Temporal memory of emotional experience

The few studies that have investigated judgments of time have suggested that the memory of duration is distorted more for emotional events than for neutral events, while in contrast there is abundant evidence that other aspects of memories of emotional events are more accurate. To reconcile this apparent discrepancy, we used a procedure in which the participants learned a standard duration over several trials under three emotional conditions: a threatening, a nonthreatening, and a neutral control condition. They were then tested either immediately or 24 h after learning. In this test phase, they had to indicate whether presented comparison durations were or were not the same as the previously learned standard duration. We found that durations were recalled better in the emotional than in the neutral condition, and that this occurred to a greater extent in the threatening than in the nonthreatening condition. Arousing emotions thus enhanced temporal memory, just as they enhance memory for other aspects of emotional events.     

Dissociative experience and mood-dependent memory

Amnesia is the main phenomenon in dissociative experiences. The present study investigated whether amnesia in participants with frequent dissociative experiences depended on state-dependent memory. Undergraduates scoring high (n=32) or low (n=32) on the Dissociative Experiences Scale Version-II (DES-II) participated in this experiment. Mood induction and a remember/know task were used in a typical mood-independent memory design. In the inconsistent mood state condition, participants in the high DES group showed decreased memory performance compared to the low DES group. These results were attributed to the recollection components of recognition and not to the familiarity component. Therefore we concluded that the normal population with highly frequent dissociative experiences showed strong state-dependent memory and had a memory bias in the recollection component of memory.     

The effect of memory schemata on memory and the phenomenological experience of naturalistic situations

Two experiments document the effect of memory schemata in naturalistic situations. Participants in both experiments watched a short videotaped lecture in which the instructor enacted several schema‐consistent actions (e.g. writing on a whiteboard) and schema‐inconsistent actions (e.g. smoking a cigarette). Following the videotaped lecture, participants completed a recognition test and rated the phenomenological content of their memories. In both experiments, memory was more accurate for schema‐inconsistent actions than for schema‐consistent actions. Participants also indicated that their memories of schema‐inconsistent actions were more vivid than schema‐consistent actions. Interestingly, in Experiment 2, the false memory rate for typical items increased across both 48‐hour and one week retention intervals. These results have important implications for the processes of normal human memory in everyday situations. Copyright © 2002 John Wiley & Sons, Ltd.     

Emotional intensity predicts autobiographical memory experience

College students generated autobiographical memories from distinct emotional categories that varied in valence (positive vs. negative) and intensity (high vs. low). They then rated various perceptual, cognitive, and emotional properties for each memory. The distribution of these emotional memories favored a vector model over a circumplex model. For memories of all specific emotions, intensity accounted for significantly more variance in autobiographical memory characteristics than did valence or age of the memory. In two additional experiments, we examined multiple memories of emotions of high intensity and positive or negative valence and of positive valence and high or low intensity. Intensity was a more consistent predictor of autobiographical memory properties than was valence or the age of the memory in these experiments as well. The general effects of emotion on autobiographical memory properties are due primarily to intensity differences in emotional experience, not to benefits or detriments associated with a specific valence.     

How conscious experience and working memory interact

Active components of classical working memory are conscious, but traditional theory does not account for this fact. Global Workspace theory suggests that consciousness is needed to recruit unconscious specialized networks that carry out detailed working memory functions. The IDA model provides a fine-grained analysis of this process, specifically of two classical working-memory tasks, verbal rehearsal and the utilization of a visual image. In the process, new light is shed on the interactions between conscious and unconscious aspects of working memory.     

Attention and recollective experience in recognition memory

The functional relation between recognition memory and conscious awareness was assessed in an experiment in which undivided attention at study was compared with two divided attention conditions, one more demanding than the other. When recognizing a word from the study list, subjects indicated whether they could consciously recollect its prior occurrence or recognized it on some other basis, in the absence of conscious recollection. Divided attention at study progressively impaired word recognition accompanied by conscious recollection. Recognition in the absence of conscious recollection was not affected by divided attention. These findings are interpreted as providing further support for the idea that recognition memory entails two distinct components, one based on associative and contextual information, the other based on a "traceless" awareness of familiarity.     

Computational models of working memory: putting long-term memory into context

Detailed computational modeling of human memory has typically been aimed at either short-term (working) memory or long-term memory in isolation. However, recent research highlights the importance of interactions between these systems for both item and order information. At the same time, computational models of both systems are beginning to converge onto a common framework in which items are associated with an evolving "context" signal and subsequently compete with one another at recall. We review some of these models, and discuss a common mechanism capable of modelling working memory and its interaction with long-term memory, focussing on memory for verbal sequences.     

Cognitive effort and recollective experience in recognition memory

The difficulty of the cognitive operations required to process study items was manipulated in two experiments investigating recollective experience. In subsequent recognition tests, subjects indicated whether their recognition judgements for items processed in these tasks were based on recollection ("remember" responses) or on familiarity ("know" responses). In Experiment 1 target items were presented in the context of a category decision task. It was found that remember responses increased with the difficulty of the category decision. For positive instances, remember responses were greater for items of low instance frequency than for items of high instance frequency, while for negative instances remember responses were greater for items from similar categories than for items from dissimilar categories. These effects were not present in know responses. In Experiment 2, remember responses were more frequent when study items had been presented in the form of anagrams to be solved than when they had been presented in the form of words to be read aloud. The incidence of know responses was not affected by the format in which study items were presented. Source judgements were also more accurate when recognition was based on recollection. It is argued that the type of conscious awareness experienced during recognition is determined by the knowledge activated by items presented in the recognition test, which in turn is determined by the nature of the operations engaged at encoding.     

