SAN FRANCISCO – When one of the most important e-mail messages of his life landed in his in-box a few years ago, Kord Campbell overlooked it.
Not just for a day or two, but 12 days. He finally saw it while sifting through old messages: A big company wanted to buy his Internet start-up.
The message had slipped by him amid an electronic flood: two computer screens alive with e-mail, instant messages, online chats, a Web browser and the computer code he was writing.
While he managed to salvage the $1.3 million deal after apologizing to his suitor, Campbell continues to struggle with the effects of the deluge of data. Even after he unplugs, he craves the stimulation he gets from his electronic gadgets. He forgets things like dinner plans, and he has trouble focusing on his family.
His wife, Brenda, complains, “It seems like he can no longer be fully in the moment.”
This is your brain on computers.
Scientists say juggling e-mail, phone calls and other incoming information can change how people think and behave. They say our ability to focus is being undermined by bursts of information.
These play to a primitive impulse to respond to immediate opportunities and threats. The stimulation provokes excitement – a dopamine squirt – that researchers say can be addictive. In its absence, people feel bored.
While many people say multitasking makes them more productive, research shows otherwise. Heavy multi-taskers actually have more trouble focusing and shutting out irrelevant information, scientists say, and they experience more stress.
And scientists are discovering that even after the multitasking ends, fractured thinking and lack of focus persist. In other words, this is also your brain off computers.
Technology use can benefit the brain in some ways, researchers say. Imaging studies show the brains of Internet users become more efficient at finding information. And players of some video games develop better visual acuity.
For better or worse, the consumption of media, as varied as e-mail and TV, has exploded. In 2008, peo-ple consumed three times as much information each day as they did in 1960. And they are constantly shifting their attention. Computer users at work change windows or check e-mail or other programs nearly 37 times an hour, new research shows.
The nonstop interactivity is one of the most significant shifts ever in the human environment, said Adam Gazzaley, a neuro-scientist at the University of California, San Francisco.
Campbell, 43, came of age with the personal computer, and he is a heavier user of technology than most. But researchers say the habits and struggles of Campbell and his family typify what many experi-ence – and what many more will, if trends continue.
As computers have changed, so has the understanding of the human brain. Until 15 years ago, scientists thought the brain stopped developing after childhood. Now they understand that its neural networks continue to develop, influenced by things like learning skills.
When Eyal Ophir arrived at Stanford in 2004, he wondered whether heavy multitasking might be leading to changes in a characteristic of the brain long thought immutable: that humans can process only a single stream of information at a time.
Going back a half-century, tests had shown that the brain could barely process two streams, and could not simultaneously make decisions about them. But Ophir, a student-turned-researcher, thought multi-taskers might be rewiring them-selves to handle the load.
Ophir, like others around the country studying how technology bent the brain, was startled by what he discovered.
The test subjects were divided into two groups: those classified as heavy multi-taskers based on their answers to questions about how they used technology, and those who were not.
In a test created by Ophir and his colleagues, subjects at a computer were briefly shown an image of red rectangles. Then they saw a similar image and were asked whether any of the rectangles had moved. It was a simple task until the addition of a twist: Blue rectangles were added, and the subjects were told to ignore them.
The multi-taskers then did a significantly worse job than the non-multitaskers at recognizing whether red rectangles had changed position. In other words, they had trouble filtering out the blue ones – the irrelevant information.
So, too, the multi-taskers took longer than non-multitaskers to switch among tasks, like differentiating vowels from consonants and then odd from even numbers. The multi-taskers were shown to be less efficient at juggling problems.
Other tests at Stanford, an important centre for research in this fast-growing field, showed multi-taskers tended to search for new information rather than accept a reward for putting older, more valuable information to work.
Researchers say these findings point to an interesting dynamic: Multi-taskers seem more sensitive than non-multitaskers to incoming information.
Melina Uncapher, a neurobiologist on the Stanford team, said she and other researchers were unsure whether the muddied multi-taskers were simply prone to distraction and would have had trouble focusing in any era. But she added that the idea that information overload causes distraction was supported by more and more research.