on each day of the four-day experiment. This dose of cortisol produces blood levels similar to those seen in people experiencing a major stress event.
Condition 2 – low level of cortisol: The participants in the low level of cortisol group were given a tablet containing 40 mg of cortisol per day. This dose is similar to the amount of cortisol circulating in the bloodstream of people undergoing minor surgical procedures such as having stitches removed.
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. This was done in order to have a control group.
What were the participants assigned to?
matched-pair design for gender and age
what control was used?
What were participants asked to do and what did it test?
asked to listen to and recall parts of a prose paragraph.
tested their verbal declarative memory.
what is known about verbal declarative memory?
is often affected by long-term stress
and the researchers knew from previous studies that cortisol could be involved in memory impairment.
what do the results indicate?
clearly indicates an effect of stress-related hormones on recall of declarative memory.
How did the placebo group perform?
The placebo group’s paragraph recall performance improved over the course of the four days, most likely dudoe to a practice effect.
How did the cortisol group perform? and what does this indicate?
the cortisol treated participants did not show an overall improvement. showed the worst performance in verbal declarative memory.
The results indicated that high cortisol levels impaired performance in the memory task
was the effect permanent?
what do the results demonstrate?
According to the researchers, these results demonstrate a clear link between levels of cortisol and remembering.
what does cortisol appear to interfere with?
It appears that cortisol interferes with the transfer of short-term memory to long-term memory that takes place in the hippocampus.
Are there several cortisol receptor sites int he hippocampus?
there are several cortisol receptor sites on the hippocampus.
Could the researchers establish a cear cause and effect?
Since this study was experimental,
the researchers could establish a clear cause and effect relationship between the IV and the DV.
how long did the experiment last and what was this not able to eliminate?
The experiment ran over several days and the participants were not in the lab the whole time,
so the researchers did not have full control over extraneous variables.
Can you generalize the results?