Local context influences memory for emotional stimuli but not electrophysiological markers of emotion-dependent attention (original) (raw)

Event-related potentials of emotional memory: Encoding pleasant, unpleasant, and neutral pictures

Cognitive, Affective, & Behavioral Neuroscience, 2002

Emotional events tend to be remembered better than nonemotional events. We investigated this phenomenon by measuring two event-related potential (ERP) effects: the emotion effect (more positive ERPs for pleasant or unpleasant stimuli than for neutral stimuli) and the subsequent memory effect (more positive ERPs for subsequently remembered items than for subsequently forgotten items). ERPs were measured while subjects rated the emotional content of pleasant, unpleasant, and neutral pictures. As was expected, subsequent recall was better for pleasant and unpleasant pictures than for neutral pictures. The emotion effect was sensitive to arousal in parietal electrodes and to both arousal and valence in frontocentral electrodes. The subsequent memory effect at centroparietal electrodes was greater for emotional pictures than for neutral pictures during an early epoch (400-600 msec). This result suggests that emotional information has privileged access to processing resources, possibly leading to better memory formation.

The neural fate of neutral information in emotion‐enhanced memory, In Psychophysiology

In this study, we report evidence that neural activity reflecting the encoding of emotionally neutral information in memory is reduced when neutral and emotional stimuli are intermixed during encoding. Specifically, participants studied emotional and neutral pictures organized in mixed lists (in which emotional and neutral pictures were intermixed) or in pure lists (only-neutral or only-emotional pictures) and performed a recall test. To estimate encoding efficiency, we used the Dm effect, measured with event-related potentials. Recall for neutral items was lower in mixed compared to pure lists and posterior Dm activity for neutral items was reduced in mixed lists, whereas it remained robust in pure lists. These findings might be caused by an asymmetrical competition for attentional and working memory resources between emotional and neutral information, which could be a major determinant of emotional memory effects.

Electrophysiological correlates of remembering emotional pictures

2011

Extensive evidence shows that emotional events tend to be remembered in greater detail and with an enhanced sense of vividness compared to neutral events. The current study investigated the neural correlates of this phenomenon during retrieval using the event-related potentials technique (ERP). Participants were asked to perform a memory recognition test of previously studied ("Old") and unstudied ("New") emotional and neutral pictures encoded a week before the test session. Next, they were asked to perform a Remember-Know task (Gardiner and Java, 1993) for each "old" decision. ERPs were created for retrieval activity corresponding to six conditions: Remember-Emotional, Remember-Neutral, Know-Emotional, Know-Neutral, New-Emotional and New-Neutral. Results showed that negative emotion enhanced three distinct subtypes of the electrophysiological old-new effect specifically for old items associated with a "Remember" judgment. This effect was observed for ERP old-new effects conforming to an early frontal P2 old-new effect peaking at~180 ms, a midfrontal old-new effect starting at~300 ms (the "FN400") and a late positive complex (LPC) with parietal maxima observed at 500-700 ms. In addition, a breakdown of our data in different levels of emotional arousal revealed that the relationship between ERP correlates of retrieval and arousal conformed to a nonlinear, inverted U-shaped function for posterior late effects (500-700) and to a linear function for early effects (P2 and FN400). Taken together, these results suggest that multiple retrieval subprocesses contribute to the emotional enhancement of recollective experience.

Event-related potentials of emotional and neutral memories: The role of encoding position and delayed testing

Psychophysiology, 2018

Previous research found that memory is not only better for emotional information but also for neutral information that has been encoded in the context of an emotional event. In the present ERP study, we investigated two factors that may influence memory for neutral and emotional items: temporal proximity between emotional and neutral items during encoding, and retention interval (immediate vs. delayed). Fortynine female participants incidentally encoded 36 unpleasant and 108 neutral pictures (36 neutral pictures preceded an unpleasant picture, 36 followed an unpleasant picture, and 36 neutral pictures were preceded and followed by neutral pictures) and participated in a recognition memory task either immediately (N 5 24) or 1 week (N 5 25) after encoding. Results showed better memory for emotional pictures relative to neutral pictures. In accordance, enhanced centroparietal old/new differences (500-900 ms) during recognition were observed for unpleasant compared to neutral pictures, most pronounced for the 1-week interval. Picture position effects, however, were only subtle. During encoding, late positive potentials for neutral pictures were slightly lower for neutral pictures following unpleasant ones, but only at trend level. To summarize, we could replicate and extend previous ERP findings showing that emotionally arousing events are better recollected than neutral events, particularly when memory is tested after longer retention intervals. Picture position during encoding, however, had only small effects on elaborative processing and no effects on memory retrieval.

Accounting for immediate emotional memory enhancement

Journal of Memory and Language, 2011

Memory for emotional events is usually very good even when tested shortly after study, before it is altered by the influence of emotional arousal on consolidation. Immediate emotion-enhanced memory may stem from the influence of emotion on cognitive processes at encoding and retrieval. Our goal was to test which cognitive factors are necessary and sufficient to account for EEM, with a specific focus on clarifying the contribution of attention to this effect. In two experiments, participants encoded negative-arousing and neutral pictures. In Experiment 1, under divided-attention conditions, negative pictures were better attended and recalled even when they were matched with neutral pictures on semantic relatedness and distinctiveness, and attention at encoding predicted subsequent emotion-enhanced memory. The memory advantage for emotional stimuli was only abolished when attention to emotional and neutral stimuli was also matched, under full-attention in Experiment 1 and under divided-attention in Experiment 2. Emotional memory enhancement was larger in Experiment 1 when the control of organization and distinctiveness was relaxed. These findings suggest that attention, organization and distinctiveness provide a necessary and sufficient account for immediate emotion-enhanced free recall memory.► Attention, organization and distinctiveness are necessary and sufficient to account for enhanced memory for emotional stimuli. ► When attention to emotional and neutral stimuli is equivalent, memory for these stimuli is equivalent. ► Attention only mediated the effects of emotional arousal on memory when primary distinctiveness was controlled.

