Event components in autobiographical memories

Autobiographical memories contain activity, location, temporal, and participant information (Lancaster & Barsalou, 1997). Our study analysed potential dominance of activity information in autobiographical memories. The results indicated stability in dominance of the activity component, defined as similar occurrence in first and subsequent reports, and a relative absence of the temporal component in these verbal reports. Activity dominance also occurred when activity information from the verbal reports was used as a retrieval cue for a subsequent report. Temporal information demonstrated a greater lack of facilitation as a retrieval cue. These findings can be explained from the perspective of embodied cognition in which underlying perceptual states that contain activity, location, and other participant information are reconstructed during retrieval, whereas temporal information, as a more abstract component, is not.     

Olfaction and emotion: The case of autobiographical memory

This study investigated (1) the influence of verbal and conceptual processing on the retrieval and phenomenological evaluation of olfactory evoked memories, and (2) whether the experienced qualities of retrieved information are affected by olfactory exposure per se. Seventy-two older adults were randomized into one of three cue conditions (odor only, name only, or odor name) and asked to relate any autobiographical event for the given cue. The results indicated that semantic knowledge of an odor's name significantly affects the age distribution of memories such that the memory peak in childhood observed for odors only was attenuated. Also, experiential factors such as pleasantness and feelings of being brought back in time were lower when odors were presented with their respective names. Olfactory evoked memories were associated with a higher emotional arousal that could not be accounted for by the perceptual stimulation alone. Taken together, the overall pattern of findings suggests that retrieval of olfactory evoked information is sensitive to semantic and conceptual processing, and that odor-evoked representations are more emotional than memories triggered by verbal information.     

Gamma oscillations distinguish true from false memories

ABSTRACT— To test whether distinct patterns of electrophysiological activity prior to a response can distinguish true from false memories, we analyzed intracranial electroencephalographic recordings while 52 patients undergoing treatment for epilepsy performed a verbal free-recall task. These analyses revealed that the same pattern of gamma-band (28–100 Hz) oscillatory activity that predicts successful memory formation at item encoding—increased gamma power in the hippocampus, prefrontal cortex, and left temporal lobe—reemerges at retrieval to distinguish correct from incorrect responses. The timing of these oscillatory effects suggests that self-cued memory retrieval begins in the hippocampus and then spreads to the cortex. Thus, retrieval of true, as compared with false, memories induces a distinct pattern of gamma oscillations, possibly reflecting recollection of contextual information associated with past experience.     

A comparison of involuntary autobiographical memory retrievals

This study compared three different ways autobiographical memories are elicited involuntarily: (1) cued by an active goal common to memory and retrieval contexts in combination with sensory information associated with this goal‐directed activity; (2) cued by sensory information that does not relate to goal‐directed activity common to both memory and retrieval contexts; and (3) activated when no identifiable cue present in retrieval context. Two hundred and twenty eight participants recorded details of a single autobiographical memory that resulted naturally from a spontaneous, non‐deliberate retrieval. Nearly all recorded memories described specific events (83%) with very few memories less than 7 days old (8%) and many memories more than 5 years old (44%). No significant differences resulted between the three retrieval types for the age, specificity or prior rehearsal of memories reported. However, the level of attention at retrieval was significantly more diffuse for retrievals without a clearly identifiable cue. The authors discuss the implications of these findings for current models of involuntary autobiographical memory retrieval. Copyright © 2006 John Wiley & Sons, Ltd.     

Smell your way back to childhood: Autobiographical odor memory

This study addressed age distributions and experiential qualities of autobiographical memories evoked by different sensory cues. Ninety-three older adults were presented with one of three cue types (word, picture, or odor) and were asked to relate any autobiographical event for the given cue. The main aims were to explore whether (1) the age distribution of olfactory-evoked memories differs from memories cued by words and pictures and (2) the experiential qualities of the evoked memories vary over the different cues. The results showed that autobiographical memories triggered by olfactory information were older than memories associated with verbal and visual information. Specifically, most odor-cued memories were located to the first decade of life (<10 years), whereas memories associated with verbal and visual cues peaked in early adulthood (11–20 years). Also, odor-evoked memories were associated with stronger feelings of being brought back in time and had been thought of less often than memories evoked by verbal and visual information. This pattern of findings suggests that odor-evoked memories may be different from other memory experiences. nt|mis|This work was supported by a grant from the Swedish Research Council (No. F0647/2001) to M.L.     

