Multimodal retrieval of autobiographical memories: sensory information contributes differently to the recollection of events

Episodic memory and recognition are influenced by cues' sensory modality: comparing odours, music and faces using virtual reality

Most everyday experiences are multisensory, and all senses can trigger the conscious re-experience of unique personal events embedded in their specific spatio-temporal context. Yet, little is known about how a cue's sensory modality influences episodic memory, and which step of this process is impacted. This study investigated recognition and episodic memory across olfactory, auditory and visual sensory modalities in a laboratory-ecological task using a non-immersive virtual reality device. At encoding, participants freely and actively explored unique and rich episodes in a three-room house where boxes delivered odours, musical pieces and pictures of face. At retrieval, participants were presented with modality-specific memory cues and were told to 1) recognise encoded cues among distractors and, 2) go to the room and select the box in which they encountered them at encoding. Memory performance and response times revealed that music and faces outperformed odours in recognition memory, but that odours and faces outperformed music in evoking encoding context. Interestingly, correct recognition of music and faces was accompanied by more profound inspirations than correct rejection. By directly comparing memory performance across sensory modalities, our study demonstrated that despite limited recognition, odours are powerful cues to evoke specific episodic memory retrieval.

Use of autobiographical stimuli as a mood manipulation procedure: Systematic mapping review

Background

In recent years, mood induction procedures have been developed in experimental settings that are designed to facilitate studying the impact of mood states on biological and psychological processes. The aim of the present study was to conduct a systematic mapping review with the intention of describing the state of the art in the use of different types of autobiographical stimuli for mood induction procedures.

Methods

Based on a search for publications from the period 2000–2021, conducted in four recognised databases (Scopus, Medline (PubMed), PsycINFO and Web of Science), we analysed a total of 126 published articles. Text mining techniques were used to extract the main themes related.

Results

The induction of emotions through autobiographical memories is an area under construction and of growing interest. The data mining approach yielded information about the main types of stimuli used in these procedures, highlighting those that only employ a single type of cue, as well as the preference for verbal cues over others such as musical, olfactory and visual cues. This type of procedure has been used to induce both positive and negative emotions through tasks that require access to personal memories of specific events from a cue, requiring the person to set in motion different cognitive processes. The use of the latest technologies (fMRI, EEG, etc.) is also shown, demonstrating that this is a cutting-edge field of study.

Conclusions

Despite the study of mood induction procedures still being a growing field, the present review provides a novel overview of the current state of the art in the field, which may serve as a framework for future studies on the topic.

Do you remember? Similarities and differences between the earliest childhood memories for the five senses

We perceive the world with our five senses. However, the role that these five senses play in early childhood memories has received relatively little attention. Against this background, participants (N = 117) were asked to write down their earliest childhood memories for the five senses and to answer additional questions regarding these memories. There was no significant difference between the five senses regarding the percentage of participants reporting a memory or between the valence and the subjective reliability of the reported memories. However, memories reported for sight were marginally longer, from a younger age, and estimated to be more important compared to memories reported for the other senses. A qualitative content analysis revealed that the vast majority of the reported memories fell into a limited number of categories. Interestingly, several categories played a role in more than one sense. Nevertheless, the reported memories also mirrored the characteristic properties that one is able to perceive with each sense. Overall, the findings support the notion that sight is the dominant sense. At the same time, they remind us that each sense provides us with unique information about ourselves and the world around us.

The Proust Machine: What a Public Science Event Tells Us About Autobiographical Memory and the Five Senses

Our senses are constantly stimulated in our daily lives but we have only a limited understanding of how they affect our cognitive processes and, especially, our autobiographical memory. Capitalizing on a public science event, we conducted the first empirical study that aimed to compare the relative influence of the five senses on the access, temporal distribution, and phenomenological characteristics of autobiographical memories in a sample of about 400 participants. We found that the access and the phenomenological features of memories varied as a function of the type of sensory cues, but not their temporal distribution. With regard to their influence on autobiographical memory, an overlap between some senses was found, with on one hand, olfaction and taste and, on the other, vision, audition, and touch. We discuss these findings in the light of theories of perception, memory, and the self, and consider methodological implications of the sensory cuing technique in memory research, as well as clinical implications for research in psychopathological and neuropsychological populations.

Sensory Cueing of Autobiographical Memories in Normal Aging and Alzheimer's Disease: A Comparison Between Visual, Auditory, and Olfactory Information

BACKGROUND

Alzheimer's disease (AD) is a chronic, neurodegenerative disease resulting in a progressive decline of autobiographical memories (AMs) which favors the development of psycho-behavioral disorders. One of the most popular psychosocial interventions in dementia care, Reminiscence Therapy, commonly uses sensory cueing to stimulate AMs retrieval. However, few empirical studies have investigated the impact of sensory stimulation on AMs retrieval in AD.

OBJECTIVE

Our goal was to determine the most relevant cue for AMs retrieval in patients with early to mild AD when comparing odors, sounds and pictures.

METHODS

Sixty AD patients, 60 healthy older adults (OA), and 60 healthy young adults (YA) participated in our study. Participants were presented with either 4 odors, 4 sounds, or 4 pictures. For each stimulus, they were asked to retrieve a personal memory, to rate it across 3 dimensions (emotionality, vividness, rarity) and then to date it.

