Journal List HHS Author Manuscripts PMC4110743 Soc Personal Psychol Compass Author manuscript available in PMC 2014 Jul 25 Published in final edited form as Soc Personal Psychol Compass 2008 Sep 1 25 18241843 Published online 2008 Aug 6 doi 101111j17519004200800138x PMCID PMC4110743 NIHMSID NIHMS598181 Affective Arousal as Information How Affective Arousal Influences Judgments Learning and Memory Justin Storbeck and Gerald L Clore Author information Copyright and License information See other articles in PMC that cite the published article Go to Abstract The affectasinformation framework posits that affect is embodied information about value and importance The valence dimension of affect provides evaluative information about stimulus objects which plays a role in judgment and decisionmaking Affect can also provide evaluative information about ones own cognitions and response inclinations information that guides thinking and reasoning In particular positive affect often promotes and negative affect inhibits accessible responses or dominant modes of thinking Affect thus moderates many of the textbook phenomena in cognitive psychology In the current review we suggest additionally that the arousal dimension of affect amplifies reactions leading to intensified evaluations increased reliance All living creatures have in common the necessity of continually evaluating aspects of their environment Even animals as primitive as snails are apparently guided by a hedonic decision mechanism that weighs the need for nutrients against the potential risk from predators Gillette Huang Hatcher Moroz 2000 In humans such evaluative processes are examined in a variety of models including the affectasinformation model Clore Storbeck 2006 Schwarz Clore 2007 That model proposes that pleasant unpleasant and arousing reactions provide bodily and experiential information about the positive value the negative value and the importance of whatever is encountered This information serves as a basis for judgments and decisions as a guide for cognitive processing and as a signal for the regulation of long term memory In this view making judgments and decisions often involves asking oneself How do I feel about it Schwarz Clore 1988 To the extent that a particular judgment object or decision alternative is experienced as the source of an affective reaction it should take on the positive or negative value of the affect Similarly in task situations to the extent that affect is experienced as feedback about current thoughts and inclinations such thoughts and inclinations should take on the positive or negative value of the affect Cognitive tasks generally elicit relational processing relating incoming information to what one already knows Positive affect should maintain and promote such processing whereas negative affect which implies a problem with ones approach should result in Clore Storbeck 2006 for a review Thus affective cues attributed to judgment objects and decision alternatives can govern judgments and decisions whereas affect experienced as feedback about taskrelevant thoughts and inclinations can regulate styles of thinking Two studies in particular illustrate the roles of affect in judgments on the one hand and learning styles on the other One of these studies Schwarz Clore 1983 found affective influences on judgments of life satisfaction Individuals were asked how satisfied they were with their lives on either rainy or sunny days in early Spring People experiencing a sunny day were found to be in happier moods and to be more satisfied with their lives than people experiencing a rainy day Another group was first asked about the weather and only then about life satisfaction They too were happier on sunny than on rainy days but their life satisfaction ratings were unaffected by their moods The results indicated that it was not mood per se that influenced peoples Baumeister Vohs Tice 2006 Cabanac Guillaume Balasko Fleury 2002 The second illustrative study Storbeck Clore 2005 found affective influences on styles of learning rather than on evaluative judgments When people are confronted with cognitive tasks their affect can confer value on particular thoughts and styles of processing Specifically the affectasinformation approach suggests that positive affect should promote the use of relational processing the dominant style of processing in such tasks whereas negative affect should inhibit that dominant style of processing making the nondominant style of itemspecific processing more likely Storbeck and Clore 2005 forthcoming tested this assumption using a paradigm in which relational processing produces false memories Brainerd Reyna 1998 Hege Dodson 2004 Word lists were presented after the mood manipulation Each word within a given list was related to a single nonpresented word referred to as a critical lure For example a list including such words as bed pillow wake rest and dream should prime the critical lure sleep As predicted happy individuals did produce more false memories ie recalled more critical lures than sad individuals Followup studies found that differences in retrieval strategies or motivation can not account for these false memory effects Storbeck Clore 2008 The results thus suggest that affective cues can guide cognitive processing by imparting value to accessible learning styles The goal of the affectasinformation and related approaches is to understand the transformative power of affect on cognition These approaches generally assume that there is adaptive value in having ready access to ones attitudes Fazio Powell 1997 and in being able to read ones own and others affective reactions Mayer Salovey Caruso 2004 This assumption is also consistent with research on the difficulties faced by individuals with damage to the prefrontal cortex damage that limits access