Effects Of Emotional Arousal Research Articles

Emotion and conflict adaptation: the role of phasic arousal and self-relevance

ABSTRACT Conflict adaptation reflects the increase in cognitive control after previous conflict between task-relevant and task-irrelevant information. Tonic (sustained) arousal elicited by emotional words embedded in a conflict task has previously been shown to increase conflict adaptation. However, the role of phasic (transient) emotional arousal remains unclear. In Experiment 1 (N = 55), we therefore investigated the effect of phasic arousal using a colour flanker task with negative, positive, and neutral words as stimuli. We hypothesised that phasic arousal elicited in this context will increase conflict adaptation in the subsequent trial. Indeed, when the words were positive or negative as compared to neutral, we observed increased conflict adaptation. In Experiment 2 (N = 54), we examined the role of the self-relevance by presenting words with a self-related pronoun (“my”) or sender-related pronoun (“his”/“her”). We expected that emotional words with high self-relevance would lead to stronger effects of emotional arousal on conflict adaptation. Confirming this hypothesis, results showed that emotional words within a self-related context again increased conflict adaptation, whereas this effect was not observed in the sender-related context. Taken together, these results are the first to show that phasic arousal elicited by emotional words increases conflict adaptation, in particular when these words have high self-relevance.

Interference Effects of Emotional Arousal on Recognition Memory: Comparison of Within-object and Between-object Bindings

According to the Object-based Binding Theory, emotional arousal enhances within-object binding, but impairs or does not affect between-object memory binding. The present study aimed to investigate the effects of negative emotional arousal on memory updating of within-object and between-object associations. Negative emotional arousal was expected to cause a higher level of interference in intrinsic associations (within object condition) than in extrinsic associations (between object condition). Angry, sad and neutral facial expressions chosen for emotion conditions are paired with various hats as neutral objects. In the within-object condition, the hat was presented together with a face, while in the between-object condition, the hat was presented as a separate object distinct from the face. First, all participants learned a list of face-hat pairs, then learned a second list with the same faces paired with new hats. In the test phase, the second list of pairs was rearranged into half correct and half incorrect, and the participants decided whether the pairs were correct or incorrect. The data were analyzed on the basis of Signal Detection Theory. We found that higher false alarms were given to angry faces in the within-object condition than in the between-object condition. This high false alarm rate indicates that negative emotional arousal prevented memory updating of within-object associations. According to analysis of memory sensitivity, in all emotion conditions, correct and incorrect pairs were better discriminated in the between-object condition than in the within-object condition. When false alarm rates and sensitivity results are considered together, the hypotheses of the study are supported and it is seen that negative emotional arousal leads to proactive interference in the within-object condition and thus makes it difficult to update memory. These results are consistent with the OBT in that negative emotional arousal exerts an enhancing effect on remembering intrinsic features of objects.

Effects of emotional arousal at memory encoding on the P300-based Concealed Information Test

Effects of emotional arousal at memory encoding on the P300-based Concealed Information Test

The Effect of Emotional Arousal on Inhibition of Return Among Youth With Depressive Tendency.

The occurrence and development of depressive symptoms were thought to be closely related to excessive attention to negative information. However, the evidences among researchers were inconsistent on whether negative emotional information could induce attention bias in depressed individuals. One possible hypothesis is that the arousal level of stimuli regulates the attention bias of depressed individuals to negative emotional stimuli. In the current study, we directly assessed the attentional inhibition of depression-tendency individuals to different arousal levels of negative emotional faces. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to distinguish the depression-tendency group from the health group. Thirty-three participants in each group completed a simpler cue-target task that comprised four kinds of experimental conditions, in which group was an inter-subject variable, while cue validity, arousal level, and stimulus onset asynchrony were internal variables. By subtracting the reaction time under the valid cue from the reaction time under the invalid cue, we got the magnitudes of inhibition of return (IOR), which reflected the effective suppression of previously noticed irrelevant information. We found that, in health group, the IOR effect was smaller at high arousal level than at low arousal level. This means that even in the normal population, higher arousal level of negative emotional information could weaken the individual’s attention inhibition ability. While in the depression-tendency group, the IOR effect only appeared at low arousal level condition, but in the high cue condition it showed the reversal pattern, that was, the cue effect. These results indicated for the first time that the attention bias of depressive individuals to negative emotional stimuli was influenced by the arousal level of stimuli, and the negative stimuli with high arousal level were more difficult to suppress.

