Physiological-Psychology-Week-12-Handouts PDF

Republic of the Philippines KOLEHIYO NG LUNGSOD NG DASMARIÑAS Brgy. Burol Main Dasmariñas, City, Cavite PSYCHOLOGY DEPARTME...

Republic of the Philippines KOLEHIYO NG LUNGSOD NG DASMARIÑAS Brgy. Burol Main Dasmariñas, City, Cavite PSYCHOLOGY DEPARTMENT Physiological/Biological Psychology Week 12 Handout EMOTIONAL BEHAVIOR BIOPSYCHOLOGY OF EMOTION I. Darwin’s Theory of the Evolution of Emotion. The publication of Darwin's book The Expression of Emotions in Man and Animals (1872) marked the first major event in the study of the biopsychology of emotion. Specific emotional reactions, like human facial expressions, tend to accompany the same emotional states in all members of a species. Darwin based this claim on anecdotal data (evidence based on personal observation and/or testimony). Darwin believed that expressions of emotion, like other behaviors, are products of evolution and he tried to understand them by comparing different species that led him to developed a theory of the evolution of emotional expression that was composed of 3 main ideas: 1. Expressions of emotion evolve from behaviors that indicate what an animal is likely to do next. 2. If the signals provided by such behaviors benefit the animal that displays them, they will evolve in ways that enhance their communicative function, and their original function may be lost. 3. Opposite messages are often signaled by opposite movements and postures, an idea called the principle of antithesis. Principle of antithesis: When the opposite of one's current state of mind is brought out, there is a strong and uncontrollable tendency to act in the opposite way, even though these actions are useless. Example: In man, the shrugging of the shoulders to express impotence or an apology. II. James-LangeTheory The first physiological theory of emotion was proposed independently by James and Lange in 1884. Emotion-inducing sensory stimuli are received and interpreted by the cortex, which triggers changes in the visceral organs via the autonomic nervous system and in the skeletal muscles via the somatic nervous system. Then, the autonomic and somatic responses trigger the experience of emotion in the brain. James and Lange argued that the autonomic activity and behavior that are triggered by the emotional event (e.g., rapid heartbeat and running away) produce the feeling of emotion, not vice versa. Example: Perception of bear ➔ Psychological Behavior ➔ Feeling of fear Summary: emotional experience depends entirely on feedback from autonomic and somatic nervous system activity. III. Cannon-Bard Theory Cannon proposed an alternative to the James-Lange theory of emotion, and it was subsequently extended and promoted by Bard (1915). Emotional stimuli have two independent excitatory effects: They excite both the feeling of emotion in the brain and the expression of emotion in the autonomic and somatic nervous systems. Views emotional experience and emotional expression as parallel processes that have no direct causal relation (in contrast to the James-Lange theory). Example: Perception of bear ➔ Feeling of fear and Psychological reaction Summary: emotional experience is totally independent on feedback from autonomic and somatic nervous system activity. IV. Modern Biopsychological View Autonomic and somatic feedback is not necessary for the experience of emotion. Each of the three principal factors in an emotional response— the perception of the emotion-inducing stimulus, the autonomic and somatic responses to the stimulus, and the experience of the emotion—can influence the other two Sham Rage The aggressive responses of decorticate animals (whose cortex has been removed) are abnormal in two respects: 1. They are inappropriately severe, and 2. They are not directed at particular targets. Bard referred to the exaggerated, poorly directed aggressive responses of decorticate animals as sham rage. Limbic System and Emotion Limbic means “border”. Papez proposed that emotional expression is controlled by several interconnected nuclei and tracts that ring the thalamus (1937). (Now known as the limbic system: the amygdala, mammillary body, hippocampus, fornix, cingulate cortex, septum, olfactory bulb, and hypothalamus.) Emotional states are expressed through the action of the other structures of the circuit on the hypothalamus and that they are experienced through their action on the cortex. This theory was revised and expanded by Paul MacLean in 1952 and became the influential limbic system theory of emotion. EMOTIONS AND THE AUTONOMIC NERVOUS SYSTEM The role of the autonomic nervous system in an emotion has focused on two issues: the degree to which specific patterns of ANS activity are associated with specific emotions and the effectiveness of ANS measures in polygraph (lie detection) Polygraphy (known as lie detector test) Method of interrogation that employs ANS indexes of emotion to infer the truthfulness of a person’s responses. If administered by skilled examiners, it can be useful additions to normal interrogation procedures, but they are far from infallible. Polography detects ANS activity, not lies. MAIN PROBLEM: rarely possible in real-life situations to know for certain whether a suspect is guilty or innocent. Consequently, many studies of polygraphy have employed the mock-crime procedure: Volunteers participate in a mock crime and are then subjected to a polygraph test by an examiner who is unaware of their “guilt” or “innocence.” Control-question Technique Usual interrogation method in which the physiological response to the target question is compared with the physiological responses to control questions whose answers are known. The assumption is that lying will be associated with greater sympathetic activation.  