Academic literature on the topic 'Odor evoked autobiographical memory'

Autobiographical memory, which contains all personal memories relative to our identity, has been found to be impaired in Alzheimer’ Disease (AD). Recent research has demonstrated that odor may serve as a powerful cue for the recovery of autobiographical memories in AD. Building on this research, we investigated emotional characteristics (arousal and valence) and subjective reliving of odor-evoked autobiographical memories in AD. We also investigated the relationship between these characteristics and depression. To this end, we invited participants with mild AD and controls to retrieve autobiographical memories after odor exposure or without odor. Results showed higher arousal, subjective reliving and more positive memories after odor exposure compared with the odor-free condition, these differences being observed only in AD participants. We also found that emotion (arousal and valence) and subjective reliving triggered by odor were associated with depressive symptoms in AD. These findings demonstrate that odor may be a useful cue to trigger more detailed, vivid and positive events in AD.

Alzheimer’s disease (AD) provides a valuable field of research into impairment of self-consciousness (SC), because AD patients have a reduced capacity to understand their mental world, to experience and relive previous personal events, as well as to interpret thoughts, feelings, and beliefs about themselves. Several studies observed that AD patients had an altered SC, but not a complete abolition of it. Emotions are an integral part of the construction of personal identity, therefore of Self. In general, most studies on emotion in AD patients have observed that emotion is not completely abolished and it lets them better remember autobiographical events with greater emotional charge. The positive effect of autobiographical memories rich in emotional content, evoked directly/automatically by sensorial stimuli such as familiar odors or music, could be used to reestablish/reinforce the permanence and coherence of the Self in AD. We studied the research of empirical evidence supporting the power of the sensorial cues associated with emotion, which could be capable of enhancing the SC in AD. We presented the studies about “Emotional stimulations” using odor, music, or taste cues in AD. All studies have shown to have a positive impact on SC in AD patients such as odor-evoked autobiographical memories, taste/odor-evoked autobiographical memories, emotional sensorial stimulation using musical cues, and multi-sensorial stimulations using healing gardens. We found research supporting the notion that emotional sensorial stimulations can even temporarily exalt memory, affective state, and personal identity, that is, the SC in AD. The emotional sensory stimulations could be used as a tool to activate the SC in AD and hence improve the quality of life of patients and caregivers.

The capacity to form olfactory images has received less attention than the formation of visual and auditory images. The evidence in favor of such ability is also inconsistent. This thesis explored some of the characteristics of olfactory imagery through three empirical studies. Study I investigated the effects of blocking spontaneous sniffing during olfactory imagery. The results indicated that the prevention of spontaneous sniffing reduced olfactory but not visual imagery capacity. Study II studied the relation between olfactory awareness (as indexed by olfactory dreams, olfactory imagery, and olfactory interest) and olfactory functions (i.e., odor threshold, episodic odor memory, and odor identification). The main findings were that compared to low, high olfactory awareness was associated with better episodic odor memory and identification, but not with higher olfactory sensitivity. Study III investigated the neural correlates of odor evoked autobiographical memories (OEAMs) as (a) a function of cue modality (i.e., odors and their verbal referents), and (b) a function of memory remoteness. The results from Study III showed that OEAMs activated regions generally associated with autobiographical memory. In addition, verbally cued OEAMs were associated with activity linked to olfactory imagery. Odor cues activated the limbic and temporal polar regions more than verbal cues; a result that may explain the phenomenological differences found between the cued memories. Moreover, OEAMs from the first decade of life were associated with higher activity in the secondary olfactory cortex, whereas memories from young adulthood were related to areas linked to semantic memory processing. Taken together these studies favor the notion of a human capacity to form olfactory images.

