12-1 How do arousal, expressive behavior, and cognition interact in emotion?

As my [DM’S] panicked search for Peter illustrates, emotions are a mix of

The puzzle for psychologists is figuring out how these three pieces fit together. To do that, we need answers to two big questions:

Historical emotion theories, as well as current research, have sought to answer these questions.

James-Lange Theory: Arousal Comes Before Emotion Common sense tells most of us that we cry because we are sad, lash out because we are angry, tremble because we are afraid. First comes conscious awareness, then the feeling. But to pioneering psychologist William James, this commonsense view of emotion had things backward. Rather, “We feel sorry because we cry, angry because we strike, afraid because we tremble” (1890, p. 1066). James’ idea was also proposed by Danish physiologist Carl Lange, and so is called the James-Lange theory. James and Lange would have guessed that I noticed my racing heart and then, shaking with fright, felt the whoosh of emotion—that my feeling of fear followed my body’s response.

Cannon-Bard Theory: Arousal and Emotion Occur Simultaneously Physiologist Walter Cannon (1871–1945) disagreed with James and Lange. Does a racing heart signal fear or anger or love? The body’s responses—heart rate, perspiration, and body temperature—are too similar, and they change too slowly, to cause the different emotions, said Cannon. He, and later another physiologist, Philip Bard, concluded that our bodily responses and experienced emotions occur separately but simultaneously. So, according to the Cannon-Bard theory, my heart began pounding as I experienced fear. The emotion-triggering stimulus traveled to my sympathetic nervous system, causing my body’s arousal. At the same time, it traveled to my brain’s cortex, causing my awareness of my emotion. My pounding heart did not cause my feeling of fear, nor did my feeling of fear cause my pounding heart.

If our bodily responses and emotional experiences occur simultaneously and one does not affect the other, as Cannon and Bard believed, then people who suffer spinal cord injuries should not notice a difference in their experience of emotion after the injury. But there are differences, according to one study of 25 World War II soldiers (Hohmann, 1966). Those with lower-spine injuries, who had lost sensation only in their legs, reported little change in their emotions’ intensity. Those with high spinal cord injury, who could feel nothing below the neck, did report changes. Some reactions were much less intense than before the injuries. Anger, one high spinal cord-injured man confessed, “just doesn’t have the heat to it that it used to. It’s a mental kind of anger.” Other emotions, those expressed mostly in body areas above the neck, were felt more intensely. These men reported increases in weeping, lumps in the throat, and getting choked up when saying good-bye, worshiping, or watching a touching movie. Our bodily responses seemingly feed our experienced emotions.

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But most researchers now agree that our emotions also involve cognition (Averill, 1993; Barrett, 2006). Whether we fear the man behind us on the dark street depends entirely on whether we interpret his actions as threatening or friendly.

12-2 To experience emotions, must we consciously interpret and label them?

Stanley Schachter and Jerome Singer (1962) believed that an emotional experience requires a conscious interpretation of arousal: Our physical reactions and our thoughts (perceptions, memories, and interpretations) together create emotion. In their two-factor theory, emotions therefore have two ingredients: physical arousal and cognitive appraisal.

Consider how arousal spills over from one event to the next. Imagine arriving home after an invigorating run and finding a message that you got a longed-for job. With arousal lingering from the run, would you feel more elated than if you received this news after awakening from a nap?

To explore this spillover effect, Schachter and Singer injected college men with the hormone epinephrine, which triggers feelings of arousal. Picture yourself as a participant: After receiving the injection, you go to a waiting room, where you find yourself with another person (actually an accomplice of the experimenters) who is acting either euphoric or irritated. As you observe this person, you begin to feel your heart race, your body flush, and your breathing become more rapid. If you had been told to expect these effects from the injection, what would you feel? The actual volunteers felt little emotion—because they attributed their arousal to the drug. But if you had been told the injection would produce no effects, what would you feel? Perhaps you would react as another group of participants did. They “caught” the apparent emotion of the other person in the waiting room. They became happy if the accomplice was acting euphoric, and testy if the accomplice was acting irritated.

This discovery—that a stirred-up state can be experienced as one emotion or another, depending on how we interpret and label it—has been replicated in dozens of experiments (Reisenzein, 1983; Sinclair et al., 1994; Zillmann, 1986). As researcher Daniel Gilbert (2006) noted, “Feelings that one interprets as fear in the presence of a sheer drop may be interpreted as lust in the presence of a sheer blouse.”

The point to remember: Arousal fuels emotion; cognition channels it.

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But is the heart always subject to the mind? Must we always interpret our arousal before we can experience an emotion? Robert Zajonc (1923–2008) (pronounced ZI-yence; 1980, 1984a) contended that we actually have many emotional reactions apart from, or even before, our interpretation of a situation. Perhaps you can recall liking something or someone immediately, without knowing why.

For example, when people repeatedly view stimuli flashed too briefly for them to interpret, they come to prefer those stimuli. Unaware of having previously seen them, they nevertheless like them. We have an acutely sensitive automatic radar for emotionally significant information, such that even a subliminally flashed stimulus can prime us to feel better or worse about a follow-up stimulus (Murphy et al., 1995; Zeelenberg et al., 2006). In experiments, thirsty people were given a fruit-flavored drink after viewing a subliminally flashed (thus unperceived) face. Those exposed to a happy face drank about 50 percent more than those exposed to a neutral face (Berridge & Winkielman, 2003). Those flashed an angry face drank substantially less.

Neuroscientists are charting the neural pathways of emotions (Ochsner et al., 2009). Our emotional responses can follow two different brain pathways. Some emotions (especially more complex feelings like hatred and love) travel a “high road.” A stimulus following this path would travel (by way of the thalamus) to the brain’s cortex (FIGURE 12.1a). There, it would be analyzed and labeled before the response command is sent out, via the amygdala (an emotion-control center).

But sometimes our emotions (especially simple likes, dislikes, and fears) take what Joseph LeDoux (2002) has called the “low road,” a neural shortcut that bypasses the cortex. Following the low road, a fear-provoking stimulus would travel from the eye or ear (again via the thalamus) directly to the amygdala (FIGURE 12.1B). This shortcut, bypassing the cortex, enables our greased-lightning emotional response before our intellect intervenes. Like speedy reflexes that also operate apart from the brain’s thinking cortex, the amygdala reactions are so fast that we may be unaware of what’s transpired (Dimberg et al., 2000).

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The amygdala sends more neural projections up to the cortex than it receives back, which makes it easier for our feelings to hijack our thinking than for our thinking to rule our feelings (LeDoux & Armony, 1999). Thus, in the forest, we can jump at the sound of rustling bushes nearby, leaving it to our cortex to decide later whether the sound was made by a snake or by the wind. Such experiences support Zajonc’s belief that some of our emotional reactions involve no deliberate thinking.

Emotion researcher Richard Lazarus (1991, 1998) conceded that our brain processes vast amounts of information without our conscious awareness, and that some emotional responses do not require conscious thinking. Much of our emotional life operates via the automatic, speedy low road. But, he asked, how would we know what we are reacting to if we did not in some way appraise the situation? The appraisal may be effortless and we may not be conscious of it, but it is still a mental function. To know whether a stimulus is good or bad, the brain must have some idea of what it is (Storbeck et al., 2006). Thus, said Lazarus, emotions arise when we appraise an event as harmless or dangerous, whether we truly know it is or not. We appraise the sound of the rustling bushes as the presence of a threat. Later, we realize that it was “just the wind.”

So, as Zajonc and LeDoux have demonstrated, some emotional responses—especially simple likes, dislikes, and fears—involve no conscious thinking (FIGURE 12.2). We may fear a big spider, even if we “know” it is harmless. Such responses are difficult to alter by changing our thinking. We may automatically like one person more than another. This instant appeal can even influence our political decisions if we vote (as many people do) for a candidate we like over the candidate expressing positions closer to our own (Westen, 2007).

But our feelings about politics are also subject to our memories, expectations, and interpretations, as Lazarus, Schachter, and Singer might have predicted. Moreover, highly emotional people are intense partly because of their interpretations. They may personalize events as being somehow directed at them, and they may generalize their experiences by blowing single incidents out of proportion (Larsen & Diener, 1987). Thus, learning to think more positively can help people feel better. Although the emotional low road functions automatically, the thinking high road allows us to retake some control over our emotional life. Together, automatic emotion and conscious thinking weave the fabric of our emotional lives. (TABLE 12.1 below summarizes these emotion theories.)

