Neutral Items Research Articles

Asymmetric effects of emotion on mnemonic interference

Emotional experiences can strengthen memories so that they can be used to guide future behavior. Emotional arousal, mediated by the amygdala, is thought to modulate storage by the hippocampus, which may encode unique episodic memories via pattern separation – the process by which similar memories are stored using non-overlapping representations. While prior work has examined mnemonic interference due to similarity and emotional modulation of memory independently, examining the mechanisms by which emotion influences mnemonic interference has not been previously accomplished in humans. To this end, we developed an emotional memory task where emotional content and stimulus similarity were varied to examine the effect of emotion on fine mnemonic discrimination (a putative behavioral correlate of hippocampal pattern separation). When tested immediately after encoding, discrimination was reduced for similar emotional items compared to similar neutral items, consistent with a reduced bias towards pattern separation. After 24h, recognition of emotional target items was preserved compared to neutral items, whereas similar emotional item discrimination was further diminished. This suggests a potential mechanism for the emotional modulation of memory with a selective remembering of gist, as well as a selective forgetting of detail, indicating an emotion-induced reduction in pattern separation. This can potentially increase the effective signal-to-noise ratio in any given situation to promote survival. Furthermore, we found that individuals with depressive symptoms hyper-discriminate negative items, which correlated with their symptom severity. This suggests that utilizing mnemonic discrimination paradigms allows us to tease apart the nuances of disorders with aberrant emotional mnemonic processing.

The Relationship between Child Maltreatment and Emotion Recognition

Child abuse and neglect affect the development of social cognition in children and inhibit social adjustment. The purpose of this study was to compare the ability to identify the emotional states of others between abused and non-abused children. The participants, 129 children (44 abused and 85 non-abused children), completed a children’s version of the Reading the Mind in the Eyes Test (RMET). Results showed that the mean accuracy rate on the RMET for abused children was significantly lower than the rate of the non-abused children. In addition, the accuracy rates for positive emotion items (e.g., hoping, interested, happy) were significantly lower for the abused children, but negative emotion and neutral items were not different across the groups. This study found a negative relationship between child abuse and the ability to understand others’ emotions, especially positive emotions.

Low level perceptual, not attentional, processes modulate distractor interference in high perceptual load displays: evidence from neglect/extinction

According to perceptual load theory (Lavie, 2005) distractor interference is determined by the availability of attentional resources. If target processing does not exhaust resources (with low perceptual load) distractor processing will take place resulting in interference with a primary task; however, when target processing uses-up attentional capacity (with high perceptual load) interference can be avoided. An alternative account (Tsal and Benoni, 2010a) suggests that perceptual load effects can be based on distractor dilution by the mere presence of additional neutral items in high-load displays so that the effect is not driven by the amount of attention resources required for target processing. Here we tested whether patients with unilateral neglect or extinction would show dilution effects from neutral items in their contralesional (neglected/extinguished) field, even though these items do not impose increased perceptual load on the target and at the same time attract reduced attentional resources compared to stimuli in the ipsilesional field. Thus, such items do not affect the amount of attention resources available for distractor processing. We found that contralesional neutral elements can eliminate distractor interference as strongly as centrally presented ones in neglect/extinction patients, despite contralesional items being less well attended. The data are consistent with an account in terms of perceptual dilution of distracters rather than available resources for distractor processing. We conclude that distractor dilution can underlie the elimination of distractor interference in visual displays.

Negative affect impairs associative memory but not item memory

The formation of associations between items and their context has been proposed to rely on mechanisms distinct from those supporting memory for a single item. Although emotional experiences can profoundly affect memory, our understanding of how it interacts with different aspects of memory remains unclear. We performed three experiments to examine the effects of emotion on memory for items and their associations. By presenting neutral and negative items with background contexts, Experiment 1 demonstrated that item memory was facilitated by emotional affect, whereas memory for an associated context was reduced. In Experiment 2, arousal was manipulated independently of the memoranda, by a threat of shock, whereby encoding trials occurred under conditions of threat or safety. Memory for context was equally impaired by the presence of negative affect, whether induced by threat of shock or a negative item, relative to retrieval of the context of a neutral item in safety. In Experiment 3, participants were presented with neutral and negative items as paired associates, including all combinations of neutral and negative items. The results showed both above effects: compared to a neutral item, memory for the associate of a negative item (a second item here, context in Experiments 1 and 2) is impaired, whereas retrieval of the item itself is enhanced. Our findings suggest that negative affect impairs associative memory while recognition of a negative item is enhanced. They support dual-processing models in which negative affect or stress impairs hippocampal-dependent associative memory while the storage of negative sensory/perceptual representations is spared or even strengthened.