RESULTS

Overall, results showed no clear dominance of one sensory modality over the others in evoking higher-quality AMs. However, they show that using pictures is the better way to stimulate AD patients' AM, as it helps to retrieve a higher number of memories that are also less frequently retrieved, followed by odors. By contrast, auditory cueing with environmental sounds presented no true advantage.

CONCLUSION

Our data should help dementia care professionals to increase the efficiency of Reminiscence Therapy using sensory elicitors. Other clinical implications and future directions are also discussed.

Eye movements of recent and remote autobiographical memories: fewer and longer lasting fixations during the retrieval of childhood memories

There is an increased interest in the study of eye movements during the retrieval of autobiographical memories. Following this trend, the aim of the current study was to evaluate eye movements during the retrieval of remote and recent autobiographical memories. We instructed 71 participants to retrieve memories of personal events from early childhood (6-10 years), late childhood/early adolescence (11-14 years), late adolescence (15-18 years), and the last month. During the retrieval of these memories, participants wore eye-tracking glasses. Analyses showed that early childhood memories triggered fewer fixations and fixations with longer durations than memories from the last month. However, no significant differences were observed for the number of saccades, saccade durations, or total amplitude of the saccades. The fewer and longer lasting fixations during the retrieval of early childhood memories can be attributed either to the visual system reconstructing remote memories from an observer perspective or to difficulties when reconstructing remote memories.

Seeing or hearing one's memories: Manipulating autobiographical memory imagery in schizophrenia

The prevalence of auditory hallucinations in schizophrenia, and theories suggesting a link between autobiographical memory and hallucination, raise the possibility of a dominant role of auditory imagery in autobiographical remembering in patients with schizophrenia, whereas visual imagery is dominant in autobiographical memory of healthy adults. The present study explored this possibility by comparing autobiographical memory characteristics, according to sensory modality, in patients with schizophrenia versus healthy controls. Twenty-eight patients and 28 matched controls were asked to retrieve autobiographical memories that were dominated by auditory, visual, gustatory-olfactory, or tactile imagery. ANOVA analysis showed that patients rated their memories lower on specificity, contextual information, feeling of reliving, overall vividness, coherence and autobiographical me-ness (i.e. whether an autobiographical memory is experienced as belonging to the self), ps < 0.03, compared with control participants. The effects of sensory modality imagery were largely similar for patients and controls, as no interaction effects were observed. The findings did not support a dominance of auditory imagery in patients' autobiographical memory. In the patient group, reduced autobiographical me-ness was predicted by lower ratings of contextual information related to the setting of the event. Future research should examine whether these effects extend to involuntary autobiographical memory in schizophrenia.

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.

An in-depth review of the methods, findings, and theories associated with odor-evoked autobiographical memory

Over the past nearly 35 years, there has been sporadic interest in what has commonly come to be known as the Proust phenomenon, whereby autobiographical memories are retrieved and experienced differently when evoked by odors as compared with other types of cues, such as words, images or sounds. The purpose of this review is threefold. First, we provide a detailed analysis of the methods used to investigate Proust effects. Second, we review and analyze the various findings from the literature and determine what we feel to be the most important and stable findings. Third, we provide a series of previously postulated and new hypotheses that attempt to account for the various findings. Given the early stage of research, the current review aims to provide a measure of organization to the field, as well serve as a guide for how future investigations may address the topic. We conclude with the recommendation that research in this area shift its focus from establishing the phenomenon towards explaining its causes.

Late-recovery from "permanent" vegetative state in the context of severe traumatic brain injury: A case report exploring objective and subjective aspects of recovery and rehabilitation

This article provides a detailed outline of the recovery of a young male patient during his emergence from a vegetative state (VS) 19 months after suffering a severe traumatic brain injury. Several similar cases have been documented, but these tend not to consider the subjective experience of the patient or family; our aim was therefore to provide a detailed account that emphasises our neuropsychological exploration of the impact of the injury on this person, and looks at the experience of his mother along the timeline from his accident to the end of a successful period in rehabilitation. Clinical details are presented including standardised and non-standard assessments, neuropsychological interventions, as well as reflections from the patient himself. Moreover, qualitative data from an interview with his mother is used to illustrate the emotional impact on family of such a vacillating diagnostic status and prognosis for the future. We conclude that late-emergence from VS is increasingly documented and further cases must be published to better understand this phenomenon. The present case illustrates the emotional impact this situation can have on a patient and his or her family, and gives an important insight into a patient's view of his or her life and identity following such an event.

Self-grounding visual, auditory and olfactory autobiographical memories

Given that autobiographical memory provides a cognitive foundation for the self, we investigated the relative importance of visual, auditory and olfactory autobiographical memories for the self. Thirty subjects, with a mean age of 35.4years, participated in a study involving a three×three within-subject design containing nine different types of autobiographical memory cues: pictures, sounds and odors presented with neutral, positive and negative valences. It was shown that visual compared to auditory and olfactory autobiographical memories involved higher cognitive and emotional constituents for the self. Furthermore, there was a trend showing positive autobiographical memories to increase their proportion to both cognitive and emotional components of the self, from olfactory to auditory to visually cued autobiographical memories; but, yielding a reverse trend for negative autobiographical memories. Finally, and independently of modality, positive affective states were shown to be more involved in autobiographical memory than negative ones.