KEY THEME

Consciousness refers to your immediate awareness of mental activity, internal sensations, and external stimuli.

KEY QUESTIONS

Its nature is difficult to define precisely. For our purposes, we’ll use a simple definition: Consciousness is your immediate awareness of your internal states—your thoughts, sensations, memories—and the external world around you.

Take a few moments to pay attention to your own experience of consciousness. You’ll notice that the contents of your awareness shift from one moment to the next. Among other activities, your mental experience might include focused attention on this textbook; awareness of internal sensations, such as hunger or a throbbing headache; or planning and active problem-solving, such as mentally rehearsing an upcoming meeting with your adviser.

Even though your conscious experience is constantly changing, you don’t experience your personal consciousness as disjointed. Rather, the subjective experience of consciousness has a sense of continuity. This characteristic of consciousness led the influential American psychologist William James (1892) to describe consciousness as a “stream” or “river.” Despite the changing focus of our awareness, our experience of consciousness as an unbroken “stream” helps provide us with a sense of personal identity that has continuity from one day to the next.

Consciousness allows us to integrate past, present, and future behavior, guide future actions, and maintain a stable sense of self (Baumeister & others, 2010, 2011). And, it gives us the ability to plan and execute long-term, complex goals and communicate with others.

Our definition of consciousness refers to waking awareness. However, psychologists also study other types of conscious experience, which we’ll consider later in the chapter. But first, we’ll take a closer look at the nature of awareness.

Lost in your thoughts, you don’t notice when your instructor calls on you in class. “Pay attention!” your professor says patiently.

But what is attention? In reality, you are always “paying attention” to something—just not always the stimuli that you’re supposed to be paying attention to. For example, when your mind “wanders,” you are focusing on your internal environment—your daydreams or thoughts—rather than your external environment (Smilek & others, 2010).

Like consciousness, attention is one of the oldest topics in psychology (Raz, 2009). And, like consciousness, attention is difficult to define precisely.

For our purposes, we’ll define attention as the capacity to selectively focus senses and awareness on particular stimuli or aspects of the environment (Chun & others, 2011; Posner & Rothbart, 2007). Most of the time, we are able to deliberately control our attentional processes, which helps us regulate our thoughts and feelings. For example, we may deliberately turn our attention to a pleasant thought or memory when troubled by a painful memory (Baumeister & others, 2010, 2011).

Psychologists have identified a number of characteristics of attention, some of which have important implications for our daily life. These are:

Multi-tasking refers to paying attention to two or more sources of stimuli at once—such as doing homework while watching television, or talking on the phone while cooking dinner. In essence, multi-tasking involves the division of attention. When attention is divided among different tasks, each task receives less attention than it would normally (Borst & others, 2010; Lavie, 2010). Some people are better at handling multiple tasks than others (Seegmiller & others, 2011). However, people generally underestimate the costs of multitasking. When you attempt to do two things at once—such as talk on the phone while studying—your performance on both tasks is impaired (Finley & others, 2014).

In general, tasks that are very different are less likely to interfere with each other. There is evidence that visual and auditory tasks draw on independent, different attention resources—at least for simple, well-rehearsed tasks. For example, listening to the radio (an auditory task) interferes less with driving (a visual task) than would a second visual task (Borst & others, 2010). However, this is not the case when one of the tasks requires a great deal of concentration. Absorption in a visual task can produce inattentional deafness, and absorption in an auditory task can produce inattentional blindness (Macdonald & Lavie, 2011).

The perils of divided attention are especially obvious when people use cell phones. As demonstrated by the unicycling clown study, using a cell phone seems to absorb a great deal of attentional resources. Partly because cell phone conversations can be so absorbing, they are especially likely to produce inattentional blindness (Chabris & Simons, 2010). One study found that driving was more impaired when drivers were talking on a cell phone than when the same drivers were legally drunk (Strayer & others, 2006). And, it turns out, using a headset or Bluetooth device while driving does not improve safety. It’s the attention devoted to the conversation that is dangerously distracting to drivers (see Baumeister & others, 2011; Drews & others, 2008). In fact, the National Safety Council (2014) found that cell phone use was involved in more than a quarter of motor vehicle crashes in 2012 – that’s 1.5 million accidents!

Distractions are just one factor that affects the quality of awareness. We’ll begin our exploration of variations in consciousness by looking at the biological rhythms that help determine the nature and quality of our daily conscious experience.