Emotion Strengthens High-Priority Memory Traces but Weakens Low-Priority Memory Traces

When people encounter emotional events, their memory for those events is typically enhanced. But it has been unclear how emotionally arousing events influence memory for preceding information. Does emotional arousal induce retrograde amnesia or retrograde enhancement? The current study revealed that this depends on the top-down goal relevance of the preceding information. Across three studies, we found that emotional arousal induced by one image facilitated memory for the preceding neutral item when people prioritized that neutral item. In contrast, an emotionally arousing image impaired memory for the preceding neutral item when people did not prioritize that neutral item. Emotional arousal elicited by both negative and positive pictures showed this pattern of enhancing or impairing memory for the preceding stimulus depending on its priority. These results indicate that emotional arousal amplifies the effects of top-down priority in memory formation.

Memory bias for negative emotional words in recognition memory is driven by effects of category membership

Recognition memory studies often find that emotional items are more likely than neutral items to be labelled as studied. Previous work suggests this bias is driven by increased memory strength/familiarity for emotional items. We explored strength and bias interpretations of this effect with the conjecture that emotional stimuli might seem more familiar because they share features with studied items from the same category. Categorical effects were manipulated in a recognition task by presenting lists with a small, medium or large proportion of emotional words. The liberal memory bias for emotional words was only observed when a medium or large proportion of categorised words were presented in the lists. Similar, though weaker, effects were observed with categorised words that were not emotional (animal names). These results suggest that liberal memory bias for emotional items may be largely driven by effects of category membership.

Cultural differences in visual search with culturally neutral items

Cultural differences in visual search with culturally neutral items

The orbitofrontal cortex is involved in emotional enhancement of memory: evidence from the dementias

The enhancing effect of emotion on subsequent memory retrieval is well established. Patients with frontotemporal dementia show profound emotion processing difficulties, yet the extent to which such deficits attenuate emotional enhancement of memory remains unknown. Here, we studied the intersection between emotion and memory using a visual forced-choice recognition test for negative and neutral stimuli in 34 patients with frontotemporal dementia compared with 10 patients with Alzheimer's disease and 15 control subjects. Control subjects and patients with Alzheimer's disease recognized more emotional than neutral items, as demonstrated by a significant interaction between emotion and memory for true recognition. This emotional enhancement effect was notably absent in the frontotemporal dementia cohort, with comparable recognition performance regardless of emotional content. Voxel-based morphometry analyses revealed distinct neural substrates for overall memory versus emotional memory performance. Overall memory performance correlated with the hippocampus, precuneus and posterior cingulate, regions crucial for successful episodic memory performance. Emotional enhancement of memory, by contrast, was associated exclusively with the integrity of the right orbitofrontal and subcallosal cortex. Our findings demonstrate differential disruption of emotional enhancement of memory in neurodegenerative disorders, and point toward the potentially pivotal role of the orbitofrontal cortex in supporting the successful retrieval of emotionally charged negative stimuli.

Emotional and non-emotional memories are suppressible under direct suppression instructions

Research on retrieval suppression has produced varying results concerning whether negatively valenced memories are more or less suppressible than neutral memories. This variability may arise if, across studies, participants adopt different approaches to memory control. Cognitive and neurobiological research points to two mechanisms that achieve retrieval suppression: thought-substitution and direct suppression (Benoit & Anderson, 2012; Bergström, de Fockert, & Richardson-Klavehn, 2009). Using the Think/No-think paradigm, this study examined whether participants can inhibit neutral and negatively valenced memories, using a uniform direct suppression strategy. Importantly, when strategy was controlled, negative and neutral items were comparably inhibited. Participants reported high compliance with direct suppression instructions, and success at controlling awareness predicted forgetting. These findings provide the first evidence that direct suppression can impair negatively valenced events, and suggest that variability in forgetting negative memories in prior studies is unlikely to arise from difficulty using direct suppression to control emotionally negative experiences.

