We know that sleep deprivation affects our brain function - but how much does it impact on our short and long-term memory?
One of the world's leading researchers in this area is Director of the Biological Basis of Behaviour Program at the University of Pennsylvania, Professor Ted Abel.
Humans spend a third of their lives sleeping - and Professor Abel says this could have lead to evolutionary disaster, given we are out of touch with our surroundings and unaware of potential dangers.
However, sleep of course, plays the key role of allowing our brain to recover and enables memories to be stored - which means messing with sleep can send our brains awry.
"It's really important for our neurocircuits, they can't just go on firing all the time, they need these periods of rest and recovery."
He says sleep is a very active process, not just the dreams that we wake up and remember, but the patterns of neuronal activity that happen during the night.
Professor Abel is visiting Otago University to speak today at a symposium on the brain mechanisms of memory.
He talked to Nine to Noon's Kathryn Ryan about how lack of sleep can affect your memory, the value of naps and sleeping after traumatic events.