Past experience influences object representation in working memory

The nature of object representation in working memory is vital to establishing the capacity of working memory, which in turn shapes the limits of visual cognition and awareness. Although current theories discuss whether representations in working memory are feature-based or object-based, no theory has considered the role of past experience. However, work with humans and non-human primates suggests that once participants learn which features are important for category membership, these diagnostic features become more salient than non-diagnostic features in long-term memory and object recognition. Critically, the brain areas involved in this diagnosticity effect are also recruited during working memory tasks. We report two experiments testing whether a diagnosticity effect exists in working memory; and whether it is present when visual information is encoded into working memory, or if it is the result of maintenance within working memory. Results showed a diagnosticity effect which was present at encoding. Maintenance did not influence the nature of object representation in working memory. These findings show that the meaning we glean from our past experience has a profound influence on the nature of object representation in working memory.     

The cellular mechanisms of memory are modified by experience

The N-methyl-D-aspartate receptor (NMDAR) is thought to be essential for synaptic plasticity and learning. However, recent work indicates that the role of this receptor depends on the prior history of the research subject. For example, animals trained on a hippocampus-dependent learning task are subsequently able to acquire new information in the absence of NMDAR activation. The current experiments were designed to identify the types of experiences that lead to NMDAR-independent learning. Using contextual fear conditioning in mice, we find that NMDAR-independent learning is only observed when (1) animals are trained on the same behavioral task and (2) initial learning is successfully encoded into long-term memory.     

Orientation dependence of spatial memory acquired from auditory experience

The present study investigated whether memory for a room-sized spatial layout learned through auditory localization of sounds exhibits orientation dependence similar to that observed for spatial memory acquired from stationary viewing of the environment. Participants learned spatial layouts by viewing objects or localizing sounds and then performed judgments of relative direction among remembered locations. The results showed that direction judgments following auditory learning were performed most accurately at a particular orientation in the same way as were those following visual learning, indicating that auditorily encoded spatial memory is orientation dependent. In combination with previous findings that spatial memories derived from haptic and proprioceptive experiences are also orientation dependent, the present finding suggests that orientation dependence is a general functional property of human spatial memory independent of learning modality.     

Long-term memory for the emotional gist and the emotional essence of an experience

We investigated accuracy in recalling past emotional behaviours and emotionality. Male couples discussed the history of their relationship, and coders rated the extent to which each partner engaged in behaviours such as complimenting or criticising. These ratings were combined into dimensions representing the deeper, emotional essence of that partner's discussion (expressions of We-ness, Fondness, Negativity, and Disappointment). Four years later, participants accurately recalled some of their own and some of their partner's emotional gist-level behaviours, but their answers indicated that they also remembered the emotional essence of the conversation. We conclude that individuals can retain the emotional essence of an experience for a long time, and that they may use this memory to infer, in part, gist-level details of the experience.     

Long-term memory for the emotional gist and the emotional essence of an experience

We investigated accuracy in recalling past emotional behaviours and emotionality. Male couples discussed the history of their relationship, and coders rated the extent to which each partner engaged in behaviours such as complimenting or criticising. These ratings were combined into dimensions representing the deeper, emotional essence of that partner's discussion (expressions of We-ness, Fondness, Negativity, and Disappointment). Four years later, participants accurately recalled some of their own and some of their partner's emotional gist-level behaviours, but their answers indicated that they also remembered the emotional essence of the conversation. We conclude that individuals can retain the emotional essence of an experience for a long time, and that they may use this memory to infer, in part, gist-level details of the experience.     

An investigation into the resource requirements of event-based prospective memory

The multiprocess view proposes that both strategic and automatic processes can support prospective memory. In three experiments, we embedded a prospective memory task in a lexical decision task; cues were either highly associated with response words or had no relation. Analyses of RTs on ongoing task trials indicated that (1) prospective memory was more dependent on the allocation of resources immediately prior to cue presentation under conditions of low association in comparison with high association and (2) processes engaged on cue trials were more resource demanding under conditions of low association in comparison with high association. These data support the claim of the multiprocess view that prospective memory can be more resource demanding under some task conditions in comparison with others. However, the prospective memory performance data were less supportive, with declines in prospective memory due to task-importance and cue-frequency manipulations comparable across the low- and high-association conditions. Taken together, these results have implications for two prominent theories of prospective memory.     

The development of landmarks in spatial memory: the role of differential experience

To assess how differential experience with objects in a spatial array might serve to establish relative landmarks within the array, first and fifth graders learned models of a town and farm under two conditions. In a homogeneous condition, all elements in the array were visited an equal number of times. In a landmark condition, the relative landmark status of an element was established by distributing the same total number of visits unequally across the elements. The effects of such landmarks on spatial memory were assessed both in reconstructions of the entire array and by pairwise distance estimations. The landmark condition led to a general improvement in spatial recall accuracy as well as providing a relative landmark within the array to help organize the space. The results suggest that different levels of experience (controlling for overall experience and object salience) can establish elements as relative landmarks in spatial memory. Although there was clear developmental improvement in spatial memory, the specific landmark effects were similar for both first and fifth graders.