Comparing two forms of a childhood perspective-taking measure using CFA and IRT.

Deficits in perspective-taking ability have been linked to social problems associated with disorders such as autism spectrum disorders (ASD) and conduct disorder. Even subtle deficits in perspective-taking are related to social adjustment and moral development. A common measure of perspective-taking abilities in children is the "Reading the Mind in the Eyes Task" ("Eyes task"; Baron-Cohen, Wheelwright, Spong, Scahill, & Lawson, 2001). The Eyes task was primarily developed for use in identifying individuals with ASDs, while its function with nonclinical populations has not been clearly addressed. Additionally, it is unknown whether the Eyes task can be used to measure specific deficits or abilities in the cognitive or emotional components of perspective-taking. In this article we assessed the structure and function of the Eyes task and an open ended or generative format of the same task (Generative Eyes Task; GET) found to measure emotional perspective-taking specifically. Confirmatory factor analyses found the traditional Eyes task to have the assumed single factor structure, while the GET has a clear 2-factor structure corresponding to emotionally valenced or neutral items. The Eyes task and the GET were also compared using item response theory. The Eyes task provided the most measurement accuracy at 2 standard deviations below the mean making it most accurate for populations with severe deficits, while the GET was most accurate at the mean level of perspective-taking. Based on these analyses, we conclude that the GET is more appropriate for use in nonclinical populations and when emotional perspective-taking abilities are of interest.

Working Memory Load Attenuates Emotional Enhancement in Recognition Memory

Emotionally arousing stimuli are perceived and remembered better than neutral stimuli. Under threat, this negativity bias is further increased. We investigated whether working memory (WM) load can attenuate incidental memory for emotional images. Two groups of participants performed the N-back task with two WM load levels. In one group, we induced anxiety using a threat of shock paradigm to increase attentional processing of negative information. During task performance we incidentally and briefly flashed emotional distracter images which prolonged response times in both load conditions. A subsequent unannounced immediate recognition memory test revealed that when load at exposure had been low, recognition was better for negative items in both participant groups. This enhancement, however, was attenuated under high load, leaving performance on neutral items unchanged regardless of the threat of shock manipulation. We conclude that both in threat and in normal states WM load at exposure can attenuate immediate emotional memory enhancement.

Goal conduciveness as a key determinant of memory facilitation.

The affective dimensions responsible for the modulation of memory by emotion are subject to debate. Several hypotheses have been suggested: The arousal hypothesis of memory facilitation suggests the arousal dimension as the key determinant in whether emotional events are more likely to be remembered than neutral events. The valence hypothesis suggests preferential status for unpleasant, as compared with pleasant, stimuli in memory. The authors tested an alternative hypothesis derived from the appraisal theory of emotion, namely, that events that are relevant to the current concerns of the individual benefit from a memory advantage. In the present study, the authors demonstrate that initially neutral but goal conducive items (for game-related gain) remain stable in memory over time, whereas memory for goal irrelevant and goal obstructive items decline over time. They furthermore found that the affective evaluation of initially neutral items changed as a function of the goal relevance manipulation and that this change was stable over time. Taken together, findings support the relevance hypothesis of memory facilitation.

Perceptual load vs. dilution: the roles of attentional focus, stimulus category, and target predictability.

Many studies have shown that increasing the number of neutral stimuli in a display decreases distractor interference. This result has been interpreted within two different frameworks; a perceptual load account, based on a reduction in spare resources, and a dilution account, based on a degradation in distractor representation and/or an increase in crosstalk between the distractor and the neutral stimuli that contain visually similar features. In four experiments, we systematically manipulated the extent of attentional focus, stimulus category, and preknowledge of the target to examine how these factors would interact with the display set size to influence the degree of distractor processing. Display set size did not affect the degree of distractor processing in all situations. Increasing the number of neutral items decreased distractor processing only when a task induced a broad attentional focus that included the neutral stimuli, when the neutral stimuli were in the same category as the target and distractor, and when the preknowledge of the target was insufficient to guide attention to the target efficiently. These results suggest that the effect of neutral stimuli on the degree of distractor processing is more complex than previously assumed. They provide new insight into the competitive interactions between bottom-up and top-down processes that govern the efficiency of visual selective attention.

