Researchers from the University of California assessed how certain factors—sleep, age and mood—can affect one's working memory capacity.
When someone is attempting to remember the name of a newly-made acquaintance, a phone number, a set of instructions, or trying to process something while reading, the individual is relying on what neuropsychologists refer to as the 'working memory'. It is a temporary workspace to store information until one no longer needs it. This allows automatic use of skills and knowledge rather than giving active thought to every single task. This is a fundamental faculty of the brain such as while driving a car one cannot be constantly thinking about a red light to stop the car. In other words, the working memory keeps a person 'mentally online'.
Consequently, the state of a person's working memory can affect the functioning of his or her most basic tasks like speaking and decision-making. However, as most people are already aware, with age, working memory can deteriorate.
Sleep and mood are also proven to have an effect on the working memory. With age, people are not as precise with their memory, thoughts, and speech as they used to be. Regarding this negative correlation between age and the working memory, scientists prefer to term it as an effect on the 'qualitative' aspect. On the other hand, poor sleep and depressed moods can reduce the likelihood of one remembering or the capability of one being able to process information or previous events. This, in contrast, has an effect on the 'quantitative' aspect.
While it has been proven that there are three main barriers—sleep, age and mood—to the effective functioning of one's mind, researchers also wanted to assess whether the factors work together and are interrelated in their impact on the working memory.
Reserchers led by Weiwei Zhang, an assistant professor of Psychology at the University carried out two studies. In the first, 110 college students were told to self-report about their sleep quality and mood. The team also discerned and studied the independent relationship of these measures to their estimated working memory capacity. In the second, 31 people between 21 and 77 years old were also examined. The team studied the relationship between age and working memory.
The study proved that all the three factors are interrelated. For example, seniors are more likely to experience negative mood than younger adults. Poor sleep quality is also often associated with depressed mood. The piecemeal approach used in previous investigations on these relationships—examining the relationship between one of these health-related factors and working memory—could open up the possibility that an observed effect may be influenced by other factors.
This research team is the first to make such a statistical study by investigating the isolated effects of sleep, age and mood on both working memory quantity and quality. This may instigate further research for treatments that could curb the effects of these barriers which limit working memory.
Zhang said, "We are more confident now about how each one of these factors impacts working memory. This could give us a better understanding of the underlying mechanism in age-related dementia. For the mind to work at its best, it is important that senior citizens ensure they have good sleep quality and be in a good mood."