Glucocorticoid enhancement of recognition memory via basolateral amygdala-driven facilitation of prelimbic cortex interactions.

Extensive evidence indicates that the basolateral amygdala (BLA) interacts with other brain regions in mediating stress hormone and emotional arousal effects on memory consolidation. Brain activation studies have shown that arousing conditions lead to the activation of large-scale neural networks and several functional connections between brain regions beyond the BLA. Whether such distal interactions on memory consolidation also depend on BLA activity is not as yet known. We investigated, in male Sprague-Dawley rats, whether BLA activity enables prelimbic cortex (PrL) interactions with the anterior insular cortex (aIC) and dorsal hippocampus (dHPC) in regulating glucocorticoid effects on different components of object recognition memory. The glucocorticoid receptor (GR) agonist RU 28362 administered into the PrL, but not infralimbic cortex, immediately after object recognition training enhanced 24-hour memory of both the identity and location of the object via functional interactions with the aIC and dHPC, respectively. Importantly, posttraining inactivation of the BLA by the noradrenergic antagonist propranolol abolished the effect of GR agonist administration into the PrL on memory enhancement of both the identity and location of the object. BLA inactivation by propranolol also blocked the effect of GR agonist administration into the PrL on inducing changes in neuronal activity within the aIC and dHPC during the postlearning consolidation period as well as on structural changes in spine morphology assessed 24 hours later. These findings provide evidence that BLA noradrenergic activity enables functional interactions between the PrL and the aIC and dHPC in regulating stress hormone and emotional arousal effects on memory.

Basolateral amygdala noradrenergic activity is required for enhancement of object recognition memory by histone deacetylase inhibition in the anterior insular cortex

Extensive evidence indicates that noradrenergic activation of the basolateral amygdala (BLA) is essential for mediating emotional arousal effects on memory consolidation in different target regions. However, the mechanism by which BLA activation regulates such information storage processes remains largely elusive. Here we demonstrate, in male Sprague-Dawley rats, that noradrenergic activation of the BLA is critically involved in enabling facilitation of memory consolidation induced by histone acetylation, a form of chromatin modification, within the insular cortex (IC) on object recognition memory. The histone deacetylase (HDAC) inhibitor sodium butyrate (NaB) administered either systemically or directly into the anterior, but not posterior, IC immediately after object recognition training enhanced long-term memory for the identity of the object. Systemic NaB administration also enhanced memory for the location of the object. This NaB-induced enhancement of both object recognition and object location memory was selectively associated with an increased ability to assess the familiarity of the training stimulus, without affecting interaction with a novel stimulus. The β-adrenoceptor antagonist propranolol infused into the BLA concurrently abolished the NaB-induced enhancement of familiarity detection underlying both object recognition and object location memory. These findings indicate that noradrenergic activity within the BLA induced by emotional arousal interacts with chromatin modification mechanisms in its target regions to affect post-learning consolidation processes underlying long-term recognition memory and discrimination of a familiar stimulus.

Emotional arousal and memory after deep encoding

Emotion often enhances long-term memory. One mechanism for this enhancement is heightened arousal during encoding. However, reducing arousal, via emotion regulation (ER) instructions, has not been associated with reduced memory. In fact, the opposite pattern has been observed: stronger memory for emotional stimuli encoded with an ER instruction to reduce arousal. This pattern may be due to deeper encoding required by ER instructions. In the current research, we examine the effects of emotional arousal and deep-encoding on memory across three studies. In Study 1, adult participants completed a writing task (deep-encoding) for encoding negative, neutral, and positive picture stimuli, whereby half the emotion stimuli had the ER instruction to reduce the emotion. Memory was strong across conditions, and no memory enhancement was observed for any condition. In Study 2, adult participants completed the same writing task as Study 1, as well as a shallow-encoding task for one-third of negative, neutral, and positive trials. Memory was strongest for deep vs. shallow encoding trials, with no effects of emotion or ER instruction. In Study 3, adult participants completed a shallow-encoding task for negative, neutral, and positive stimuli, with findings indicating enhanced memory for negative emotional stimuli. Findings suggest that deep encoding must be acknowledged as a source of memory enhancement when examining manipulations of emotion-related arousal.

Dissociable contributions of the amygdala to the immediate and delayed effects of emotional arousal on memory.