to affective information Damasio 1994 In everyday life affective reactions transform events actions and objects into desirable or undesirable events praiseworthy or blameworthy actions and appealing or unappealing objects Ortony Clore Collins 1988 Go to Arousal as Information Affective experience is often treated as having two dimensions valence and arousal eg Russell 1980 Wundt 1886 Research on affect has focused mainly on the valence or goodbad dimension The arousal dimension has been examined less often at least in recent years In this review we extend the affectasinformation approach to consider how arousal also serves as information by signaling importance or urgency Specifically arousal can play a role in judgments processing and memory by indicating the personal relevance of an issue the urgency of a potential response or the importance of an event A number of questions surround the concept of arousal To what does the term arousal refer There appears to be no convincing evidence that arousal is a single unitary entity Neiss 1988 It is sometimes thought of as activation Russell Barrett 1999 motivation or tension Thayer 1989 Within a given emotion is arousal the same thing as emotional intensity That might be the case if emotional intensity is thought of as variations in the amplitude of an emotional response But emotional intensity is itself multidimensional involving a duration as well as an amplitude dimension see Frijda Ortony Sonnemans Clore 1992 Consistent with Russell and Barrett 1999 we treat arousal as a psychological concept associated with emotional states that is variously indexed by activation of the sympathetic nervous system the autonomic nervous system or the endocrine system For example the modulation of memory by arousal can occur with the activation of the peripheral or the central nervous systems or the various endocrine systems see McGaugh 2004 for extensive review A critical feature of our model is that any source of arousal can modulate judgment thoughts and memory as long as it is implicitly attributed to or associated with an emotional reaction toward the object of that judgment thought or memory For instance the enhancement of memory can reflect either arousal that is actually elicited by the toberemembered object Cahill et al 1996 or that comes from an irrelevant source such as a cold presser task Cahill Gorski Le 2003 or an upsetting film Nielson Powless 2007 as discussed in the final section In this review we conclude that arousal can be both beneficial and detrimental to cognitive performance The YerkesDodson law 1908 specified an inverted Ushaped curve with low levels of arousal having little impact on performance medium levels enhancing performance and high levels being detrimental However many investigators have failed to find support for such a curvilinear relation Matthews 1985 Neiss 1988 Revelle Loftus 1992 More recent models propose that the influence of arousal on performance is determined by an interaction of personality style eg extraversion trait anxiety and task requirements eg Matthews 1985 2006 Revelle Loftus 1992 In a similar vein we suggest that the interaction of affective arousal and processing style determines task performance If the cognitive style invoked by affective arousal is appropriate for the task performance will be benefited but if inappropriate performance should be impaired This suggestion is compatible with much earlier work that focused on the interaction of arousal and task difficulty in performance eg Bargh Cohen 1978 In the next section we examine how arousal influences judgment processing and memory by conveying information about urgency or importance Go to Judgments According to the affectasinformation approach people often make judgments essentially by asking themselves How do I feel about it Schwarz Clore 1988 Positive feelings then generally lead to positive judgments and negative feelings to negative judgments But in addition to the information provided by affective valence affective arousal or excitement should also provide information about the importance or personal relevance of objects and events Therefore part of asking How do I feel about it may involve asking How strongly do I feel about it If so then we might expect that feeling strongly about something should intensify whatever value is signaled by affective valence Thus arousal may make an object seem more important or may intensify its apparent affective value so that positive objects seem more positive and negative objects more negative Marketing schemes often seek to exploit such effects to make products seem more desirable Television advertisements for new cars for example may include arousing imagery such as highspeed driving along dangerous roads or attractive and exciting models If the resulting arousal is experienced as a reaction to the car itself then any implicit positive evaluation and desire for the car might be expected to increase A series of wellknown studies by Zillmann and colleagues eg Zillmann 1971 show clearly that cues of emotional arousal are easily transferred from irrelevant target sources to relevant ones but only when the arousal manipulation occurs in close temporal proximity of the target judgment We assume then that when asking oneself How strongly do I feel about the car feelings of positive value may be intensified by both relevant and irrelevant sources of arousal According to the affectasinformation approach Clore et al 2001 Schwarz Clore 1983 2007 the influence of affect on judgment requires that the affect be associated with attributed to or experienced as a reaction to the object of judgment A classic experiment showing the role of such causal attributions for arousal was conducted by Dutton and Aron 1974 Participants crossed a high suspension bridge over a deep ravine