Overgeneral autobiographical memory in adolescents at risk for depression

Autobiographical memory functioning is implicated in the course and onset of depression in adults (Williams et al., 2007), and there is preliminary evidence that adolescents with a diagnosis of depression have a bias towards retrieving overgeneral autobiographical memories (Kuyken & Howell, 2006; Kuyken, Howell, & Dalgleish, 2006; Park, Goodyer, & Teasdale, 2002). In two independent studies we asked whether adolescents at risk for depression exhibit autobiographical memory deficits. In the first community study of 179 adolescents, risk was operationalised as higher scores on neuroticism. We found that neuroticism was associated with greater retrieval of categoric memories to negative cue words and that severity of depressive symptoms mediated this relationship. In the second study, groups of formerly depressed (n=15) and never depressed adolescents (n=15) were matched on age, gender, depressive symptoms and verbal fluency, and again compared on their autobiographical memory functioning. Mirroring the findings from Study 1 we found that risk, operationalised here as a history of depression in remission, was associated with greater retrieval of categoric memories to negative cue words. Taken together, these studies show that risk for depression is associated with a greater tendency to retrieve categoric memories to negative cue words and suggest that autobiographical retrieval may be implicated in onset of depression in adolescence.     

Odour-induced mental time travel into the past and future: Do odour cues retain a unique link to our distant past?

Proustian memories, or memories spontaneously evoked by taste and odours, have been argued to be uniquely linked to our remote past. This view suggests an asymmetry between odour-cued memories and odour-cued representations of future events regarding their temporal distance to the present. We investigated the temporal distribution and other phenomenological qualities of autobiographical memories and future events employing a 2 (temporal direction: past vs future)×3 (cue type: verbal, visual, and odour) mixed design. We found that while odour-evoked memories were predominantly from the first decade of life, the future condition showed a marked preponderance of odour-cued events in the upcoming year. Odour-evoked memories were also less specific than the verbal and visual conditions. The odour condition was responsible for interactions concerning coherency of the events and the events’ significance to the life story. The results support the view that odours possess a unique ability to evoke remote autobiographical memories.     

Odour-induced mental time travel into the past and future: do odour cues retain a unique link to our distant past?

Proustian memories, or memories spontaneously evoked by taste and odours, have been argued to be uniquely linked to our remote past. This view suggests an asymmetry between odour-cued memories and odour-cued representations of future events regarding their temporal distance to the present. We investigated the temporal distribution and other phenomenological qualities of autobiographical memories and future events employing a 2 (temporal direction: past vs future) × 3 (cue type: verbal, visual, and odour) mixed design. We found that while odour-evoked memories were predominantly from the first decade of life, the future condition showed a marked preponderance of odour-cued events in the upcoming year. Odour-evoked memories were also less specific than the verbal and visual conditions. The odour condition was responsible for interactions concerning coherency of the events and the events' significance to the life story. The results support the view that odours possess a unique ability to evoke remote autobiographical memories.     

来源记忆提取的情境线索效应

探索当存在多维来源信息时,对一个维度的来源信息的再现是否会促进对另一个维度的来源记忆的提取,即出现情境线索效应。以汉字词语作为项目刺激,以背景颜色作为情境线索,通过两个实验分别考察对呈现位置和背景形状的提取是否会出现情境线索效应。结果发现：只在对背景形状的提取中出现了情境线索效应,并且线索负载越高,效应越小。该结果表明对来源记忆提取时,来源信息间的高可结合性是引发情境线索效应的重要因素。     

Retrieval‐induced forgetting of autobiographical memory details

Several studies suggest that intrusive and overgeneral autobiographical memory are correlated. Thus, paradoxically, in some patients a hyperaccessibility of memory for one (series of) event(s) goes hand‐in‐hand with a scarcity of memories for other personal experiences. This clinical observation is reminiscent of the laboratory phenomenon of retrieval‐induced forgetting (RIF). This refers to the finding that repeatedly recalling some experimental stimuli impairs subsequent recall of related (i.e., tied to the same retrieval cue) stimuli. RIF of emotional autobiographical memories might provide an experimental model for the clinical memory phenomena in question. The present paper reports two experiments that explored the merits of applying the retrieval practice paradigm to relatively broad categories of autobiographical memories. Both studies found a significant RIF effect in that practised memories were recalled better than unrelated unpractised (baseline) memories. In addition, unpractised memories that were related to the practised memories were recalled more poorly than baseline memories. Implications of these findings for modelling the co‐occurrence of intrusive and overgeneral memories are discussed.     