Emotional arousal enhances memory encoding and consolidation leading to better immediate and delayed memory. Although the central noradrenergic system and the amygdala play critical roles in both effects of emotional arousal, we have recently shown that these effects are at least partly independent of each other, suggesting distinct underlying neural mechanisms. Here we aim to dissociate the neural substrates of both effects in 70 female participants using an emotional memory paradigm to investigate how neural activity, as measured by fMRI, and a polymorphism in the α2B-noradrenoceptor vary for these effects. To also test whether the immediate and delayed effects of emotional arousal on memory are stable traits, we invited back participants who were a part of a large-scale behavioral memory study ∼3.5 yr ago. We replicated the low correlation of the immediate and delayed emotional enhancement of memory across participants (r = 0.16) and observed, moreover, that only the delayed effect was, to some degree, stable over time (r = 0.23). Bilateral amygdala activity, as well as its coupling with the visual cortex and the fusiform gyrus, was related to the preferential encoding of emotional stimuli, which is consistent with affect-biased attention. Moreover, the adrenoceptor genotype modulated the bilateral amygdala activity associated with this effect. The left amygdala and its coupling with the hippocampus was specifically associated with the more efficient consolidation of emotional stimuli, which is consistent with amygdalar modulation of hippocampal consolidation.

Emotional Arousal at Memory Encoding Enhanced P300 in the Concealed Information Test.

Previous studies have reported that the concealed information test (CIT) is a reliable and powerful method for detecting information. However, the external validity of the CIT studies has not been fully proven. In particular, few studies have examined the effects of emotional arousal at memory encoding on physiological responses in the CIT. The present study investigated the influence on the CIT of the magnitude of emotional arousal at memory encoding of a mock crime, using the P300 component of the event-related brain potential (ERP). In accord with the assumptions of excitation-transfer theory, we presented emotionally arousing pictures before a mock crime. Participants were randomly assigned to either a high emotional arousal group (n = 10) or a low emotional arousal group (n = 11), viewing pictures expected to arouse emotion at a high or low level, respectively. Subsequently, all participants enacted the same mock crime, in which they were instructed to stab a pillow with a sharp-edged tool (e.g., a kitchen knife or ice pick) as if harassing a mannequin lying on a bed. After the antecedent emotional experience, the P300-based CIT was conducted. Participants in the high arousal group showed significantly greater P300 amplitudes in response to a probe stimulus compared with the low arousal group. No differences were found between the groups in response to irrelevant stimuli. These results support the notion that emotional arousal influences the P300 in the CIT paradigm.

The (limited) effect of emotional arousal in the regulation of accuracy in eyewitness memory

Abstract Witnesses encoding a crime are likely to feel negative emotions with high arousal, e.g., anxiety or fear. Negative emotions improve memory for central information and impair memory for peripheral information. In this study we explored the effects of emotional arousal and type of information in the regulation of accuracy. The regulation of accuracy allows participants to maximize accuracy, for example, by deciding on the number of alternatives in their response (the plurality option). Participants were induced with high-and low-arousal negative emotions and then shown a slideshow of a crime. Afterwards, they answered questions about central and peripheral contents of the event. Questions followed the basic plurality option procedure. First, participants selected one alternative (single answer); second, they selected three alternatives (plural answer); and, finally, they decided on reporting either the single or the plural answer. Results showed successful manipulation of arousal, and that the regulation of accuracy led to a greater increase in accuracy for peripheral than for central information, but no differences depending on the level of arousal. We also identified two factors that increased accuracy in the plurality option: the ability to discard answers with low chances of being correct and the addition of answers with higher chances of being correct. Either one, or both, can increase witness accuracy.

Dissociation of immediate and delayed effects of emotional arousal on episodic memory.

