New York, Nov 25 (IANS): Do you find it difficult to remember lessons despite reading them over and over again because of the stress that examinations put? If yes, this new study may provide you a solution.

Researchers have found that learning by taking practice tests, a strategy known as retrieval practice, can protect memory against the negative effects of stress.

"Our results suggest that it is not necessarily a matter of how much or how long someone studies, but how they study," said corresponding author on the study Amy Smith from Tufts University in Massachusetts, US.

In experiments involving 120 student participants, individuals who learned a series of words and images by retrieval practice showed no impairment in memory after experiencing acute stress.

Participants who used study practice, the conventional method of re-reading material to memorise it, remembered fewer items overall, particularly after stress, showed the study published in the journal Science.

"Typically, people under stress are less effective at retrieving information from memory," said senior study author Ayanna Thomas, Associate Professor at Tufts University.

"We now show for the first time that the right learning strategy, in this case retrieval practice or taking practice tests, results in such strong memory representations that even under high levels of stress, subjects are still able to access their memories," Thomas added.

The research team asked participants to learn a set of 30 words and 30 images. These were introduced through a computer programme, which displayed one item at a time for a few seconds each.

To simulate note taking, participants were given 10 seconds to type a sentence using the item immediately after seeing it.

One group of participants then studied using retrieval practice, and took timed practice tests in which they freely recalled as many items as they could remember.

The other group used study practice. For these participants, items were re-displayed on the computer screen, one at a time, for a few seconds each. Participants were given multiple timed periods to study.

The researchers found that participants who learned through study practice remembered fewer words overall, and those who were stressed remembered even less.

"Even though previous research has shown that retrieval practice is one of the best learning strategies available, we were still surprised at how effective it was for individuals under stress. It was as if stress had no effect on their memory," Smith said.