Journal of the International Neuropsychological Society (2013), 19, 1–9.
Copyright E INS. Published by Cambridge University Press, 2013.
doi:10.1017/S1355617713000945
SHORT REVIEW
Oversimplification in the Study of Emotional
Memory
Kelly A. Bennion, Jaclyn H. Ford, Brendan D. Murray, AND Elizabeth A. Kensinger
Department of Psychology, Boston College, Chestnut Hill, Massachusetts
(RECEIVED April 10, 2013; FINAL REVISION August 1, 2013; ACCEPTED August 1, 2013)
Abstract
This Short Review critically evaluates three hypotheses about the effects of emotion on memory: First, emotion usually
enhances memory. Second, when emotion does not enhance memory, this can be understood by the magnitude of
physiological arousal elicited, with arousal benefiting memory to a point but then having a detrimental influence. Third,
when emotion facilitates the processing of information, this also facilitates the retention of that same information. For
each of these hypotheses, we summarize the evidence consistent with it, present counter-evidence suggesting boundary
conditions for the effect, and discuss the implications for future research. (JINS, 2013, 19, 1–9)
Keywords: Affect, Episodic memory, Limbic system, Long-term memory, Recall, Recognition, Stress
whose existence can shed light on the multifaceted nature of
the effects of emotion on memory.
INTRODUCTION
‘‘Emotional memory’’ is a shorthand phrase to refer to a
memory for an event that elicits emotional reactions. These
events and reactions can vary. The events may be rewarding
or aversive; they may vary in intensity and time-course.
These features can influence the nature of the emotional
reactions. For instance, reactions to a public or personal event
that unfolds over minutes or hours may include physiological
responses, changes in cognitive processes, the conscious
feeling of a change in affective state, and the labeling of that
feeling. Reactions to an item that is presented briefly within
the context of a laboratory experiment are likely to include
fleeting physiological and cognitive responses, but the
participant may not be aware of them.
The effects of these emotional reactions on memory are
complex, yet they are often distilled to three tenets. First, the
experience of emotion enhances memory. Second, when
emotion does not enhance memory, this is usually because of
the impairing effects of high levels of arousal. Third, when
emotion facilitates an early stage of processing, this conveys
benefits at a later stage. These views are pervasive because
there is evidence, and often a long history, in their support.
But as this review highlights, there are boundary conditions
Emotional Enhancement of Memory: Underlying
Mechanisms and Limitations
It is commonly believed that an emotional event will be
remembered better than an event lacking emotion (reviewed
by Buchanan, 2007 and Hamann, 2001). William James
(1890) described the effect of an emotional event as ‘‘a scar
upon the cerebral tissues’’ (p. 670), and the term ‘‘flashbulb
memories’’ was used to describe the purportedly permanent
representation created for an exceptionally emotional event
(Brown & Kulik, 1977). Several studies have shown that
emotional public events are remembered better than everyday
events with a similar retention interval (e.g., Conway et al.,
1994; Paradis, Solomon, Florer, & Thompson, 2004), and
laboratory studies have shown emotional enhancement
in memory for words (e.g., Kleinsmith & Kaplan, 1963;
Sharot & Phelps, 2004), images (e.g., Bradley, Greenwald,
Petry, & Lang, 1992), narratives (e.g., Cahill & McGaugh,
1995), and personal events (e.g., D’Argembeau, Comblain,
& Van der Linden, 2003).
In explaining flashbulb memories, Brown and Kulik
proposed the role of a special emotional memory mechanism
based on Robert Livingston’s ‘‘Now Print’’ theory (1967).
This theory (1967) suggests that when the brain recognizes
an event as both novel and significant, the limbic system
Correspondence and reprint requests to: Elizabeth A. Kensinger,
McGuinn Hall, Room 300, 140 Commonwealth Avenue, Chestnut Hill, MA
02467. E-mail: elizabeth.kensinger@bc.edu
1
2
K.A. Bennion et al.
releases a command that permanently ‘‘prints’’ all recent
brain events, leading to facilitated retrieval of all event details
at a later time. Select aspects of this theory have been supported.
There is increased limbic activity, and a strengthened relation
between the amygdala and other medial temporal lobe and
cortical regions during emotional relative to neutral event
encoding (reviewed by LaBar & Cabeza, 2006). Item-by-item
fluctuations in connectivity relate to the durability of an
emotional memory (Ritchey, Dolcos, & Cabeza, 2008), with
items associated with greater connectivity remembered over
longer delays. State-based differences in connectivity also
may influence how well emotional events are retained; for
instance, functional coupling between the amygdala and
medial prefrontal cortex during rest may relate to the ability to
retain emotionally positive memories, at least among older
adults (Sakaki, Nga, & Mather, 2013). Thus, there is evidence
that amygdala engagement—through its interactions with
other regions—can lead to a strong, long-lasting memory.
Critical aspects of the ‘‘Now Print’’ theory, however, have
not been supported. Amygdala activation does not preserve
memory for all attended event details, and amygdala
engagement during an emotional event does not circumvent
the medial temporal lobe processes that typically enable
memory consolidation (Kensinger, 2009). Thus, there is
no ‘‘special’’ memory mechanism in the strongest sense
(see McCloskey, Wible, & Cohen, 1988; Weaver, 1993).