Retrieval process of overgeneral memory and the capture and executive control hypothesis: using Autobiographical Memory Test with thought sampling

ABSTRACT

The retrieval process for underlying overgeneral autobiographical memory remains unclear. In this study, we identified what leads to self-referential and categoric thoughts and examined the influence error-monitoring ability has on the reporting of categoric memories. We also examined whether cue self-relevance and/or executive control task performance are related to the number of specific memories reported. Using thought sampling, 94 college students completed the Autobiographical Memory Test, as well as a verbal fluency task and a depression scale. The results indicated that depressive symptoms and negative highly self-relevant cues were associated with self-referential/categoric thoughts during memory retrieval. Further, preceding self-referential/categoric thoughts and low error-monitoring ability predicted immediate after-reporting of categoric memories. Simultaneously, highly self-relevant cues and executive control task performance predicted the reporting of many specific memories. Subdividing the retrieval process and examining the process involved in depression are essential.     

The Effect of Imageability and Predicability of Cues in Autobiographical Memory

Four experiments investigated the role of imagery in the recollection of autobiographical memories. The first two experiments examined the effects of word imageability and word frequency on the retrieval of personal memories in a cued autobiographical memory task. They showed that the imageability of cues (but not frequency) mediates specificity in the recall of personal memories. Experiment 2 explored how different imagery modalities (visual, olfactory, tactile, auditory, and motor) influence autobiographical retrieval. Consistent with research on imagery modalities in verbal learning paradigms, visual imageability emerged as the most significant predictor of specificity. Experiments 3 and 4 examined how far a knowledge-based account of imagery effects might account for these effects, using predicability as a measure of semantic richness of a cue. Results found that visual imageability of cues accounted for more variance in specificity of recall than did predicability. The results are explained in terms of the way images represent the most efficient form of summarizing the information that can be used at each stage of the recollection process: setting the retrieval plan, strategic search, and evaluation of candidate episodes.     

The episodic nature of involuntary autobiographical memories

Involuntary autobiographical memories are conscious and unintended recollections of personal experiences. In Study 1, involuntary memories were compared with voluntary word-cued memories, both retrieved in naturalistic settings via a self-paced procedure. The involuntary memories more frequently referred to specific episodes, came with more physical reaction, had more impact on mood, and dealt with more unusual and less positive events. Study 2 demonstrated that these differences were not due to differences between verbal and nonverbal cues, by using Francis Galton's "memory walk" as a nonverbal method to cue voluntary memories. In both studies, systematic differences were found between specific and nonspecific memories. The findings show that the way autobiographical memories are sampled greatly affects the findings and that involuntary retrieval more often provides access to memories of specific episodes and associated emotional states.     

The neural basis of autobiographical and semantic memory: new evidence from three PET studies

A novel, neuropsychologically informed paradigm (extended retrieval of events in response to a cue word) was used to investigate the neural basis of autobiographical and semantic memory. Contrasting retrieval of autobiographical memories with retrieval of semantic facts (ABM-SEM) in 24 subjects across three PET studies revealed bilateral involvement of the middle temporal gyrus (BA 21) and medial frontal cortex (BA 9/10). The opposite contrast, SEM-ABM, resulted in increased regional cerebral blood flow in left posterior temporal regions (BA 37) and left prefrontal cortex (BA 45/46). Laterality maps suggest that the bilateral pattern seen in our studies, but not often in other neuroimaging investigations, reflects the use of a task stressing retrieval of specific personal events. Further comparisons revealed that the activation in the right anterior temporal lobe during autobiographical recall was virtually identical to that seen during retrieval of information about famous people or events in contrast with retrieval of general semantic facts. These findings suggest that the retrieval of an autobiographical event requires participation from conceptual knowledge, and that this type of knowledge is bilaterally distributed in the temporal lobes.     

How intention to retrieve a memory and expectation that a memory will come to mind influence the retrieval of autobiographical memories

