Ever since childhood, kids are told that getting enough sleep at night is one of the most important things they can do to perform well in school.

But by high school, most students have disregarded this advice and stay up until the early morning doing homework.

While they may consider it necessary, research shows that staying up this late actually hurts more than it helps.

Studies have found that lack of sleep alters the way different parts of the brain behave and can lead to difficulty solving problems, making decisions, and forming new memories.

However, lack of sleep affects procedural memory more severely than it does declarative memory.

Procedural memory involves motor and perceptual skills, whereas declarative memory involves memorization of facts.

So if you put off studying for a vocabulary test in English until two in the morning, then it would be best to stay up late and cram, but if you have a test about World War II and its effects, then it would be best to get a good night’s sleep.

Scientists have found that there are three stages of creating and storing a memory: acquisition, in which the brain learns or experiences something new, consolidation, in which the memory becomes cemented in the brain, and recall, which is the ability to bring the memory to mind later.

While acquisition and recall occur while a person is conscious, sleep is necessary for consolidation to occur or else it will be much harder for the brain to recall or absorb new information.

It is during sleep that memories are strengthened and cemented in the brain, so without sleep, memories remain in the same raw form that they were in when they were first formed.

Researchers believe that during sleep, the brain sorts through recent memories and decides which memories to keep and which ones to disregard.

In addition to helping consolidate memories, sleep is also important for priming the brain for learning the next day.

During sleep, the brain goes through three main phases: light sleep, deep sleep, and rapid eye-movement (REM). These phases are divided into non-REM and REM.

It is during the non-REM phases of sleep that the brain is prepared for learning. Research shows that one’s ability to learn can drop by 40 percent without a good night’s sleep.

So the next time you have a history test that you put off studying for, don’t pull an all-nighter, because the information won’t stick without sleep, and it will just end up hurting your grade.