Chapter 9 Emotion - Instructor: Layla Gould PDF

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Instructor: Layla Gould...

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What is Emotion ● Hard to define and describe, internal ● A product of the brain ● Emotional states have 2 components: ○ Physiological sensation ○ Cognitive experience, or feeling, of the emotion itself ● Self monitoring of ○ Physiological changes (in ourselves and others) ○ Subjective cognitive states ○ Can get mixed up sometimes ● Emotion = sudden, intense reactions to events, more short-term feelings (eg. feeling sad after hearing unexpected bad news) ● Mood = more diffuse and tend to last longer (eg. being depressed, or overall good mood) Basic Emotional States ● Happy, surprise, contempt, sadness, fear, disgust, anger ● First discovered by Darwin ● Innate, universal, automatic (except for contempt, debated) ● Ekman: first cross-cultural study of emotional expression ○ Are emotional expressions culturally learned? ■ If yes - variation in how these “basic emotional states” are interpreted in diff cultures ■ If no - same identification and interpretation of expressions ○ Fore tribe members from Papua New Guinea asked to match the facial expressions to stories about emotional states ○ Result: emotional expressions are not culturally learned ● Seven elements of Basic Emotional States ○ Distinct facial expression ○ distinct physiological state (eg. increased heart rate) ○ facial expression and physiological states that occur together - difficult to separate ○ instantaneous onset of facial expression / physiological state ○ distinctive eliciting stimuli (one thing should only make you feel one emotion, a spider should cause fear and not happiness at the same time) ○ automatic appraisal of the eliciting stimuli (emotion should be automatic, instantaneous) ○ similar expression of emotional states in related primates ○ (will not be asked to list all 7 in exam) ● Adaptive Value of Emotional States ○ learned response (learn to fear things that harm us) ○ evolved avoidance mechanism (fear of spiders, learn to avoid them) ○ motivator to produce socially adaptive/acceptable behaviour (fear of public speaking - due to desire to fit in with the group and scared of being judged and

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not accepted) cues to produce or avoid specific behaviours communication of information (basic states help us communicate how we are feeling with our expressions)

Theories of Emotional States ● Several explanations of how cognitive and physical features of emotional responses give rise to emotional status ● James-Lange Theory ○ Emotionally provocative stimulus => Physiological response (emotion) => cognitive experience (feeling) ■ Snake => increased heart rate => thinking “i am afraid” ○ We feel our body’s response first, then interpret that as an emotion ○ Cant distinguish b/w emotions (eg. fear or excitement) ○ Not much evidence support it ○ If you are in a bad mood you should smile, so cognitively you would interpret that as you are in a better mood ● Cannon-Bard Theory ○ Emotionally provocative stimulus => activation of thalamus ○ Some signals sent to the cortex => cognitive experience ○ Some signals sent to the hypothalamus => physiological response ○ Allows us to distinguish what we are feeling ● Schacter-Singer Theory (Adding context) ○ Emotionally provocative stimulus => physiological arousal => cognitive appraisal of situation/context => feeling ■ Snake => increased heart rate => realizing “I’m at the zoo, this is fun!” => feeling happy ■ Roller coaster => heart rate racing => fun ■ Driving car off the cliff => same physiological response, diff context => terrifying Laterality of Emotion ● Production of Emotion ○ Facial expression ■ Everyone has an asymmetrical smile ■ Voluntary expression mediated by precentral gyrus ● Upper half of face - symmetrical, bilateral, controlled by both sides ● Lower half of face - contralateral ○ RH (“the emotion side”) - left side of face, goes up higher ○ LH - right side of face ■ Involuntary expressions mediated by thalamus - bilateral ○ Anatomy of a Smile ■ Social smile = consciously activate the muscles in the cheek that stretch mouth sideways

