7-2 How does selective attention direct our perceptions?

Through selective attention, our awareness focuses, like a flashlight beam, on a minute aspect of all that we experience. We may think we can fully attend to a conversation or a class lecture while checking and returning text messages. Actually, our consciousness focuses on but one thing at a time.

By one estimate, our five senses take in 11,000,000 bits of information per second, of which we consciously process about 40 (Wilson, 2002). Yet our mind’s unconscious track intuitively makes great use of the other 10,999,960 bits. Until reading this sentence, for example, you have been unaware of the chair pressing against your bottom or that your nose is in your line of vision. Now, suddenly, your attentional spotlight shifts. You feel the chair, your nose stubbornly intrudes on the words before you. While focusing on these words, you’ve also been blocking other parts of your environment from awareness, though your peripheral vision would let you see them easily. You can change that. As you stare at the X below, notice what surrounds these sentences (the edges of the page, the desktop, the floor).

X

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A classic example of selective attention is the cocktail party effect—your ability to attend to only one voice among many. But what happens when another voice speaks your name? Your cognitive radar, operating on your mind’s other track, instantly brings that unattended voice into consciousness. This effect might have prevented an embarrassing and dangerous situation in 2009, when two Northwest Airlines pilots “lost track of time.” Focused on their laptops and in conversation, they ignored alarmed air traffic controllers’ attempts to reach them and overflew their Minneapolis destination by 150 miles. If only the controllers had known and spoken the pilots’ names.

Talk, text, route plan, or attend to music selections while driving, and your selective attention will shift back and forth between the road and its electronic competition. Indeed, it shifts more often than we realize. One study left people in a room free to surf the Internet and to control and watch a TV. On average, participants guessed their attention switched 15 times during the 28-minute session. But they were not even close. Eye-tracking revealed eight times that many attentional switches—120 in all (Brasel & Gips, 2011). Such “rapid toggling” between activities is today’s great enemy of sustained, focused attention.

We pay a toll for switching attentional gears, especially when we shift to complex tasks, like noticing and avoiding cars around us. The toll is a slight and sometimes fatal delay in coping (Rubenstein et al., 2001). About 28 percent of traffic accidents occur when people are chatting or texting on cell phones—something one in four drivers admits to doing (National Safety Council, 2010; Pew, 2011). In brain areas vital to driving, fMRI scans indicate that activity decreases an average 37 percent when a driver is attending to conversation (Just et al., 2008). One study, which tracked long-haul truck drivers for 18 months, showed they were at 23 times greater risk of a collision while texting (VTTI, 2009). Another study, which focused vehicle video cams on teen drivers, found that 58 percent of crashes followed driver distraction from other passengers or phones (AAA, 2015). Mindful of such findings, most U.S. states now ban drivers from texting while driving.

Even hands-free cell-phone talking is more distracting than chatting with passengers, who can see the driving demands, pause the conversation, and alert the driver to risks.

At the level of conscious awareness, we are “blind” to all but a tiny sliver of visual stimuli. To demonstrate this inattentional blindness, researchers showed people a one-minute video in which images of three black-shirted men tossing a basketball were superimposed over the images of three white-shirted players (Becklen & Cervone, 1983; Neisser, 1979). The viewers’ supposed task was to press a key every time a black-shirted player passed the ball. Most viewers focused their attention so completely on the game that they failed to notice a young woman carrying an umbrella saunter across the screen midway through the video (FIGURE 7.3). Seeing a replay of the video, viewers were astonished to see her (Mack & Rock, 2000). This inattentional blindness is a by-product of what we are really good at: focusing attention on some part of our environment.

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In a repeat of the experiment, smart-aleck researchers sent a gorilla-suited assistant through a swirl of players (Simons & Chabris, 1999). During its 5- to 9-second cameo appearance, the gorilla paused and thumped its chest. The chest-thumping gorilla did not steal the show: Half the conscientious pass-counting viewers failed to see it. Psychologists like to have fun, and they have continued to do so with the help of invisible gorillas. When 24 radiologists were looking for cancer nodules in lung scans, 20 of them missed the gorilla superimposed in the upper right (FIGURE 7.4)—though, to their credit, their focus enabled them to discover the much tinier cancer tissue (Drew et al., 2013). The serious point to this psychological mischief: Attention is powerfully selective. Your conscious mind is in one place at a time.

Given that most people miss someone in a gorilla suit while their attention is riveted elsewhere, imagine the fun that magicians can have by manipulating our selective attention. Misdirect people’s attention and they will miss the hand slipping into the pocket. “Every time you perform a magic trick, you’re engaging in experimental psychology,” says magician Teller (2009), a master of mind-messing methods. One Swedish psychologist was surprised on a Stockholm street by a woman exposing herself; only later did he realize that he had been pickpocketed, outwitted by thieves who understood the power of selective inattention (Gallace, 2012).

Magicians also exploit our change blindness. Participants in laboratory experiments on change blindness have failed to notice that, after a brief visual interruption, a big Coke bottle had disappeared, a railing had risen, or clothing color had changed (Chabris & Simons, 2010; Resnick et al., 1997). Two-thirds of those who were focused on giving directions to a construction worker failed to notice when he was replaced by another worker during a a staged interruption (FIGURE 7.5). Out of sight, out of mind.

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Some stimuli, however, are so powerful, so strikingly distinct, that we experience popout, as with the only smiling face in FIGURE 7.6. We don’t choose to attend to these stimuli; they draw our eye and demand our attention.

The dual-track mind is active even during sleep, as we see next.