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Emotion & the Brain. Nathan Spreng August 10 Cognitive Neuroscience: Psy393. Lecture Outline. Neurobiology of Emotion Amygdala Depression Emotional Executive Functions Self & Social Cognition About the exam. Circuitry of Emotion. ( A ) Orbital PFC in green Ventromedial PFC in red.
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Emotion & the Brain Nathan Spreng August 10 Cognitive Neuroscience: Psy393
Lecture Outline • Neurobiology of Emotion • Amygdala • Depression • Emotional Executive Functions • Self & Social Cognition • About the exam
Circuitry of Emotion (A) Orbital PFC in green Ventromedial PFC in red. (B) Dorsolateral PFC (C) Amygdala. (D) Anterior cingulate cortex. (E) Insula • Each interconnected structure plays a role in different aspects of emotion • abnormalities in one or more of these regions and/or in the interconnections among them are associated with failures • of emotion regulation • increased impulsivity • increased chance of aggression Davidson, Putnam & Larson, 2000
Neurobiology of Emotions • fMRI activation—many activated sites, substantial overlap between different emotions. • Not one-to-one • Commonalities: Insula activation—disgust.
Kluver-Bucy Syndrome • Hyperorality • Psychic blindness • Blunted emotions • Hypersexuality • Dietary change • Naturalistic studies: Loss of respect for social rank, social isolation or socially indiscriminate, withdrawn, impaired mothering, and death (Franzen & Myers, 1973)
Afferent Connections (Aggleton, 1993)
Efferent Connections (Aggleton, 1993)
Amygdala influences object processing in the ventral stream The amygdala modulates downstream processing-- -arousal and attention to evocative stimuli -early visual processing of emotional faces can be influenced by amygdalar activity. (Aggleton, 1993)
Case Study • Urbach-Weithe disease • Bilateral calcification of the amygdala • Impaired recognition of emotion in facial expressions (Adolfs, et al., 1994) • Increased trustworthiness and approachability of unfamiliar faces (Adolfs, et al., 1998)
Cerebral blood flow and Affective Stimuli • Amygdala involved in processing of emotional facial expressions (Morris, et al., 1998) • Amygdala (and orbitofrontal cortex) in pleasant and unpleasant pictures and faces ` (Keightly et al., 2003)
fMRI encoding of emotional events Amygdala activity during encoding associated with recall of + and - stimuli. Amygdalar activity associates with later memory for individual emotional experience(Canli, et al., 2000) negative (Hamann, 2001) positive
PET study • Emotional (negative) relative to neutral film viewing • Increased right amygdalar activity • Partial Least Squares analysis (ANCOVA) and structural equation modeling • Significantly increased amygdala influences on ipsilateral • Parahippocampal gyrus • Ventrolateral prefrontal cortex (Kilpatrick & Cahill, 2003)
PTSD and Memory • Limbic system activation in response to vivid recollection • September 11th relative to everyday memory control. • Right amygdala • Hypothalamus • autonomic and endocrine responses • Note additional visual association cortex activation
PTSD and Memory • Amygdalar and visual cortex activation in • PTSD memories of Air Transat passengers vs. controls • In response to viewing video recreation of the AT disaster.
POSITIVE Disinhibition Impulsivity Vulgarity Irritability Emotional liability Inappropriate laughter, crying Bizarre social behavior NEGATIVE Apathy Reduced initiative (Abulia) Reduced interest in daily activities/self-care Akinetic mutism Social withdrawal Affective Symptoms of Frontal Lobe Disorders
Frontal-subcortical circuitsAlexander, Delong, & Strick (1986); Cummings (1993)
Depression • Definition (DSM IV-R): • “...the presence of a persistent negative mood state occurring in conjunction with an array of core behavioral symptoms, including disturbances of attention, motivation, motor and mental speed, sleep, appetite, and libido as well as anhedonia, anxiety, guilt, and recurrent thoughts of death with or without suicidal ideations or attempts.” (A.P.A.)
Abnormalities in Depression • Limbic • anterior cingulate (from http//www9.biostr.washington.edu/da.html)
Abnormalities in Depression • Limbic • anterior cingulate • Paralimbic • anterior insula • ventral frontal (from http//www9.biostr.washington.edu/da.html)
Abnormalities in Depression • Limbic • anterior cingulate • Paralimbic • ventral frontal • anterior insula • Neocortical • parietal • prefrontal (from http//www9.biostr.washington.edu/da.html)
Lesion-Deficit & Physiological Studies • Mood: • Mapped to limbic and paralimbic areas (cingulate, insula) and prefrontal cortex ….but with much variability • Attention: • Mapped to right prefrontal, parietal, and dorsal anterior cingulate regions
Limbic-Cortical Dysregulation(Mayberg, 1997) • Similar patter of inter-regional interactions and regional reciprocity in functional brain activity inversely associated with: • Transient normal sadness in healthy adults • remission of chronic dysphoric symptoms in unipolar depressed patients following treatment
PET Experiments • Experiment 1: • Healthy Adults • PET scanned: induced sad & neutral conditions • Experiment 2: • Unipolar depressed patients • Remission: dysphoric mood & other symptoms • PET scanned before, and after 6 week treatment
Results: Experiment 1 • Transient Sadness - Neutral • Increased Activation: • Ventral limbic and paralimbic sites (subgenual cingulate; ventral, mid-, and posterior insula) • Decreased Activation: • dorsal cortical regions (right dorsolateral PFC, inferior parietal, dorsal anterior cingulate, posterior cingulate
Results: Experiment 2 • Post-treatment - Pre-treatment • Increased Activation: • dorsal cortical regions (right dorsolateral PFC, inferior parietal, dorsal anterior cingulate, posterior cingulate) • Decreased Activation: • ventral limbic and paralimbic sites (subgenual cingulate, ventral, mid-, and posterior insula)
Areas of Activation (Mayberg, 1997)
Common Changes (Mayberg, 1997)
Limbic-Cortical Model:Negative Mood / Depression dorsalACC: cognitive ventralACC: emotional reciprocal inhibition across tasks (Mayberg, 1997)
15 minute break • Evals
Executive Emotional Systems • Orbitofrontal cortex has been associated with at least three partially dissociable cognitive systems • Nonsocial response reversal system (Rolls) • Somatic Marker hypothesis (Damasio) • Social response reversal system (Blair)
Pandya & Yeterian (1996) Dual evolutionary trends in architectonic development Inter-trend dimension • Archicortical (dorsal) trend • Paleocortical (ventral) trend Intra-trend dimension • Increasing laminar definition from limbic origins to cortical extent • Highest forms of consciousness impaired by damage to most recently evolved cortex
Focal cortical contusion Vessalius (1536) Courville (1934) Pandya & Yeterian (1996) Contusions in these locations regardless of the site of impact
Functions of the ventral brain • Monkey studies (Franzen & Myers, 1973; Kling & Steklis, 1976) • Loss of respect for social rank • Social isolation, death • Inhibition (impulse control) • Learning and reversal of stimulus-reward associations • Primary reinforcers (rewards): food, sex, social affiliation • Making and decoding emotional signals • Self-regulation • Not assessed in standard laboratory exam
Pathways of the OFC Rolls, 2000
Inputs and Outputs of OFC Rolls, 2000
Roll’s Theory of Emotion:Nonsocial response reversal • Emotions: states elicited by rewards and punishers • Reward: something an animal will do for work • Punisher: something an animal will avoid or escape from • Emotions are modulated when a reward or punisher is received, omitted, or terminated. • Emotion/motivational state provide an interface between sensory inputs and action systems. (Rolls, 1998; 2000)
Roll’s Theory of Emotion • In orbitofrontal cortex and amygdala, primary reinforcers are represented. • Secondary reinforcers learned there. • Hedonic value of stimuli is processed. (Rolls, 1998; 2000)
Representation of primary reinforcers • Learning trials not necessary • Taste, smell, objects, faces, texture, touch • Reward value (not identity) represented in OFC • Neuronal responses modulated by hunger • Primary representation precedes secondary representation (e.g., taste-objects) • “OFC is involved in emotional responses by correcting stimulus-reinforcer associations when they become inappropriate.” (Rolls, 2002)
Visual discrimination reversal Rolls, 2000
Brain mechanisms underlying emotion (Rolls, 1998)
OFC- Neuroimaging findings I • Four (suite) vs. two (colour) guessing. • Monitoring reward value of possible responses. • Delayed matching-to-sample vs. Delayed nonmatching-to-sample • Association between stimulus and forthcoming reward. • Medial OFC- association between stimuli and correct rewarded responses.
Reversal of prior stimulus-reward associations When a previously rewarded stimulus is no longer rewarding Dealing with ambiguity • Reversal learning • Go-NoGo • Object alternation • Extinction • Delayed match to sample • Delayed nonmatch to sample
PET • Eating chocolate past satiety • When reward becomes punishment • Medial to Lateral OFC Small, et al., 2001