I was reading somewhere and found that there are various levels of stress depending on time. It said that when under stress for 30 mins, memory is not as efficient. So I have two questions here. A- Is this true and by how much is it lowered? B- Would a better form of testing have a test split into 30 min parts so that it is most fair?
I would suggest reading Electrophysiology/neuronal activity on page 7 and looking at page 30.