Chapter 11Emotion
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conditioned emotional responseA classically conditioned response that occurs when a neutral stimulus is followed by an aversive stimulus; usually includes autonomic, behavioral, and endocrine components such as changes in heart rate, freezing, and secretion of stress-related hormones.
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Fear
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• Research with Laboratory Animals
• Behavioral studies have shown that extinction is not the same as forgetting. Instead, the animal learns that the CS is no longer followed by an aversive stimulus, and as a result of this learning, the expression of the CR is inhibited; the memory for the association between the CS and the aversive stimulus is not erased.
• This inhibition is supplied by the ventromedial prefrontal cortex (vmPFC).
• ventromedial prefrontal cortex (vmPFC)
• The region of the prefrontal cortex at the base of the anterior frontal lobes, adjacent to the midline.
Fear
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• Anger, Aggression, and Impulse Control
• Almost all species of animals engage in aggressive behaviors, which involve threatening gestures or actual attack directed toward another animal.
• Aggressive behaviors are species-typical; that is, the patterns of movements (for example, posturing, biting, striking, and hissing) are organized by neural circuits whose development is largely programmed by an animal’s genes.
• Many aggressive behaviors are related to reproduction.
• For example, aggressive behaviors that gain access to mates, defend territory needed to attract mates or to provide a site for building a nest, or defend offspring against intruders can all be regarded as reproductive behaviors.
• Other aggressive behaviors are related to self-defense, such as that of an animal threatened by a predator or an intruder of the same species.
Fear
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• Anger, Aggression, and Impulse Control
• threat behavior• A stereotypical species-typical behavior that warns another animal that it may be attacked if it
does not flee or show a submissive behavior. • defensive behavior
• A species-typical behavior by which an animal defends itself against the threat of another animal.
• submissive behavior• A stereotyped behavior shown by an animal in response to threat behavior by another animal;
serves to prevent an attack.
• predation
• Attack of one animal directed at an individual of another species on which the attacking animal normally preys.
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Fear
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• Research with Humans
• Role of Serotonin
• Several studies have found that serotonergic neurons play an inhibitory role in human aggression.
• If low levels of serotonin release contribute to aggression, perhaps drugs that act as serotonin agonists might help to reduce antisocial behavior.
• In fact, a study by Coccaro and Kavoussi (1997) found that fluoxetine (Prozac), a serotonin agonist, decreased irritability and aggressiveness, as measured by a psychological test.
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Communication of Emotions
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• Facial Expression of Emotions: Innate Responses
• Darwin obtained evidence for his conclusion that emotional expressions were innate by observing his own children and by corresponding with people living in various isolated cultures around the world.
• He reasoned that if people all over the world, no matter how isolated, show the same facial expressions of emotion, then these expressions must be inherited instead of learned.
• Ekman and Friesen (1971) studied the ability of members of an isolated tribe in New Guinea to recognize facial expressions of emotion produced by Westerners.
• They had no trouble doing so and themselves produced facial expressions that Westerners readily recognized
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Communication of Emotions
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• Role of the Amygdala and Prefrontal Cortex
• In fact, some people with blindness caused by damage to the visual cortex can recognize facial expressions of emotion even though they have no conscious awareness of looking at a person’s face, a phenomenon known as affective blindsight (de Gelder et al., 1999, Anders et al., 2004).
• affective blindsight
• The ability of a person who cannot see objects in his or her blind field to accurately identify facial expressions of emotion while remaining unconscious of perceiving them; caused by damage to the visual cortex.
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By themselves, eyes are able to convey a fearful expression.
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Communication of Emotions
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• Neural Basis of the Communication of Emotions: Expression
• As Duchenne put it, “The first [zygomatic major muscle] obeys the will but the second [orbicularis oculi] is only put in play by the sweet emotions of the soul; the . . . fake joy, the deceitful laugh, cannot provoke the contraction of this latter muscle” (Duchenne, 1862/1990, p. 72).
Communication of Emotions
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• Neural Basis of the Communication of Emotions: Expression
• This observation is confirmed by two neurological disorders with complementary symptoms (Hopf et al., 1992; Topper et al., 1995; Urban et al., 1998; Michel et al., 2008).
• The first, volitional facial paresis, is caused by damage to the face region of the primary motor cortex or to the fibers connecting this region with the motor nucleus of the facial nerve, which controls the muscles responsible for movement of the facial muscles. (Paresis, from the Greek “to let go,” refers to a partial paralysis.)
• volitional facial paresis
• Difficulty in moving the facial muscles voluntarily; caused by damage to the face region of the primary motor cortex or its subcortical connections.
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Communication of Emotions
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• Neural Basis of the Communication of Emotions: Expression
• In contrast, emotional facial paresis is caused by damage to the insular region of the prefrontal cortex, to the white matter of the frontal lobe, or to parts of the thalamus.
• This system joins the system responsible for voluntary movements of the facial muscles in the medulla or caudal pons.
• People with this disorder can move their face muscles voluntarily but do not express emotions on the affected side of the face.
• emotional facial paresis
• Lack of movement of facial muscles in response to emotions in people who have no difficulty moving these muscles voluntarily; caused by damage to the insular prefrontal cortex, subcortical white matter of the frontal lobe, or parts of the thalamus.
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Feelings of Emotions
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• The James-Lange Theory
• William James (1842–1910), an American psychologist, and Carl Lange (1834–1900), a Danish physiologist, independently suggested similar explanations for emotion, which most people refer to collectively as the James-Lange theory (James, 1884; Lange, 1887).
• James-Lange theory
• A theory of emotion that suggests that behaviors and physiological responses are directly elicited by situations and that feelings of emotions are produced by feedback from these behaviors and responses.
Feelings of Emotions
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• The James-Lange Theory
• Basically, the theory states that emotion-producing situations elicit an appropriate set of physiological responses, such as trembling, sweating, and increased heart rate.
• The situations also elicit behaviors, such as clenching of the fists or fighting.
• The brain receives sensory feedback from the muscles and from the organs that produce these responses, and it is this feedback that constitutes our feeling of emotion.
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Feelings of Emotions
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• The James-Lange Theory
• A well-known physiologist, Walter Cannon, criticized James's theory.
• He said that the internal organs were relatively insensitive and that they could not respond very quickly, so feedback from them could not account for our feelings of emotions.
• In addition, he observed that cutting the nerves that provide feedback from the internal organs to the brain did not alter emotional behavior (Cannon, 1927).
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