Moreover, even though people retain high confidence in
‘‘flashbulb’’ memories (e.g., Talarico & Rubin, 2003, 2007),
their accuracy decreases over time (e.g., Christianson, 1989,
1992; Rubin & Kozin, 1984). This disconnect between
accuracy and confidence is consistent with research showing
that emotion enhances the sense of recollection experienced
during memory retrieval (reviewed by Phelps & Sharot,
2008) and may lead to a shift in participants’ response biases:
Emotional words (new and old) are more likely to receive
an ‘‘old’’ response than neutral words (see Table 1). Although
emotion can sometimes enhance the accuracy of a memory
representation (e.g., Choi, Kensinger, & Rajaram, 2013;
Kensinger, Garoff-Eaton, & Schacter, 2007), or at least
the accuracy with which some details of an event are
remembered (see next section), emotion may change the
qualitative characteristics of how an event is remembered
even when it does not affect the likelihood that the event is
remembered.
The mixed effects of emotion on memory accuracy may
be explained by the frequent presence of two confounds that
can exaggerate or mask the enhancing effects of emotion
on memory. First, emotional stimuli are often more interrelated than neutral stimuli. This semantic relatedness can
have an additive effect with arousal on memory (Buchanan,
Etzel, Adolphs, & Tranel, 2006) and in some cases may
entirely explain the mnemonic benefit attributed to emotion
(e.g., Maratos & Rugg, 2001; Talmi, Luk, McGarry, &
Moscovitch, 2007; Talmi, Schimmack, Paterson, & Moscovitch,
2007). This interrelatedness can also lead to enhanced
conceptual priming and an increased sense of familiarity for
both old and new emotional stimuli, leading to increased
false memories as well as true memories (see Brainerd,
Stein, Silveira, Rohenkohl, & Reyna, 2008). When interrelatedness is controlled, emotion may not enhance false
Table 1. Effect of emotion on discrimination and response bias in tests of memory recognition
Brainerd et al., 2008
Choi et al., 2013
Dougal & Rotello, 2007
Fernandez-Rey & Redondo, 2007
Hit rate
False alarm rate
Negative . Neutral
Neutral . Positive
Negative . Neutral
Negative . Neutral
Neutral . Positive
Negative 5 Positive 5
Neutral
Positive 5 Negative
Positive 5 Neutral
Negative . Neutral
Negative . Positive
Arousing . Neutral
Negative . Neutral
Negative . Positive
Arousing . Neutral
Negative . Positive
Johansson, Mecklinger, & Treese, 2004
Maratos et al., 2000
Vo et al., 2008
Sensitivity
Liberal response bias
Negative . Neutral
Negative . Neutral
Neutral . Positive
Negative . Neutral
Positive . Neutral
Negative . Positive
Negative , Neutral
Positive , Neutral
Negative , Positive
Arousing , Neutral
Negative . Neutral
Negative . Positive
Negative . Positive
Arousal . Neutral
(low confidence
only)
Emotional . Neutral
Negative . Positive
Negative . Neutral
Negative . Positive
Positive . Neutral
Negative . Neutral
Emotional 5 Neutral
Windmann & Kruger, 1998
Negative . Neutral
Negative . Positive
Positive . Neutral
Not reported
Negative . Neutral
Negative . Neutral
Positive . Neutral
Not reported
Windmann & Kutas, 2001
Negative . Neutral
Negative . Neutral
Neutral . Negative
Negative 5 Positive 5
Neutral
Neutral . Negative
(control participants
only)
Negative 5 Neutral
Negative . Neutral
Note. Table 1 focuses on standard recognition assessments and does not include studies designed to intentionally elicit false memories. Additionally, only
studies that specifically report some measure of response bias are included.
Emotional memory
memory (e.g., Choi et al., 2013). Second, the distinctiveness
of an emotional stimulus among neutral items has been
shown to contribute to the enhanced memory for the
emotional items. Emotional stimuli typically benefit from
presentation in mixed lists (containing both emotional
and neutral items) but not in pure lists (Schmidt, 2012b;
Talmi, Luk, et al., 2007). Controlling for distinctiveness may
eliminate many of the benefits of emotion on memory,
although some benefits—such as enhanced memory for taboo
words—may remain, suggesting that they benefit from
emotion-specific processes (reviewed by Schmidt, 2012a).
The current state of the emotional memory literature suggests that the presence of emotion often contributes to a more
durable memory representation. However, this enhancement
is not always present, and when it is, it may reflect the contribution of confounding processes not directly linked to the
emotionality of the memoranda. By designing studies to
directly control for and manipulate these parameters (see
Table 2 for examples), researchers can better understand
the underlying cognitive and neural mechanisms directly
impacted by emotion. Such an understanding may be essential
to research examining memory impairments and preservations
in special populations. If emotional enhancement is held as a
certainty in the memory literature, the field risks disregarding
important research that does not show the effect.
Arousal and Memory: Beyond Yerkes-Dodson
(1908) and Easterbrook (1959)
A second claim is that, when emotion does not enhance
memory, this can be understood by the magnitude of
physiological arousal elicited. Yerkes and Dodson (1908)
proposed that for complex tasks, performance increases
with physiological or mental arousal up to a point, at which
the effect of arousal becomes detrimental. This has been
supported by animal and human studies on the effects of
glucocorticoids and/or stress on memory, such that moderate
levels during learning enhance subsequent memory, while
lower or higher doses either show an impairing effect
(e.g., Lupien et al., 1997) or no effect on memory (e.g.,
Roozendaal, Williams, & McGaugh, 1999).
