ch 10. emotional learning and memory · emotional learning and memory sue corkin monday, dec 3,...

Ch 10. Emotional Learning and Memory

Sue CorkinMonday, Dec 3, 2007

todays road map what is the Papez circuit? what is the limbic system? classical fear conditioning two routes for emotional learning: cortical and

subcortical the amygdala relation between the emotional memory system and

the declarative memory system two dimensions: valence and arousal what cognitive processes underlie the recollective

memory enhancement for emotional information? what neural processes underlie the recollective

memory enhancement for emotional information?

Papez circuit hippocampal

formation mammillary

bodies anterior

thalamus cingulate

cortex parahippo-

campal gyrus hippocampal

formation

Papez, James W. (1937) A proposed mechanism of emotion. Arch NeurolPsychiat, 38, 725.

EmotionalStimulus

Feelings

Bodily Response

SensoryCortex

Thalamus

Hippocampus AnteriorThalamus

Hypothalamus

CingulateCortex

limbic system

hippocampal formation amygdala (McLean) cingulate gyrus thalamus and hypothalamus

Broca, Paul (1878) Anatomie compare des circonvolutions crbrales. Le grand lobe limbique et la scissure limbique dans la srie des mammifres. Rev. dAnthrop, ser 2, 1, 285.

MacLean, Paul D. (1952) Some psychiatric implications of physiological studies on frontotemporal portion of limbic system (visceral brain). Electroencephalogr Clin Neurophysiol, 4, 407.

Cingulate Cortex

of the Thalamus X hypothalamus

Hypothalamus Amygdala

Mamillary body

Image courtesy of the NIH.

classical fear conditioning

left: rat hears a sound, which has little effect on BP or movementcenter: rat hears same sound, coupled with foot shock; after several pairings, BP rises and rat freezes when it hears the soundright: rat has been fear conditioned; sound alone achieves the same physiological changes as did sound and shock together

LeDoux, 1994

Images removed due to copyright restrictions.

what are the cerebral roots of fear learning?

is auditory cortex required for auditory fear conditioning? no

what about auditory thalamus? yes

what about the auditory midbrain? yes

What about the hippocampus? no

LeDoux, 1994

Images removed due to copyright restrictions.Illustration of rat brain with areas highlighted: auditory cortex,

hippocampus, auditory thalamus, and amygdala.

brain lesions have been crucial in pinpointing the sites that mediate

experiencing and learning about fear

LeDoux, 1994


The auditory pathway in the rat brain consists of sound entering the ear and being turned into an electrical signal that travels down the auditory nerve to the auditory

midbrain, to the auditory thalamus, and finally to the auditory cortex.

If a lesion is made in the auditory midbrain or auditory thalamus, fear conditioning is disrupted. If the lesion is made in the auditory cortex, however, conditioning is not

disrupted. These findings imply that the fear conditioning pathway involves the auditory midbrain and auditory thalamus, but not the auditory cortex. The pathway

may involve additional, unknown structures.

auditory cortex is not needed to establish simple fear conditioning

LeDoux, 1994


The auditory pathway in the rat brain consists of sound entering the ear and being turned into an electrical signal that travels down the auditory nerve to the auditory

midbrain, to the auditory thalamus, and finally to the auditory cortex.

If a lesion is made in the auditory midbrain or auditory thalamus, fear conditioning is disrupted. If the lesion is made in the auditory cortex, however, conditioning is not

disrupted. These findings imply that the fear conditioning pathway involves the auditory midbrain and auditory thalamus, but not the auditory cortex. The pathway

may involve additional, unknown structures.

BUT it is needed to interpret stimuli when they become more intricate

one of two stimuli was paired with foot shock intact rabbits expressed fear responses only to the

sound that had been coupled with the shock after receiving auditory cortex lesions, however, they

responded to both tones that is, when auditory cortex was absent, and animals

had to rely solely on the thalamus and amygdala for learning, the two stimuli were indistinguishable

conclusion: projections to the amygdala from sensory regions of the cortex (e.g., auditory cortex) are important in processing the emotional significance of complex stimuli

LeDoux, 1994

anatomy of emotion

cells in some regions of the auditory thalamus give rise to fibers that reach several subcortical locations

could these neural projections be the connections through which the stimulus elicits the response we identify with fear?

researchers made lesions in each of the subcortical regions with which these fibers connect

the damage had an effect in only one area:LeDoux, 1994

the amygdala

certain parts of the thalamus (top - light pink) communicate with areas in the amygdala (bottom - light yellow) that process the fear-causing sound stimuli

LeDoux, 1994


structure of the amygdala

lateral nucleus: receives input from sensory regions of the brain and transmits these signals to the basolateral, accessory basal, and central nucleicentral nucleus: connects to the brain stem, bringing about the physiological changes LeDoux, 1994

Accessorybasal nucleus

Basalnucleus

Centralnucleus

Lateralnucleus

Amygdala

Stimulus

Thalamus

Cortex

Hippocampus

Figure by MIT OpenCourseWare.