Emotionally arousing events are usually better remembered than neutral ones. This phenomenon is in humans mostly studied by presenting mixed lists of neutral and emotional items. An emotional enhancement of memory is observed in these studies often already immediately after encoding and increases with longer delays and consolidation. A large body of animal research showed that the more efficient consolidation of emotionally arousing events is based on an activation of the central noradrenergic system and the amygdala (Modulation Hypothesis; Roozendaal & McGaugh, 2011). The immediately superior recognition of emotional items is attributed primarily to their attraction of attention during encoding which is also thought to be based on the amygdala and the central noradrenergic system. To investigate whether the amygdala and noradrenergic system support memory encoding and consolidation via shared neural substrates and processes a large sample of participants (n = 690) encoded neutral and arousing pictures. Their memory was tested immediately and after a consolidation delay. In addition, they were genotyped in two relevant polymorphisms (α2B-adrenergic receptor and serotonin transporter). Memory for negative and positive emotional pictures was enhanced at both time points where these enhancements were correlated (immediate r = 0.60 and delayed test r = 0.46). Critically, the effects of emotional arousal on encoding and consolidation correlated only very low (negative r = 0.14 and positive r = 0.03 pictures) suggesting partly distinct underlying processes consistent with a functional heterogeneity of the central noradrenergic system. No effect of genotype on either effect was observed.

Top-down modulation of alpha power and pattern similarity for threatening representations in visual short-term memory

Recent studies have shown that top-down attention biases task-relevant representations in visual short-term memory (VSTM). Accumulating evidence has also revealed the modulatory effects of emotional arousal on attentional processing. However, it remains unclear how top-down attention interacts with emotional memoranda in VSTM. In this study, we investigated the mechanisms of alpha oscillations and their spatiotemporal characteristics that underlie top-down attention to threatening representations during VSTM maintenance with electroencephalography. Participants were instructed to remember a threatening object and a neutral object in a cued variant delayed response task. Retrospective cues (retro-cues) were presented to direct attention to the hemifield of a threatening object (i.e., cue-to-threat trials) or a neutral object (i.e., cue-to-neutral trials) during a retention interval prior to the probe test. We found a significant retro-cue-related alpha lateralisation over posterior regions during VSTM maintenance. The novel finding was that the magnitude of alpha lateralisation was greater for cue-to-threat objects compared to cue-to-neutral ones. These results indicated that directing attention towards threatening representations compared to neutral representations could result in greater regulation of alpha activity contralateral to the cued hemifield. Importantly, we estimated the spatiotemporal pattern similarity in alpha activity and found significantly higher similarity indexes for the posterior regions relative to the anterior regions and for the cue-to-threat objects relative to cue-to-neutral objects over the posterior regions. Together, our findings provided the oscillatory evidence of greater top-down modulations of alpha lateralisation and spatiotemporal pattern similarity for attending to threatening representations in VSTM.

Effect of post-encoding emotion on recollection and familiarity for pictures.

Although prior studies have examined the effect of post-encoding emotional arousal on recognition memory for words, it is unknown whether the enhancement effect observed on words generalizes to pictures. Furthermore, prior studies using words have showed that the effect of emotional arousal can be modulated by stimuli valence and delay in emotion induction, but it is unclear whether such modulation can extend to pictures and whether other factors such as encoding method (incidental vs. intentional encoding) can be modulatory. Five experiments were conducted to answer these questions. In Experiment 1, participants encoded a list of neutral and negative pictures and then watched a 3-min neutral or negative video. The delayed test showed that negative arousal impaired recollection regardless of picture valence but had no effect on familiarity. Experiment 2 replicated the above findings. Experiment 3 was similar to Experiment 1 except that participants watched a 3-min neutral, negative, or positive video and conducted free recall before the recognition test. Unlike the prior two experiments, the impairment effect of negative arousal disappeared. Experiment 4, where the free recall task was eliminated, replicated the results from Experiment 3. Experiment 5 replicated Experiments 1 and 2 and further showed that the impairment effects of negative arousal could be modulated by delay in emotion induction but not by encoding method or stimuli valence. Taken together, the current study suggests that the enhancement effect observed on words may not generalize to pictures.

Local context effects during emotional item directed forgetting in younger and older adults

ABSTRACTThis paper explored the differential sensitivity young and older adults exhibit to the local context of items entering memory. We examined trial-to-trial performance during an item directed forgetting task for positive, negative, and neutral (or baseline) words each cued as either to-be-remembered (TBR) or to-be-forgotten (TBF). This allowed us to focus on how variations in emotional valence (independent of arousal) and instruction (TBR vs. TBF) of the previous item (trial n-1) impacted memory for the current item (trial n) during encoding. Different from research showing impairing effects of emotional arousal, both age groups showed a memorial boost for stimuli when preceded by items high in positive or negative valence relative to those preceded by neutral items. This advantage was particularly prominent for neutral trial n items that followed emotional items suggesting that, regardless of age, neutral memories may be strengthened by a local context that is high in valence. A trending age difference also emerged with older adults showing greater sensitivity when encoding instructions changed between trial n-1 and n. Results are discussed in light of age-related theories of cognitive and emotional processing, highlighting the need to consider the dynamic, moment-to-moment fluctuations of these systems.

