The role of attention and relatedness in emotionally enhanced memory

Examining the positive and negative pictures separately revealed that emotionally enhanced memory (EEM) for positive pictures was mediated by attention, with no significant influence of emotional arousal, whereas the reverse was true of negative pictures. Consistent with this finding, in Experiment 2 EEM for negative pictures was found even when task emphasis was manipulated so that equivalent attention was allocated to negative and neutral pictures. The results show that attention and semantic relatedness contribute to EEM, with the extent varying with emotional valence. Negative emotion can influence memory independently of these 2 factors.     

Facial reactions to different emotionally relevant stimuli

Facial EMG activity was measured from the Corrugator supercilii and the Zygomatic major muscle regions while 48 subjects were exposed to pictures of angry and happy facial expressions, snakes and flowers as well as low and high preference nature scenes. The valency perspective predicted that facial reactions should be related to the intensity of the positive and the negative valency of stimuli. The mimicking behavior approach predicted that facial reactions should only be reflected as a mimicking response to the facial stimuli, whereas the evolutionary:biological perspective predicted that the most clearcut positive and negative facial reactions should be evoked by facial stimuli and by snakes. In support of the latter perspective, the present results showed that angry faces and snakes evoked the most distinct Corrugator supercilii muscle response, whereas happy faces evoked the largest Zygomatic major muscle response.     

Interactions between brainstem noradrenergic neurons and the nucleus accumbens shell in modulating memory for emotionally arousing events

The nucleus accumbens shell (NAC) receives axons containing dopamine-β-hydroxylase that originate from brainstem neurons in the nucleus of the solitary tract (NTS). Recent findings show that memory enhancement produced by stimulating NTS neurons after learning may involve interactions with the NAC. However, it is unclear whether these mnemonic effects are mediated by norepinephrine (NE) release from NTS terminals onto NAC neurons. The present studies approached this question by examining the contribution of NAC α-noradrenergic receptors in mediating this effect and assessed whether glutamatergic activation of the NTS alters NE concentrations in the NAC. Rats were trained for 6 d to drink from a water spout located at the end of an inhibitory avoidance chamber. On day 7, a 0.35-mA footshock was initiated once the rat approached the spout and remained active until it escaped into the neutral compartment. Blockade of α-noradrenergic receptors in the NAC with phentolamine (0.5 μg/0.5 μL) attenuated memory enhancement produced by glutamatergic (50 ng/0.5 μL) infusion on NTS neurons (P < 0.01). Experiment 2 used in vivo microdialysis to assess whether glutamate activation of NTS alters NAC NE concentrations. NE levels were unchanged by NTS infusion of phosphate-buffered saline (PBS) or low dose glutamate (50 ng/0.5 μL) but elevated significantly (P < 0.05) by combining the same dose with the footshock (0.35 mA, 2 sec) given in Study 1 or infusion of (100 ng/0.5 μL) glutamate alone. Findings demonstrate that NE released from NTS terminals enhances representations in memory by acting on α-noradrenergic receptors within the NAC.     

The role of overt rehearsal in enhanced conscious memory for emotional events

This study tested the hypothesis that overt rehearsal is sufficient to explain enhanced memory associated with emotion by experimentally manipulating rehearsal of emotional material. Participants viewed two sets of film clips, one set of emotional films and one set of relatively neutral films. One set of films was viewed in each of two sessions, with approximately 1 week between the sessions. Participants were given a free recall test of all of films viewed approximately 1 week after the second session. Rehearsal was manipulated by instructing one group of participants not to discuss the films with anyone (no talk group) and instructing a second group to discuss both sets of films with at least three people (forced talk group). A third group consisted of participants instructed not to discuss the films with anyone, but who did not comply with these instructions (talkers group). All groups recalled significantly more of the emotional films than the neutral films. Furthermore, the relative number of emotional and neutral films recalled did not differ significantly among the three groups. The results indicate that overt rehearsal is insufficient to explain the enhancing effects of emotion on memory.     

P300 to emotionally relevant stimuli as an indicator of aggression levels

Severe acts of aggression have been associated with prefrontal dysfunction. Less severe aggression may be associated with more subtle abnormalities. P300 event‐related potentials were recorded from 32 healthy volunteers during a novel modified oddball task. The task required participants to respond only to rare, food words (targets), which occurred randomly among neutral words. Aggressive words appeared randomly with the same frequency as the target words. A median split divided subjects into high‐ and low‐aggression groups based on their scores on the Buss–Durkee Hostility Inventory. The groups did not differ in their responses to the target words. Participants with higher aggression scores had lowered responses to the aggressive words at the frontal relative to the other electrode sites. Cognitive processing of aggressive stimuli was less efficient at frontal sites in individuals who reported higher levels of aggression. This result extends work showing frontal P300 decrements in more severe aggressive groups, using simple oddball tasks. Aggr. Behav. 32:1–8, 2006. © 2006 Wiley‐Liss, Inc.     

