Why stress can make you draw a blank
It's a common experience to go 'blank' in high stress situations such as job interviews or exams, now researchers from Germany and America have pinpointed why these particular kinds of memory lapses occur.
Reporting in Nature Neuroscience, researchers from the University of Zurich and the University of California have found that cortisol, a hormone which is produced in response to stress, impairs long term memory recall. Researchers already knew that cortisol affected memory, but this research looks specifically at which part of the memory process it interferes with.
The research, which shows that stress can affect how well we remember facts, also has implications for the reliability of court testimonials.
Subjects were given the rather stressful task of memorising 60 German nouns, and then asked to recall the words both unprompted, and also from a longer list of nouns. They were also tested on immediate recall, and recall 24 hours later.
During various parts of the memorising and recall process they were given cortisol tablets, to simulate stress.
The researchers found that subjects given cortisol immediately after the test remembered the list just as well as control subjects. However, they did not do as well when asked to recall the nouns 24 hours later. Cortisol given immediately before the task of committing the nouns to memory did not seem to affect how well they were remembered.
Interestingly, although people given cortisol did not recall the nouns as well 24 hours later, they did do just as well as control subjects with another group of words presented immediately after the recall test.
The researchers suggest that cortisol (stress) does not affect short term recall, or the ability to store information in the first place. But the work does suggest it affects longer term recall, and that it may interfere with situations where people must remember important information under stress.