Researchers from the University of Pennsylvania looked at how mice that were stopped from sleeping fared on a memory task.
The creatures were kept awake for varying amounts of time, to pinpoint just how little sleep had to be lost for their recall to be damaged, the Daily Mail reported.
"What we found is that when we deprived animals of sleep, that impaired storage of memories," researcher Ted Abel said.
"And most importantly we found out that a very short period of time would block memory consolidation, it was as short as three hours, which for mice is something like 20 per cent of their sleep over 24 hours," Abel said.
"In human terms, it would be the equivalent of dropping an eight-hour night of sleep to six hours, which is something we do all the time," Abel added.
It is thought that the replay of our memories while we are asleep is essential for their proper storage in the brain.
The study also suggested that there is a critical period after learning during in which memories are consolidated, meaning that loss of sleep at some points in time may be more damaging than at others.
Researchers added that any information lost due to lack of sleep is gone forever - meaning that sleeping longer the next night won't bring it back.
"The important thing about sleep is that is allows the brain to do things that it is far too busy to do during the day. Sleep is the quiet time that gives the brain time to do the filing," Neil Stanley, one of Britain's leading sleep experts, said.
The study was presented at the Society for Neuroscience's annual conference in New Orleans.