ch 10. emotional learning and memory · emotional learning and memory sue corkin monday, dec 3,...
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Ch 10. Emotional Learning and Memory
Sue CorkinMonday, Dec 3, 2007
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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?
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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
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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.
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Cingulate Cortex
of the Thalamus X hypothalamus
Hypothalamus Amygdala
Mamillary body
Image courtesy of the NIH.
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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.
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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.
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brain lesions have been crucial in pinpointing the sites that mediate
experiencing and learning about fear
LeDoux, 1994
Images removed due to copyright restrictions.
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.
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auditory cortex is not needed to establish simple fear conditioning
LeDoux, 1994
Images removed due to copyright restrictions.
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.
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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
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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
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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
Images removed due to copyright restrictions.
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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.
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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.
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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???
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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.
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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.
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two routes for emotional learning: one cortical and one subcortical
LeDoux, 1994
Image removed due to copyright restrictions.
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.
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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
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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
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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)
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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)
Russell, 1980; Lang et al., 1993
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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
Russell, 1980; Lang et al., 1993
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study
test
orgasm
misery
+
translate
orgasm
+
translate
purchase
remember
know
new
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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
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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
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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
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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
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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
-
relatively automatic and/or prioritized processing of emotion
LeDoux, 1994
Image removed due to copyright restrictions.
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.
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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
Russell, 1980; Lang et al., 1993
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what is the role of attention at encoding?
NOHARD
EASYNO HARD
EASYCOTTAGE
+CEMETARY ORGASM
Sound 1
Sound 2
neutralnegative taboo
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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*
** *
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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
VALENCE WORDSAROUSING
WORDS
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what neural structures support the processing of valence and arousing words
to enhance recollection?
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amygdala
hippocampusprefrontal cortex
Image removed due to copyright restrictions.
Illustration of a brain with the prefrontal cortex, amygdala, and hippocampus each highlighted.
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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
Russell, 1980; Lang et al., 1993
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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
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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
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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)
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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?
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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.
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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
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.
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*
**
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
L anterior hippocampus
*
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
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.
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L amygdala
L anterior hippocampus
-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.
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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
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.
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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.
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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
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automaticArousal
controlledValence
Neutral
Emotional Memory Enhancement Effect
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
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different neural processes support the enhancement effects
Arousal
Valence
Neutral
Emotional Memory Enhancement Effect
L inferior PFC, L hippocampus (supports controlled processing)
L amygdala, L hippocampus(supports automatic processing)
Word Type
Images removed due to copyright restrictions.
Images of human brains with the relevant areas highlighted.
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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
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