A team of psychologists has found strong associations between working memory – a fundamental building block of a functioning mind – and three health-related factors: sleep, age, and depressed mood.
The team also reports that each of these factors is associated with different aspects of working memory.
Working memory is the small amount of information that can be held in mind and used in the execution of cognitive tasks, in contrast with long-term memory, the vast amount of information saved in one’s life. Working memory is one of the most widely-used terms in psychology.
It has often been connected or related to intelligence, information processing, executive function, comprehension, problem-solving, and learning, in people ranging from infancy to old age and in all sorts of animals.
This concept is so omnipresent in the field that it requires careful examination both historically and in terms of definition, to establish its key characteristics and boundaries.
By weaving together history, a little philosophy, and empirical work in psychology, in this opening section I hope to paint a clear picture of the concept of working memory.
In subsequent sections, implications of working memory for cognitive development, learning, and education will be discussed in turn, though for these broad areas it is only feasible to touch on certain examples.
Some researchers emphasize the possibility of training working memory to improve learning and education.
Organizing knowledge, for example, reduces one’s memory load because the parts don’t have to be held in mind independently.
Take, for example, the possibility of doing some scouting ahead so that you will know what this article is about, making your task of reading easier.
If you tried to read through the headings of this article, you might have trouble remembering them (placing them all in working memory) so as to anticipate how they fit together.
If you read Figure 1, though, it is an attempt to help you organize the information. If it helps you associate the ideas to one another to build a coherent framework, it should help you read by reducing the working-memory load you experience while reading. In doing so, you are building a rich structure to associate the headings with one another in long-term memory (e.g., Ericsson & Kintsch, 1995), which reduces the number of ideas that would have to be held independently in working memory in order to remember the organization.
Figure 1
Schematic diagram of the arguments in the present article.
Early History of Working Memory Research
In 1690, John Locke distinguished between contemplation, or holding an idea in mind, and memory, or the power to revive an idea after it has disappeared from the mind (Logie, 1996).
The holding in mind is limited to a few concepts at once and reflects what is now called working memory, as opposed to the possibly unlimited store of knowledge from a lifetime that is now called long-term memory.
Working memory can be defined as the small amount of information that can be held in an especially accessible state and used in cognitive tasks.
Philosophers have long been interested in the limits of what can be contemplated, as noted by a leading British economist and logician, William Stanley Jevons.
In an article in Science in 1871, he mused (p. 281): “It is well known that the mind is unable through the eye to estimate any large number of objects without counting them successively.
A small number, for instance three or four, it can certainly comprehend and count by an instantaneous and apparently single act of mental attention.” Then he devised a little experiment to test this hypothesis, on himself.
On each trial, he casually reached into a jar full of beans, threw several beans onto a table, and tried to estimate their number without counting.
After 1,027 trials, he made no errors for sets of 3 or 4 beans, with some small errors for sets of 5 beans, and with increasing magnitudes of error as a function of set size thereafter, up to 15 beans.
Despite the problematic nature of the method (in that the bean thrower was also the bean judge), the finding that normal adults typically can keep in mind only about 3 or 4 items has been replicated many times in modern research, using methods similar to Jevons (e.g., Mandler & Shebo, 1982) and using many other methods (Cowan, 2001).
The limited amount that could be held in mind at once played an important role in early experimental psychology, e.g., in the early experimental work of Hermann Ebbinghaus (1885/1913) and Wilhelm Wundt (1894/1998).
On the American front, William James (1890)wrote about a distinction between primary memory, the items in consciousness and the trailing edge of what is perceived in the world, and secondary memory, the items in storage but not currently in consciousness.
Recent investigators have considered multiple possible reasons why primary memory might be limited to just a few items at once, including biological accounts based on the need to avoid confusion between concurrent objects in memory, and evolutionary and teleological accounts based on ideas about what capacity might be ideal for learning and memory retrieval (Cowan, 2010; Sweller, 2011), but as yet the reason is unknown.
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 researchers, led by Weiwei Zhang, an assistant professor of psychology at the University of California, Riverside, found that age is negatively related to the “qualitative” aspect of working memory – that is, how strong or how accurate the memory is.
In other words, the older the person, the weaker and less precise the person’s memory.
In contrast, 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,” Zhang said.
“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 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.
Research results appear in the Journal of the International Neuropsychological Society.
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.
“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.”
More information: Weizhen Xie et al. Poor Sleep Quality and Compromised Visual Working Memory Capacity, Journal of the International Neuropsychological Society (2019). DOI: 10.1017/S1355617719000183
Provided by University of California – Riverside