Oxytocin facilitates protective responses to aversive social stimuli in males

The neuropeptide oxytocin (OXT) can enhance the impact of positive social cues but may reduce that of negative ones by inhibiting amygdala activation, although it is unclear whether the latter causes blunted emotional and mnemonic responses. In two independent double-blind placebo-controlled experiments, each involving over 70 healthy male subjects, we investigated whether OXT affects modulation of startle reactivity by aversive social stimuli as well as subsequent memory for them. Intranasal OXT potentiated acoustic startle responses to negative stimuli, without affecting behavioral valence or arousal judgments, and biased subsequent memory toward negative rather than neutral items. A functional MRI analysis of this mnemonic effect revealed that, whereas OXT inhibited amygdala responses to negative stimuli, it facilitated left insula responses for subsequently remembered items and increased functional coupling between the left amygdala, left anterior insula, and left inferior frontal gyrus. Our results therefore show that OXT can potentiate the protective and mnemonic impact of aversive social information despite reducing amygdala activity, and suggest that the insula may play a role in emotional modulation of memory.

The role of attention in the associative binding of emotionally arousing words

In the present study, we examined the role of attention in modulating the memory benefit of emotional arousal for same-valence word pair associations. To assess the role of attention either at encoding or at retrieval, participants studied lists of positive, neutral, and negative words pairs under full attention, divided attention at encoding, or divided attention at retrieval, and then were tested on the single words and on the associations between words. Consistent with past studies, memory accuracy was higher for emotional items than for neutral items, and no memory difference was observed across emotional arousal conditions for associations when encoding occurred under full attention. In contrast, memory accuracy was higher for emotionally arousing items and associations relative to neutral items when encoding occurred under divided attention. Finally, dividing attention at retrieval revealed similar effects across emotion conditions, suggesting that retrieval of emotional stimuli relative to neutral stimuli, unlike encoding, does not benefit from automatic processing. The discussion emphasizes the role of automatic processing during encoding in producing the benefit of emotionally enhanced memory, as well as the extent to which controlled attention is responsible for eliminating or reversing (relative to neutral materials) emotionally enhanced memory for associations. Additionally, the implications of the divided-attention-at-retrieval manipulation include consideration of the way in which emotional items may be consciously processed during encoding.

The emotion-induced memory trade-off: More than an effect of overt attention?

Although it has been suggested that many effects of emotion on memory are attributable to attention, in the present study we addressed the hypothesis that such effects may relate to a number of different factors during encoding or postencoding. One way to look at the effects of emotion on memory is by examining the emotion-induced memory trade-off, whereby enhanced memory for emotional items often comes at the cost of memory for surrounding background information. We present evidence that this trade-off cannot be explained solely by overt attention (measured via eyetracking) directed to the emotional items during encoding. Participants did not devote more overt attention to emotional than to neutral items when those items were selectively remembered (at the expense of their backgrounds). Only when participants were asked to answer true/false questions about the items and the backgrounds--a manipulation designed to affect both overt attention and poststimulus elaboration--was there a reduction in selective emotional item memory due to an increase in background memory. These results indicate that the allocation of overt visual attention during encoding is not sufficient to predict the occurrence of selective item memory for emotional items.

The cognitive neuroscience of memory

The cognitive neuroscience of long-term memory is ingrained with the assumptions that a particular task measures a single cognitive process and that each cognitive process is mediated by a single brain region. However, these assumptions are simplistic and hindering progress toward understanding the true mechanisms of memory. This special issue of Cognitive Neuroscience presents five empirical papers and two theoretical discussion papers with peer commentaries on the spatial and/or temporal mechanisms of memory. Using fMRI, Yu et al. show ventral parietal cortex sub-regions mediate dissociable aspects of recollection, and Mickley Steinmetz et al. study time-delay effects on processes engaged during emotional versus neutral item encoding. Employing ERPs, Galli et al. investigate anticipatory activity and recall, and Evans et al. study the effect of cognitive demands on recollection activity. Using fMRI and ERPs, Herzmann et al. investigate spatial-temporal activity associated with recognition. Voss et al. review electrophysiological, fMRI, and behavioral evidence indicating implicit memory can influence explicit memory measures. Gotts et al. review electrophysiological, fMRI, and modeling evidence to evaluate proposals of repetition priming and highlight neural synchronization. These papers embrace complex cognitive and neural processes, and thus will provide a framework for future studies to investigate the mechanisms of memory.

