Recent research from a team at the University Medical Centre in Freiburg, Germany led by Christoph Nissen, says that a lack of sleep or good quality sleep may have detrimental effect on the brain’s memory connections.
The 20 participants had their brains examined after a good night and restless night’s sleep. After a good nights sleep participants performed better during memory tests, however after a bad or restless nights sleep didn’t fare so well. After a restless nights sleep there were higher levels of theta brainwaves, which are associated with sleep and the subconscious, the theory is that being awake or after prolonged periods of poor quality sleep the brain reaches a saturation point and is unable to retain new information, this is easily restored however with a good night’s sleep.
Source: New Scientist