Pitkanen & Amaral, 1998

Image removed due to copyright restrictions.

Illustration of the intrinsic connections in the lateral nucleus of the amygdala.See figure in Pitkanen, A., and D.G. Amaral. "Organization of the Intrinsic Connections of the Monkey andAmygdaloid Complex: Projections Originating in the Lateral Nucleus." J Comp Neurol 398 (1998): 431-458.

neurochemical markers in the amygdala Glutamate NMDA/AMPA Glutamine GAD/GABA Parvalbumin Calbindin Aspartate Histimine Dopamine Norepinephrine Epinephrine Serotonin AChE ChAT

Somatostatin Vasopressin CRF NGF Cholecystokinin Neuropeptide Y Neurphysin Estrogen Neurotensin Substance P VIP Enkephalin Dynorphin Protein kinase C Benzodiazepene receptors

Stefanacci, 2???

Amaral

Basal forebrain

Striatum

Claustrum

Hippocampalformation

Amygdala

Neocortex Occipital Temporal Insular Cingulate Frontal

Brainstem

Hypothalamus

Thalamus

Connections of the Amygdaloid Complex

Figure by MIT OpenCourseWare.

more evidence that the amygdala supports emotional memory

cells in the amygdala fire during encoding of emotional information

the magnitude of this activation correlates with likelihood of later retrieving emotional information

patients with amygdalar damage show a blunted memory enhancement effectcopyright protected material used with permission of

author and University of Iowas Virtual Hospital, www.vh.org

Image removed due to copyright restrictions.MRI image of a human brain, with the amygdala highlighted.

two routes for emotional learning: one cortical and one subcortical

LeDoux, 1994


The cortical route for emotional learning involves input from the senses - for example, a visual stimulus - that travels to the visual thalamus, to the visual cortex, to

the amygdala. The subcortical route bypasses the visual cortex, with the signal travelling to the visual thalamus and then straight to the amygdala.

the amygdala is not the only learning center

the establishment of memories is a function of an entire network

what about the hippocampus? important when learning and remembering are

conscious events (i.e., declarative memory) removal of the hippocampus in rats has little effect

on fear conditioning, but this is not declarative learning (i.e., independent of conscious awareness)

emotional information may be stored within declarative memory, but it is kept there as a cold declarative fact LeDoux, 1994

relation between the emotional memory system and the

declarative memory system emotional and declarative memories are stored and retrieved in

parallel their activities are joined seamlessly in our conscious

experience but that does not mean that we have direct conscious access to

emotional memory it means that we have access to the consequences (i.e., the

way we behave and the way our bodies feel) emotion exerts a powerful influence on declarative memory the amygdala plays an essential role in modulating the storage

and strength of declarative memoriesLeDoux, 1994

Low (negative)

High (positive)

VALENCE

AR

OU

SA

LL

ow

(ca

lmin

g)

Hig

h (

exci

tin

g

or

agit

atin

g)

rapeslaughter

Russell, 1980; Lang et al., 1993

emotional items differ from neutral items along 2 dimensions: valence (negative or positive) & arousal (calming or exciting)

some items differed from the neutral ones primarily in valence, and others differed primarily in arousal

Low (negative)

High (positive)

VALENCE

AR

OU

SA

LL

ow

(ca

lmin

g)

Hig

h (

exci

tin

g

or

agit

atin

g)


some items differed from the neutral ones primarily in valence, and others differed primarily in arousal

Low (negative)

High (positive)

VALENCE

AR

OU

SA

LL

ow

(ca

lmin

g)

Hig

h (

exci

tin

g

or

agit

atin

g)TABOO

NEGATIVE


study

test

orgasm

misery

+

translate

orgasm

+

translate

purchase

remember

know

new

participants are more likely to Remember valence (negative) than neutral words, and even more likely

to Remember high-arousal (taboo) words

0

10

20

30

40

50

60

70

80

Taboo Negative Neutral

R K

Cor

rect

ed R

ecog

nitio

n

** N=20 men, ages 19-33

Kensinger & Corkin, 2003, Memory & Cognition

what cognitive processes underlie memory enhancement for

negative, emotional information?

participants remember the negative words better than the neutral words because negative emotion

increases the subjective richness of memories, and

increases the contextual details associated with those memories

memory enhancement is stronger for arousing (taboo) words than for non-arousing valence (negative) words

what cognitive processes underlie the recollective memory enhancement

for emotional information?