EXAMPLE: did you steal that purse - target question, have you ever been in jail before - control question Consequently, it is less likely to successfully identify lies in real life than in experiments. - In real-life situations, questions such as “Did you steal that purse?” are likely to elicit an emotional reaction from all suspects, regardless of their guilt or innocence, making it difficult to detect deception. Guilty-knowledge Technique The polygrapher must have a piece of information concerning the crime that would be known only to the guilty person. The polygrapher simply assesses the suspect’s reaction to a list of actual and contrived details of the crime. Innocent suspects, because they have no knowledge of the crime, react to all such details in the same way; the guilty react differentially. Emotion and Facial Expression Universality of Facial Expression Several studies have found that people of different cultures make similar facial expressions in similar situations and that they can correctly identify the emotional significance of facial expressions displayed by people from cultures other than their own. Primary Facial Expression Ekman’s Six Primary Facial Expressions 1. Surprise 2. Anger 3. Sadness 4. Disgust 5. Fear 6. Happiness They further concluded that all other facial expressions of genuine emotion are composed of mixtures of these six primaries. Facial Feedback Hypothesis Hypothesis that our facial expressions influence our emotional experience. The effects of facial experience of emotion. Participants reported feeling happier and less angry when they viewed slides while making a happy face and less happy and angrier when they viewed slides while making an angry face. Voluntary Control of Facial Expression It is possible to inhibit true facial expressions and to substitute false ones. here are many reasons for choosing to put on a false facial expression. Some of them are positive (putting on a false smile to reassure a worried friend), and some are negative (putting on a false smile to disguise a lie). TWO WAYS TO DISTINGUISH TRUE EXPRESSIONS FROM FALSE ONES 1. Microexpressions (brief facial expressions) of the real emotion often break through the false one. Such microexpressions last only about 0.05 second, but with practice they can be detected without the aid of slow-motion photography. 2. There are often subtle differences between genuine facial expressions and false ones that can be detected by skilled observers.  The most widely studied difference between a genuine and a false facial expression was first described by the French anatomist Duchenne in 1862. Duchenne said that the smile of enjoyment could be distinguished from deliberately produced smiles by consideration of the two facial muscles that are contracted during genuine smiles: Orbicularis Oculi and Zygomaticus. The zygomaticus major can be controlled voluntarily, whereas the orbicularis oculi is normally contracted only by genuine pleasure. Thus, inertia of the orbicularis oculi in smiling unmasks a false friend—a fact you would do well to remember. Ekman named the genuine smile the Duchenne smile. Facial Expressions: Current Perspectives Four important qualifications to Ekman’s original theory: 1. It is now clear that Ekman’s six primary facial expressions of emotion rarely occur in pure form—they are ideals with many subtle variations. 2. The existence of other primary emotions has been recognized. 3. It is now clear that body cues, not just facial expressions, play a major role in expressions of emotion. For example, pride is expressed through a small smile, with the head tilted back slightly and the hands on the hips, raised above the head, or clenched in fists with the arms crossed on the chest. 4. There is evidence that Ekman’s six primary facial expressions may not be as universal as originally believed. FEAR, DEFENSE, AND AGGRESSION Fear is the emotional reaction to threat, the motivating force for defensive behaviors. Defensive behaviors are behaviors whose primary function is to protect an organism from threat or harm. Aggressive behaviors are behaviors whose primary function is to threaten or harm. Aggression and Testosterone The fact that social aggression occurs more commonly among men is usually explained with reference to the organizational and activational effects of testosterone. Neural Mechanisms of Fear Conditioning Fear conditioning is the establishment of fear in response to a previously neutral stimulus (conditional stimulus) by perceiving it several times before the delivery of an aversive stimulus (the unconditional stimulus). In an experiment, a rat hears a tone, then receives a mild electric shock to its feet. After several pairings of the tone and the shock, the rat responds to the tone with a variety of defensive behaviors and sympathetic nervous system responses. Amygdala and Fear Conditioning LeDoux and colleagues began their search for the neural mechanisms of auditory fear conditioning— fear conditioning that uses a sound as a conditional stimulus—by making lesions in the auditory pathways of rats. 1. They found that bilateral lesions to the medial geniculate nucleus (auditory relay nucleus of the thalamus) blocked fear conditioning to a tone, but bilateral lesions to the auditory cortex did not. 2. This indicated that for auditory fear conditioning to occur, it is necessary for signals elicited by the tone to reach the medial geniculate nucleus but not the auditory cortex. 3. The pathway from the medial geniculate nucleus to the amygdala plays a key role in fear conditioning. The amygdala receives input from all sensory systems, and it is believed to be the structure in which the emotional significance of sensory signals is learned and retained. Sound signals from the medial geniculate nucleus of the thalamus reach the amygdala directly, or indirectly via the auditory cortex. The amygdala assesses the emotional significance of the sound on the basis of previous encounters with it, and then the amygdala activates the appropriate response circuits. Contextual Fear Conditioning and the Hippocampus The process by which benign contexts come to elicit fear through their association with fear inducing stimuli is called contextual fear conditioning. It is reasonable to expect that the hippocampus is involved in this because of the fact that the hippocampus plays a key role in memory for spatial locations. Bilateral hippocampal lesions block the subsequent development of a fear response to the context without blocking the development of a fear response to the explicit conditional stimulus. Amygdala Complex and Fear Conditioning The amygdala is actually a cluster of many nuclei, often referred to as the amygdala complex. The lateral nucleus of the amygdala is critically involved in the acquisition, storage, and expression of conditioned fear. The prefrontal cortex is thought to act on the lateral nucleus of the amygdala to suppress conditioned fear. The hippocampus is thought to interact with that part of the amygdala to mediate learning about the context of fear-related events. The amygdala is thought to control defensive behavior via outputs from the central nucleus of the amygdala. ….Nothing Follows….