> SOUTHERN INDIANA — I have to admit that I can be easily distracted. I’ve always had a relatively short attention span and modern technology has made it even worse. With e-mail, texting, Facebook and Twittering, it’s a wonder people get anything done at all.

The contemporary work environment, however, seems to lend itself to brief, but intensive efforts. Gloria Mark, from the University of California, found that the average time that white collar workers spend on a task before being interrupted or switching activities was only about three minutes. Then it usually takes at least 23 minutes to get back on task.

But how beneficial is being able to focus your attention for sustained lengths of time anyway? In the 1990s, Arien Mack from the New School for Social Research and Irvin Rock from the University of California at Berkeley, coined the term “inattentional blindness” to describe our failure to notice certain things, precisely when our attention is fully engaged. In their best-known study, subjects were instructed to look at a cross shape on a computer and judge which arms were longer. The cross shape was flashed on the screen only briefly. On one trial, an additional shape was also flashed on the screen. Afterward, the participants were asked if they saw anything, other than the cross. Up to 75 percent of participants failed to see the unexpected shape, even if it was presented in a different color.

 Cornell psychologist Ulric Neisser and his colleagues conducted related research using two videos of people engaged in common activities such as playing games or participating in sports. The two videos were superimposed over each other and shown to a group of subjects. When participants were instructed to focus their attention on the events in only one video, they often failed to notice unexpected events taking place in the other one. They were in essence blind to the other video.

 Building on such research, Daniel Simons and Christopher Chabris (then at Harvard University) published a well-known 1999 study in which participants watched a short video of people playing basketball. The subjects were instructed to count the number of passes made by the players wearing white uniforms and to ignore the players in black. Under these conditions, amazingly 50 percent of observers failed to notice when a person in a gorilla suit walked onto the basketball court, faced the camera, beat his chest and then exited. When I viewed this film, I found that it was necessary for me to block out everything else to keep track of the white team’s passes. When I followed the instructions and stayed on task, I too missed seeing the gorilla.

 This research has real-life implications. Everyone is well aware of the dangers of divided attention when driving. A 2009 study by Car and Driver magazine found that reading e-mail in an auto impaired reaction time more than being legally intoxicated, and texting was even worse. The Virginia Tech Transportation Institute reported that texting drivers of heavy vehicles (like large trucks) ran a risk of crashing that was about 23 times more likely than nondistracted drivers.

Drivers involved in accidents frequently say that they “looked, but failed to see” the other vehicle. This is especially common in collisions between cars and motorcycles. We usually expect to see other cars, but not motorcycles. Inattentional blindness seems to best explain these kinds of accidents.

In regards to driving, our difficulty perceiving sudden unexpected objects may have an evolutionary basis, according to Chabris. He suggests that this may be because our brains developed in the time before technology allowed humans to move so rapidly. Our nervous systems have not had the time to evolve a way to properly attend to something approaching us at 60 mph.

In his 2007 book, “How Doctors Think,” Harvard Professor of Medicine Jerome Groopman discusses how attention and expectations can impact medical practice. He describes a study in which a sample of radiologists were asked to assess a series of chest X-rays. On one of the X-rays, the patient was completely missing a collar bone.

Since radiologists are typically taught to focus their attention looking for positive things (lumps, masses, abnormal structures, etc.) the missing bone was an unexpected situation (an invisible gorilla). Remarkably the radiologists were so intent on finding something, that 60 percent of them failed to notice the missing clavicle.

You would think that the ability to focus attention would be universally adaptive, but ironically once we zero in on one thing, we greatly limit our ability to perceive other changes in our environment, even important ones.      

 I’ve learned that distractibility comes with a price. We have one of those plastic Dumpsters with wheels that I roll out to the road each week so it can be emptied. One morning I was running late and was preoccupied with all the errands I planned to do on the way to work. I needed to stop at the bank, the grocery store, get gas and go to the post office. Although my attention was focused on my several tasks, I managed to remember that it was trash day, so I hooked the Dumpster onto the back of the truck to haul it out to the road.

My first errand stop was the bank about a mile away. As luck would have it, the truck was running a little rough that day. Never-the-less I made it to the bank and completed my transaction. As I pulled away, the teller inside the bank building looked out the window and shot me a funny expression, but I’ve grown used to that sort of thing.

As soon as I turned the corner, I heard a noise that sounded like a flat tire. I pulled over and that’s when I realized that the stupid Dumpster was still attached to the truck. I was mortified to discover that I had been dragging it all over town, like a tiny red trailer. I had even pulled it through the bank’s drive-in window lane.

Although the state police would have probably been highly amused, I was just glad that I didn’t take it out onto the interstate highway. As usual my wife Diane is correct. I’ve got to start paying more attention to things before some invisible gorilla attacks me.

— Terry L. Stawar, Ed.D., lives in Georgetown and is the CEO of LifeSpring the local community mental health center in Jeffersonville. He can be reached at tstawar@lifespr.com. Checkout his Welcome to Planet-Terry blog and podcast at www.planetterry.wordpress.com