CONTROLLED(self-initiated)

intentional, conscious

attention-demanding

AUTOMATIC

incidental, not conscious

not attention-demanding

OR

elaborative encoding benefits memory

Craik & Lockhart, 1975

0

10

20

30

40

50

60

70

Letters Rhyme Sentence

Per

cen

tag

e R

eco

gn

ized

is the word in capital letters?

does the word rhyme with pet?

would the word fit in the sentence He met a _____ on the street.

negative emotional information could be remembered better because of controlled, self-initiated processing

what cognitive processes underlie the recollective memory enhancement

for emotional information?



attention-demanding

AUTOMATIC



OR

relatively automatic and/or prioritized processing of emotion

LeDoux, 1994


The cortical route for emotional learning involves input from the senses - for example, a visual stimulus - that travels to the visual thalamus, to the visual cortex, to

the amygdala. The subcortical route bypasses the visual cortex, with the signal travelling to the visual thalamus and then straight to the amygdala.

are there separate cognitivemechanisms for valence and arousal?

Low (negative)

High (positive)

VALENCE

AR

OU

SA

LL

ow

(ca

lmin

g)

Hig

h (

exci

tin

g

or

agit

atin

g)TABOO

NEGATIVE


what is the role of attention at encoding?

NOHARD

EASYNO HARD

EASYCOTTAGE

+CEMETARY ORGASM

Sound 1

Sound 2

neutralnegative taboo

0

10

20

30

40

50

60

70

80

no secondary task: remembertaboo > negative > neutral

TAB NEG NEU TAB VAL NEU TAB VAL NEU

No Second Task Easy second task Hard second task

Co

rrec

ted

Rec

og

nit

ion

**

R K

0

10

20

30

40

50

60

70

80

TAB NEG NEU TAB NEG NEU TAB VAL NEU

No Second Task Easy Second Task Hard second task

Co

rrec

ted

Rec

og

nit

ion

easy secondary task: remembertaboo > valence = neutral

**

* R K

0

10

20

30

40

50

60

70

80

hard secondary task: Remembertaboo > valence = neutral

TAB NEG NEU TAB NEG NEU TAB NEG NEU

No Second Task Easy Second Task Hard Second Task

Co

rrec

ted

Rec

og

nit

ion

R K*

** *

what cognitive processes underlie the recollective memory enhancement for

emotional information?



attention-demanding

AUTOMATIC



OR

VALENCE WORDSAROUSING

WORDS

what neural structures support the processing of valence and arousing words

to enhance recollection?

amygdala

hippocampusprefrontal cortex


Illustration of a brain with the prefrontal cortex, amygdala, and hippocampus each highlighted.

are there separate brain mechanismsfor valence and arousal?

Low (negative)

VALENCE

AR

OU

SA

LL

ow

(ca

lmin

g)

Hig

h (

exci

tin

g

or

agit

atin

g)

High (positive)

AROUSING

VALENCE


what brain regions support memory enhancement?

14 men , 14 women3T head-only Allegra scannerdata analyzed using SPM99

RAPESORROW

+MURDER

FORECAST

Negative, nonarousing

Neutral

Fixation

Negative, arousing

Negative, arousing

memory performance during scanningMemory as a function of wordtype and memory strength

0

10

20

30

40

50

60

70

80

90

NegativeArousing

Valence-Only Neutral

Cor

rect

ed R

ecog

nitio

n

KnowRemember

Negative Nonarousin

g Kensinger & Corkin, PNAS, 2004

are there two brain networks for emotional memory?

one for valence (how positive or negative the information is) and

one for arousal (how exciting or calming the information is)

subsequent memory paradigm

Wagner & Davachi, 2001

Question: What was the pattern of brain activity when people encoded words they later remembered vs. when they encoded words they later forgot?

L inferior PFC (BA 47)

subsequent memory effect for valence (negative) and neutral words: activation in 2 areas

predicted successful encoding

*

*

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

es_R es_F en_R en_F

Peak %

Sig

nal

Ch

an

ge

forrem rem forValence Neutral

L anterior hippocampus

**

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

SR SF NR NF

Valence Neutralforrem rem for

Pea

k %

Sig

nal

Ch

ang

e

Pea

k %

Sig

nal

Ch

ang

e

Courtesy of National Academy of Sciences, U. S. A. Used with permission. Source: Kensinger, Elizabeth A., and Suzanne Corkin. "Two Routes to Emotional Memory: Distinct Neural Processes for Valence and Arousal." PNAS 101 (2004): 3310-3315. Copyright 2004 National Academy of Sciences, U.S.A.

