New York, May 11 (IANS): Memory slips with age, but getting a fair amount of sleep every night and having a cheerful mood each day may help you stay sharp even when you grow old, suggests new research.

Poor sleep quality and a depressed mood are linked to a reduced likelihood of remembering a previously experienced event, said the study published in the Journal of the International Neuropsychological Society.

The researchers found strong associations between working memory and three health-related factors such as sleep, age and depressed mood.

Working memory is the part of short-term memory that temporarily stores and manages information required for cognitive tasks such as learning, reasoning and comprehension.

Working memory is critically involved in many higher cognitive functions, including intelligence, creative problem-solving, language and action-planning. It plays a major role in how we process, use and remember information.

The study found that age is negatively related to the "qualitative" aspect of working memory -- that is, how strong or how accurate the memory is.

"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 Weiwei Zhang, Assistant Professor at the University of California, Riverside in the US.

"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", Zhang added.

The researchers performed two studies. In the first study, they sampled 110 college students for self-reported measures of sleep quality and depressed mood and their independent relationship to experimental measures of working memory.

In the second study, the researchers sampled 31 members of a community ranging in age from 21 to 77 years. In this study, the researchers investigated age and its relationship to working memory.

The researchers are 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.