The long‐term impact of emotionally stressful events on memory characteristics and life story

The characteristics and organization of memories from World War II (WWII) were examined in relation to posttraumatic stress reactions. In Study 1, 145 Danes recalled and rated four memories from WWII. They rated the WWII period for posttraumatic stress reactions and importance to identity and life story. Memory clarity, rehearsal and consequences correlated positively with posttraumatic stress reactions and with WWII importance to identity and life story. In Study 2, a subgroup of 58 participants nominated five life story memories, divided their life story into chapters and rated WWII for posttraumatic stress reactions and importance to identity and life story. Posttraumatic stress reactions correlated positively with percentage of life story chapters about WWII, the tendency to connect non‐WWII memories with the WWII period and subjective clarity and rehearsal of WWII memories. The results contradict the idea that posttraumatic stress reactions are associated with vague and poorly integrated trauma memories. Copyright © 2008 John Wiley & Sons, Ltd.     

Enhanced memory for negatively emotionally charged pictures without selective rumination

Emotionally charged materials have been found to elicit higher levels of recall in many studies. However, the use of slow presentations and/or uncontrolled retention intervals may have allowed subjects to rehearse emotional materials preferentially. The authors presented a series of 5 pictures (1 emotionally charged) at a rate of 4 pictures per second, precluding selective rehearsal. In Experiment 1, subjects recalled the pictures immediately or after performing an arithmetic task for 20 s. In Experiment 2, the pictures were described as to-be-ignored distractors, and the memory test was unexpected. Stimulus emotionality greatly enhanced recall in all conditions. The speed of the presentations and the fact that enhancement did not spread to temporally adjacent items argues against some widely discussed mechanisms for emotional enhancement.     

Functions of parent-child reminiscing about emotionally negative events

Parent-child reminiscing about negative experiences influences children's developing "emotional self-concept", which comprises three interrelated functions: self-defining (this is the kind of emotional person I am), self-in-relation (this is how I express and share my emotions with others), and coping (this is how I cope with and resolve negative emotion). In this study, we examined how 70 mostly white, middle-class mothers discuss three negative experiences (fear, anger, and sadness) with their 4-year-old children. Conversations about fear elaborate on the facts of the event and emotional resolutions, thus focusing on coping. Conversations about sadness contain evaluative feedback and emotional resolutions, thus focusing on self-in-relation and coping. Finally, conversations about anger highlight the emotional state itself, thus focusing on self-definition. Mothers are also more elaborative and more evaluative with daughters than with sons, and place emotional events in a more interpersonal context with daughters than sons. Thus girls may be forming a more elaborated and more interpersonal emotional self-concept than boys.     

Memory for emotionally arousing events over time in Autism Spectrum Disorder

Emotionally arousing events are typically better remembered and more resistant to forgetting than neutral events. Findings from word list paradigms suggest that this may not hold for individuals with Autism Spectrum Disorder (ASD), who also tend to be less accurate as eyewitnesses under some circumstances. To test whether attenuated effects of arousal on memory may be responsible for poorer eyewitness testimonies in ASD, we asked adults with and without the disorder to view either arousing or neutral versions of a narrated slide sequence (Experiment 1) or video clip (Experiment 2) before assessing their memory for the material. Both groups exhibited increases in psychophysiological arousal during the arousing compared with the neutral version of the narratives, and both groups also demonstrated a memory advantage for the arousing events. Contrary to predictions, these observations indicate that stimulus induced arousal modulates memory for naturalistic events relatively typically in ASD. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Tunnel memory for traumatic events

In four experiments subjects remembered the critical information in a traumatic slide as either more focused spatially than in its original presentation or more focused spatially than information in a matched neutral slide. Subjects comprehend a neutral scene by automatically extending its boundaries and understanding the visual information in a broader external context. However, when subjects are negatively aroused by a scene, they process more elaborately those critical details that were the source of the emotional arousal, and they maintain or restrict the scene's boundaries. ‘Tunnel memory’ results from this greater elaboration of critical details and more focused boundaries. Tunnel memory may explain the superior recognition and recall of central, emotion-arousing details in a traumatic event, as shown in previous research on emotion and memory. © 1998 John Wiley & Sons, Ltd.     

A few seemingly harmless routes to a false memory

Since the invention of photography we have learned to rely on photos to help us remember significant moments in our lives. We have come to believe that photographs are accurate and valuable records of events that—years down the track—we may not be able to remember. In this paper, we review recent research demonstrating that photographs can also help us to “remember” events that never really happened. We trace the development of the leading false autobiographical memory paradigm, and we then describe research on the power of both fake narrative stories and fake photographs to cultivate false memories.     