L’affaiblissement de la mémoire autobiographique survient de manière précoce dans la maladie d’Alzheimer, caractérisé par une sémantisation des souvenirs personnels, une diminution de l’expérience subjective et par une incapacité à utiliser les représentations du passé afin de se projeter mentalement dans le futur. Des études menées chez l’individu jeune suggèrent que la stimulation olfactive est un indice particulièrement efficace, permettant d’augmenter la qualité du rappel autobiographique. Dans ce travail de thèse, nous avons entrepris quatre études menées chez des individus avec une maladie d’Alzheimer à un stade modéré, et dont l’objectif était d’évaluer les effets de la stimulation olfactive sur le contenu de la mémoire autobiographique,la distribution temporelle des souvenirs autobiographiques et la capacité à se projeter dans le futur. Les résultats de ces deux premières études montrent que la stimulation olfactive améliore la spécificité, l’expérience subjective, le contenu émotionnel des souvenirs autobiographiques,et contribue à diminuer le temps nécessaire pour accéder aux souvenirs (étude 1 et 2). Dans une troisième étude, nous avons comparé les effets de la stimulation olfactive sur la récupération de souvenirs récents et anciens. Les résultats de l’étude 3 montrent que les odeurs permettent d’augmenter la spécificité autobiographique pour l’ensemble des périodes de vie explorées. Enfin notre quatrième étude nous a permis de différencier les effets de la stimulation olfactive sur l’évocation d’événements autobiographiques passés et futurs dans la maladie d’Alzheimer. Les résultats de l’étude 4 suggèrent que la stimulation olfactive agit de manière similaire sur la spécificité, et le contenu émotionnel de ces deux types d’événements. En revanche, la stimulation olfactive ne contribue pas de manière équivalente au temps de récupération/construction et à la phénoménologie associée aux événements autobiographiques passés et futurs. De manière générale, ces travaux permettent de conclure à un effet positif de la stimulation olfactive sur la récupération de souvenirs autobiographiques et la projection dans le futur chez des individus avec une maladie d’Alzheimer à un stade modéré
Alzheimer’s disease is associated with an impairment of autobiographical memory,characterized by an over-generalization of personal memories, a decrease in subjective experience as well as by difficulties to project themselves into the future. Several studies haves hown that odor may alleviate decline of autobiographical retrieval in patients in the mild stage of Alzheimer’s disease. In this thesis, we carried out four experimental studies to assess the effects of olfactory stimulation on the specificity of autobiographical memory, the distribution of autobiographical memory and the ability of patients to project themselves into the future to imagine upcoming personal scenarios. Findings of the Study1 and Study2 demonstrate that olfactory stimulation improves the specificity, subjective experience, as well as emotional content of autobiographical memories in patients with mild Alzheimer’s disease. Findings of these two studies also demonstrate that olfactory stimulation reduces retrieval time of memories. In Study3, we compared the effects of olfactory stimulation on the recovery of recent and old memories. Results demonstrated that odors improved autobiographical specificity forall of the periods of life explored in the patients. In Study4, we compared the effects of olfactory stimulation on past and future thinking in patients with mild Alzheimer's disease. Results demonstrated that olfactory stimulation improves both the specificity and the emotional content of past and future thinking. However, olfactory stimulation did not contribute in the same way to the recovery / construction time and to the phenomenology associated with past and future autobiographical events. Overall, this thesis suggest that odor may be an effective cue to improve past and future thinking in patients with mild Alzheimer’s disease

Chapter 8, “Odor, Memory, and Proust,” draws together the previous themes of emotion and language and relates them to memory. The chapter begins by examining some evidence from the psychology of autobiographical memory concerning voluntary and involuntary memory and its relation to age. The second part of the chapter discusses psychologists’ use and misuse of the Proustian type of involuntary memory, exploring the way Proust at the end of Remembrance of Things Past expounds his idea of sensory epiphanies, which are signs of transcendence and many of which involve smell. The chapter ends by contrasting the Proustian literary epiphanies with the directness of two Holocaust memoirs that bring horrendous smell experiences to expression with a vividness that shows one need not be a literary professional in order to express smell convincingly in language.

This chapter analyzes how four films containing a strong autobiographical dimension break with the consensual and normative image the transition fashioned out of the past: En Algún Lugar del Cielo (dir. Alejandra Carmona, 2003), Calle Santa Fe (dir. Carmen Castillo, 2007), Mi Vida con Carlos (dir. Germán Berger-Hertz, 2010), and El Edificio de los Chilenos (dir. Macarena Aguiló, 2010). It argues that the rupture lies in the work of memory these films bring to the foreground. Whereas the transition passively referred to the past and evoked it without question, these filmmakers not only receive an image of the past, they search for it. In this quest, the autobiographical form plays a decisive role, allowing them to reveal the work of remembering and sometimes to undertake a critical scrutiny of memory, as Carmen Castillo does in Calle Santa Fe.