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Caption:A strong working memory can prevent the elderly people from becoming socially isolated and improve their overall happiness.

Unlocking our memory’s secrets

More focus on task preparation could help the elderly improve their short-term memory

A collaboration between Osaka University researcher Mariko Osaka and colleagues in Japan and the US has outlined how various brain networks function when working memory is activated.

Working memory is essential for briefly retaining the information needed to complete a task or activity, such as remembering what groceries we planned to buy. Osaka, an expert in working memory from the Graduate School of Human Sciences, describes its function as the “brain’s scratch pad”.

Specifically, Osaka’s team has shown that while certain regions of the brain, known as the default mode network, play a key role when preparing to perform tasks, these preparatory regions switch off as the task is executed1.

The team’s finding could have implications for improving the attention control of elderly people and strengthening their working memory capacity. “Without an effective working memory, elderly people can easily forget appointments and become isolated from their friends, which leads to depression,” says Osaka. “In a rapidly aging society, it is important for the elderly to maintain a healthy mind and to be happy.”

To study the brain regions involved in working memory, the researchers scanned the brains of study participants as they completed a series of dual tasks that required them to recall words while also doing simple addition problems. To understand the differences in brain function between preparation and execution of the tasks, participants were given time to prepare for the tasks.

The researchers found both the default mode network and the brain regions involved with directing working memory, known as the executive working memory network, were activated during task preparation. But as the task was being executed, activity of the working memory network increased while the default mode network turned off.

The results suggest that the default mode network deactivates to direct resources to task-relevant regions such as the working memory network. However, activation of both networks during task preparation also highlights the importance of this stage in successfully completing a task, Osaka says.

The preparation stage might involve strategic planning, including retaining information to recall at a later time by using prospective memory, and retrieving episodic memory of previously performed tasks.

The team also examined the relationship between brain activity and working memory capacity (measured by a memory span test involving recalling words in sentences).

They found some indication that greater working-memory span was associated with a higher level of activation in the medial prefrontal cortex region of the default mode network during task preparation.

Osaka says the results indicate people with a higher working-memory span might have more processing capacity. This opens up a possible field of endeavour for her research.

Longer preparation times may help regulate attention control, inhibition and monitoring of task performance, she says.

“I will take this work into my research around strengthening working memory capacity and better attention control in the elderly,” she says. “It will help elderly people maintain a healthy mind and a happy life.”

Related link

Graduate School of Human Sciences, Osaka University

img_p_20160302.jpg Professor Mariko Osaka
Graduate School of Human Sciences
Osaka University

1. Koshino, H., Minamoto, T., Yaoi, K., Osaka, M. & Osaka, N. Coactivation of the Default Mode Network regions and Working Memory, Scientific Reports 4, 5954 (2014).


working memory; default mode network; memory span; medial prefrontal cortex; posterior cingulate cortex

This research project was supported by the Osaka University International Joint Research Promotion Program, which aims to further enhance research quality and promote globalization at Osaka University through advanced research with overseas collaborators. The research described in this article is part of Professor Osaka’s project under the program, for which she is jointly working with the following researchers: Professor Hideya Koshino, California State University, San Bernardino, United States Professor Victor Pestoff, Ersta Sköndal University College, Sweden Associate Professor Daniela Jopp, University of Lausanne, Switzerland Professor Yayoi Saito, Graduate School of Human Science, Osaka University Professor Shinichi Sato, Graduate School of Human Science, Osaka University Associate Professor Yasuyuki Gondo, Graduate School of Human Science, Osaka University Associate Professor Nobu Ishiguro, Graduate School of Language and Culture, Osaka University

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