The Effect Of Sleep And Mood On Working Memory

Two latest studies evaluate how working memory – the memory used daily in decision making process is influenced by age, mood and sleeping conditions and also if these factors have an effect on memory together or individually.

Working memory is defined as the short-term memory used by an individual daily, going through situations, conversing and ability to take decisions.

When a person ages, this capability causes a decline, however there are other elements – mostly depressed mood and poor sleep – which can affect in the short and long run.

Researchers from four institutions – the University of California, Riverside, the University of California, Berkeley, and the University of Michigan, in Ann Arbor, and the National Institute of Neurological Disorders and Stroke, in Bethesda, MD – lately performed two studies to find out the elements that affect the working memory.

Different from the previous research, but, the new study observes how the factors impact the qualitative and quantitative approaches of working memory. These terms are linked particularly to the power and accuracy of working memory, and to see if memories using this faculty are stored in the brain.

The research team whose information is in the Journal of the International Neuropsychological Society also tried to comprehend if the elements impacting working memory individually or when they influenced each other, then performed on this mental component altogether.

“Other researchers have already linked each of these factors separately to overall working memory function, but our work looked at how these factors are associated with memory quality and quantity — the first time this has been done,” says lead researcher Weiwei Zhang, Ph.D. “All three factors are interrelated,” he further on adds, “For example, seniors are more likely to experience negative mood than younger adults. Poor sleep quality is also often associated with depressed mood.”

Effect on quality vs. quantity

Later, when the studies examined the factors differently, the researchers decided to discuss together. “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,” mentions Zhang.

This research consisted of two individual studies with information that was complementary. The investigators selected 110 college students which were told to give self-reported estimates relating to their regular sleep quality and their encounter with depressed mood. Further on, the research team then examined how the measures relate to the individuals chosen working memory performance.

The second study when on to the researchers expanding their observation to individuals of various ages, selecting 31 from the local community, having an age range of 21 and 77 years. The difference in ages gave exposure for the authors to dig deep in finding the relation between age and functioning of working memory.

The results were given, first indicating that an individual’s age is in opposite connection to qualitative working memory which explains that as we grow older, the less exact our working memory works. The researchers also got to know that those who go through depressed moods and poor sleep quality are related to worse quantitative working memory. This means, less sleeping hours and more negative mood encounters will mean less storage of short term memories.

Thus, the team came to a conclusion that sleep quality, mood and age all work together to cause decline in working memory. The statistical analysis advises that each component acts on working memory independently which means they are grouped to various underlying mechanisms.

“We are more confident now about how each one of these factors impacts working memory,” concludes Zhang, interpreting that a better know how of the components that affect memory can also have better medical meanings.