#working memory capacity

While you are browsing online, you could be squandering memories -- or losing important information.

Contrary to common wisdom, an idle brain is in fact doing important work -- and in the age of constant information overload, it's a good idea to go offline on a regular basis, says a researcher from Stockholm's KTH Royal Institute of Technology.

Erik Fransén, whose research focuses on short-term memory and ways to treat diseased neurons, says that a brain exposed to a typical session of social media browsing can easily become hobbled by information overload. The result is that less information gets filed away in your memory.

The problem begins in a system of the brain commonly known as the working memory, or what most people know as short-term memory. That's the system of the brain that we need when we communicate, Fransén says.

"Working memory enables us to filter out information and find what we need in the communication," he says. "It enables us to work online and store what we find online, but it's also a limited resource."

Models show why it has limits. At any given time, the working memory can carry up to three or four items, Fransén says. When we attempt to stuff more information in the working memory, our capacity for processing information begins to fail.

"When you are on Facebook, you are making it harder to keep the things that are 'online' in your brain that you need," he says. "In fact, when you try to process sensory information like speech or video, you are going to need partly the same system of working memory, so you are reducing your own working memory capacity.

"And when you try to store many things in your working memory, you get less good at processing information."

You're also robbing the brain of time it needs to do some necessary housekeeping. The brain is designed for both activity and relaxation, he says. "The brain is made to go into a less active state, which we might think is wasteful; but probably memory consolidation, and transferring information into memory takes place in this state. Theories of how memory works explain why these two different states are needed.

The width of blood vessels in the retina, located at the back of the eye, may indicate brain health years before the onset of dementia and other deficits, according to a new study published in Psychological Science, a journal of the Association for Psychological Science. Research shows that younger people who score low on intelligence tests, such as IQ, tend to be at higher risk for poorer health and shorter lifespan, but factors like socioeconomic status and health behaviors don't fully account for the relationship. Psychological scientist Idan Shalev of Duke University and colleagues wondered whether intelligence might serve as a marker indicating the health of the brain, and specifically the health of the system of blood vessels that provides oxygen and nutrients to the brain.

To investigate the potential link between intelligence and brain health, the researchers borrowed a technology from a somewhat unexpected domain: ophthalmology.

Shalev and colleagues used digital retinal imaging, a relatively new and noninvasive method, to gain a window onto vascular conditions in the brain by looking at the small blood vessels of the retina, located at the back of the eye. Retinal blood vessels share similar size, structure, and function with blood vessels in the brain and can provide a way of examining brain health in living humans.

The researchers examined data from participants taking part in the Dunedin Multidisciplinary Health and Development Study, a longitudinal investigation of health and behavior in over 1000 people born between April 1972 and March 1973 in Dunedin, New Zealand.

The results were intriguing.

Having wider retinal venules was linked with lower IQ scores at age 38, even after the researchers accounted for various health, lifestyle, and environmental risk factors that might have played a role.

Individuals who had wider retinal venules showed evidence of general cognitive deficits, with lower scores on numerous measures of neurospsychological functioning, including verbal comprehension, perceptual reasoning, working memory, and executive function.

Surprisingly, the data revealed that people who had wider venules at age 38 also had lower IQ in childhood, a full 25 years earlier.

It's "remarkable that venular caliber in the eye is related, however modestly, to mental test scores of individuals in their 30s, and even to IQ scores in childhood," the researchers observe.

The findings suggest that the processes linking vascular health and cognitive functioning begin much earlier than previously assumed, years before the onset of dementia and other age-related declines in brain functioning.

"Digital retinal imaging is a tool that is being used today mainly by eye doctors to study diseases of the eye," Shalev notes. "But our initial findings indicate that it may be a useful investigative tool for psychological scientists who want to study the link between intelligence and health across the lifespan."

The current study doesn't address the specific mechanisms that drive the relationship between retinal vessels and cognitive functioning, but the researchers surmise that it may have to do with oxygen supply to the brain.

Turns out, that old “practice makes perfect” adage may be overblown.

New research led by Michigan State University’s Zach Hambrick finds that a copious amount of practice is not enough to explain why people differ in level of skill in two widely studied activities, chess and music.

In other words, it takes more than hard work to become an expert. Hambrick, writing in the research journal Intelligence, said natural talent and other factors likely play a role in mastering a complicated activity.

“Practice is indeed important to reach an elite level of performance, but this paper makes an overwhelming case that it isn’t enough,” said Hambrick, associate professor of psychology.

The debate over why and how people become experts has existed for more than a century. Many theorists argue that thousands of hours of focused, deliberate practice is sufficient to achieve elite status.

Hambrick disagrees.

“The evidence is quite clear,” he writes, “that some people do reach an elite level of performance without copious practice, while other people fail to do so despite copious practice.”

Hambrick and colleagues analyzed 14 studies of chess players and musicians, looking specifically at how practice was related to differences in performance. Practice, they found, accounted for only about one-third of the differences in skill in both music and chess.

So what made up the rest of the difference?

Based on existing research, Hambrick said it could be explained by factors such as intelligence or innate ability, and the age at which people start the particular activity. A previous study of Hambrick’s suggested that working memory capacity – which is closely related to general intelligence – may sometimes be the deciding factor between being good and great.

While the conclusion that practice may not make perfect runs counter to the popular view that just about anyone can achieve greatness if they work hard enough, Hambrick said there is a “silver lining” to the research.

“If people are given an accurate assessment of their abilities and the likelihood of achieving certain goals given those abilities,” he said, “they may gravitate toward domains in which they have a realistic chance of becoming an expert through deliberate practice.”

From David Z. Hambrick and Elizabeth J. Meinz are associate professors of psychology at Michigan State University and Southern Illinois University, Edwardsville in their article "Sorry Strivers Talent Matters" published November 19, 2011:

A high level of intellectual ability gives you an enormous real-world advantage.

In our own recent research, we have discovered that “working memory capacity,” a core component of intellectual ability, predicts success in a wide variety of complex activities. In one study, we assessed the practice habits of pianists and then gauged their working memory capacity, which is measured by having a person try to remember information (like a list of random digits) while performing another task. We then had the pianists sight read pieces of music without preparation.