A closely related explanation for why emotion does not
always enhance memory is that increased arousal leads to
a restriction of observed cues (Easterbrook, 1959). This
narrowing of attention enables memory for salient details to
be enhanced, at the cost of memory for less salient details.
At high arousal, however, this restriction of cue usage is
thought to preclude processing of information crucial to event
memory, such as the physical characteristics of a perpetrator
(e.g., Christianson, 1992; Loftus, Loftus, & Messo, 1987).
While these hypotheses have been supported by prior
literature, effects may be relevant under narrower circumstances than typically assumed. The Yerkes-Dodson law was
based on a study requiring mice to discriminate between two
boxes while receiving shocks of various strength, and their
claim of a U-shaped curve applied only to complex tasks. In
their ‘‘easy’’ condition, there was a linear relation between
3
shock strength and learning success. Moreover, in reanalyzing
their data, Baumler and Lienert (1993) found that the
dependent variable critically matters; although defining the
learning criterion as ‘‘hits’’ yields an inverted U-shaped
curve for complex tasks, defining the criterion as errors
results in a linear arousal-performance relation for complex
tasks and no relation for the easy task (Baumler & Lienert,
1993; Hanoch & Vitouch, 2004). Thus, the U-shaped curve
may exist only for complex tasks, and only when data are
scored in a particular way. Similarly, the Easterbrook (1959)
hypothesis was originally based upon tasks investigating
drive, motivational concentration, perception, and motor
skill, and focused on cue usage during encoding-stage
processes. It has since been applied more broadly to a variety
of long-term memory studies and has not been reconciled
with evidence that arousal often influences post-encoding
processes rather than attention narrowing during encoding
(e.g., Riggs, McQuiggan, Farb, Anderson, & Ryan, 2011;
Mickley Steinmetz & Kensinger, 2013). Whereas the
Yerkes-Dodson law and Easterbrook’s attention-narrowing
account are valid explanations for arousal-enhanced memory
(or the lack thereof) in some cases, the effects of arousal on
memory may also depend on other factors.
One such factor is the content of the memoranda: Although
stress often enhances emotional memory (e.g., Cahill,
Gorski, & Le, 2003) it typically impairs (Payne et al., 2007),
or has no effect on (Buchanan & Lovallo, 2001) memory
for neutral information. The effects of arousal on memory
for neutral stimuli may further depend on their salience
(Mather & Sutherland, 2011). Arousal may enhance memory
for goal-relevant, salient neutral stimuli while having no
effect on, or even impairing, memory for other neutral stimuli
(e.g., Sutherland & Mather, 2012).
Even among emotional information, the effects of arousal
may differ depending upon the valence of the stimuli (i.e.,
whether they are positive or negative). For example, free
recall of negatively arousing, but not positively arousing
words, is enhanced by pre-learning stress (Schwabe, Bohringer,
Chatterjee, & Schachinger, 2008). Further evidence for
complex interactions between arousal and valence has been
shown using fMRI: High (compared to low) arousal is associated with increased amygdala connectivity to the inferior
frontal gyrus and middle occipital gyrus while encoding
negative stimuli, and decreased amygdala connectivity to
these regions while encoding positive stimuli (Mickley
Steinmetz, Addis, & Kensinger, 2010).
Another factor is the relation between the arousal experienced and the memory task. Arousal can be relevant to the
task, as in the original Yerkes-Dodson experiment, or irrelevant to the task, as often occurs in studies of mood induction.
Research has suggested that when the arousal is task-relevant,
such as when the content of the to-be-remembered information
is arousing, memory for those arousal-inducing, salient details
often comes at the cost of memory for other information (the
emotion-induced memory trade-off; reviewed by Reisberg &
Heuer, 2004). When arousal is task-irrelevant, the effects may
be more variable. Libkuman, Nichols-Whitehead, Griffith
4
K.A. Bennion et al.
Table 2. Factors to consider when designing a study to assess emotional memory
Factor
Why consider this factor?
Semantic
coherence/
relatedness
Stronger semantic clustering If not using categorized
neutral items
of emotional (vs. neutral)
stimuli can contribute to
If selecting emotional
emotional enhancement
stimuli from a small
of memory by making
number of categories
stimuli easier to organize.
(e.g., vicious animals,
It also can boost false
injured people)
memories because lures
are more closely related to
studied items.
Attention allocation
Emotional stimuli often
attract attention. This can
enhance memory for the
emotional stimuli but can
reduce memory for
neutral (or low-priority;
see Mather & Sutherland,
2011) stimuli competing
for processing resources.
Many effects of emotion
may be due to the
incongruent or
unexpected nature of the
stimulus or event, rather
than to an emotional
response to that stimulus
or event.
Distinctiveness
When is it most prevalent?
How to manipulate?
Possible to control for in
data analyses?