While involuntary memories are retrieved with no intention and are usually unexpected (when one is not waiting for a memory to arise), voluntary memories are intended and expected (when one is searching and waiting for a memory to arise). The present study aimed to investigate the effects of retrieval intentionality (i.e. wanting to retrieve a memory) and monitoring processes (i.e. waiting for a memory to appear) during autobiographical memory retrieval. In addition, we introduced two novel laboratory conditions that have not been used in previous research on voluntary memories: in the first, participants were asked to report anything they could think of in response to each cue word; in the second, they could skip a word if nothing came to mind. These novel manipulations allowed us to differentiate between voluntary memories retrieved in response to experimenter-generated cues (when participants were forced to provide a memory or a thought for each cue) and self-selected cues (when participants were free to not answer a cue if they found it too difficult). We found that highly accessible memories were mostly experienced when retrieval was involuntary and unexpected, while memories with low accessibility were accessed through intentional retrieval and monitoring processes. Response times for memories recalled in the experimenter-generated cue conditions were longer compared to the self-selected cue conditions. This novel finding shows that experimenter-generated recall favours memories with low accessibility; it further supports the idea that, in a substantial number of trials, voluntary memories are directly rather than effortfully retrieved. The idea that the driving force behind differences between involuntary and voluntary memories is not the intention per se is further discussed.     

Nonspecific verbal cues alleviate forgetting by young children

Verbal reminders play a pervasive role in memory retrieval by human adults. In fact, relatively nonspecific verbal information (e.g. ‘Remember the last time we ate at that restaurant?’) will often cue vivid recollections of a past event even when presented outside the original encoding context. Although research has shown that memory retrieval by young children can be initiated by physical cues and by highly specific verbal cues, the effect of less specific verbal cues is not known. Using a Visual Recognition Memory (VRM) procedure, we examined the effect of nonspecific verbal cues on memory retrieval by 4‐year‐old children. Our findings showed that nonspecific verbal cues were as effective as highly specific nonverbal cues in facilitating memory retrieval after a 2‐week delay. We conclude that, at least by 4 years of age, children are able to use nonspecific verbal reminders to cue memory retrieval, and that the VRM paradigm may be particularly valuable in examining the age at which this initially occurs.     

Retrieval‐induced forgetting of emotional and unemotional autobiographical memories

This experiment extended the retrieval‐induced forgetting (RIF) procedure from simple, episodic information to emotional and unemotional autobiographical memories. In the elicitation phase, participants generated specific memories from their past in response to negative, neutral, or positive category cues. In the retrieval‐practice phase, they practised retrieving (and elaborated further on) some of the memories for some of the categories. In the final test phase, they tried to recall all memories. Memories that received retrieval practice were recalled more often on final test than baseline memories, whereas memories that were not practised, yet competed with practised memories via a shared category cue, were recalled less often than baseline memories. We discuss the roles of inhibition, competition, emotion, and self‐relevance, and consider what laboratory manipulations of memory might reveal about everyday and pathological personal memory.     

Visual imagery in autobiographical memory: The role of repeated retrieval in shifting perspective

Recent memories are generally recalled from a first-person perspective whereas older memories are often recalled from a third-person perspective. We investigated how repeated retrieval affects the availability of visual information, and whether it could explain the observed shift in perspective with time. In Experiment 1, participants performed mini-events and nominated memories of recent autobiographical events in response to cue words. Next, they described their memory for each event and rated its phenomenological characteristics. Over the following three weeks, they repeatedly retrieved half of the mini-event and cue-word memories. No instructions were given about how to retrieve the memories. In Experiment 2, participants were asked to adopt either a first- or third-person perspective during retrieval. One month later, participants retrieved all of the memories and again provided phenomenology ratings. When first-person visual details from the event were repeatedly retrieved, this information was retained better and the shift in perspective was slowed.     

Dissociable contributions within the medial temporal lobe to encoding of object-location associations

The crucial role of the medial temporal lobe (MTL) in episodic memory is well established. Although there is little doubt that its anatomical subregions-the hippocampus, peri-, entorhinal and parahippocampal cortex (PHC)-contribute differentially to mnemonic processes, their specific functions in episodic memory are under debate. Data from animal, human lesion, and neuroimaging studies suggest somewhat contradictory perspectives on this functional specialization: a general participation in declarative memory, an exclusive involvement in associative mnemonic processes, and a specific contribution to spatial memory are reported for the hippocampus, adjacent cortices, and the PHC. A functional lateralization in humans dependent on the verbalizability of the material is also discussed herein. To further elucidate the differential contributions of the various MTL subregions to encoding, we employed an object-location association memory paradigm. The memory for each of the studied associations was tested twice: by the object, and by the location serving as retrieval cue. The memory accuracy in response to both cue types was also assessed parametrically. Brain activity during encoding which leads to different degrees of subsequent memory accuracy under the two retrieval conditions was compared. We found the bilateral posterior PHC to participate in encoding of both the object associated with a location and the location associated with an object. In contrast, activity in an area in the left anterior PHC and the right anterior MTL was only correlated with the memory for the location associated with an object.