We ‘mean’ well, but are we missing something?

The present brief review for this Special Issue summarizes some of the original research on the emotional modulation of memory. The review begins by highlighting the pioneering research from James L. McGaugh and colleagues demonstrating modulatory effects of post-training drug administration on memory consolidation, in particular the stress hormone epinephrine. The subsequent discovery of a critical role for the basolateral amygdala in emotional modulation of memory is described. Within the context of a multiple systems approach to memory focusing on selective roles for the hippocampus and dorsolateral striatum in cognitive and habit memory, the original studies indicating that robust emotional arousal can bias animals and humans toward the predominant use of habit memory are reviewed. This effect of emotional arousal on the relative use of multiple memory systems depends on a modulatory role of the basolateral amygdala. Finally, we briefly consider how an emotion-induced enhancement of dorsolateral striatal-dependent memory may be relevant to understanding maladaptive habitual behaviors in certain human psychopathologies.

Effects of Emotional Arousal Induced by Crime-Related Words on Visual Feature Binding

Effects of Emotional Arousal Induced by Crime-Related Words on Visual Feature Binding

Emotionally arousing context modulates the ERP correlates of neutral picture processing: An ERP test of the GANE model.

The time scale of the effects of emotional arousal on neutral information processing is crucial for the predictions of the glutamate amplifies noradrenergic effects (GANE) model. GANE suggests that when emotional and neutral stimuli are presented in a sequence, neutral information processing will change. We review the literature on event-related potentials, including our own data set, to test this prediction.

Importance of amygdala noradrenergic activity and large-scale neural networks in regulating emotional arousal effects on perception and memory.

Mather and colleagues postulate that norepinephrine promotes selective processing of emotionally salient information through local "hotspots" where norepinephrine release interacts with glutamatergic activity. However, findings in rodents and humans indicate that norepinephrine is ineffective in modulating mnemonic processes in the absence of a functional amygdala. We therefore argue that emphasis should shift toward modulatory effects of amygdala-driven changes at the network level.

Homogenization of Classification Functions Measurement (HOCFUN): A Method for Measuring the Salience of Emotional Arousal in Thinking.

The problem of the measurement of emotion is a widely debated one. In this article we propose an instrument, the Homogenization of Classification Functions Measure (HOCFUN), designed for assessing the influence of emotional arousal on a rating task consisting of the evaluation of a sequence of images. The instrument defines an indicator (κ) that measures the degree of homogenization of the ratings given over 2 rating scales (pleasant-unpleasant and relevant-irrelevant). Such a degree of homogenization is interpreted as the effect of emotional arousal on thinking and therefore lends itself to be used as a marker of emotional arousal. A preliminary study of validation was implemented. The association of the κ indicator with 3 additional indicators was analyzed. Consistent with the hypotheses, the κ indicator proved to be associated, even if weakly and nonlinearly, with a marker of the homogenization of classification functions derived from a separate rating task and with 2 indirect indicators of emotional activation: the speed of performance on the HOCFUN task and an indicator of mood intensity. Taken as a whole, such results provide initial evidence supporting the HOCFUN construct validity.

Time-limited effects of emotional arousal on item and source memory.

Two experiments investigated the time-limited effects of emotional arousal on consolidation of item and source memory. In Experiment 1, participants memorized words (items) and the corresponding speakers (sources) and then took an immediate free recall test. Then they watched a neutral, positive, or negative video 5, 35, or 50 min after learning, and 24 hours later they took surprise memory tests. Experiment 2 was similar to Experiment 1 except that (a) a reality monitoring task was used; (b) elicitation delays of 5, 30, and 45 min were used; and (c) delayed memory tests were given 60 min after learning. Both experiments showed that, regardless of elicitation delay, emotional arousal did not enhance item recall memory. Second, both experiments showed that negative arousal enhanced delayed item recognition memory only at the medium elicitation delay, but not in the shorter or longer delays. Positive arousal enhanced performance only in Experiment 1. Third, regardless of elicitation delay, emotional arousal had little effect on source memory. These findings have implications for theories of emotion and memory, suggesting that emotion effects are contingent upon the nature of the memory task and elicitation delay.