Use a design that fully
crosses emotional
content and semantic
relatedness
If standardized database
available, use
calculated coherence of
emotional and neutral
stimuli as a covariate in
analyses
If processing demands of
task are high (e.g.,
limited time to process
stimuli; multiple stimuli
competing for resources)
Manipulate task demands
(e.g., divided attention
and full attention)
Measure eye gaze and use
looking time as a
covariate (Note: this
will only co-vary overt,
not covert, attention)
If frequency (both within
the study session and
within an everyday
context) is not matched
between emotional and
neutral stimuli
Compare performance in
mixed lists to
performance in pure lists
Alter salience of neutral
stimuli by manipulating
the stimuli or the task
Include ratings of
frequency, familiarity,
and surprise as
covariates
Compare surprising events
that elicit different
magnitudes of emotional
reactions (e.g., gardenIf familiarity and frequency
path sentences ending in
are not matched between
emotional vs. semantic
emotional and neutral
non sequitur)
events
If mixed lists are used rather
than pure lists (this may
also affect induced
arousal of person; see
below)
Arousal
Arousal can influence
Stimulus characteristic: if
Stimulus characteristic:
Stimulus characteristic:
memory in several ways,
stimuli are not matched
select stimuli to include
include ratings of
depending on whether the
for arousal; if an event is
multiple levels of arousal
arousal as a covariate
arousal refers to the
surprising; likely to be
(e.g., low- and highratings given to a single
correlated with the
arousal negative stimuli) Induced state of person:
include change in
stimulus within a stream
intensity of the emotional
Induced state of person:
cortisol or alpha
of stimuli, to the state of
response
compare pure to mixed
amylase as an estimate
an individual induced by
lists of emotional stimuli
of arousal response
Induced state of person:
the presented stimuli or
(although
this
may
when
emotional
stimuli
event, or to the natural
Natural state of person:
also affect stimulus
are presented in a block
state of an individual that
include baseline
distinctiveness; see
(rather than intermixed
is unrelated to the stimuli
cortisol or alphaabove)
with
neutral
stimuli),
or
or event.
amylase level as an
when an event is of
Include intentional mood
estimate of natural
relatively long duration
induction
as
part
of
arousal state
(more than a few
experimental design
seconds)
(Continued )
5
Emotional memory
Table 2. Continued
Factor
Why consider this factor?
Possible to control for in
data analyses?
When is it most prevalent?
How to manipulate?
Natural state of person:
individual variations are
always present but may
be exaggerated when
comparing different
patient groups or age
groups
Natural state of person:
direct manipulation likely
impossible, but can
compare groups selected
a priori to differ in
baseline state (e.g., highvs. low-anxiety group)
Note. This table does not present an exhaustive list. Depending on the goals of the experiment, other factors to consider may include: valence of the stimuli
(how positive or negative), discrete emotions elicited by the stimuli, mood of the participant, stimulus complexity, event rehearsal
and Thomas (1999) found that sustained physiological
arousal—induced by stationary running or biking—had little
impact on memory for details of scenes. Sutherland and
Mather (2012), however, showed that brief presentation
of negative arousing sounds increased short-term memory
for high-salience letters but had no benefit on memory for
low-salience letters.
These studies demonstrate that when arousal does not
enhance memory, this could be due not only to dose, but also
to task complexity, the way performance is measured, the
content of the memoranda, and the relevance of the arousal to
the task. Considering only one of these factors often leads to
mixed findings (see Table 3), emphasizing the need to assess
multiple factors, and their potential interactions.
Specific manipulation
Study
Key finding for effect of arousal
Content of Memoranda
Emotional vs. neutral
Abercrombie et al., 2003
Buchanan & Lovallo, 2001
Cahill et al., 2003
Payne et al., 2007
Rimmele et al., 2003
Schwabe & Wolf, 2010
Domes et al., 2004
Ø Negative and Neutral
Ø Positive and Negative; No effect on Neutral
Ø Negative; No effect on Neutral
Ø Negative; Neutral
Negative; Ø Neutral
Positive, Negative, Neutral
Positive; No effect on Negative
Schwabe et al., 2008
Smeets et al., 2007
Ø Negative; No effect on Positive
Memory for stressor-related words . Stressor-unrelated
Smeets et al., 2009
Christianson, 1984
Memory for stressor-related words . Stressor-unrelated
Ø Central; No effect on Peripheral
Easterbrook, 1959
Heuer & Reisberg, 1990
Kebeck & Lohaus, 1986
Loftus et al., 1987
Sutherland & Mather, 2012
Cue-utilization: Ø Central; Peripheral
Ø Central and Peripheral
Ø Central; Peripheral
Weapon focus effect: Ø Central; Peripheral
Ø High-salience stimuli; No effect on Low-salience
stimuli
Salience of neutral
stimuli
Level of Arousal
Gold & Van Buskirk, 1975 Inverted-U; moderate (not lower or higher) doses of
epinephrine enhance spatial memory
Lupien et al., 1997
High stress memory for word pairs
Yerkes & Dodson, 1908
Inverted-U between shock strength and learning success
on complex tasks
Libkuman et al., 1999
Task-relevant arousal Ø memory for scene details
Task-irrelevant arousal 5 no effect
Å
Features of Arousal
Å
Memoranda central or
peripheral to the
elicitor of arousal
Å
Memoranda related, or
unrelated, to stressor
Å
Positive vs. negative
valence
Å
Manipulation category
ÅÅÅ
Table 3. Representative examples of the mixed behavioral patterns revealed by studies examining how stimulus content or features of the
arousal response influence the effect of arousal on memory
Relevance of Arousal
to Task: Reason for
physiological arousal
6
Facilitated Processing of Emotional Information
Does Not Guarantee Memory Accuracy
The third claim we address is that the facilitated processing of
emotional information precipitates facilitated retention of that
information. There is no doubt that emotional information
benefits from prioritized processing. We rapidly orient our
attention to emotional stimuli (e.g., Öhman, Flykt, & Esteves,
2001), and we process emotional information faster and more
fluently than non-emotional information (Kityama, 1990),
even in the absence of full attention (Kensinger & Corkin,
2004; Talmi, Schimmack, et al., 2007; Talmi, Anderson,
Riggs, Caplan, & Moscovitch, 2008). This prioritized processing can be related to memory benefits, both because
attended stimuli are often well-remembered (reviewed by
Chun & Turk-Browne, 2007) and because the amygdala
engagement triggered by emotional arousal facilitates both
perceptual (e.g., Vuilleumier, Armony, Driver, & Dolan,
2001; Vuilleumier, Richardson, Armony, Driver, & Dolan,
2004) and mnemonic processes (reviewed by LaBar &
Cabeza, 2006). However, the assumptions that facilitated
processing always produces enhanced memory, and that the
cause of the memory enhancement is facilitated processing,
are not always correct.
