Human working memory is based on dynamic interaction networks in the brain

A study of 80 pairs of middle-income Canadian mothers and their year-old babies has revealed that children of mothers who answered their children's requests for help quickly and accurately; talked about their children's preferences, thoughts, and memories during play; and encouraged successful strategies to help solve difficult problems, performed better at a year and a half and 2 years on tasks that call for executive skills, compared to children whose mothers didn't use these techniques.

Using a large data set of 241 brain-lesion patients, researchers have mapped the location of each patient's lesion and correlated that with each patient's IQ score to produce a map of the brain regions that influence intelligence. Consistent with other recent findings, and with the theory that general intelligence depends on the brain's ability to integrate several different kinds of processing, they found general intelligence was determined by a distributed network in the frontal and parietal cortex, critically including white matter association tracts and frontopolar cortex.

Mindfulness Training had a positive effect on both working memory capacity and mood in a group of Marine reservists during the high-stress pre-deployment interval. While those who weren’t given the 8-week MT program, as well as those who spent little time engaging in mindfulness exercises, showed greater negative mood and decreased working memory capacity over the eight weeks, those who recorded high practice time showed increased capacity and decreased negative mood. A civilian control group showed no change in working memory capacity over the period.

A study involving over 1000 older men and women (60-75) with type-2 diabetes has found that those with higher levels of the stress hormone cortisol in their blood are more likely to have experienced cognitive decline. Higher fasting cortisol levels were associated with greater estimated cognitive decline in general intelligence, working memory and processing speed. This was independent of mood, education, metabolic variables and cardiovascular disease. Strategies aimed at lowering stress levels may be helpful for older diabetics.

Consistent with studies showing that gender stereotypes can worsen math performance in females, a year-long study involving 17 first- and second-grade teachers and their 52 boy and 65 girl students has found that boys' math performance was not related to their (female) teacher's math anxiety while girls' math achievement was. Early elementary school teachers in the United States are almost exclusively female. Math achievement was unrelated to teacher math anxiety in both boys and girls at the beginning of the school year.

‘Working memory’ is thought to consist of three components: one concerned with auditory-verbal processing, one with visual-spatial processing, and a central executive that controls both. It has been hypothesized that the relationships between the components changes as children develop. Very young children are more reliant on visuospatial processing, but later the auditory-verbal module becomes more dominant. It has also been found that the two sensory modules are not strongly associated in younger (5-8) American children, but are strongly associated in older children (9-12).

It’s now well established that older brains tend to find it harder to filter out irrelevant information. But now a new study suggests that that isn’t all bad. The study compared the performance of 24 younger adults (17-29) and 24 older adults (60-73) on two memory tasks separated by a 10-minute break. In the first task, they were shown pictures overlapped by irrelevant words, told to ignore the words and concentrate on the pictures only, and to respond every time the same picture appeared twice in a row.

Previous research has shown that older adults are more likely to incorrectly repeat an action in situations where a prospective memory task has become habitual — for example, taking more medication because they’ve forgotten they’ve already taken it. A new study has found that doing something unusual at the same time helps seniors remember having done the task. In the study, older adults told to put a hand on their heads whenever they made a particular response, reduced the level of repetition errors to that of younger adults.

I've reported before on the idea that the drop in working memory capacity commonly seen in old age is related to the equally typical increase in distractability. Studies of brain activity have also indicated that lower WMC is correlated with greater storage of distractor information. So those with higher WMC, it's thought, are better at filtering out distraction and focusing only on the pertinent information. Older adults may show a reduced WMC, therefore, because their ability to ignore distraction and irrelevancies has declined.

Why does that happen?

A small study that fitted 29 young adults (18-31) and 31 older adults (55-82) with a device that recorded steps taken and the vigor and speed with which they were made, has found that those older adults with a higher step rate performed better on memory tasks than those who were more sedentary. There was no such effect seen among the younger adults.