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.     

A naturalistic study of autobiographical memories evoked by olfactory and visual cues: testing the Proustian hypothesis

The emotional and evocative qualities of autobiographical memories evoked by odors and visual cues were compared using a new repeated-measures paradigm in which the sensory cue was presented after the memory had been retrieved by its verbal label. Memory cues were chosen to be able to elicit salient memories. Results revealed that memories recalled in the context of odors were significantly more emotional than those recalled in the context of the same cue presented visually and by the verbal label for the cue. Odor-evoked memories also tended to make participants feel more "brought back" to the original event. This work is the first unequivocal demonstration that naturalistic memories evoked by odors are more emotional than memories evoked by other cues.     

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.     

Emotional organization of autobiographical memory

The emotional organization of autobiographical memory was examined by determining whether emotional cues would influence autobiographical retrieval in younger and older adults. Unfamiliar musical cues that represented orthogonal combinations of positive and negative valence and high and low arousal were used. Whereas cue valence influenced the valence of the retrieved memories, cue arousal did not affect arousal ratings. However, high-arousal cues were associated with reduced response latencies. A significant bias to report positive memories was observed, especially for the older adults, but neither the distribution of memories across the life span nor response latencies varied across memories differing in valence or arousal. These data indicate that emotional information can serve as effective cues for autobiographical memories and that autobiographical memories are organized in terms of emotional valence but not emotional arousal. Thus, current theories of autobiographical memory must be expanded to include emotional valence as a primary dimension of organization.     

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.     

Proust nose best: Odors are better cues of autobiographical memory

The Proust phenomenon is an enduring piece of folk wisdom that asserts that odors are particularly powerful autobiographical memory cues. We provide a more formal exposition of this phenomenon and test it in two experiments, using a novel double-cuing methodology designed to negate less interesting explanations. In both studies, recall of an autobiographical event was initially cued by a verbal label (an odor name) for a fixed period, following which a second, extended recall attempt was cued by the same verbal label, the relevant odor, an irrelevant odor, or a visual cue. The focus of Experiment 1 was participants' ratings of the emotional quality of their autobiographical memories. In Experiment 2, content analysis was employed to determine the quantity of information in participants' recollections. Results revealed that odor-cued autobiographical memories were reliably different in terms of qualitative ratings and reliably superior in the amount of detail yielded. Moreover, visual cues and incongruent olfactory cues appeared to have a detrimental effect on the amount of detail recalled. These results support the proposal that odors are especially effective as reminders of past experience.     

Manipulating cues in involuntary autobiographical memory: Verbal cues are more effective than pictorial cues

In two experiments, pictorial cues were compared with their verbal labels to assess their effectiveness in eliciting involuntary autobiographical memories. Cues were relatively complex in Experiment 1 (e.g., relaxing on a beach) and simple objects in Experiment 2 (e.g., a ball). In both experiments, participants went through a vigilance task in which they were presented with frequent nontarget and rare target visual stimuli. Pictures or their corresponding verbal labels were also displayed on both target and nontarget stimuli, but participants were told that these were irrelevant to the task. They were asked to interrupt the vigilance task whenever they became aware of task-unrelated mental contents and to report them. In both experiments, more involuntary memories were elicited in the verbal cue condition, rather than in the pictorial cue condition. This result is discussed in relation to previous work that highlighted the greater effectiveness of verbal cues in memory tasks.     

Comparing music- and food-evoked autobiographical memories in young and older adults: A diary study

Previous research has found that music brings back more vivid and emotional autobiographical memories than various other retrieval cues. However, such studies have often been low in ecological validity and constrained by relatively limited cue selection and predominantly young adult samples. Here, we compared music to food as cues for autobiographical memories in everyday life in young and older adults. In two separate four-day periods, 39 younger (ages 18–34) and 39 older (ages 60–77) adults recorded their music- and food-evoked autobiographical memories in paper diaries. Across both age groups, music triggered more frequent autobiographical memories, a greater proportion of involuntary memories, and memories rated as more personally important in comparison to food cues. Age differences impacted music- and food-evoked memories similarly, with older adults consistently recalling older and less specific memories, which they rated as more positive, vivid, and rehearsed. However, young and older adults did not differ in the number or involuntary nature of their recorded memories. This work represents an important step in understanding the phenomenology of naturally occurring music-evoked autobiographical memories across adulthood and provides new insights into how and why music may be a more effective trigger for personally valued memories than certain other everyday cues.     