which induced an emotionally arousing state On the other side of the bridge the male participants met an attractive female experimenter who debriefed them about the experiment a process that included giving them her telephone number The investigators found that a couple of days later in comparison with a control group that crossed a low nonarousing bridge the aroused males were more likely to telephone her Consistent with predictions the young men tended to misattribute the feelings of arousal caused by the height of the bridge as a reaction to These and other studies suggest that arousal intensifies evaluative judgments However the effect is observed primarily when individuals assess their own feelings toward an evaluated object not necessarily when asked to evaluate the target directly Gorn et al 2001 Martin et al 1992 Affective feelings thus appear to serve primarily as explicit information about peoples implicit reaction to objects which are not necessarily taken to be indications of the quality of the objects themselves Brain activation patterns are also more intense when evaluating arousing targets In research in which brain activation patterns were recorded as participants evaluated emotionally arousing words the words judged as arousing increased brain activation particularly in the amygdala which is known to be involved in stimulus evaluation Atchley Stringer Mathias Ilardi Minatrea 2007 Keil et al 2003 In addition when particular task goals increase the evaluative importance of stimuli the amygdala becomes more active for both positive and negative stimuli Cunningham Van Bavel Johnsen 2008 These results suggest that arousal may signal the importance of stimuli by intensifying activation in areas of the brain involved in evaluation Judgments concerning memory such as whether or not one has previously seen an item are also influenced by arousal For example participants might study both emotional and nonemotional pictures and later when shown several pictures indicate whether they recognize them or not In the recognition memory literature investigators distinguish between a memory of actually seeing something remember and a memory based on a sense of something being familiar known A common finding is that emotional stimuli are more often recognized than nonemotional stimuli and that people claim to remember them I saw that picture and I remember the details rather then merely knowing them that picture looks familiar but I do not remember any of the details Kensinger Corkin 2003 Ochsner 2000 However remembering the emotional stimuli better does not correlate with accuracy Presumably the brain sometimes treats the arousal from a stimulus as a cue of familiarity and as a result participants can misattribute feelings of perceptual fluency as remembering the event even though their memory may not be any more accurate compared to a known nonemotional event Dougal Rotello 2007 Sharot Delgado Phelps 2004 Thus arousal cues may lead to erroneous judgments of events as remembered when they are more likely known but not actually remembered The effects of arousal on judgment that we have reviewed appear to result from misattributions of arousal As mentioned above Zillmanns 1971 theory of excitation transfer maintained that arousal cues can be misattributed or transferred from one source to another In that view attribution of the arousal to the object of judgment is critical for finding such effects A test of this hypothesis involved first priming positive negative or neutral ideas and then having participants engage in physical exercise Sinclair Hoffman Mark Martin Pickering 1994 The participants then made selfevaluative judgments either immediately after stepping down from a treadmill or after a delay The arousal from physical exercise had no impact in the immediate selfevaluation condition but when sufficient time had passed and the source of the feelings had become unclear then feelings of arousal intensified whatever selfevaluative judgments were consistent with the earlier priming manipulation These effects of arousal on judgment have been extended to evaluations of social groups Studies examining high arousal emotions including anger anxiety and frustration have found increases in stereotypic judgments toward outgroup members when compared to judgments in low arousal states Bodenhausen 1993 Dollard Doob Miller Mowrer Sears 1939 Stephan Stephan 1985 In addition research shows that white individuals who show increased amygdala activation when viewing unfamiliar black faces are also more likely to evaluate AfricanAmericans negatively Phelps et al 2000 The results indicate that as measured by amygdala activation arousal intensified implicit biases among Whites against African Americans More generally the amygdala responds to arousal more than valence becoming more active in high arousal situations and therefore intensifying evaluations Adolphs Russell Tranel 1999 Storbeck Robinson McCourt 2006 Again high arousal appears to amplify accessible judgments including stereotyped judgments of individuals seen by raters as members of an outgroup Can arousal carry affective value In the usual characterization of affect arousal and valence are seen as independent dimensions However Michael Robinson 1998 proposes that in fact valence is not independent of arousal see also Jennings McGinnis Lovejoy Stirling 2000 Specifically high arousal triggers a defensive reaction which is initially negative whereas low arousal triggers an appetitive reaction which is initially positive Atchley et al 2007 Mehrabian Russell 1974 Robinson 1998 Robinson Storbeck Meier Kirkeby 2004 In demonstrating this principle Robinson et al asked participants to evaluate emotional pictures that varied orthogonally in arousal and valence They found that high arousing negative and low arousing positive pictures were evaluated faster and more accurately compared to high arousing positive and low arousing negative pictures Thus high arousal appears to carry a negative value and low arousal a positive value Another demonstration of this implicit valencearousal relationship found that advertisements were rated more negatively after writing about exciting events than after writing about less exciting events Faseur Geuens 2006 The authors conclude that high arousal can lead to negative evaluations although it was not clear that the valence of the induced affective states was adequately assessed Summary We suggested that people make everyday evaluative judgments by asking themselves implicitly How do I feel about it or How strongly do I feel about it In this process the valence and arousal aspects of affect can be thought of as providing value and importance information respectively Arousal can intensify evaluative reactions leading to more polarized judgments A tendency for high arousal to be treated as negative may account for arousalproduced increases in stereotypic judgments toward outgroup members And judgments of memory can be influenced when arousal is experienced as fluency or familiarity As with affective valence the impact of affective arousal depends on it being experienced as a reaction to the object of judgment Like other affective cues irrelevant arousal Go to Styles of Learning Processing and Attention A common model of arousal assumes that high arousal narrows attentional focus Easterbrook 1959 The weapon focus phenomenon in which witnesses to an armed robbery failed to remember the robber but did remember the gun illustrates this idea Christianson Loftus 1987 Loftus 1979 It suggests that highly arousing events promote attention to important objects with the result that peripheral information remains unattended Heuer Reisberg 1990 Some evidence for this narrowing of attention under arousal comes from research showing that individuals prone to anxiety disorders or depression are more likely to attend to central threatrelated details Matthews 2006 In task situations arousal cues can be experienced as taskrelevant feedback concerning the urgency or importance of current thoughts and inclinations High arousal cues intensify tendencies to act in line with current thoughts and inclinations whereas low arousal cues do not Thus high arousal may intensify reliance on ones currently active processing strategies eg itemspecific or relational Evidence that arousal cues might enhance itemspecific processing comes from research comparing exposure to fear vs neutral faces Phelps Ling Carrasco 2006 Participants engaged in a perceptual discrimination task requiring them to detect the orientation of fuzzy vertical or horizontal lines Gabor patches Just prior to presentation of the Gabor patches participants were exposed unconsciously to fearful or neutral faces The arousing fear faces led to superior detection of the orientation of the Gabor patches when compared with the low arousal neutral faces indicating that the fear faces actually increased the visual sensitivity to perceptual contrasts This study did not assess the role of arousal separately from the role of other aspects of fear but arousal seems likely to have been critical We hypothesize that arousal can increase dedication to whatever processing strategy may have been cued by positive or negative affect When people are in happy moods they tend to relate information together using relational processing strategies In doing so there can be associated costs in that happy individuals are more prone to false memories when recalling information from highly related or structured events Bless Clore Golisano Rabel Schwarz 1996 Storbeck Clore 2005 The role of arousal in such false memory production has been examined by comparing the effects of high and low arousal positive states Corson Verrier 2007 Arousal was found to amplify the tendency for positive mood to foster relational processing since aroused individuals in positive moods produced more false memories than individuals in positive but low arousal states Physiological studies also provide support for the hypothesis that arousal intensifies dedication to currently active processing strategies Particular processing strategies can be elicited in numerous ways including through task instructions Phelps et al 2006 and through the induction of affect eg Storbeck Clore 2005 Evidence comes from studies in which presented images varied in arousal and valence and physiological responses including heart rate respiration and skin conductance were recorded Gomez Stahel Danuser 2004 The physiological measures revealed that negative affect promoted itemspecific processing but in addition arousal also intensified reliance on the accessible processing strategy by increasing the readiness to act on current thoughts and inclinations see also Hamm Schupp Weike 2003 In terms of the formulation we propose affect can be seen as promoting whatever processing strategy is activated and arousal can be seen as enhancing this tendency by signaling the urgency of the situation Perception Recent discoveries point to a role for affect even in perceptions of physical reality Most investigators of visual perception would contend that perceptions of the basic geometry of the world should be impervious to emotional and motivational factors Indeed the only suggestion by serious scientists that affect might influence perception a movement referred to as the New Look in perception Bruner Postman 1947 has long been discredited Nevertheless the standard view of perception has recently been challenged by robust findings that perceptions of physical layout are resource dependent Proffitt 2006 Perceptions of physical slant distance and height have been found to reflect