The effects of negative emotion on encoding-related neural activity predicting item and source recognition

We report here a study that obtained reliable effects of emotional modulation of a well-known index of memory encodingthe electrophysiological "Dm" effectusing a recognition memory paradigm followed by a source memory task. In this study, participants performed an old-new recognition test of emotionally negative and neutral pictures encoded 1 day before the test, and a source memory task involving the retrieval of the temporal context in which pictures had been encoded. Our results showed that Dm activity was enhanced for all emotional items on a late positivity starting at $ 400 ms poststimulus onset, although Dm activity for high arousal items was also enhanced at an earlier stage (200-400 ms). Our results also showed that emotion enhanced Dm activity for items that were both recognised with or without correct source information. Further, when only high arousal items were considered, larger Dm amplitudes were observed if source memory was accurate. Three main conclusions are drawn from these findings. First, negative emotion can enhance encoding processes predicting the subsequent recognition of central item information. Second, if emotion reaches high levels of arousal, the encoding of contextual details can also be enhanced over and above the effects of emotion on central item encoding. Third, the morphology of our ERPs is consistent with a hybrid model of the role of attention in emotion-enhanced memory (Pottage and Schaefer, 2012).

Binding neutral information to emotional contexts: Brain dynamics of long-term recognition memory

Cognitive, affective & behavioral neuroscience, 2015

There is abundant evidence in memory research that emotional stimuli are better remembered than neutral stimuli. However, effects of an emotionally charged context on memory for associated neutral elements is also important, particularly in trauma and stress-related disorders, where strong memories are often activated by neutral cues due to their emotional associations. In the present study, we used event-related potentials (ERPs) to investigate long-term recognition memory (1-week delay) for neutral objects that had been paired with emotionally arousing or neutral scenes during encoding. Context effects were clearly evident in the ERPs: An early frontal ERP old/new difference (300-500 ms) was enhanced for objects encoded in unpleasant compared to pleasant and neutral contexts; and a late central-parietal old/new difference (400-700 ms) was observed for objects paired with both pleasant and unpleasant contexts but not for items paired with neutral backgrounds. Interestingly, objects...

Electroencephalographic Brain Dynamics of Memory Encoding in Emotionally Arousing Context

Frontiers in Behavioral Neuroscience, 2011

Emotional content/context enhances declarative memory through modulation of encoding and retrieval mechanisms. At encoding, neurophysiological data have consistently demonstrated the subsequent memory effect in theta and gamma oscillations. Yet, the existing studies were focused on the emotional content effect and let the emotional context effect unexplored. We hypothesized that theta and gamma oscillations show higher evoked/induced activity during the encoding of visual stimuli when delivered in an emotionally arousing context. Twenty-five healthy volunteers underwent evoked potentials (EP) recordings using a 21 scalp electrodes montage. They attended to an audiovisual test of emotional declarative memory being randomly assigned to either emotionally arousing or neutral context. Visual stimulus presentation was used as the time-locking event. Grand-averages of the EP and evoked spectral perturbations were calculated for each volunteer. EP showed a higher negative deflection from 80 to 140 ms for the emotional condition. Such effect was observed over central, frontal and prefrontal locations bilaterally. Evoked theta power was higher in left parietal, central, frontal, and prefrontal electrodes from −50 to 300 ms in the emotional condition. Evoked gamma power was higher in the emotional condition with a spatial distribution that overlapped at some points with the theta topography. The early theta power increase could be related to expectancy induced by auditory information processing that facilitates visual encoding in emotional contexts. Together, our results suggest that declarative memory enhancement for both emotional content and emotional context are supported by similar neural mechanisms at encoding, and offer new evidence about the brain processing of relevant environmental stimuli.

Effects of emotion on memory specificity: Memory trade-offs elicited by negative visually arousing stimuli

Journal of Memory and Language, 2007

Two different types of trade-offs have been discussed with regard to memory for emotional information: A trade-off in the ability to remember the gist versus the visual detail of emotional information, and a trade-off in the ability to remember the central emotional elements of an event versus the nonemotional (peripheral) elements of that same event. The present study examined whether these two trade-offs interact with one another when participants study scenes that elicit an emotional response due to the inclusion of a negative visually arousing object. Participants studied scenes composed of a negative or a neutral object placed on a background. Their memory was then tested for the ''gist'' and visual detail of the objects and the backgrounds. The results revealed that there is a pervasive memory trade-off for central emotional versus peripheral nonemotional elements of scenes. With some encoding tasks, a trade-off for gist versus visual detail also resulted, but this trade-off occurred only when memory for the nonemotional background of a scene was assessed. There was no gist/detail trade-off for the emotional objects in a scene.