Focusing on One Thing May Blind People to the Obvious

WEDNESDAY April 20, 2011 -- A new study offers insight into "inattention blindness," a phenomenon that causes people to lose sight of seemingly obvious things while they focus intensely on something else.

The study authors, in an effort to shed light on how inattention blindness may make drivers more prone to traffic accidents if they are talking on their cell phone, used a video from earlier research on what is called "selective attention" as an example of how people can lose focus on everything around them while being very focused on one thing.

The video shows a small group of people passing around two basketballs. Viewers are told to count how many times the ball is passed by the players in white shirts. Many viewers focus so intensely on the task that they fail to notice a person in a gorilla suit enter the frame and walk between the players.

"Because people are different in how well they can focus their attention, this may influence whether you'll see something you're not expecting -- in this case, a person in a gorilla suit walking across the computer screen," study lead author Janelle Seegmiller, a psychology doctoral student at the University of Utah, said in a university news release.

In the new study, the researchers tested 197 students, aged 18 to 35, who hadn't seen the video before. The subjects had previously been tested with a set of math and memory problems, and had to get 80 percent right to be accepted into the study.

The study authors were focusing on something called working-memory capacity, which "is how much you can process in your working memory at once," Seegmiller explained. "Working memory is the stuff you are dealing with right at that moment, like trying to solve a math problem or remember your grocery list. It's not long-term memory."

The subjects watched the video, and researchers measured their working-memory capacity. Again, subjects had to get 80 percent of the basketball passes right for their results to be analyzed.

According to the report, 58 percent of the students noticed the gorilla, while the rest did not. Among those who accurately counted the number of passes of the ball, 67 percent of those with high working-memory capacity noticed the gorilla, but only 36 percent of those with low working-memory capacity did.

In other words, people with a high working-memory capacity are not only better at focusing their attention; they are better able to switch the focus of their attention and multitask when necessary, the researchers explained.

The findings may explain why some people are more prone to inattention blindness than others.

The study is scheduled for publication in the May issue of the Journal of Experimental Psychology: Learning, Memory and Cognition.

Study co-author Jason Watson, assistant professor of psychology, said: "The potential implications are that if we are all paying attention as we are driving, some individuals may have enough extra flexibility in their attention to notice distractions that could cause accidents."

But, he continued, "that doesn't mean people ought to be self-distracting by talking on a cell phone while driving -- even if they have better control over their attention. Our prior research has shown that very few individuals [only 2.5 percent] are capable of handling driving and talking on a cell phone without impairment."