available physical social and emotional resources eg Schnall Harber Stefanucci Proffitt 2008 For example Proffitt et al find that hills appear steeper when resources are limited or threatened as when individuals are physically exhausted elderly or carrying a heavy backpack Consistent with this view the apparent incline of hills is increased by sad affect when standing at the bottom of a hill Reiner Stefanucci Proffitt Clore 2008 and by fear when standing at the top Stefanucci Proffitt Clore Parekh forthcoming In addition studies assessing perceptions of the distance from a balcony to the ground below find that the distance is increased by mild fear Stefanucci Proffitt 2008 To examine the role of arousal in this process in one experiment participants viewed emotionally arousing pictures just before estimating the height of the balcony which increased overestimation of the distance to the ground Stefanucci Storbeck 2008 In a followup study when viewing the arousing pictures some individuals were asked to try to regulate their reaction by viewing the pictures in a way that would make them more or less arousing The results showed that the upregulation group provided significantly higher estimates of the balcony height than the control or downregulation group Whether arousal acts by increasing the level of fear or by potentiating the fearperception relationship in some other way is not yet clear Nevertheless the results indicate that fear can influence height perception and that increases in the magnitude of arousal can magnify this phenomenon Time perception In addition to perceptions of physical reality perceptions of time may also be altered by emotional states In one experiment participants viewed a series of pictures varying in both arousal and valence and then estimated how long the pictures were shown Angrilli Cherubini Pavese Manfredini 1997 The results indicate that highly arousing images were perceived as having been shown for a longer period of time than less arousing images The authors argued that arousal influenced attention by speeding up the internal clock within the brain Angrilli et al 1997 Noulhiane Mella Samson Ragot Pouthas 2007 Attentional capture In addition to polarizing judgments intensifying processing styles and altering perception arousal also activates attention In the service of detecting and evaluating potentially dangerous objects quickly attention appears to be drawn to arousing stimuli Facial expressions are effective conveyers of arousal cues and expressions that convey arousing information eg fear surprise anger tend to capture attention For example measures of cortical brain activity electroencephalograph or EEG measures indicate that threatening faces garner more attention Schupp et al 2004 and hold attention longer than nonthreatening faces Lipp 2006 Threatening faces are also detected especially quickly among nonthreatening faces Fox Russo Bowles Dutton 2001 Ohman Lundqvist Esteves 2001 Tipples Atkinson Young 2002 For example angry faces are detected more quickly than happy faces Schubo Gendolla Meinecke Abele 2006 Since fear is generally considered a high arousal negative state such findings are consistent with the current view that the negative component promotes itemspecific processing and that arousal by signaling urgency intensifies such processing Together they appear to promote the detection of arousing or potentially important stimuli Summary We have proposed that arousal can be viewed as taskrelated feedback about the urgency or importance of current thoughts and inclinations When high arousal cues are present therefore dedication to currently activated thoughts inclinations and processing strategies may be intensified This effect included some data suggesting that fearful arousal can influence even visual acuity Phelps et al 2006 In addition we presented evidence from studies of the role of fear in the perception of heights showing that arousal also intensifies the effects of emotion on perception Additionally evidence was reviewed showing how arousal slows the perception of time Finally we briefly reviewed evidence of the role of arousal in activating and guiding attention We proposed that the cognitive consequences of specific emotions can often be predicted by considering how the valence aspect influences processing style and arousal aspect governs the degree of dedication to that style In the case of fear negative valence elicits itemspecific processing and high Go to Memory What would life be like if we remembered everything We might never to be late to meetings professors would remember all their students names and grocery lists would no longer be needed However one mnemonist who reportedly was able to remember almost everything found this skill a burden Luria 1968 He lacked the ability to observe patterns in the environment extrapolate from facts ignore irrelevant details and construct complex thoughts It seems that remembering everything is not as beneficial as one might imagine Hence some mechanism is needed to inform us about what is important to remember and what we can safely forget As seen in the previous section arousal draws attention to salient environmental stimuli but in addition it marks information as important for memory It signals importance both implicitly through adrenergic hormones and explicitly through subjective experience That is adrenergic hormones are typically released in stressful or emotionally arousing situations a process that is believed to result in enhanced long term memory for associated events For example most people remember where they were on September 11 2001 but few recall much about September 10th or 12th of that year This kind of memory consolidation relies on both the peripheral and central nervous systems The adrenal gland releases epinephrine into the