L inferior PFC (BA 47)

Valence Neutral

**

Arousal

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

eh_r eh_m es_r es_m en_r en_m

Peak %

Sig

nal

Ch

an

ge

forrem rem forforrem

no subsequent memory effect in L inferior PFC for arousing words


*

**

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

AR AF SR SF NR NF

Peak %

Sig

nal C

han

ge

NeutralArousalforrem rem forforrem

Valence

subsequent memory effect for arousing (taboo) words

activation in 2 areas predicted successful encoding

L amygdala


*

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

AR AF SR SF NR NF

Peak %

Sig

nal C

han

ge

forrem rem forNeutral

forremArousal Valence


L amygdala


-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

-0.1 0 0.1 0.2 0.3 0.4 0.5 0.6

Peak % Signal Change in Hippocampus

r = .60

amount of activation in these regions was correlated significantly, suggesting that the 2 areas

act cooperatively

Courtesy of National Academy of Sciences, U. S. A. Used with permission. Source: Kensinger, Elizabeth A., and Suzanne Corkin. "Two Routes to Emotional Memory: Distinct Neural Processes for Valence and Arousal." PNAS 101 (2004):

3310-3315. Copyright 2004 National Academy of Sciences, U.S.A.

a left prefrontal-hippocampal network supports the recollective enhancement

for valence (negative) words as well as for neutral words

these areas support controlled processing of information, which results in successful encoding

left prefrontal cortex left hippocampus


an amygdalar-hippocampal networksupports the recollective enhancement

for arousing (taboo) words

automatic orienting toward emotional stimuli

may benefit memory Courtesy of National Academy of Sciences, U. S. A. Used with permission. Source: Kensinger, Elizabeth A., and Suzanne Corkin. "Two Routes to Emotional

Memory: Distinct Neural Processes for Valence and Arousal." PNAS 101 (2004): 3310-3315. Copyright 2004 National Academy of Sciences, U.S.A.

Arousal

Valence

Neutral

Emotional Memory Enhancement Effect

Word Type

remember

conclusionsitems with valence or with arousal are more vividly remembered than neutral items

this effect is greater for arousing words than for valence words

automaticArousal

controlledValence

Neutral


Word Type

remember

different cognitive processes support the enhancement effects

valence (negative) words are enhanced by additional, elaborative, encoding processesarousing (taboo) words are enhanced automatically

different neural processes support the enhancement effects

Arousal

Valence

Neutral


L inferior PFC, L hippocampus (supports controlled processing)

L amygdala, L hippocampus(supports automatic processing)

Word Type


Images of human brains with the relevant areas highlighted.

time for questions &

2 student presentations

Image removed due to copyright restrictions.Photo of a very stressed-looking woman.

Ch 10. Emotional Learning and Memorytodays road mapPapez circuitlimbic systemclassical fear conditioningwhat are the cerebral roots of fear learning?brain lesions have been crucial in pinpointing the sites that mediate experiencing and learning about fearauditory cortex is not needed to establish simple fear conditioningBUT it is needed to interpret stimuli when they become more intricateanatomy of emotionthe amygdalastructure of the amygdalaneurochemical markers in the amygdalamore evidence that the amygdala supports emotional memorytwo routes for emotional learning: one cortical and one subcorticalthe amygdala is not the only learning centerrelation between the emotional memory system and the declarative memory systemstudyparticipants are more likely to Remember valence (negative) than neutral words, and even more likely to Remember high-arouwhat cognitive processes underlie memory enhancement for negative, emotional information?elaborative encoding benefits memory relatively automatic and/or prioritized processing of emotionwhat is the role of attention at encoding?no secondary task: remembertaboo > negative > neutraleasy secondary task: remembertaboo > valence = neutralhard secondary task: Remembertaboo > valence = neutralwhat brain regions support memory enhancement?memory performance during scanningare there two brain networks for emotional memory?subsequent memory paradigmL inferior PFC (BA 47)L inferior PFC (BA 47)L amygdalaL amygdala different neural processes support the enhancement effectstime for questions & 2 student presentations

ch 10. emotional learning and memory · emotional learning and memory sue corkin monday, dec 3,...

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