The Effects of Sleep Deprivation on Memory

Introduction

Sleep is a vital need for human and animal alike. Many of us do not give much thought to what happens when we do not sleep well or miss an entire night of sleep entirely. Often, we shrug it off and plan to make up for the missed sleep over the weekend. We do not consider the long -term consequences of this choice or realize how much sleep deprivation takes a toll. However, research indicates that there are several effects of sleep deprivation on the mind and body. So, the question is; does sleep deprivation effect memory? The answer is yes, it does. Sleep deprivation affects our memory and our ability to remember our declarative memories clearly. Sleep deprivation can affect several different types of memory including our semantic memory, emotional working memory, and our procedural memory. So, before you think about pulling another all -night study session, consider these facts first.

Sleep’s Role in Memory

When we sleep at night, our brain does many important things while we are unconscious. Sleep is vital for storing memories. When we are awake our brain spends much of its time encoding the information it is receiving from our various senses. When we sleep our brain begins to consolidate the information from the day and begin to store it in our memories. “Recent research highlights the importance of slow-wave sleep for memory consolidation.” This suggests that deep sleep is necessary for consolidation to occur because slow- wave sleep only occurs in stage 3 and 4 of the sleep cycle. “Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during slow wave sleep and transform representative memories for integration into long term memory.” Deep sleep is key to retaining new memories and ensuring that they become permanently stored. If you do not reach the deeper stages of sleep, then there is a good chance that the information your brain has received throughout the day will not be consolidated effectively or stored for long term memory.

Effects on Semantic Memory

One very important aspect of memory that is affected by sleep deprivation is our semantic memory, in particular it is very detrimental to adolescents. Adolescents’ semantic memory can be adversely affected by sleep deprivation. The studied is targeted at adolescents because they chronically do not get the recommended eight-hour amount of daily sleep. In the study conducted by the Centre of Cognitive Neuroscience, they tested whether adolescents’ abilities to retain information were affected by sleep deprivation. Their study involved a control group allowed to sleep for nine hours a night and a group on a five-hour restriction for five nights to test the effects. After the fourth night of sleep restriction, the sleep deprived group and control group were tasked with learning about various types of arthropods over a six-hour period. They were then tested thirty minutes after learning the information and then again three days later. The results of this study indicated a significant deficit in retention ability in the sleep deprived group. This study mentions that our understanding of the effects of sleep deprivation on memory are very limited still. Further research is needed to understand just how much our declarative memories are affected by inadequate sleep. This study illustrates the need for stressing the importance of sleep health, not only for adolescents but for adults as well. This study is one of three that has examined the effects of sleep restriction across more than one night. It could be possible that prolonged sleep deprivation can be extremely detrimental to semantic memory over a long period of time.

Effects on Emotional Working Memory

One interesting aspect of our memories that are affected by sleep deprivation include our emotional working memory. When a person does not get enough sleep, they often are more irritable than they would usually be and may have difficulty with simple tasks “There is neural evidence that supports an increase in emotional reactivity and a decrease in cognitive control over emotional reactions towards positive and negative stimuli.” The study conducted by Schwarz was interesting because it examined an effect of sleep deprivation not commonly studied, emotional working memory. The study had a control group who was well rested and a group of sleep deprived individuals who were given the N-back test on different images after having the emotional and sleepiness states evaluated. The results indicated that those who were sleep deprived were deficient in the accuracy of their working memories during the N-back test. Overall the results suggest that sleep deprivation has a detrimental effect on our working memory as well as our emotional control. The study does admit that one possible limitation is that the sleep control group was not under supervision, which could have affected the accuracy of the results.

Effects on Procedural Memory

When we do not sleep enough, it has a negative effect on our cognitive abilities the next day. You may find it more difficult to perform everyday tasks or find you are more prone to making mistakes. Procedural memory is responsible for your ability to walk, talk, and perform basic motor functions. This lack of sleep causes our attentional processes to function at less than optimal capacity, making said tasks more taxing. Chronic sleep deprivation impairs the memories ability to perform tasks accurately. (Roger Ratcliff, 2018). Not only does sleep deprivation affect our memory but it also affects how well we can perform our daily tasks. Michigan State University conducted a study to find out how sleep deprivation affects procedural memory. In the study they had a control group sleep at home normally and an experimental group stay overnight, awake for twenty-four hours. They then were given a specific task that required a sequence of to be followed in order to correctly complete the task. Once again, the results indicated that sleep deprivation negatively impacts the subject’s ability to perform accurately during the sequence task. “In some participants, sleep deprivation caused a breakdown in ability or perhaps the willingness, to perform the task as instructed, which they had managed to do the previous evening.” This demonstrates how much of an effect twenty-four hours of sleep deprivation can have on our basic abilities to function. Imagine if you are chronically sleep deprived, how difficult daily tasks would become as well as how difficult regulating emotions would be. Another study has suggested that acquiring sufficient sleep is necessary for storing memories as well as being able to accurately recall them when questioned. 

Conclusion

All these studies indicate that sleep deprivation does have a profound effect on memory. It does not affect one singular part of our memory but many aspects of it. Sleep deprivation alters our brains chemistry (Roger Ratcliff, 2018) and causes a huge detriment to our brains ability to function properly. Adolescents and adults alike suffer deficits to their ability to retain long term information. It negatively affects our working memory and causes emotional dysregulation, making normal every day tasks feel impossible. The most concerning effect of sleep deficit is the affects it can have on our procedural memory, which can have harmful consequences in our day to day lives. The evidence presented in these studies stresses the importance of getting adequate sleep every night, so that we may function at optimal capacity every day. Further research is required to fully understand all of the effects of sleep deprivation on the many memory processes as well as other cognitive functions of the brain.