Every science has concepts so fundamental they are nearly impossible to define. Biologists agree on what is alive but not on precisely what life is. In physics, matter and energy elude simple definition. To psychologists, consciousness is similarly a fundamental yet slippery concept.

3-1 What is the place of consciousness in psychology’s history?

At its beginning, psychology was “the description and explanation of states of consciousness” (Ladd, 1887). But during the first half of the twentieth century, the difficulty of scientifically studying consciousness led many psychologists—including those in the emerging school of behaviorism—to turn to direct observations of behavior. By the 1960s, psychology had nearly lost consciousness and was defining itself as “the science of behavior.” Consciousness was likened to a car’s speedometer: “It doesn’t make the car go, it just reflects what’s happening” (Seligman, 1991, p. 24).

After 1960, psychology began regaining consciousness. Neuroscience advances linked brain activity to sleeping, dreaming, and other mental states. Researchers began studying consciousness altered by drugs, hypnosis, and meditation. (More on hypnosis in Chapter 6 and meditation in Chapter 11.) Psychologists of all persuasions were affirming the importance of cognition, or mental processes.

Most psychologists now define consciousness as our awareness of ourselves and our environment (Paller & Suzuki, 2014). This awareness allows us to assemble information from many sources as we reflect on our past, adapt to our present, and plan for our future. And it focuses our attention when we learn a complex concept or behavior. When learning to drive, we focus on the car and the traffic. With practice, driving becomes semi-automatic, freeing us to focus our attention elsewhere. Over time, we flit between different states of consciousness, including normal waking awareness and various altered states (Figure 3.1).

Today’s science explores the biology of consciousness. Scientists now assume, in the words of neuroscientist Marvin Minsky (1986, p. 287), that “the mind is what the brain does.”

Evolutionary psychologists presume that consciousness offers a reproductive advantage (Barash, 2006; Murdik et al., 2011). By considering consequences and reading others’ intentions, consciousness helps us to cope with novel situations and act in our long-term interests. Even so, that leaves us with what researchers call the “hard problem”: How do brain cells jabbering to one another create our awareness of the taste of a taco, the idea of infinity, the feeling of fright? The question of how consciousness arises from the material brain is one of life’s deepest mysteries. Such questions are at the heart of cognitive neuroscience—the interdisciplinary study of the brain activity linked with our mental processes.

A stunning demonstration of consciousness appeared in brain scans of a noncommunicative patient—a 23-year-old woman who had been in a car accident and showed no outward signs of conscious awareness (Owen, 2014; Owen et al., 2006). When researchers asked her to imagine playing tennis, fMRI scans revealed activity in a brain area that normally controls arm and leg movements (FIGURE 3.2). Even in a motionless body, the researchers concluded, the brain—and the mind—may still be active. A follow-up analysis of 42 behaviorally unresponsive patients revealed 13 more who also showed meaningful, though diminished, brain responses to questions (Stender et al., 2014).

Some neuroscientists believe that conscious experience arises from synchronized activity across the brain (Gaillard et al., 2009; Koch & Greenfield, 2007; Schurger et al., 2010). If a stimulus activates enough brain-wide coordinated neural activity—as strong signals in one brain area trigger activity elsewhere—it crosses a threshold for consciousness. A weaker stimulus—perhaps a word flashed too briefly to consciously perceive—may trigger localized visual cortex activity that quickly fades. A stronger stimulus will engage other brain areas, such as those involved with language, attention, and memory. Such reverberating activity (detected by brain scans) is a telltale sign of conscious awareness (Boly et al., 2011). For example, awareness of your body involves communication between several brain areas (Blanke, 2012; Olivé et al., 2015). How the synchronized activity produces awareness—how matter makes mind—remains a mystery.

3-2 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

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.

Selective Attention and Accidents

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.

Selective Inattention

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 3.3). 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.

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 3.4)—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 3.5). Out of sight, out of mind.

Some stimuli, however, are so powerful, so strikingly distinct, that we experience popout, as with the only smiling face in FIGURE 3.6. 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.

3-3 What is the dual processing being revealed by today’s cognitive neuroscience?

Discovering which brain region becomes active with a particular conscious experience strikes many people as interesting, but not mind blowing. (If everything psychological is simultaneously biological, then our ideas, emotions, and spirituality must all, somehow, be embodied.) What is mind blowing to many of us is the growing evidence that we have, so to speak, two minds, each supported by its own neural equipment.