Adaptive memory: enhanced source memory for animate entities

ABSTRACT

The animacy effect refers to enhanced memory for animate over inanimate items. In two studies, we examined whether this memory advantage generalises to source memory. A multinomial processing tree model was used to disentangle item recognition, source memory, and guessing processes. In Study 1, animate and inanimate words were presented at different spatial locations on the screen. Animacy was associated with enhanced source memory for the spatial locations of the items. In Study 2, pseudowords were associated with animate and inanimate properties. Replicating previous results, the pseudowords were better remembered when they were associated with animate properties than when they were associated with inanimate properties. What is more, participants had enhanced source memory for the association between the pseudowords and the animate properties. The results strengthen the idea that animate items are associated with richer mnemonic representations than inanimate items.     

Working memory affects false memory production for emotional events

Whereas a link between working memory (WM) and memory distortions has been demonstrated, its influence on emotional false memories is unclear. In two experiments, a verbal WM task and a false memory paradigm for negative, positive or neutral events were employed. In Experiment 1, we investigated individual differences in verbal WM and found that the interaction between valence and WM predicted false recognition, with negative and positive material protecting high WM individuals against false remembering; the beneficial effect of negative material disappeared in low WM participants. In Experiment 2, we lowered the WM capacity of half of the participants with a double task request, which led to an overall increase in false memories; furthermore, consistent with Experiment 1, the increase in negative false memories was larger than that of neutral or positive ones. It is concluded that WM plays a critical role in determining false memory production, specifically influencing the processing of negative material.     

Children's reports of emotionally laden events: adapting the interview to the child

This study examined the influence of expressive vocabulary and temperament on children's verbal reports about emotionally laden events in different interview conditions. In one of three conditions, 58 children aged between 5 and 7 years were interviewed about a time they had felt happy and a time they had felt scared. The interview conditions were: drawing, in which they were asked to draw and tell; re‐enactment, in which they were asked to re‐enact and tell; and verbal, in which they were simply asked to tell. The principal finding was that, whereas for children in the verbal interview condition expressive vocabulary was associated with the amount of information reported and for children in the re‐enactment condition, temperament had a moderate association with the amount reported, for children in the drawing interview condition, neither temperament nor expressive language was associated with the amount of information reported. Children in the drawing condition reported more information than those in the other two interview conditions. The possible mechanisms underlying these findings and their implications for interviewing children in clinical contexts are discussed. Copyright © 2002 John Wiley & Sons, Ltd.     

Sex-related difference in amygdala activity during emotionally influenced memory storage

We tested the possibility suggested by previous imaging studies that amygdala participation in the storage of emotionally influenced memory is differentially lateralized in men and women. Male and female subjects received two PET scans for regional cerebral glucose-one while viewing a series of emotionally provocative (negative) films, and a second while viewing a series of matched, but emotionally more neutral, films. Consistent with suggestions from several previously published studies, enhanced activity of the right, but not the left, amygdala in men was related to enhanced memory for the emotional films. Conversely, enhanced activity of the left, but not the right, amygdala in women was related to enhanced memory for the emotional films. These results demonstrate a clear gender-related lateralization of amygdala involvement in emotionally influenced memory, and indicate that theories of the neurobiology of emotionally influenced memory must begin to account for the influence of gender.     

Event-based prospective memory for poorly attended events

In the most frequently used paradigm for studying event-based prospective memory (PM, Einstein & McDaniel, 1990), participants perform an ongoing task and are asked to perform an additional task when a particular stimulus (the PM cue) is presented. In this study three experiments examined how PM performance depends on stimulus selection, which is a major process involved in executive task control according to current theorizing. Participants made semantic judgments about a target word accompanied by two nontargets (distracters). The target was indicated by its spatial position (Experiment 1) or color (Experiment 2). The findings indicated that PM performance was much poorer when the PM cue was irrelevant to the ongoing task, in spite of the fact that nontargets were processed semantically as shown in Experiment 3.     

Reminiscence bump in memory for public events

People tend to recall more personal events from adolescence and early adulthood than from other lifetime periods. Most evidence suggests that differential encoding causes this reminiscence bump. However, the question why personal events are encoded better in those periods is still unanswered. To shed more light on this discussion, we examined memory for public events. Since it is often impossible to ascertain that queried events are equally difficult, we circumvented the issue of equivalence by calculating deviation scores for each trial. We found that participants more frequently answered questions correctly about events that occurred in the period in which they were between 10 and 25 years old. Furthermore, we found that the reminiscence bump was more pronounced for cued recall than for recognition. We argue that these results support the biological account that events are stored better, because the memory system is working more efficiently during adolescence and early adulthood. These results do not falsify the other accounts for differential encoding, because they are not mutually exclusive.     

Ecologically relevant stimuli and color memory

Ecologically relevant stimuli were developed as an alternative to Munsell color chips. Colored pictures of familiar objects were used to study color memory. We investigated the typicality of color to particular objects. Contextually typical colors were remembered more accurately than atypical colors were. Moreover, this variable had a stronger effect on memory than focality did. We concluded that memory for ecologically relevant material is more impressed by a color's relation to experience than by its intrinsic properties.