One demonstration of a disconnect between the effects of
emotion on short-term processing and long-term retention
comes from studies of working memory. Working memory
efficiency can be slowed when emotional stimuli are held in
mind (Kensinger & Corkin, 2003), likely because emotional
reactions distract from the memory maintenance task.
Emotional information may disrupt inter-item binding in
working memory (e.g., remembering the relative locations of
high and low arousal pictures; Mather et al., 2006) and may
also disrupt dorsolateral prefrontal processes related to
holding information in mind during delayed-response working
memory tasks (e.g., Dolcos & McCarthy, 2006; Dolcos,
Diaz-Granados, Wang, & McCarthy, 2008). Yet these same
stimuli that impede working memory performance can be
remembered well over the long-term (Kensinger & Corkin,
2003), revealing a distinction between the impairing effect of
emotion on short-term processing and the beneficial effect
on long-term retention. In these instances, the intrusive
processing of the emotional content may lead to a more
durable memory representation.
Emotion can also have the opposite direction of effect,
benefiting short-term processing but impeding long-term
retention. For instance, in Murray and Kensinger (2012),
participants were faster to form a mental image combining
one emotional and one neutral item into a pair, rather than
two non-emotional items. However, that facilitated imagery
did not lead to facilitated later memory: Individuals remembered the emotional pairs less well than the non-emotional
pairs. In this case, the fluent processing of the emotional
items may circumvent the effortful, deep processing that
would translate into later memory benefits. The fluent
processing may even bias individuals to believe that they
have spent enough time learning information, when in fact
K.A. Bennion et al.
additional effort would benefit the creation of a durable
memory representation. For instance, Zimmerman and
Kelley (2010) demonstrated that participants were overconfident when estimating which negative word pairs they
would later remember. Likely because of the fluency with
which individuals processed the negative pairs, they were
misled to believe they had encoded them strongly and would
retain them well.
Facilitated processing of emotional cues at retrieval may
also mislead individuals, but at this stage of memory, it
may cause them to endorse previously unstudied emotional
items as ‘‘old’’ (Dougal & Rotello, 2007; Fernandez-Rey &
Redondo, 2007; Maratos, Allan, & Rugg, 2000). As discussed earlier, sometimes this bias may result from the
increased familiarity that stems from the inherent semantic
interrelatedness of emotional items. Other times it may
result because emotion facilitates the processing of retrieval
cues. People may misattribute that ease-of-processing for a
sense of familiarity that the information was previously
encountered (e.g., Windmann & Kutas, 2001).
These pieces of counter-evidence emphasize that facilitated processing of emotional information at one stage of
processing does not guarantee similar facilitation at another
stage. These results highlight the need to avoid the inference
that if emotion has not enhanced memory retrieval, it has not
facilitated earlier stages of processing. As we have reviewed,
retrieval deficits can be indicative of facilitated processing
at encoding that reduces post-encoding elaboration or
time-on-task. More generally, these complexities provide an
important reminder that memory retrieval provides only a
limited window into the set of processes used to form and
maintain a memory.
IMPLICATIONS AND APPLICATIONS
Although there is support for these three hypotheses,
delineating their limiting parameters is important both for
basic and clinical research. First, clinical alterations in the
effects of emotion on memory may reflect a re-setting of the
boundaries for the effect rather than a generalized change
in its presence or absence. For instance, patients with
Alzheimer’s disease often show little-to-no enhancement of
emotional memory within a laboratory setting. Yet when
memory for a real-life experience is assessed, the patients often
are more likely to remember the occurrence of that event
compared to a more mundane event (Waring & Kensinger,
2009). Future research could test how the factors that set
the boundary in healthy populations—including semantic
relatedness, valence, arousal, and personal involvement—are
modified in clinical populations.
Second, a move away from a dose-response (quantitybased) explanation for the effects of arousal may enable a
focus on the quality of the arousal response. ‘‘Arousal’’ can
incorporate multiple phenomena—mental feelings of excitation or agitation, short-lived physiological changes, and
specific responses of the hypothalamic-pituitary-adrenal
system. These facets of arousal may have distinct effects
Emotional memory
on memory. Thus, when trying to understand how arousal
affects memory—either in healthy populations or in individuals with affective disorders—it is critical to operationalize
‘‘arousal’’ and to tease apart the influences of these various
aspects of arousal.
Third, by realizing the complex relations between the
effects of emotion on different stages of processing, we may
come closer to a holistic explanation for the effects of emotion on memory in different populations. For instance, we
have shown that, unlike young adults, older adults are not
faster at binding emotional pairs than neutral ones. Yet when
memory is tested, older adults show a mnemonic advantage
for the emotional integrations (Murray & Kensinger, in
press). These results can only be explained by realizing that
facilitation in one aspect of processing can be disconnected
from benefits in another.