The impact of emotion on prospective memory and monitoring: No pain, big gain

The emotionally enhanced memory effect is robust across studies of retrospective memory, with heightened recall for items with emotional content (e.g., words like "murder") relative to neutral items (e.g., words like "envelope"). Only a handful of studies have examined the influence of emotion on prospective memory (PM), with mixed results. In some cases emotion enhances PM, and in others it impairs PM. Interpretation of these findings is clouded by methodological differences across studies and by the fact that, to date, no study has examined the impact of emotion on PM monitoring. In our study, we assessed PM performance when PM targets were neutral, negative, and positive, and also investigated monitoring across these different PM target types. Participants showed heightened PM performance for positive and negative relative to neutral targets, yet there was no evidence of additional monitoring for emotional targets. In fact, measures of monitoring were significantly reduced when the PM targets were emotional rather than neutral. Our findings suggest that it is possible to boost PM performance in a focal task using emotional cues, and that the use of emotional cues reduces the need for monitoring.

When Often Becomes Always, and Sometimes Becomes Never: Miscomprehension in Surveys

There is ongoing concern within the literature about the quality of survey data used in research. Typically efforts have focussed on increasingly sophisticated analytic approaches to ameliorate these problems. This paper draws on linguistic theory to suggest that the process of item interpretation poses a considerable threat to construct validity. We explore three types of miscomprehension: instructional miscomprehension (where respondents do not follow instructions); sentential miscomprehension (where item syntax is inappropriately enriched or depleted) and lexical miscomprehension (where different meanings of words are employed). We report on two studies. The first combines open-ended questions and Likert scales to ascertain what respondents think survey items mean. The second study draws on the results of the first and allows respondents to select from among neutral items and those which have been either sententiallly or lexically miscomprehended. We find strong evidence for all three forms of miscomprehension, which is often not statistically evident and may cause respondents to tap into other concepts or hold very different interpretations of items. Effectively two individuals may respond that they 'agree' to a particular item but what they are agreeing to may be two very different things. We discuss the implications of this for management research, possible means of amelioration and directions for future research

The effects of emotion and encoding strategy on associative memory

Research has demonstrated that when discrete pieces of information are integrated together at encoding--imagining two items together as a single entity, for example--there is a mnemonic benefit for their relationship. A separate body of literature has indicated that the presence of emotional information can have an impact on the binding of associated neutral details, in some cases facilitating associative binding (MacKay et al. Memory and cognition 32:474-488, 2004; Mather, perspectives on psychological science 2:33-52, 2007), and in other cases impeding the processing of associated details (Easterbrook, Psychological Review 66:183-201, 1959; Kensinger, Emotion review 1:99-113, 2009). In the present experiments, we investigated how memory for neutral words is affected by the emotionality of the information with which they are presented (whether with an emotional word or a second neutral word) and the encoding context (integrated or nonintegrated strategy). Participants viewed word pairs and were instructed to visualize the items as an integrated unit or to visualize them separately from one another. The results of Experiment 1 showed a disproportionate mnemonic benefit for neutral items that were integrated with other neutral items over those integrated with emotional items. The results of Experiments 2A and 2B showed that this effect interacted with encoding time: When given 2 s to encode, participants showed no effect of integration on memory for neutral-neutral pairs, but showed a significant mnemonic benefit for integrating emotional-neutral pairs. When given 4 or 6 s, the integrative benefit increased significantly for neutral-neutral pairs but decreased for emotional-neutral pairs. These results suggest that creating an integrated mental image of two neutral items requires a more time-consuming process than integrating an emotional and a neutral item, but that extra effort may result in a downstream mnemonic benefit.