We learn and even make decisions through mental replay of past events, according to a new study. The research brings human knowledge closer to understanding how the memories stored in brain affect the way we act, says an article published by National Institutes of Health.

Researchers used rat models to study how learning occurs during wakeful periods and in particular the role of Sharp Wave Ripples or SWRs. These ripples are known to fire signals during sleep and are associated with learning process.

“It appears to be these ripple-like bursts in electrical activity in the hippocampus [part of brain that plays central role in memory storage and retrieval] that enable us to think about future possibilities based on past experiences and decide what to do,” Dr. Loren Frank of the University of California, lead author of the study said in a report by National Institutes of Health.

Earlier research has focused on the role of hippocampus and consolidation of memories during sleep or rest.

To find out the effect of SWRs, the researchers conducted experiments on rats that either suppressed these SWRs completely or delayed them. During the study period, the rats were made to run in a maze that had a reward at the end. To reach the reward, the rats had to be able to remember which route to take in the maze.

The researchers suppressed SWR in some rats using electrodes that detect SWR and interrupt them. Thus the researchers were able to stop the “memory flashes”.

Some rats weren’t fitted with these electrodes and they acted as a control group.

After the study, they found that the rats with suppressed or delayed SWRs did badly in finding the reward whereas rats without the electrodes reached the right end almost always.

Most research in the field of learning describes sleep as an important factor. Taking breaks during tasks gives better results says a study that was published in 2010 in the journal Neuron.

What if people are unable to check their stack of memory cards to make an immediate decision? Like older people who may lack the experience but have to perform a task/give out an answer quickly? Experts say that people must not give in to impulse and take time to think and ask for more information. Sometimes even preparing oneself for future events can help make quick decisions. Like preparing answers to expected questions during the interview.

The study is published in the journal Science.