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 effects of cue modality on the quality of personal memories retrieved

We investigated the effect of cue modality on the specificity, speed, vividness, and age of autobiographical memory retrieval. Cues were presented as either an odour, a visual image, or a word label. Odour-cued memories were older, more likely to be categoric, and were slower to be retrieved. Few gender differences were found although females reported more vivid memories than males. We suggest that cue modality directly affects retrieval processes; odour cues are more likely to initiate a perceptual search strategy, in contrast to memories cued by visual images and words, which are usually conceptually/verbally mediated.     

The effects of cue modality on the quality of personal memories retrieved

We investigated the effect of cue modality on the specificity, speed, vividness, and age of autobiographical memory retrieval. Cues were presented as either an odour, a visual image, or a word label. Odour-cued memories were older, more likely to be categoric, and were slower to be retrieved. Few gender differences were found although females reported more vivid memories than males. We suggest that cue modality directly affects retrieval processes; odour cues are more likely to initiate a perceptual search strategy, in contrast to memories cued by visual images and words, which are usually conceptually/verbally mediated.     

The language used in describing autobiographical memories prompted by life period visually presented verbal cues,event-specific visually presented verbal cues and short musical clips of popular music

Here, we examined linguistic differences in the reports of memories produced by three cueing methods. Two groups of young adults were cued visually either by words representing events or popular cultural phenomena that took place when they were 5, 10, or 16 years of age, or by words referencing a general lifetime period word cue directing them to that period in their life. A third group heard 30-second long musical clips of songs popular during the same three time periods. In each condition, participants typed a specific event memory evoked by the cue and these typed memories were subjected to analysis by the Linguistic Inquiry and Word Count (LIWC) program. Differences in the reports produced indicated that listening to music evoked memories embodied in motor-perceptual systems more so than memories evoked by our word-cueing conditions. Additionally, relative to music cues, lifetime period word cues produced memories with reliably more uses of personal pronouns, past tense terms, and negative emotions. The findings provide evidence for the embodiment of autobiographical memories, and how those differ when the cues emphasise different aspects of the encoded events.     

The reminiscence bump is blind to blindness: Evidence from sound- and odor-evoked autobiographical memory

The reminiscence bump is the disproportionally high reporting of autobiographical memories from adolescence and early adulthood and is typically observed when memories are evoked by cues, such as words, pictures, and sounds. However, when odors are used the bump shifts to early childhood. Although these findings indicate that sensory modality affects the bump, the influence of the individual’s sensory function on the reminiscence bumps is unknown. We examined the reminiscence bumps of sound- and odor-evoked autobiographical memories of early blind and sighted individuals, since early blindness implies considerable effects on sensory experience. Despite differences in sensory experience between blind and sighted individuals, the groups displayed similar age distributions of both sound- and odor-evoked memories. The auditory bump spanned the first two decades of life, whereas the olfactory bump was once again found in early childhood. These results demonstrate that the reminiscence bumps are robust to fundamental differences in sensory experience.     

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.     

On the prevalence of directly retrieved autobiographical memories

In this study, we used process measures to understand how people recall autobiographical memories in response to different word cues. In Experiment 1, participants provided verbal protocols when cued by object and emotion words. Participants also reported whether memories had come directly to mind. The self-reports and independent ratings of the verbal protocols indicated that directly recalled memories are much faster and more frequent than generated memories and are more prevalent when cued by objects than emotions. Experiment 2 replicated these results without protocols to eliminate any demand characteristics or output interference associated with the protocol method. In Experiment 3, we obtained converging results using a different method for assessing retrieval strategies by asking participants to assess the amount of information required to retrieve memories. The greater proportion of fast direct retrievals when memories are cued by objects accounts for reaction time differences between object and emotion cues, and not the commonly accepted explanation based on ease of retrieval. We argue for a dual-strategies approach that disputes generation as the canonical form of autobiographical memory retrieval and discuss the implication of these findings for the representation of personal events in autobiographical memory. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Shaping our personal past: Assessing the phenomenology of autobiographical memory and its association with object and spatial imagery

A new instrument has been developed that allows a comprehensive assessment of the relevant dimensions of the phenomenology of autobiographical memories (Assessment of the Phenomenology of Autobiographical Memory, APAM), and their association with visual object and spatial imagery has been examined. An initial version of APAM consisting of 30 items (the first 28 measured on a seven-point Likert-type scale) was developed and administered to a sample of 138 undergraduates. To test whether each item consistently measured the same dimension across different memories, all questions were rated for 12 cues. Results showed that 25 Likert-type items possessed adequate levels of internal consistency and unidimensionality across cues. We also found that higher levels of visual object imagery were associated with more sensory details and recollective qualities of memory, and with stronger experience of sensory and emotional reliving. The theoretical and practical usefulness of APAM as well as the relevance of visual object imagery in the phenomenology of autobiographical memory are discussed.     