peripheral nervous system which triggers changes in the central nervous system Packard Williams Cahill McGaugh 1995 Within the brain the effects of norepinephrine on the amygdala appear to be the critical process in the modulation of longterm memory Norepinephrine can be activated by multiple neuromodulators such as gammaaminobutyric acid opioid petides and glucocorticoids McGaugh 1989 2004 Activation of the amygdala can then influence memory consolidation processes in other areas of the brain as well Packard Cahill McGaugh 2001 suggesting that the process is not limited to fear conditioning for a more extensive treatment of the memory consolidation process see McGaugh 2004 Arousal apparently has its greatest influence on memory for events about 2 days after encoding Christianson 1984 McGaugh 2004 The process is believed to be the basis of traumatic stress disorder eg Cahill 1997 Traumatic stress problems are common among police emergency workers disaster teams rape or assault victims and the military The high arousal associated with intense incidents can create intrusive memories and emotions long after the event As a side note we should mention that intense arousal is also sometimes associated with amnesia and forgetting see Cahill 1997 For example evidence in the anxiety and phobia literatures shows reduced memory for relevant anxietyarousing material eg Christianson 1984 However we assume that this pattern reflects attentional disengagement during learning rather than arousal effects on forgetting The basic effect of enhanced memory after a delay occurs even when arousal is induced after learning has already been completed The effect is thus not due to heightened attention during learning but rather to hormonal modulation of processes that take place afterward The process is perhaps not completely different than that of engaging in practice in that it presumably involves sustaining the activation of appropriate neural connections However the fact that the process occurs after learning and can involve even irrelevant arousal raises questions about how the arousal gets linked to relevant rather than irrelevant stimuli One possibility is Cahill Alkire 2003 Cahill et al 2003 That is perhaps the object itself must be at least minimally arousing to signal its importance in order for a secondary source of arousal to enhance memory for it An excellent example of research demonstrating both how affect governs processing and how arousal governs remembering involves a straightforward word learning task Hurlemann et al 2005 Individuals were asked to remember interrelated words which were presented in a serial manner However on occasion an unrelated emotional word referred to as an oddball was presented Negative oddballs produced retrograde amnesia for the preceding word whereas positive oddballs produced especially good memory for it retrograde hypermnesia These results appear to involve the same affectmediated processing effects discussed earlier That is negative words led to itemspecific processing which prevented the previous word from being encoded whereas positive words fostered relational processing so that memory was superior for both the emotional word and the preceding words In a second experiment Does arousal influence all types of memory Arousal not only enhances explicit episodic memory but can also enhance implicit or associationbased memories Arousalenhanced learning of implicit associations was shown in a study involving a repetition priming paradigm Thomas LaBar 2005 The phenomenon consists of faster recognition of repeated words as the memory trace gets stronger The results showed the largest repetition priming effects for negative high arousing words compared with negative low arousing or neutral words Recent findings also suggest that arousal can enhance memories relevant to selfschemas Rameson Lieberman 2007 Investigators observed that information relevant to selfschemas evokes an affectively arousing response that leads the information to be better remembered compared with information that was not selfrelevant These findings moreover indicate that emotional arousal can enhance implicit as well as explicit memory Misattributed arousal Arousal has the property of being sticky and attaching itself to any associated object making that object seem important and causing it to be well remembered Extraneous arousal can be varied through the administration of either adrenergic betablockers to reduce arousal or betaenhancers to increase arousal Other techniques for increasing arousal include a cold presser task which involves placing one hand in a bucket of ice water and various anxiety inductions such as engaging in public speaking An example of such research is a study in which participants placed an arm in either a bucket of ice water or warm Cahill et al 2003 One week later participants were brought back for a memory test and those in the ice water condition showed greater memory for emotional pictures compared with those in the warm water condition Only emotional pictures benefited from the extraneous source of arousal perhaps because the additional arousal produced by these pictures signalled their potential importance relative to the neutral pictures Another approach to investigating arousal involves the administration of drugs to stimulate or suppress arousal OCarroll Drysdale Cahill Shajahan Ebmeier 1999 A stress hormone stimulant produced the strongest memory effects whereas a stress hormone depressant produced the weakest memory for an emotionally arousing story relative to controls Such results nicely demonstrate the relationship between level of arousal and memory Imaging results also find a similar correlation between arousal and remembering Specifically several studies have found that the more arousing the stimulus the more active