Sleeping after processing new material helps retain information.
Studying the night before an exam might not be such a bad idea after all. In fact, going to sleep shortly after learning new information is most beneficial for recall. According to the Big Sleep Survey, a huge number of Australians are walking around feeling tired, with over 50 per cent of participants saying that they feel tired at least a few days a week. So what does this mean for our memory retention?
There are different forms of memories — declarative memory refers to the ability to consciously remember facts and events, and can be broken down into episodic memory (memory for events) and semantic memory (memory for facts about the world). Jessica Payne, a psychologist at the University of Notre Dame in Sydney, and colleagues studied 207 students who attained six hours of sleep per night to determine the effect of sleep on these different memories.
Students were randomly assigned to study declarative, semantically related or unrelated word pairs at 9 a.m. or 9 p.m., and returned for testing 30 minutes, 12 hours or 24 hours later. After 12 hours, memory overall was found to be superior following a night of sleep compared to a day of wakefulness. At the 24-hour mark — with all subjects having received both a full night of sleep and a full day of wakefulness — students’ memories were superior when sleep occurred shortly after learning, rather than following a full day of wakefulness.
“Our study confirms that sleeping directly after learning something new is beneficial for memory.” Payne said.
Researchers suggest that sleep helps learning and memory in two distinct ways. First, a sleep-deprived person cannot focus attention optimally and therefore cannot learn efficiently. Second, sleep itself has a role in the consolidation of memory, which is essential for learning new information.
Although the exact mechanisms are not known, learning and memory are often described in terms of three functions: acquisition, consolidation and recall. Acquisition refers to the introduction of new information into the brain, consolidation represents the processes by which a memory becomes stable, and finally, recall refers to the ability to access the information — whether consciously or unconsciously — after it has been stored.
Each of these steps is necessary for proper memory function. Acquisition and recall occur only during wakefulness, but researchers suggest that memory consolidation takes place during sleep through the strengthening of the neural connections that form our memories.
“This means that it would be a good thing to rehearse any information you need to remember just prior to going to bed. In some sense, you may be ‘telling’ the sleeping brain what to consolidate,” Payne said.
Getting enough sleep is still vital in retaining information. In fact, seventeen hours of sustained wakefulness leads to a decrease in performance equivalent to a blood alcohol level of 0.05 per cent, so there’s no use in planning a 24-hour study bender the night before a big exam.
Source: Science Daily