The involuntary nature of music-evoked autobiographical memories in Alzheimer's disease

The main objective of this paper was to examine the involuntary nature of music-evoked autobiographical memories. For this purpose, young adults, older adults, and patients with a clinical diagnosis of probable Alzheimer's disease (AD) were asked to remember autobiographical events in two conditions: after being exposed to their own chosen music, and in silence. Compared to memories evoked in silence, memories evoked in the "Music" condition were found to be more specific, accompanied by more emotional content and impact on mood, and retrieved faster. In addition, these memories engaged less executive processes. Thus, with all these characteristics and the fact that they are activated by a perceptual cue (i.e., music), music-evoked autobiographic memories have all the features to be considered as involuntary memories. Our paper reveals several characteristics of music-evoked autobiographical memories in AD patients and offers a theoretical background for this phenomenon.     

Effect of self-discrepancy on specificity of autobiographical memory retrieval

Research using a cue word paradigm has consistently shown that depression, in both adults and adolescents, is associated with difficulties in retrieving specific autobiographical memories. Inspired by previous work stating that depressed feelings are related to a perceived discrepancy between attributes of the actual and the ideal self, the present study aimed to investigate the hypothesis that cues bringing discrepancies between the actual and ideal selves to the foreground might promote or facilitate the recall of overgeneral (instead of specific) autobiographical memories. In two studies adolescents provided autobiographical memories in response to 10 high-discrepant and 10 low-discrepant words. As predicted, results in both studies showed an effect of cue word discrepancy on the specificity of autobiographical memories such that participants retrieved a smaller proportion of specific and a greater proportion of overgeneral memories in response to high-discrepant words as compared to low-discrepant words. The findings are discussed in terms of the self-memory system (SMS) as a conceptual framework of autobiographical memory (Conway & Pleydell-Pearce, 2000).     

The temporal distribution of autobiographical memory: changes in reliving and vividness over the life span do not explain the reminiscence bump

When autobiographical memories are elicited with word cues, personal events from middle childhood to early adulthood are overrepresented compared to events from other periods. It is, however, unclear whether these memories are also associated with greater recollection. In this online study, we examined whether autobiographical memories from adolescence and early adulthood are recollected more than memories from other lifetime periods. Participants rated personal events that were elicited with cue words on reliving or vividness. Consistent with previous studies, most memories came from the period in which the participants were between 6 and 20 years old. The memories from this period were not relived more or recalled more vividly than memories from other lifetime periods, suggesting that they do not involve more recollection. Recent events had higher levels of reliving and vividness than remote events, and older adults reported a stronger recollective experience than younger adults.     

More than a feeling: Emotional cues impact the access and experience of autobiographical memories

Remembering is impacted by several factors of retrieval, including the emotional content of a memory cue. Here we tested how musical retrieval cues that differed on two dimensions of emotion—valence (positive and negative) and arousal (high and low)—impacted the following aspects of autobiographical memory recall: the response time to access a past personal event, the experience of remembering (ratings of memory vividness), the emotional content of a cued memory (ratings of event arousal and valence), and the type of event recalled (ratings of event energy, socialness, and uniqueness). We further explored how cue presentation affected autobiographical memory retrieval by administering cues of similar arousal and valence levels in a blocked fashion to one half of the tested participants, and randomly to the other half. We report three main findings. First, memories were accessed most quickly in response to musical cues that were highly arousing and positive in emotion. Second, we observed a relation between a cue and the elicited memory’s emotional valence but not arousal; however, both the cue valence and arousal related to the nature of the recalled event. Specifically, high cue arousal led to lower memory vividness and uniqueness ratings, but cues with both high arousal and positive valence were associated with memories rated as more social and energetic. Finally, cue presentation impacted both how quickly and specifically memories were accessed and how cue valence affected the memory vividness ratings. The implications of these findings for views of how emotion directs the access to memories and the experience of remembering are discussed.