During a 1959 television appearance, Jack Kerouac was asked how long it took him to write his novel “On The Road.” His response—three weeks—amazed the interviewer and ignited an enduring myth that the book was composed in a marathon of nonstop typing.
Like the Kerouac of legend, some people possess the incredible ability to focus for long periods of time. Others constantly struggle to keep their minds on task. Individuals diagnosed with attention deficit hyperactivity disorder (ADHD), for example, are often restless and easily distracted. Even people without ADHD may find their minds wandering while trying to concentrate at school or work.
Although the ability to sustain attention varies widely from person to person, characterizing these individual differences has been difficult. Unlike intelligence, which has traditionally been measured (though not without controversy) with pencil-and-paper IQ tests, attentional abilities are not captured by performance on a single test.
In a study recently published in Nature Neuroscience, my colleagues and I set out to identify a new way to measure attention. Like IQ, this measure would serve as a general summary of a complex cognitive ability. But unlike IQ, it would be based on a person’s unique pattern of brain connectivity—that is, synchronous activity observed across distinct parts of their brain. We previously showed that every person’s pattern of brain connectivity is unique—like a fingerprint—and predicts fluid intelligence, or the ability to solve problems in novel situations. Do unique patterns of brain connectivity predict attention, too?
How You’re Connected Predicts Your Focus
First we asked 25 volunteers to perform a task while an MRI scanner measured their brain activity. Their instructions were simple: Watch a stream of images and press a button when you see cities, but don’t press when you see mountains. Most of the pictures were of cities, with the occasional mountain thrown in unpredictably. It was challenging to maintain focus on the task, which lasted more than 30 minutes. Some people performed very well. But others made frequent errors—either failing to click for a city, or pressing for a mountain by mistake.
Could we relate participants’s accuracy to their patterns of brain connectivity while they responded to the city and mountain pictures? To analyze the brain data, we first divided each person’s brain into 268 distinct regions, a number previously shown to characterize brain function well.