As these examples highlight, although there is support for
the hypotheses reviewed here, there is danger in accepting
them as rules-of-thumb and much to be gained by taking the
boundary conditions seriously.
ACKNOWLEDGMENTS
Preparation of this manuscript was supported by grant MH080833
from the National Institute of Health (to E.A.K.). The authors
thank Angela Gutchess and Jessica Payne for helpful conversations
related to the content of this review. The authors have no conflicts
of interest.
REFERENCES
Abercrombie, H.C., Kalin, N.H., Thurow, M.E., Rosenkranz, M.A.,
& Davidson, R.J. (2003). Cortisol variation in humans affects
memory for emotionally laden and neutral information. Behavioral
Neuroscience, 117, 505–516.
Baumler, G., & Lienert, G.A. (1993). Reevaluation of the
Yerkes-Dodson law by nonparametric-tests of trend. Studia
Psychologica, 35, 431–436.
Bradley, M.M., Greenwald, M.K., Petry, M.C., & Lang, P.J. (1992).
Remembering pictures: Pleasure and arousal in memory. Journal
of Experimental Psychology: Learning, Memory, and Cognition,
18, 379–390.
Brainerd, C.J., Stein, L.M., Silveira, R.A., Rohenkohl, G., & Reyna, V.F.
(2008). How does negative emotion cause false memories?
Psychological Science, 19, 919–925.
Brown, R., & Kulik, J. (1977). Flashbulb memories. Cognition, 5,
73–99.
Buchanan, T. (2007). Retrieval of emotional memories. Psychological
Bulletin, 133, 761–779.
Buchanan, T.W., Etzel, J.A., Adolphs, R., & Tranel, D. (2006). The
influence of autonomic arousal and semantic relatedness on
memory for emotional words. International Journal of Psychophysiology, 61, 26–33.
Buchanan, T.W., & Lovallo, W.R. (2001). Enhanced memory for
emotional material following stress-level cortisol treatment in
humans. Psychoneuroendocrinology, 26, 307–317.
Cahill, L., Gorski, L., & Le, K. (2003). Enhanced human memory
consolidation with post-learning stress: Interaction with the
degree of arousal at encoding. Learning & Memory, 10, 270–274.
7
Cahill, L., & McGaugh, J.L. (1995). A novel demonstration of
enhanced memory associated with emotional arousal. Consciousness
and Cognition, 4, 410–421.
Choi, H.Y., Kensinger, E.A., & Rajaram, S. (2013). Emotional
content enhances true but not false memory for categorized
stimuli. Memory & Cognition, 41, 403–415.
Christianson, S.-A. (1984). The relationship between induced
emotional arousal and amnesia. Scandinavian Journal of
Psychology, 25, 147–160.
Christianson, S.-A. (1989). Flashbulb memories: Special, but not so
special. Memory and Cognition, 17, 435–443.
Christianson, S.-A. (1992). Emotional stress and eyewitness
memory: A critical review. Psychological Bulletin, 112, 284–309.
Chun, M.M., & Turk-Browne, N.B. (2007). Interactions between
attention and memory. Current Opinion in Neurobiology, 17,
177–184.
Conway, M.A., Anderson, S.J., Larsen, S.F., Donnely, C.M.,
McDaniel, M.A., McClelland, A.G.R., y Logie, R.H. (1994).
The formation of flashbulb memories. Memory & Cognition, 22,
326–343.
D’Argembeau, A., Comblain, C., & Van der Linden, M. (2003).
Phenomenal characteristics of autobiographical memories for
positive, negative, and neutral events. Applied Cognitive Psychology,
17, 281–294.
Dolcos, F., Diaz-Granados, P., Wang, L., & McCarthy, G. (2008).
Opposing influences of emotional and non-emotional distracters
upon sustained prefrontal cortex activity during a delayed-response
working memory task. Neuropsychologia, 46, 326–335.
Dolcos, F., & McCarthy, G. (2006). Brain systems mediating
cognitive interference by emotional distraction. The Journal of
Neuroscience, 26, 2072–2079.
Domes, G., Heinrichs, M., Rimmele, U., Reichwald, U., &
Hautzinger, M. (2004). Acute stress impairs recognition for
positive words – Association with stress-induced cortisol
secretion. Stress, 7, 173–181.
Dougal, S., & Rotello, C.M. (2007). ‘‘Remembering’’ emotional
words is based on response bias, not recollection. Psychonomic
Bulletin & Review, 14(3), 423–429.
Easterbrook, J.A. (1959). The effect of emotion on cue utilization and
the organization of behavior. Psychological Review, 66, 183–201.
Fernandez-Rey, J., & Redondo, J. (2007). Recognition memory for
pictorial stimuli: Biasing effects of stimulus emotionality.
Psicothema, 19, 375–380.
Gold, P.E., & Van Buskirk, R.B. (1975). Facilitation of timedependent memory processes with posttrial epinephrine injections.
Behavioral Biology, 13, 145–153.
Hamann, S. (2001). Cognitive and neural mechanisms of emotional
memory. Trends in Cognitive Sciences, 5, 394–400.
Hanoch, Y., & Vitouch, O. (2004). When less is more: Information,
emotional arousal, and the ecological reframing of the YerkesDodson law. Theory & Psychology, 14, 427–452.
Heuer, F., & Reisberg, D. (1990). Vivid memories of emotional
events: The accuracy of remembered minutiae. Memory &
Cognition, 18, 496–506.
