emotion & the brain

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.

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social isolation or socially indiscriminate, withdrawn, impaired mothering, and death (Franzen & Myers, 1973)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

(Aggleton, 1993)

The amygdala modulates downstream processing---arousal and attention to evocative stimuli-early visual processing of emotional faces can be influenced by amygdalar activity.

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

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

(Hamann, 2001)

Amygdala activity during encoding associated with recall of + and - stimuli.

positive negative

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.

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 circuitsAlexander, Delong, & Strick (1986); Cummings (1993)

Circuit Connections Syndrome

Dorsolateral Superior Parietal, other DLPFC, premotor

Dysexecutive, Abulic/Depressed

Orbitofrontal Amygdala, cingulate, anterior/ventral/medial temporal, insula

Irritable, impulsive, environmental dependency, OCDDepression, 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.)

Abnormalities in Depression

• Limbic– anterior cingulate

(from http//www9.biostr.washington.edu/da.html)



• Paralimbic– anterior insula

– ventral frontal

(from http//www9.biostr.washington.edu/da.html)



• 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

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

Pandya & Yeterian (1996)

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

Courville (1934)Vessalius (1536)

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

http://cercor.oupjournals.org/content/vol10/issue3/images/large/16399f01.jpeg

Inputs and Outputs of OFC

Rolls, 2000

http://cercor.oupjournals.org/content/vol10/issue3/images/large/16399f02.jpeg

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

• Inhibition (impulse control)

• Learning and reversal of stimulus-reward associations– Primary reinforcers

(rewards): food, sex, social affiliation


Functions of the paleocortical (ventral) trend

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 disorderLevine 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

“We make judgments not only by assessing probabilities and consequences, but also (and primarily) by evaluating their emotional attributes” -- Antonio Damasio

Somatic Marker Hypothesis

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)

Courtesy of Antoine Bechara, University of Iowa

Iowa Gambling Task

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


• 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


• Neuroimaging: R-OFC in processing angry, but not sad, facial expressions

• Angry vs. neutral face• Blair, et al., 1999

http://cercor.oupjournals.org/content/vol10/issue3/images/large/16899h5.jpeg


• 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 systemGallese 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

• 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

ImpairedNon-ImpairedR

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

Humor appreciationShammi & Stuss, 1999

Good luck on the exam!Tuesday SF3202, 2-5pm

Answers:Multiple choice:

Short answers:

Diagram:

Brain

“c”

“yes”

“memory”

“executive functions”

“emotion” or “affect” (1/2 credit)

emotion & the brain

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