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

•

f

MRI activation—many activated sites, substantial overlap between different emotions.

• Not one-to-one • Commonalities: Insula activation—disgust.

Emotional Recollections

Emotional Recollections

Subcortical Structures of the Limbic System

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• Dietary change • Naturalistic studies: Loss of respect for social rank, social isolation or socially indiscriminate, withdrawn, impaired mothering, and death (Franzen & Myers, 1973)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.

(Hamann, 2001) positive negative Amygdalar activity associates with later memory for individual emotional experience (Canli, et al., 2000)

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 11 th 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.

Affective Symptoms of Frontal Lobe Disorders • 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

Frontal-subcortical circuits

Alexander, Delong, & Strick (1986); Cummings (1993) Circuit Connections Syndrome Dorsolateral Superior Parietal, other DLPFC, Dysexecutive, premotor Abulic/Depressed Orbitofrontal Amygdala, cingulate, Irritable, impulsive, anterior/ventral/medial temporal, environmental insula dependency, OCD Depression, neurovegetative changes (medial) Cingulate DLPFC, VLPFC, Lateral and medial temporal, hypothalamus, midbrain, amygdala, insula Apathy, indifference

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.)

Video

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)

• Evals

15 minute break

Dr. “Zorro”

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)

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 Pandya & Yeterian (1996)

Focal cortical contusion

Vessalius (1536) Courville (1934) Pandya & Yeterian (1996) Contusions in these locations regardless of the site of impact

Vascular system

Stuss & Levine (2002)

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 • Reversal learning • Go-NoGo • Object alternation • Extinction • Delayed match to sample • Delayed nonmatch to sample When a previously rewarded stimulus is no longer rewarding Dealing with ambiguity

• PET • Eating chocolate past satiety • When reward becomes punishment • Medial to Lateral OFC Small, et al., 2001

Functions of the paleocortical (ventral) trend

Pandya & Yeterian (1996) • Inhibition (impulse control) • Learning and reversal of stimulus-reward associations – Primary reinforcers (rewards): food, sex, social affiliation

Inhibition/Impulse Control

• Male subjects viewed erotic film excerpts while they either – responded in a normal manner (arousal) – voluntarily attempted to inhibit sexual arousal • Sexual arousal experienced, activation in "limbic" and paralimbic structures: – right amygdala, right anterior temporal pole, and hypothalamus. • Inhibition of the sexual arousal activation – right ventral PFC & right anterior cingulate gyrus – No activation was found in limbic areas • Emotional self-regulation is implemented by a neural circuit: – prefrontal regions and subcortical limbic structures – under voluntary control Beauregard, et al., 2001

• Self-regulatory disorder

Levine et al., (1998, 1999, 2000)

– Inability to regulate behavior according to internal goals and constraints, especially in unstructured situations • “Acquired sociopathy”

Eslinger & Damasio(1985)

– An emotion dysfunction defined largely by emotional shallowness and lack of guilt – Antisocial behaviour

Somatic Marker Hypothesis

“We make judgments not only by assessing probabilities and consequences, but also (and primarily) by evaluating their

emotional

attributes” -- Antonio Damasio

Somatic Marker Hypothesis

• Link between factual knowledge and bioregulatory states • During decision-making, emotional and visceral representations bias decision making • Representations associated with an option (from prior experience) are re-activated to bias decision making covertly • Somatosensory pattern marks the scenario as either good or bad, allowing the rapid rejection/endorsement of specific option-outcome pairs

Iowa Gambling Task

Four decks to pick cards: • Two decks have high immediate, but low overall reward (the bad decks: A & B). • Two decks have a low immediate, but high overall reward (the good decks: C & D) • Reward contingencies must be discovered Bechara

et al.

(1994)

Iowa Gambling Task

Courtesy of Antoine Bechara, University of Iowa

Iowa Gambling Task

Courtesy of Antoine Bechara, University of Iowa

Iowa Gambling Task

Courtesy of Antoine Bechara, University of Iowa

Iowa Gambling Test

• Patients with VMPFC damage draw excessively from decks with negative consequences (high reward/higher loss vs. low reward, lower loss) • Healthy participant generate high skin conductance prior to making a bad decision before knowing the best strategy • Somatic markers: patients with VMPFC damage fail to generate skin conductance response in relation to bad decks • Patients with non-VMPFC damage can also be impaired (e.g., Manes et al., 2002) • Psychopaths impaired Bechara et al. (1994) Cognition

Social response reversal system

• OFC in response reversal – Changes reinforcement contingencies • Social cues in modulating social behaviour where social rules or expectations have been violated Blair, 2001

Social response reversal system

• Angry expressions are known to curtail the behaviour – previously experience associated with another individual's angry responses or other negative valence expressions – eg staring expressions of others that can precede a sense of embarrassment, and perhaps others' disgusted expressions • Evolutionary origins: – regulating behaviour in disputes between conspecifics – at different levels in a social hierarchy

Social response reversal system

• Neuroimaging: R OFC in processing angry, but not sad, facial expressions • Angry vs. neutral face • Blair, et al., 1999

Social response reversal system

• Patients who present with reactive aggression following OFC lesions have – impaired in processing angry expressions – and judging the appropriateness of behaviors in particular social contexts (Blair & Cipolotti, 2000).

The self and social cognition

• Self-awareness • Moral reasoning • Theory of mind • Humor

Self awareness

• Craik et al. (1999): Self- vs. other- reference (adjective judgment): left medial prefrontal • Kelley et al. (2002): Event related design; fMRI – mPFC less deactivated than control conditions

Moral Reasoning

• Moral decision making task • vs. categorical judgements • Frontal Polar • Medial PFC Moll, Oliveira-Souza & Eslinger, 2003

Mirror neuron system

Gallese et al., 2004

• Neurons in monkey ventral premotor cortex fire in response to performance and observation of goal directed action • Human mirror-neuron network: inferior parietal, inferior frontal • Emotional states (pain. disgust): anterior insula • Internal replication of others’ actions and emotions – Links first- (“I do…”) and third-person (“She does….”) experience • Direct understanding; may scaffold cognitive representation

Emotion identification and empathy • VPFC patients impaired on the identification of facial expression – not attributable to primary or secondary difficulties in perception – relates specifically to the emotional nature of the stimuli • Exhibited some combination of disinhibition or socially inappropriate behaviour • Reduction or absence of the ability to feel or experience emotions • Inability to empathize Hornak, et al., 1996

Theory of mind:

Attribution of mental states

• Understanding the joke depends on the ability to attribute mental states to others (left) or does not (right) • Contrasting: Medial PFC

Theory of mind:

Attribution of mental states

 PET: Fletcher et al (1995); Goel et al (1995): L MPFC  Focal lesion: Happe (1999): R hemisphere stroke; Stone et al (1998): ventral but not dorsolateral prefrontal  Stuss et al. (2001): Transfer of inference: (visual perspective taking) R PFC; Deception: ventral PFC Non-Impaired

R

Impaired

Humor appreciation

Shammi & Stuss, 1999

Good luck on the exam!

Tuesday SF3202, 2-5pm

Answers: Multiple choice: Short answers: “c” “yes” “executive functions” “memory” “emotion” or “affect” (1/2 credit) Brain Diagram: