Retrieval and phenomenology of autobiographical memories in blind individuals

When Imagination Feels Like Reality: A Case Study of False Memories and Maladaptive Daydreaming in Visual Impairment

Background

When a person experiences maladaptive daydreaming (MD), they spend a prolonged period daydreaming with a strong sense of presence. The symptoms of MD are often excessive, interfere with functioning, and are linked to distress and comorbid mental disorders. In this paper, apparent false memory is described in the context of a woman with MD and visual impairment due to a progressive eye condition. Her vivid daydreams seemed indistinguishable from actual memories. Case Report. A 35-year-old woman with a lifelong MD reported three incidents of fabricating detailed false memories of events that her family confirmed never occurred: obtaining a new job, miscarrying twins, and hospitalization for COVID-19. She experienced anxiety and shame when the stories were disproven. The assessment confirmed MD, PTSD, OCD, and other disorders. Her verbal memory was below average, especially for longer narratives. Her misattributions of daydreams as real-life memories may relate to reliance on vivid mental images over deteriorating vision and source monitoring deficits.

Conclusion

This first reported case of confabulations in an individual with MD and visual disability suggests daydreams could potentially be mistaken for actual events in some MD cases. While sensitive, more research is needed on the prevalence of false memories among individuals with MD. The default mode network, prefrontal cortex, and their connectivity may be implicated in generating vivid daydreams and misattributing them to actual episodic events. Understanding the relationship between sensory impairments, dissociation, and susceptibility to memory distortions could inform interventions to improve reality testing for some MD patients.

Journeying to the past: time travel and mental time travel, how far apart?

Spatial models dominated memory research throughout much of the twentieth century, but in recent decades, the concept of memory as a form of mental time travel (MTT) to the past has gained prominence. Initially introduced as a metaphor, the MTT perspective shifted the focus from internal memory processes to the subjective conscious experience of remembering. Despite its significant impact on empirical and theoretical memory research, there has been limited discussion regarding the meaning and adequacy of the MTT metaphor in accounting for memory. While in previous work I have addressed the general limitations of the MTT metaphor in explaining memory, the objective of this article is more focused and modest: to gain a better understanding of what constitutes MTT to the past. To achieve this objective, a detailed analysis of the characteristics of MTT to the past is presented through a comparison with time travel (TT) to the past. Although acknowledging that TT does not refer to an existing physical phenomenon, it is an older concept extensively discussed in the philosophical literature and provides commonly accepted grounds, particularly within orthodox theories of time, that can offer insights into the nature of MTT. Six specific characteristics serve as points of comparison: (1) a destination distinct from the present, (2) the distinction between subjective time and objective time, (3) the subjective experience of the time traveler, (4) their differentiation from the past self, (5) the existence of the past, and (6) its unchangeability. Through this research, a detailed exploration of the phenomenal and metaphysical aspects of MTT to the past is undertaken, shedding light on the distinct features that mental time travel to the past acquires when it occurs within the realm of the mind rather than as a physical phenomenon. By examining these characteristics, a deeper understanding of the nature of mental time travel is achieved, offering insights into how it operates in relation to memory and the past.

Real-world implications of aphantasia: episodic recall of eyewitnesses with aphantasia is less complete but no less accurate than typical imagers

Individuals with aphantasia report an inability to voluntarily visually image and reduced episodic memory, yet episodic accounts provided by witnesses and victims are fundamental for criminal justice. Using the mock-witness paradigm, we investigated eyewitness memory of individuals with aphantasia versus typical imagers. Participants viewed a mock crime and 48 hours later were interviewed about the event, randomly allocated to one of three conditions. Two interview conditions included techniques designed to support episodic retrieval mode, namely (i) Mental Reinstatement of Context (MRC) and (ii) Sketch Reinstatement of Context (Sketch-RC). A third Control condition did not include retrieval support. Aphantasic mock-eyewitnesses recalled 30% less correct information and accounts were less complete, but they made no more errors and were as accurate as typical imagers. Interaction effects revealed reduced correct recall and less complete accounts for aphantasic participants in MRC interviews versus Sketch-RC and Control. Aphantaisic participants in the Control outperformed those in both the Sketch-RC and MRC, although Sketch-RC improved completeness by 15% versus MRC. Our pattern of results indicates reduced mental imagery ability might be compensated for by alternative self-initiated cognitive strategies. Findings offer novel insights into episodic recall performance in information gathering interviews when ability to voluntarily visualize is impoverished.

Lifelong impairment in episodic re-experiencing: Neuropsychological and neuroimaging examination of a new case of Severely Deficient Autobiographical Memory

Autobiographical memory (AM) represents a complex and multimodal cognitive function, that allows an individual to collect and retrieve personal events and facts, enabling to develop and maintain the continuity of the self over time. Here we describe the case of DR (acronym of the fictional name Doriana Rossi), a 53-year-old woman, who complains of a specific and lifelong deficit in recalling autobiographical episodes. Along with an extensive neuropsychological assessment, DR underwent a structural and functional MRI examination to further define this impairment. The neuropsychological assessment revealed a deficit in episodic re-experiencing of her own personal life events. DR showed reduced cortical thickness in the Retrosplenial Complex in the left hemisphere, and in the Lateral Occipital Cortex, in the Prostriate Cortex and the Angular Gyrus in the right hemisphere. An altered pattern of activity in the calcarine cortex was detected during ordering of autobiographical events according to her own personal timeline. The present study provides further evidence about the existence of a severely deficient autobiographical memory condition in neurologically healthy people, with otherwise preserved cognitive functioning. Furthermore, the present data provide new important insights into neurocognitive mechanisms underpinning such a developmental condition.

Human Auditory Ecology: Extending Hearing Research to the Perception of Natural Soundscapes by Humans in Rapidly Changing Environments

Research in hearing sciences has provided extensive knowledge about how the human auditory system processes speech and assists communication. In contrast, little is known about how this system processes "natural soundscapes," that is the complex arrangements of biological and geophysical sounds shaped by sound propagation through non-anthropogenic habitats [Grinfeder et al. (2022). Frontiers in Ecology and Evolution. 10: 894232]. This is surprising given that, for many species, the capacity to process natural soundscapes determines survival and reproduction through the ability to represent and monitor the immediate environment. Here we propose a framework to encourage research programmes in the field of "human auditory ecology," focusing on the study of human auditory perception of ecological processes at work in natural habitats. Based on large acoustic databases with high ecological validity, these programmes should investigate the extent to which this presumably ancestral monitoring function of the human auditory system is adapted to specific information conveyed by natural soundscapes, whether it operate throughout the life span or whether it emerges through individual learning or cultural transmission. Beyond fundamental knowledge of human hearing, these programmes should yield a better understanding of how normal-hearing and hearing-impaired listeners monitor rural and city green and blue spaces and benefit from them, and whether rehabilitation devices (hearing aids and cochlear implants) restore natural soundscape perception and emotional responses back to normal. Importantly, they should also reveal whether and how humans hear the rapid changes in the environment brought about by human activity.

Are involuntary autobiographical memory and déjà vu natural products of memory retrieval?

Involuntary autobiographical memories (IAMs) and déjà vu are phenomena that occur spontaneously in daily life. IAMs are recollections of the personal past, whereas déjà vu is defined as an experience in which the person feels familiarity at the same time as knowing that the familiarity is false. We present and discuss the idea that both IAMs and déjà vu can be explained as natural phenomena resulting from memory processing and, importantly, are both based on the same memory retrieval processes. Briefly, we hypothesise that both can be described as "involuntary" or spontaneous cognitions, where IAMs deliver content and déjà vu delivers only the feeling of retrieval. We map out the similarities and differences between the two, making a theoretical and neuroscientific account for their integration into models of memory retrieval and how the autobiographical memory literature can explain these quirks of daily life and unusual but meaningful phenomena. We explain the emergence of the déjà vu phenomenon by relating it to well-known mechanisms of autobiographical memory retrieval, concluding that IAMs and déjà vu lie on a continuum.

What Do We Mean by “Soundscape”? A Functional Description

The concept of soundscape was originally coined to study the relationship between humans and their sonic environment. Since then, several definitions of soundscapes have been proposed based on musical, acoustical and ecological perspectives. However, the causal mechanisms that underlie soundscapes have often been overlooked. As a consequence, the term “soundscape” is frequently used in an ambiguous way, alternatively pointing to objective realities or subjective percepts. Through an interdisciplinary review, we identified the main biotic and abiotic factors that condition non-anthropogenic terrestrial soundscapes. A source-filter approach was used to describe sound sources, sound propagation phenomena and receiver’s characteristics. Interdisciplinary information was cross-referenced in order to define relationships between factors, sound sources and filters. Those relationships and the associated references were organized into a functional block diagram. This representation was used to question the different uses and meanings of the soundscape concept found in the literature. Three separate categories were then suggested: distal soundscape, proximal soundscape and perceptual soundscape. Finally, practical examples of these different categories were described, in relation to the diagram. This new systemic approach to soundscapes should help ecoacousticians, bioacousticians, psychoacousticians and environmental managers to better understand soundscapes and protect natural areas in a more significant way.