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Whether you are falling in love or grieving a death, you need little convincing that emotions involve the body. Feeling without a body is like breathing without lungs. Some physical responses are easy to notice. Other emotional responses we experience without awareness.

12-3 What is the link between emotional arousal and the autonomic nervous system? How does arousal affect performance?

In a crisis, the sympathetic division of your autonomic nervous system (ANS) mobilizes your body for action (FIGURE 12.3). It directs your adrenal glands to release the stress hormones epinephrine (adrenaline) and norepinephrine (noradrenaline). To provide energy, your liver pours extra sugar into your bloodstream. To help burn the sugar, your respiration increases to supply needed oxygen. Your heart rate and blood pressure increase. Your digestion slows, diverting blood from your internal organs to your muscles. With blood sugar driven into the large muscles, running becomes easier. Your pupils dilate, letting in more light. To cool your stirred-up body, you perspire. If wounded, your blood would clot more quickly.

According to the Yerkes-Dodson law, arousal affects performance in different ways, depending on the task, with moderate arousal leading to optimal performance (Yerkes & Dodson, 1908). When taking an exam, it pays to be somewhat aroused—alert but not trembling with nervousness. Too little arousal (as when sleepy) can be disruptive. And, as we’ll see, prolonged high arousal can tax the body.

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When the crisis passes, the parasympathetic division of your ANS gradually calms your body, as stress hormones slowly leave your bloodstream. After your next crisis, think of this: Without any conscious effort, your body’s response to danger is wonderfully coordinated and adaptive—preparing you to fight or flee. So, do the different emotions have distinct arousal fingerprints?

12-4 Do different emotions activate different physiological and brain-pattern responses?

Imagine conducting an experiment measuring the physiological responses of emotion. In each of four rooms, you have someone watching a movie: In the first, the person is viewing a horror show; in the second, an anger-provoking film; in the third, a sexually arousing film; in the fourth, a boring film. From the control center, you monitor each person’s perspiration, breathing, and heart rate. Could you tell who is frightened? Who is angry? Who is sexually aroused? Who is bored?

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With training, you could probably pick out the bored viewer. But discerning physiological differences among fear, anger, and sexual arousal is much more difficult (Barrett, 2006). Different emotions can share common biological signatures.

A single brain region can also serve as the seat of seemingly different emotions. Consider the broad emotional portfolio of the insula, a neural center deep inside the brain. The insula is activated when we experience various negative social emotions, such as lust, pride, and disgust. In brain scans, it becomes active when people bite into some disgusting food, smell the same disgusting food, think about biting into a disgusting cockroach, or feel moral disgust over a sleazy business exploiting a saintly widow (Sapolsky, 2010). Similar multitasking regions are found in other brains areas.

Yet our emotions—such as sexual arousal, fear, anger, and disgust—feel different to us, and they often look different to others. We may appear “paralyzed with fear” or “ready to explode.” Fear and joy prompt similar increased heart rate, but they stimulate different facial muscles. During fear, your brow muscles tense. During joy, muscles in your cheeks and under your eyes pull into a smile (Witvliet & Vrana, 1995).

Some of our emotions also differ in their brain circuits (Panksepp, 2007). Observers watching fearful faces showed more amygdala activity than did other observers who watched angry faces (Whalen et al., 2001). Brain scans and EEG recordings show that emotions also activate different areas of the brain’s cortex. When you experience negative emotions such as disgust, your right prefrontal cortex tends to be more active than the left. Depression-prone people, and those with generally negative personalities, have also shown more right frontal lobe activity (Harmon-Jones et al., 2002).

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Positive moods tend to trigger more left frontal lobe activity. People with positive personalities—exuberant infants and alert, enthusiastic, energized, and persistently goal-directed adults—have also shown more activity in the left frontal lobe than in the right (Davidson, 2000, 2003; Urry et al., 2004). Indeed, the more a person’s baseline frontal lobe activity tilts left—or is made to tilt left by perceptual activity—the more upbeat the person typically is (Drake & Myers, 2006).

To sum up, we can’t easily see differences in emotions from tracking heart rate, breathing, and perspiration. But facial expressions and brain activity can vary with the emotion. So, do we, like Pinocchio, give off telltale signs when we lie? For more on that question, see Thinking Critically About: Lie Detection.

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