James, W. (1890). The principles of psychology. New York: Henry
Holt.
Johansson, M., Mecklinger, A., & Treese, A.C. (2004). Recognition
memory for emotional and neutral faces: An event-related potential
study. Journal of Cognitive Neuroscience, 16, 1840–1853.
Kebeck, G., & Lohaus, A. (1986). Effect of emotional arousal on
free recall of complex material. Perceptual & Motor Skills, 63,
461–462.
8
Kensinger, E.A. (2009). Remembering the details: Effects of
emotion. Emotion Review, 1, 99–113.
Kensinger, E.A., & Corkin, S. (2003). Effect of negative emotional
content on working memory and long-term memory. Emotion, 3,
378–393.
Kensinger, E.A., & Corkin, S. (2004). Two routes to emotional
memory: Distinct neural processes for valence and arousal.
Proceedings of the National Academy of Sciences of the United
States of America, 101, 3310–3315.
Kensinger, E.A., Garoff-Eaton, R.J., & Schacter, D.L. (2007).
Effects of emotion on memory specificity: Memory trade-offs
elicited by negative visually arousing stimuli. Journal of Memory
and Language, 56, 575–591.
Kityama, S. (1990). Interaction between affect and cognition in
word perception. Journal of Personality and Social Psychology,
58, 209–217.
Kleinsmith, L.J., & Kaplan, S. (1963). Paired associates learning as
a function of arousal and interpolated interval. Journal of
Experimental Psychology, 65, 190–193.
LaBar, K.S., & Cabeza, R. (2006). Cognitive neuroscience of
emotional memory. Nature Reviews Neuroscience, 7, 54–64.
Libkuman, T.M., Nichols-Whitehead, P., Griffith, J., & Thomas, R.
(1999). Source of arousal and memory for detail. Memory &
Cognition, 27, 166–190.
Livingston, R.B. (1967). Reinforcement. In G.C. Quarton,
T. McInechuck, and F.O. Schmitt (Eds.), The neurosciences: A study
program (pp. 568–576). New York: Rockefeller University Press.
Loftus, E.F., Loftus, G.R., & Messo, J. (1987). Some facts about
‘‘weapon focus’’. Law and Human Behavior, 11, 55–62.
Lupien, S.J., Gaudreau, S., Tchiteya, B.M., Maheu, F., Sharma, S.,
Nair, N.P.V., y Meaney, M.J. (1997). Stress-induced declarative
memory impairment in healthy elderly subjects: Relationship to
cortisol reactivity. Journal of Clinical Endocrinology and
Metabolism, 82, 2070–2075.
Maratos, E.J., Allan, K., & Rugg, M.D. (2000). Recognition
memory for emotionally negative and neutral words: An ERP
study. Neuropsychologia, 38, 1452–1465.
Maratos, E.J., & Rugg, M.D. (2001). Electrophysiological correlates
of the retrieval of emotional and non-emotional context. Journal
of Cognitive Neuroscience, 13, 877–891.
Mather, M., Mitchell, K.J., Raye, C.L., Novak, D.L., Green, E.J., &
Johnson, M.K. (2006). Emotional arousal can impair feature
binding in working memory. Journal of Cognitive Neuroscience,
18, 614–625.
Mather, M., & Sutherland, M.R. (2011). Arousal-biased competition
in perception and memory. Perspectives on Psychological Science,
6, 114–133.
McCloskey, M., Wible, C.G., & Cohen, N.J. (1988). Is there a
special flashbulb-memory mechanism? Journal of Experimental
Psychology: General, 117, 171–181.
Mickley Steinmetz, K.R., Addis, D.R., & Kensinger, E.A. (2010).
The effect of arousal on the emotional memory network depends
on valence. Neuroimage, 53, 318–324.
Mickley Steinmetz, K.R., & Kensinger, E.A. (2013). The emotioninduced memory trade-off: More than an effect of overt attention?
Memory and Cognition, 41, 69–81.
Murray, B.D., & Kensinger, E.A. (2012). The effects of emotion and
encoding strategy on associative memory. Memory and Cognition,
40, 1056–1069.
Murray, B.D., & Kensinger, E.A. (in press). Age-related changes in
associative memory for emotional and non-emotional integrative
representations. Psychology and Aging.
K.A. Bennion et al.
Öhman, A., Flykt, A., & Esteves, F. (2001). Emotion drives
attention: Detecting the snake in the grass. Journal of Experimental Psychology: General, 130, 466–478.
Paradis, C.M., Solomon, L.Z., Florer, F., & Thompson, T. (2004).
Flashbulb memories of personal events of 9/11 and the day after
for a sample of New York City residents. Psychological Reports,
95, 304–310.
Payne, J.D., Jackson, E.D., Hoscheidt, S., Ryan, L., Jacobs, W.J., &
Nadel, L. (2007). Stress administered prior to encoding impairs
neutral but enhances emotional long-term episodic memories.
Learning and Memory, 14, 861–868.
Phelps, E.A., & Sharot, T. (2008). How (and why) emotion
enhances the subjective sense of recollection. Current Directions
in Psychological Science, 17, 147–152.
Reisberg, D., & Heuer, F. (2004). Memory for emotional events. In
D. Reisberg & P. Hertel (Eds.), Memory and emotion. Oxford:
University Press.
Riggs, L., McQuiggan, D.A., Farb, N., Anderson, A., & Ryan, J.D.
(2011). The role of overt attention in emotion-modulated
memory. Emotion, 11, 776–785.