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Duchenne smile = additional set of muscles around the eyes that make lower lids of eyes swell and edges crinkle, genuine smile, can’t be forced ○ Valence Hypothesis = asymmetry for expression or perception of emotions depends on valence ■ RH = negative emotion ■ LH = positive emotion ■ Support from lesion studies: ● RH damage - positive mood, pathological laughter ● LH damage - negative mood, depression, increased crying ■ Mixed results, support is weak: ● Stronger leftward posing bias when an individual expressed happiness ● left side of the face more prominently displayed negative emotions ● leftward bias for sadness, no bias for happiness ■ Posing Bias ● Right cheek forward - more serious ● Left cheek forward - more emotions ○ Right Hemisphere Hypothesis = RH is responsible for all expression or perception of all emotional info regardless of valence ■ Support from studies on healthy controls ● Faster to identify emotions in left visual field ● No difference for positive or negative emotions Perception of Emotion ○ Experimentally testing perception is easier than production ○ Visual tests examine facial emotional processing ■ Chimeric faces - 1/2 face ● Assessment of emotional content of chimeric faces is based on the left side of the face ● Left-left composite usually perceived as more emotional ■ Lateral presentation of a single face ● Identification of emotion more accurate in left visual field ○ Auditory tests examine emotional prosody processing ■ Dichotic listening tasks ● Left Ear Advantage (LEA) ○ better at identifying emotional tones in speech and hear non speech emotional tones (eg. crying, laughing) better (eg. over white noise) ○ RH lesion patients showed greater impairment in interpreting emotions in people’s voice than LH lesion patients ● Right Ear Advantage (REA) ○ better at identifying / pick out specific words, the basic language aspect of it, eg, pick out the word “sadness” in a string of words or in white noise, right ear does better at

this Neuroanatomy of Emotion ● Cortical Structure ○ Limbic System = process expression and perception of emotional states ■ Higher order cognition - how we think about our feelings ■ Cognitive components of emotional states ■ Insula = generally involved in negative emotions, but also everything ■ Disgust, fear, learning to avoid noxious stimuli, phobias ■ Empathy and love ○ Prefrontal Cortex ■ Regulation of emotional behaviour, controls our emotion ■ Anticipate consequences of action ■ Positive emotions - happiness and love ■ Patient J. P: Agenesis of the Frontal Lobe ● normal intelligence, typical language/motor skills ● as a child, showed no emotion except for anger ● problem child, criminal record ● at 19, found out he was missing RH frontal lobe completely, and 50% of LH frontal lobe ● Evidence that emotion and social behaviour is controlled by RH frontal lobe ○ Cingulate Cortex ■ Paying attention to our emotion states ■ Conscious, subjective, emotional awareness - aware of how we are feeling, self monitoring ■ Motivation ○ Hippocampus ■ Personal or episodic memories that include emotional content ■ Creates a replay of emotions from the past, lets you relive it ■ Sometimes may blend w/ current emotions or override them ● Eg. if you think of a sad memory that is associated w/ a negative emotion, that could ruin your good mood in the moment; or if you think of a happy memory and it makes you happy, memory triggers that emotion that may override your current emotion ● Our brain forgets the pain of having a baby, the joy overrides the pain of having a baby. “I’m not letting my brain trick me into having a baby” ● Subcortical Structure ○ Amygdala = negative emotions, esp fear ■ Activated even before conscious perception of fearful faces - unconscious fear processing ■ Patient S.M: “the woman with no fear” ● exclusive and complete bilateral amygdala destruction

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no fear of anything at all impaired in recognizing negative social cues (eg. people giving her nasty looks), cannot interpret negative emotions in ppl expressions ● difficulty judging trustworthiness of others or dangerous situations ● experiences relatively little negative emotion ○ Hypothalamus = physiological component of emotional state (eg. heart rate) ○ Olfactory Bulb = carries message about smell directly to the limbic system ■ Only sense that doesn’t go through the thalamus, all other senses are sent to the thalamus first then redirected to the limbic areas ■ Strong association b/w a smell and a memory/emotion Different Emotions Activation Diff Regions of Brain ○ Fearful faces ■ left anterior insula ■ bilateral anterior cingulate ○ Happy Faces ■ posterior right superior temporal gyrus ■ visual cortex, lingual and fusiform gyri ○ Disgusted faces ■ anterior insula in both sides Feeling Hatred ○ Amygdala - negative emotion ○ Insula - disgust, emotion ○ Brain areas concerned w/ action and calculation (same calculation as an animal would show when they are about to attack a prey) Feeling Love ○ caused by release of dopamine (feel good transmitter) into the reward system of the brain (cortico-basal ganglia-thalamo-cortical loop - involved in reward processing) ○ decrease in serotonin - lowered sense of control, less certainty and stability, obsession ○ decrease in activity in prefrontal cortex (reasoning, control centre) and amygdala (threat-response system) - more likely to take risks, make rush decisions ○ brain on cocaine looks the same as brain in love ○ Bartels & Zeki study: ■ show participants pics of their friends (like) and life partners (love romantically) ■ Loved ones: left insula, anterior cingulate cortex ■ Friends: Right prefrontal, parietal, and middle temporal cortex, posterior cingulate cortex ■ love activates separate neural regions than positive stimuli (eg. happy faces, films, friends) Brain of a Psychopath

