Your Brain On ... line


by Faith Hickman Brynie

January 21, 2010

Just as we shape our tools, our tools shape us. They change our capabilities and our expectations—and can change how we perceive the world. Now, as the 40th anniversary of the Internet slips by, researchers are asking how new and powerful digital technologies are transforming the brains that use them.

Vision and the video game

Video games may seem an unlikely tool for brain research, but Daphne Bavelier and her team at the University of Rochester have, over several years, conducted numerous experiments that reveal how playing computer games affects the human visual system. “Research on action video game playing is providing a lot of information about how malleable the brain really is,” says her sometime collaborator Matt Dye, a professor of speech and hearing science at the University of Illinois at Urbana-Champaign.

One area of interest has been “visual attention,” the ability to focus on an object, event, or feature within the visual field. Unlike “paying attention,” which can be consciously controlled, visual attention happens automatically in the brain, for example, when we read, drive, or interact with other people.

One measure of visual attention is the attentional blink. After one stimulus is perceived, the visual system is “blind” to another for a short period of time. That “blink” may reflect the time a brain needs to switch from one task to the next. While a student in Bavelier’s lab, Shawn Green (now at the University of Minnesota) found that skilled players of action video games  have a shorter attentional blink than nongamers or players of slower simulation-type games. Some people, including Green himself, have no measurable blink at all. The research was published in Psychological Science in 2007.

Green also studied the number of objects that the visual system can perceive at once. Without deliberately counting, game players easily track five objects, while nongame players stop at three. With more objects, the brain needs to count; again game players excel, counting more accurately and making fewer mistakes.

Dye and Bavelier recently tested children for their ability to search for a target. The researchers also measured recovery time after attending to a target as well as the number of objects the children could track simultaneously. Their research demonstrated that these visual capacities develop at different times and at different rates as children mature.

On all three measures, however, action game players performed better than nongamers, no matter what the stage of development. The researchers ruled out the idea that gamers have better attentional skills to begin with (and, perhaps, choose to play computer games for that reason). Training studies show that learning, not inborn skill, makes the difference. When volunteers are trained to play action video games, their visual attention scores increase.

“Training on action video games enhances performance across a range of visual skills,” says Dye. Such research, says Green, has implications for education. Children who play video games may learn better if educational materials and presentations match their enhanced visual and attentional skills. Dye and Bavelier reported their findings in the Oct. 29 issue of Vision Research.

Imaging brain-machine interaction

While Bavalier and her colleagues have used behavioral tests, other researchers are taking a more direct route, using imaging technologies to measure brain activity while volunteers use a computer.

The idea has been around for a while. In 1992, Richard Haier and his team at the University of California, Irvine, reported on positron emission tomography (PET) scans of eight young men while they played the computer game Tetris. Haier measured the rate of glucose use in the cerebrum before the volunteers practiced the game and after four to eight weeks of practice.

Haier found that, while game scores rose by a factor of 7, the brain’s use of glucose declined with practice. Furthermore, those subjects who improved their Tetris performance the most showed the largest decreases in glucose metabolism after practice. Haier concluded that changes in cognitive strategy are part of the learning process. As a skill is mastered, the brain finds more efficient circuits for performing it.

Gary Small is a professor of psychiatry at the University of California, Los Angeles. Last January, he and his team reported on a functional magnetic resonance imaging (fMRI) study that compared patterns of brain activation during reading and Internet searching in older people. The UCLA team worked with 24 healthy volunteers between the ages of 55 and 76. Half were new to Internet use, while the other half had considerable experience. The researchers found that the pattern of activity in the brain while reading a book page was similar in the two groups. Inexperienced individuals displayed a similar pattern to book-reading when they searched online. The big difference appeared when the savvy volunteers searched online. “We found a twofold increase in activity throughout the brain, especially the frontal lobes,” Small says. The findings appeared in February in the American Journal of Geriatric Psychiatry. 

At the 2009 meeting of the Society for Neuroscience in Chicago, Small extended those findings, reporting on scans of brain activity after the inexperienced subjects practiced Internet searching for 7 hours over two weeks. The images showed a significant increase in brain activity, but not in all parts of the brain. Increased activity was concentrated in areas of the frontal lobe that control decision making and complex reasoning. Increases were seen also in working, or short-term, memory.

“Performing Internet searches for even a relatively short period of time can change brain activity patterns and enhance function," Small says.

Brain training

For that reason, a number of organizations and companies are developing computer-based brain-training programs designed to enrich a healthy brain..

One brain-training program is an online version of a memory-challenging computer game developed by University of Michigan researchers and assessed in a study published in the Proceedings of the National Academy of Sciences last April. Susanne Jaeggi and her team reported that their game increased short-term working memory, which was its intended purpose. But it achieved more. It also improved “fluid intelligence,” which is the ability to solve novel problems independently of previous learning.

The Michigan study stands among only a few that have demonstrated transfer of one learned skill to another cognitive domain. Most of the others show only that practice makes perfect; as Small puts it, “if you do crossword puzzles, you are going to get better at doing crossword puzzles.” The Michigan study, however, demonstrated a transfer effect as well as a dose effect: the more time people spent using the program, the greater their improvement in both memory and fluid intelligence.

Such research has also spawned a host of efforts to use computers in rehabilitating aging, dysfunctional or damaged brains. These studies are still in the exploratory phase. Small, for example, has collaborated in the development of the Dakim Brain Fitness Unit, a touch-screen system that is available in assisted-living facilities.

Other researchers are experimenting with computer-based systems designed to help disabled patients regain or enhance specific sensory or motor abilities. For example, Susan Brown’s Motor Control Laboratory at the University of Michigan is using a home- and Internet-based training program to improve upper limb and hand function in adults with cerebral palsy. Lucia Vaina’s Neurovisual Clinic at Boston University designs, develops, and tests computer applications to restore visual skills lost in some stroke patients.