Rimmele, U., Domes, G., Mathiak, K., & Hautzinger, M. (2003).
Cortisol has different effects on human memory for emotional and
neutral stimuli. Neuroreport, 14, 2485–2488.
Ritchey, M., Dolcos, F., & Cabeza, R. (2008). Role of amygdala
connectivity in the persistence of emotional memories over time:
An event-related fMRI investigation. Cerebral Cortex, 18,
2494–2504.
Roozendaal, B., Williams, C.L., & McGaugh, J.L. (1999). Glucocorticoid receptor activation in the rat nucleus of the solitary tract
facilitates memory consolidation: Involvement of the basolateral
amygdala. European Journal of Neuroscience, 11, 1317–1323.
Rubin, D.C., & Kozin, M. (1984). Vivid memories. Cognition, 16,
63–80.
Sakaki, M., Nga, L., & Mather, M. (2013). Amygdala functional
connectivity with medial prefrontal cortex at rest predicts the
positivity effect in older adults. Journal of Cognitive Neuroscience,
25, 1206–1224.
Schmidt, S.R. (2012a). Extraordinary memories for exceptional
events. New York: Psychological Press.
Schmidt, S.R. (2012b). Memory for emotional words in sentences:
The importance of emotional contrast. Cognition & Emotion, 26,
1015–1035.
Schwabe, L., Bohringer, A., Chatterjee, M., & Schachinger, H.
(2008). Effects of pre-learning stress on memory for neutral, positive,
and negative words: Different roles of cortisol and autonomic
arousal. Neurobiology of Learning and Memory, 90, 44–53.
Schwabe, L., & Wolf, O.T. (2010). Learning under stress impairs
memory formation. Neurobiology of Learning and Memory, 93,
183–188.
Sharot, T., & Phelps, E.A. (2004). How arousal modulates memory:
Disentangling the effects of attention and retention. Cognitive,
Affective, & Behavioral Neuroscience, 4, 294–306.
Smeets, T., Giesbrecht, T., Jelicic, M., & Merckelbach, H. (2007).
Context-dependent enhancement of declarative memory performance following acute psychosocial stress. Biological Psychology,
76, 116–123.
Smeets, T., Wolf, O.T., Giesbrecht, T., Sijstermans, K., Telgen, S.,
& Joëls, M. (2009). Stress selectively and lastingly promotes
learning of context-related high arousing information. Psychoneuroendocrinology, 34, 1152–1161.
Sutherland, M.R., & Mather, M. (2012). Negative arousal amplifies the
effects of saliency in short-term memory. Emotion, 12, 1367–1372.
Emotional memory
Talarico, J.M., & Rubin, D.C. (2003). Confidence, not consistency,
characterizes flashbulb memories. Psychological Science, 14,
455–461.
Talarico, J.M., & Rubin, D.C. (2007). Flashbulb memories are
special after all; In phenomenology, not accuracy. Applied
Cognitive Psychology, 21, 557–578.
Talmi, D., Anderson, A.K., Riggs, L., Caplan, J.B., & Moscovitch,
M. (2008). Immediate memory consequences of the effect of
emotion on attention to pictures. Learning and Memory, 15,
172–182.
Talmi, D., Luk, B.T.C., McGarry, L.M., & Moscovitch, M. (2007).
The contribution of relatedness and distinctiveness to emotionallyenhanced memory. Journal of Memory and Language, 56,
555–574.
Talmi, D., Schimmack, U., Paterson, T., & Moscovitch, M. (2007).
The role of attention and relatedness in emotionally enhanced
memory. Emotion, 7, 89–102.
Vo, M.L.-H., Jacobs, A.R., Kuchinke, L., Hogmann, M., Conrad, M.,
Schacht, A., & Hutzler, F. (2008). The coupling of emotion and
cognition in the eye. Psychophysiology, 45, 130–140.
Vuilleumier, P., Armony, J.L., Driver, J., & Dolan, R.J. (2001).
Effects of attention and emotion on face processing in the human
brain: An event-related fMRI study. Neuron, 30, 829–841.
9
Vuilleumier, P., Richardson, M.P., Armony, J.L., Driver, J., &
Dolan, R.J. (2004). Distant influences of amygdala lesion on
visual cortical activation during emotional face processing.
Nature Neuroscience, 7, 1271–1278.
Waring, J.D., & Kensinger, E.A. (2009). Emotional memory in
Alzheimer’s disease. In M.-K. Sun (Ed.), Research progress in
Alzheimer’s disease and dementia (Vol. 4, pp. 9–36). Hauppage,
NY: Nova Publishers.
Weaver, C.A., III. (1993). Do you need a ‘‘flash’’ to form a flashbulb
memory? Journal of Experimental Psychology: General, 122,
39–46.
Windmann, S., & Kruger, T. (1998). Subconscious detection of
threat as reflected by an enhanced response bias. Consciousness
& Cognition, 7, 603–633.
Windmann, S., & Kutas, M. (2001). Electrophysiological correlates
of emotion-induced recognition bias. Journal of Cognitive
Neuroscience, 13, 577–592.
Yerkes, R.M., & Dodson, J.D. (1908). The relation of strength
stimulus to rapidity of habit-formation. Journal of Comparative
Neurology and Psychology, 18, 459–482.
Zimmerman, C.A., & Kelley, C.M. (2010). ‘‘I’ll remember this!’’
Effects of emotionality on memory predictions versus memory
performance. Journal of Memory and Language, 62, 240–253.