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behavioural patterns - compassion, empathy, guilt - differ from the general population lower activation in regions associated w/ emotion processing non limbic strategies to process emotional info, different strategies from healthy individuals Psychopathy - biological developmental disorder, don’t understand right or wrong, don’t feel fear ■ ventral striatum activated when seeing other ppl in pain Sociopath - moral compass off due to upbringing or belief system, understand right and wrong but diff definition of right and wrong from other ppl

Disorders of Emotion ● Pseudobulbar Affect (PBA) ○ uncontrollable episodes of crying and/or laughing, or other emotional displays ○ NOT a mood disorder ○ due to neurological disorder or brain injury or stroke ○ damage to prefrontal cortex ○ treatment = antidepressants ● Aprosodia = deficit prosodic processing following right hemisphere damage ○ Motor aprosodia = inability to produce prosody normally, resulting monotone speech ○ Sensory aprosodia = inability to recognize prosody in others’ voice ○ Sometimes RH damage can also lead to selective impairment in recognizing facial expressions ● Kluver-Bucy Syndrome ○ result of damage to bilateral anterior temporal region ○ Symptoms: ■ Tameness, loss of fear, compulsive eating ■ hyper sexuality ■ Hypermetamorphosis (can’t stop interacting w/ everything around us) ■ socially unacceptable behaviour ■ oral examination of objects ■ visual agnosia ● Capgras Syndrome ○ a disconnection bw face (FFA, temporal lobe) and emotional (limbic) processing ○ believe that families or loved ones are replaced by identical imposter ○ ability to perceive express experience emotion and face is intact ○ do not show the normal emotional response to seeing a loved one ○ recognize loved one’s faces, but not feeling the love, not receiving a person as loved one at all, think they are someone else who looks identical who’s pretending to be the loved one ● Depression ○ mood disorder, extended periods of depressed mood

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evidence of genetic contribution ■ 50-70% concordance for monozygotic twins ■ 13-20% concordance for dizygotic twins ○ decrease in: ■ Dopamine ■ Norepinephrine ■ serotonin - most often talked about, antidepressants usually target this ○ Pathology: ■ loss of cortical mass in frontal and temporal areas ■ 10-30% of ppl w depression show enlarged ventricles ■ less glucose metabolism in LH frontal regions ■ less blood flow in frontal regions and basal ganglia ■ increased RH activity ■ (don’t need to remember these) Bipolar Disorder ○ alternate b/w depressive and manic states ○ Pathology ■ decreased lvl of serotonin and GABA ■ hyperactivity in limbic system when in manic state ■ reduced prefrontal cortex activation ■ abnormal connections bw frontal lobes and basal ganglia Anxiety ○ various disorders characterized by a sense of danger, distress, or fear ○ Generalized Anxiety Disorder = anxious sensations in the absence of an identifiable stimulus ■ increase activity in frontal and temporal activation ○ Posttraumatic Stress Disorder = anxious sensations in response to reminders of a traumatic event ■ reduced hippocampal volume, increased amygdala activity, decreased activity in Broca’s area (language) ○ Obsessive Compulsive Disorder = unwanted obsessions and recurrent behaviours to alleviate the discomfort caused by the obsession ■ decreased metabolism in orbitofrontal cortex, caudate nucleus, anterior cingulate, thalamus, parietal cortex, basal ganglia ○ Phobias = anxious somatic sensations in response to a specific stimulus ■ dysfunction of the amygdala...