the amygdala and the more active the amygdala the better the longterm memory Cahill et al 1996 Dolcos LaBar Cabeza 2004 Hamann Eli Grafton Kilts 1999 Kilpatrick Cahill 2003 Semantic relations When words are semantically related they are typically remembered better Tulving Pearlstone 1966 Against this background research has investigated whether emotional arousal can further enhance memory for semantically related words Buchanan Etzel Adolphs Tranel 2006 The results showed that in fact semantically related words that elicited arousal as detected by changes in heart rate were especially likely to be remembered In addition arousing nonrelated words and related nonarousing words that elicited some arousal as evidenced by heart rate change during learning were more likely to be remembered than words that did not elicit arousal Thus physiological measures of arousal successfully predicted memory performance for both emotional and semantically related but nonemotional words Summary In this section we have reviewed research showing that arousal has consequences for processing and remembering information High arousal served to enhance memory relative to low arousal by signaling importance implicitly through adrenergic hormones and explicitly through subjective experience Subjective experience presumably directs attention to the arousing event and adrenergic hormones activate memory consolidation processes The consolidation of information in long term memory can occur when adrenaline is administered after learning has taken place so that arousal may operate mainly on information that was already slightly arousing during initial exposure Go to Conclusions We characterized affective experience along the dimensions of valence and arousal Our research has been guided by an affectasinformation approach focused primarily on the valence dimension The current article extends this approach to include an arousalasimportance corollary A review of relevant literature suggests several possible conclusions about the cognitive consequences of variations in arousal When people ask themselves how they feel about the object of judgment they necessarily also ask How strongly do I feel about it As a result arousal can make judgments of positive objects more positive and of negative objects more negative Similarly arousal can make romantic attraction stronger jokes funnier and heights scarier Any source of arousal can affect judgment processing and memory when implicitly attributed to a relevant object Indeed arousal from irrelevant sources can be readily misattributed when associated in time with the relevant object The amygdala is more responsive to arousal than to valence The increase in amygdala activation during arousing situations may play an important role in intensifying evaluations Although arousal and valence are often treated as independent in actuality there is a tendency for high arousal stimuli to be treated as provisionally negative In addition to influences on judgment arousal also affects cognitive processing attention and perception Arousal activates attentional processes High arousal in particular may narrow attention to arousalrelevant objects leaving peripheral information unattended Arousal experienced as information about importance or urgency can intensify dedication to whatever cognitive processing is currently dominant For example the tendency to process information relationally in positive states is increased when the positive states also involve high arousal Arousal influences perceptions in several ways It was found to intensify the effect of fear on perceptions of height to contribute to the effect of fear on visual sensitivity to perceptual contrasts and to influence perceptions of the passage of time Whereas the valence component of affect signals what to learn the arousal component signals what to remember The effect of arousal on long term memory can operate implicitly through adrenergic hormones and explicitly through the effect of subjective experience on attention The hormonal effect is evident after a delay of a couple of days and it can occur even when arousal is induced after learning has already taken place Some evidence suggests that for general arousal to make objects or events memorable they must be at least slightly arousing themselves but evidence on this point is inconsistent Methods of varying arousal include the administration of betablockers to reduce arousal or betaenhancers to increase arousal Behavioral methods include the cold presser task which involve placing ones hand in a bucket of ice water and inducing anxiety through techniques such as public speaking Sometimes arousal is associated only with increases in the vividness of memories without also being associated with accuracy Go to Acknowledgments Support is acknowledged from NIMH Grant MH 50074 and NSF Grant BCS 0518835 to Gerald L Clore Go to Biography Justin Storbecks research is located at the intersection of social cognitive and affectiveneuroscience Current projects examine the influence that emotional arousal has on stereotypes implicit evaluations learning styles attention and longterm memory He is currently a PostDoc Fellow with Gerald L Clore at the University of Virginia He earned his BA and BS degrees from the University of Illinois at UrbanaChampaign and his PhD from the University of Virginia Information about past fellowship support and published articles and chapters can be found at httppeoplevirginiaedujls6sgstorbeckhtml Go to References Adolphs R Russell J Tranel D A role for the human amygdala in recognizing emotional arousal from unpleasant stimuli Psychological Science 1999 10 167171 Angrilli A Cherubini P Pavese A Manfredini S The influence of affective factors on time perception Perception 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