Emotional Behaviors How are emotions and physiological responses linked? Common Sense View Perception of event Feeling of Fear/Anxiety/Stress Physiological reactions I. _____________________(1884): 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 Perception of bear Physiological reactions Feeling of Fear Example: the sight of a bear elicits increases in several autonomic (heart rate, blood pressure, etc), endocrine (hormonal) and behavioral responses (running), which in turn produce the conscious feeling of fear. II. ___________________ (1900s): The theory that emotional experience and emotional expression are parallel processes that have no direct causal relation (i.e., autonomic and behavioral responses are completely independent from “feelings”) Perception of bear Physiological reactions Feeling of Fear Strong predictions of these two theories: - James-Lange theory predicts that without autonomic and somatic feedback, people would have no emotions - Cannon-Bard theory predicts just the opposite, that person does not need autonomic and somatic feedback to be aware of emotions Studies have indicated that both theories are right and wrong at the same time III. Modern biopsychological view of emotions. Antonio Damasio has recently suggested his _________________________ of emotion, which suggests that signals (markers) arising from internal and external environment (emotional stimuli) act to guide behavior and decision making, usually in an unconscious process The limbic circuit (Papez, 1937) and emotion: Influential early neuroanatomical circuit of several interconnected brain structures believed to be important for emotional expression and feelings Papez proposed that emotional __________ was produced by activity of the limbic circuit upon the hypothalamus, and that emotional __________ was the product of limbic activity upon the cortex (from the cingulate cortex) The Amygdala and Emotions The Kluver-Bucy (1939) syndrome: originally observed in monkeys sustaining bilateral anterior temporal lobectomies (especially the amygdaloid complex) Behavioral outcome of this surgical procedure include the following: - __________________ - consumption of nearly everything edible; - increased, but inappropriate, sexual activity (often towards inanimate objects); - tendency to repeatedly investigate same objects; - tendency to investigate objects with mouth; - _____________________________ This syndrome has been observed in patients sustaining bilateral removal of the amygdaloid complex and some types of encephalitis. FEAR The feeling of fear produces a constellation of endocrine, autonomic, and behavioral responses that are very characteristic. Examples: increased heart rate, blood pressure, respiration, arousal, ulcers, urination, defecation, glucocorticoid secretion, facial expression of fear, fight or flight response, etc All these autonomic and behavioral reactions in response to fearful situations have been shown to be organized, integrated, and controlled by the ________________________. - lesions of the amygdala in laboratory animals normally eliminate all these fear reactions Example: Normal rats are very scared of cats, (natural predators of rodents), and rats do not normally approach cats, even if the cat is anesthetized; however, rats with bilateral damage to the amygdala will climb all over anesthetized cats and even pull their wiskers!!! Amygdala & Fear Conditioning Sensory cue: Sight, smell, sound etc Noxious Stimulus Thalamus Cortex Prefrontal Cortex x Amygdala Associative Processes Hypothalamus Brainstem Endocrine, Sympathetic & Behavioral Responses Possible clinical relevance for anxiety disorders, post-traumatic stress disorder (PTSD). HUMAN FEAR Patients evaluated for neurosurgery and subjected to electrical brain stimulations show autonomic signs of fear when stimulated in ______________ but no reports of _____________________ - however, ____________________ produces both autonomic fear responses and experiential reports of fear Bilateral damage to the amygdala in humans also prevents the elicitation of several _____________ ______________________ in response to fear provoking stimuli Negatively charged stimuli which are fearful also help remember details of the situation; people with amygdala damage do not show this facilitating effect of negative emotions on memory Finally, human subjects who participate in brain imaging experiments (PET or fMRI scans) and are shown __________________________ display particularly high brain activity levels of the amygdala bilaterally Imaging studies e.g. functional magnetic resonance imaging (fMRI) which indirectly measures neuronal activation, also show that the amygdala is central to the fear respsonse. fMRI is based on the facts that: 1. active neurons use oxygen, so there will be increased blood flow to the area. 2. oxyhemoglobin and deoxyhemoglobin have different magnetic properties e.g. The amygdala is activated after seeing pictures of fearful or angry faces. It does not require conscious awareness of emotion to be activated. Amygdala Miller et al., (2005) J. Neuropsychiatry Clin. Neurosci. 17:1-6 Masked fearful faces Masked angry faces
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