At any moment, we are aware of little more than what’s on the screen of our consciousness. But beneath the surface, unconscious information processing occurs simultaneously on many parallel tracks. When we look at a bird flying, we are consciously aware of the result of our cognitive processing (“It’s a hummingbird!”) but not of our subprocessing of the bird’s color, form, movement, and distance. One of the grand ideas of recent cognitive neuroscience is that much of our brain work occurs off stage, out of sight. Perception, memory, thinking, language, and attitudes all operate on two levels—a conscious, deliberate “high road,” and an unconscious, automatic “low road.” The high road is reflective, the low road intuitive (Evans & Stanovich, 2013; Kahneman, 2011). Today’s researchers call this dual processing. We know more than we know we know.

If you are a driver, consider how you move into a right lane. Drivers know this unconsciously but cannot accurately explain it (Eagleman, 2011). Most say they would bank to the right, then straighten out—a procedure that would actually steer them off the road. In reality, an experienced driver, after moving right, automatically reverses the steering wheel just as far to the left of center, and only then returns to the center position. The lesson: The human brain is a device for converting conscious into unconscious knowledge.

Or consider this story, which illustrates how science can be stranger than science fiction. During my sojourns at Scotland’s University of St Andrews, I [DM] came to know cognitive neuroscientists David Milner and Melvyn Goodale (2008). A local woman, whom they called D. F., suffered brain damage when overcome by carbon monoxide, leaving her unable to recognize and discriminate objects visually. Consciously, D. F. could see nothing. Yet she exhibited blindsight—she acted as though she could see. Asked to slip a postcard into a vertical or horizontal mail slot, she could do so without error. Asked the width of a block in front of her, she was at a loss, but she could grasp it with just the right finger-thumb distance.

How could this be? Don’t we have one visual system? Goodale and Milner knew from animal research that the eye sends information simultaneously to different brain areas, which support different tasks (Weiskrantz, 2009, 2010). Sure enough, a scan of D. F.’s brain activity revealed normal activity in the area concerned with reaching for, grasping, and navigating objects, but damage in the area concerned with consciously recognizing objects. (See another example in FIGURE 3.7.)

How strangely intricate is this thing we call vision, conclude Goodale and Milner in their aptly titled book, Sight Unseen (2004). We may think of our vision as a single system that controls our visually guided actions. Actually, it is a dual-processing system. A visual perception track enables us “to think about the world”—to recognize things and to plan future actions. A visual action track guides our moment-to-moment movements.

The dual-track mind also appeared in a patient who lost all of his left visual cortex, leaving him blind to objects and faces presented on the right side of his field of vision. He nevertheless could sense the emotion expressed in faces, which he did not consciously perceive (de Gelder, 2010). The same is true of normally sighted people whose visual cortex has been disabled with magnetic stimulation. Such findings suggest that brain areas below the cortex are processing emotion-related information.

People often have trouble accepting that much of our everyday thinking, feeling, and acting operates outside our conscious awareness (Bargh & Chartrand, 1999). Some “80 to 90 percent of what we do is unconscious,” says Nobel Laureate and memory expert Eric Kandel (2008). We are understandably inclined to believe that our intentions and deliberate choices rule our lives. But consciousness, though enabling us to exert voluntary control and to communicate our mental states to others, is but the tip of the information-processing iceberg. Being intensely focused on an activity (such as reading this chapter, we’d love to think) increases your total brain activity no more than 5 percent above its baseline rate. And even when you rest, activity whirls inside your head (Raichle, 2010).

Parallel processing enables your mind to take care of routine business. Unconscious parallel processing is faster than conscious sequential processing, but both are essential. Sequential processing is best for solving new problems, which requires your focused attention. Try this: If you are right-handed, move your right foot in a smooth counterclockwise circle and write the number 3 repeatedly with your right hand—at the same time. Try something equally difficult: Tap a steady beat three times with your left hand while tapping four times with your right hand. Both tasks require conscious attention, which can be in only one place at a time. If time is nature’s way of keeping everything from happening at once, then consciousness is nature’s way of keeping us from thinking and doing everything at once.

Learning Objectives

Test Yourself by taking a moment to answer each of these Learning Objective Questions (repeated here from within the chapter). Research suggests that trying to answer these questions on your own will improve your long-term memory of the concepts (McDaniel et al., 2009).

Question

Question

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Terms and Concepts to Remember

Test yourself on these terms.

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Experience the Testing Effect

Test yourself repeatedly throughout your studies. This will not only help you figure out what you know and don’t know; the testing itself will help you learn and remember the information more effectively thanks to the testing effect.

Question 3.1

Question 3.2

Question 3.3

Use to create your personalized study plan, which will direct you to the resources that will help you most in .