A new study shows how three health-related factors — sleep, age, and depressed mood — may each contribute to a different aspect of working memory.
Working memory is the part of short-term memory that temporarily stores and manages information necessary for cognitive tasks such as learning, reasoning, and comprehension. It is critically involved in many higher cognitive functions, including intelligence, creative problem-solving, language, and action-planning and plays a major role in how we process, use, and remember information.
As we get older, our working memory tends to weaken and lose precision. In addition, poor sleep quality and depressed mood are linked to a reduced likelihood of remembering a previously experienced event — the “quantitative” aspect of working memory.
“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,” said researcher Dr. Weiwei Zhang, an assistant professor of psychology at the University of California, Riverside.
“All 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.”
The study is the first to statistically isolate the effects of the three factors on working memory quantity and quality. Although all three factors contribute to a common complaint about foggy memory, they seem to behave in different ways and may result from potentially independent mechanisms in the brain.
These findings could lead to future interventions and treatments to counteract the negative impacts of these factors on working memory.
The team conducted two experiments. In the first, they sampled 110 college students for self-reported measures of sleep quality and depressed mood and investigated how these factors independently affected their working memory.
In the second experiment, the researchers sampled 31 members of a community ranging in age from 21 to 77 years. In this instance, the researchers investigated age and its relationship to working memory.
“We are more confident now about how each one of these factors impacts working memory,” Zhang said. “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.”
The findings are published in the Journal of the International Neuropsychological Society.