How Sleeps Affects Memory
Millions of college students pull all-nighters in preparation for final exams, but according to sleep experts, they’d be better served by setting their revision aside and getting a solid night’s sleep. Both too little and too much sleep are tied to memory problems, which is why it is essential to spend between seven and eight hours in bed each night.
What the Research Says
Another study, conducted at Beth Israel Deaconess Medical Center and published in Neuroscience, found that subjects instructed on a sequence of finger motions resembling piano playing were better able to recall those movements after they spent the majority of the following twelve-hour period sleeping. Those who remained awake for twelve hours struggled to recall the finger motions.
How Does Sleep Impact Memory?
Researchers at Beth Israel Deaconess Medical Center believe that while sleeping the brain shifts memories to storage regions that are far more efficient. This makes later retrieval of those memories faster and more reliable. Sleep (or lack thereof) also impacts memories in these remarkable ways:
Calming the Stress Response
The stress response plays a significant role in sleep and memory. After a solid seven hours of sleep, the limbic system — which is responsible for stress and fear — is less active. As a result, those who get enough sleep experience less anxiety, which could otherwise interfere with memory retrieval.
Poor Blood Flow and Beta Amyloid Deposits
On a long-term basis, those who do not sleep enough may experience a myriad of problems that impact memory, including diabetes and high blood pressure. Both conditions impact the quality of blood flow and oxygen delivery to the brain, making it difficult for brain cells to perform at peak level. Furthermore, those deprived of sleep are believed to receive additional deposits of the protein beta amyloid, which is linked to dementia.
REM Sleep and Emotional Memories
People are far more likely to hang on to emotionally-charged memories, and rapid eye movement (REM) sleep may be to blame. A 2013 study published in Neurobiology of Learning and Memory found that subjects exposed to both neutral and negative images remembered the latter better after receiving several hours of REM sleep than those with a similar period of slow wave sleep. REM-rich periods of sleep are believed to accelerate consolidation of emotional memories, thereby producing a “hyperassociative” mode in which recently awakened individuals are better able to recall emotionally-charged memories, and more likely to engage in creative thinking.
The Importance of Sleep Quality
Amount of sleep is by no means the only factor that impacts memory; sleep quality is also essential. Subjects in the aforementioned Journal of the American Geriatrics Society study who slept nine hours or more performed worse on memory-related tasks because the quality of those nine hours was so poor. A high-quality mattress from the right mattress store can make all the difference, ensuring that each hour of sleep contributes to better memory consolidation.