Introduction to Brain and Behaviors Exam Four Emotion Psychologists define emotion by cognition action and feeling Emotional situations arouse the autonomic nervous system each situation evokes its own unique mixture of sympathetic and parasympathetic arousal James Lange Theory emotional feelings result from the body s actions o This suggests that an event first provokes the autonomic arousal and skeletal responses and that the feeling aspect of emotion is the perception of those responses o Event Appraisal the cognitive aspect Action the behavioral aspect including physiology Emotional feeling the feeling aspect o Panic attacks are marked by extreme sympathetic nervous system arousal this includes rapid heartbeat and fast breathing but this is only is perceived as a panic attack if it occurs spontaneously o Perditions people with a weak autonomic and skeletal response should feel less emotion and increasing one s response should enhance an emotion o Testing the theory Paralyzed people report feeling emotion to the same degree as prior to their injury People with pure autonomic failure still report feeling emotion but less intensely Pure autonomic failure is a condition when output from the autonomic nervous system to the body fails Pen experiment smiling slightly increases happiness and inducing a frown leads to the sating of stimuli as slightly less pleasant Botox blocks transmissions at synapses andm nerve muscles junctions so people have slower times in reading unhappy sentences and a weaker than usual emotional response after watching short videos o M bius syndrome people with this condition cannot move their facial muscles to smile Surgery can be performed to create an artifical smile the lack of a smile prior to surgery does not interfere with happiness or sense of humor but it does affect the ability to make friends The basic human emotions include anger fear disgust surprise happiness and sadness o Each emotion has a unique expression defined by the shape of the mouth eyes and elicits brain activity in different areas The measurement of evoked responses indicate that the brain is specialized to attend strongly to facial expressions Emotions tend not to be localized in specifc parts of the cortex also a single emotion increases activity in various parts of the brain Digust is localized in the insular cortex o Different parts react to different types of disgusting scenes including the primary taste o The insular cortex also reacts to frightening stimuli and angry faces so it is not complelty dedicated to digust Emotions have various functions o They motivate us by forming appetites to satisfy and aversions to avoid o They have survial values like fear and anger o Contemplating moral decisions activates the prefrontal cortex cingulate gyrus and cortex amygdala Introduction to Brain and Behaviors Exam Four The two hemispheres of the brain play different roles in emotion o Left frontal and temporal lobes o Right frontal and temporal lobes Behavioral activation system BAS is marked by low to moderate autonomic arousal and a tendency to approach which could characterize either happiness or anger Greater activity is characteristic of happier more out going friendlier people Damage results in a better ability to detect others emotions Behavioral inhibition system BIS increases attention and arousal inhibits action and stimulates emotions such as fear and disgust Greater activity is characteristic of people who are socially withdrawn less satisfies with life and prone to unpleasant emotions Damage results in problems with the ability to detect others emotions When inactive people do not experience strong emotions and do not remember feeling them The right hemisphere seems to be more responsive to emotional stimuli than the left Damage to the prefrontal cortex impairs decision making leading to impulsive decision making without consideration of the consequences This stems from a failure to anticipate the unpleasantness of an outcome for instance Phineas Gage Those with damage to the ventromedial prefrontal cortex show decreased guilt The limbic system includes the forebrain areas surrounding the thalamus it has traditionally been regarded as critical for emotion Many researchers have used PET and fMRI techniques to identify the cortical areas that respond while people look at emotional pictures or listen to emotional stories The areas are the frontal and temporal lobes o Olfactory bulb o Hypothalamus o Hippocampus Memory o Amygdala Connected to the hypothalamus Storage of memories associated with emotional events It is the emotional center of the brain especially negative emotions fear aggression and anger fMRI studies suggest the amygdala responds strongly to emotional stimuli facial expressions Activity is strongest when the meaning is unclear and required processing and strong for angry and frightened faces Damage to the amygdala impairs the processing of emotional information it affects the ability to recognize emotions specifically in photographs particularly for fear and disgust but not in real life o Cingulate gyrus Part of the cortex Coordinated sensory input with emotions emotional responses to pain and regulates aggressive behaviors Attach and Escape Behaviors o Attack and escape behaviors are associated with anger and fear pain a threat or other unpleasant stimuli can trigger an attack Introduction to Brain and Behaviors Exam Four o Attack behaviors are associated with increased activity in the corticomedial area o Provocation makes people more likely to attack for a period of time an initial attack increases the probability of a second attack o Violent tendencies increase with exposure to lead when you witness victim of violence in childhood o Violence can be hereditary shown through identical twin studies o Higher levels of testosterone increases aggression o Triple imbalance hypothesis violence depends on other chemicals including cortisol and serotonin Cortisol is a stress response that increases blood sugar and suppresses the immune system Serotonin tends to inhibit violent impulses When cortisol is low and testosterone is high aggression levels are higher o Low levels of serotonin also increase aggressive behaviors Valzelli s study 1973 with male juvenile mice found that social isolation decreased serotonin turnover and increased aggressive behavior Turnover the amount of a neurotransmitter that is released and resynthesized by neurons 5 hydroxyindoleacetic acid
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