Odor is more effective than a visual cue or a verbal cue for the recovery of autobiographical memories in AD

Alzheimer's disease (AD) is associated with an impairment of autobiographical memories, leading to the production of nonspecific memories. Recent research has demonstrated that odor can serve as a powerful cue for the retrieval of autobiographical memories in AD. Moreover, studies conducted in young adults have showed that odor-evoked autobiographical memories are evoked with more details compared with memories triggered by other sensory modalities. Building on the latter research, we compared specificity, subjective experience, emotional characteristics and retrieval time of autobiographical memories evoked by odor cue, visual cue and verbal cue. To this end, we invited participants with mild AD and control participants to retrieve autobiographical memories after the presentation of an odor, a visual representation of the odorant, or a verbal label of the odorant. Results showed more specificity, higher arousal and more positive memories after odor exposure compared to the visual cue and verbal cue in AD and control participants. In AD participants, autobiographical were retrieved faster after odor-exposure compared to memories evoked by a visual cue and a verbal cue, suggesting the automatic nature of odor-evoked autobiographical memories. Overall, these findings demonstrate that odor is more effective than visual or verbal cues for autobiographical retrieval in AD.

Properties of autobiographical memories are reliable and stable individual differences

Autobiographical memory research typically focuses on individual memories with variability in individual participants' responses serving as error variance. Integrating individual-difference and experimental approaches demonstrated that properties of autobiographical memories are stable individual differences with stable patterns of correlations. In two sessions approximately one week apart, different cues were used to prompt seven autobiographical memories. Each memory was rated on 12 properties including visual imagery, emotional intensity, narrative coherence, reliving, and past rehearsals. In two studies with samples from different populations (Ns of 200 and 160), each property had a high reliability in both sessions (median α = .90), and the mean of each property averaged over seven memories correlated highly with itself over sessions (median r = .72). Multiple regressions predicting three properties from Session 1 with the remaining nine properties of Session 2 and exploratory factor analyses yielded solutions consistent with expectations from studies of individual memories. Moreover, the correlation matrices of the 12 properties across studies and sessions were extremely similar. Thus, separate sessions, cues, samples, and properties provided generalizable data about individual differences in autobiographical memory. Practical, theoretical, and methodological implications include that individual differences in memory affect: life stories and narrative structure internal to events, stable clinical syndromes and symptoms, experimental results previously attributed to the properties of individual memories, and the confidence people have in the accuracy of their autobiographical and episodic memories.

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.

Subjective age-of-acquisition norms for 600 Turkish words from four age groups

The main purpose of this study was to report age-based subjective age-of-acquisition (AoA) norms for 600 Turkish words. A total of 115 children, 100 young adults, 115 middle-aged adults, and 127 older adults provided AoA estimates for 600 words on a 7-point scale. The intraclass correlations suggested high reliability, and the AoA estimates were highly correlated across the four age groups. Children gave earlier AoA estimates than the three adult groups; this was true for high-frequency as well as low-frequency words. In addition to the means and standard deviations of the AoA estimates, we report word frequency, concreteness, and imageability ratings, as well as word length measures (numbers of syllables and letters), for the 600 words as supplemental materials. The present ratings represent a potentially useful database for researchers working on lexical processing as well as other aspects of cognitive processing, such as autobiographical memory.

Phenomenological Reliving and Visual Imagery During Autobiographical Recall in Alzheimer's Disease

Multiple studies have shown compromise of autobiographical memory and phenomenological reliving in Alzheimer's disease (AD). We investigated various phenomenological features of autobiographical memory to determine their relative vulnerability in AD. To this aim, participants with early AD and cognitively normal older adult controls were asked to retrieve an autobiographical event and rate on a five-point scale metacognitive judgments (i.e., reliving, back in time, remembering, and realness), component processes (i.e., visual imagery, auditory imagery, language, and emotion), narrative properties (i.e., rehearsal and importance), and spatiotemporal specificity (i.e., spatial details and temporal details). AD participants showed lower general autobiographical recall than controls, and poorer reliving, travel in time, remembering, realness, visual imagery, auditory imagery, language, rehearsal, and spatial detail-a decrease that was especially pronounced for visual imagery. Yet, AD participants showed high rating for emotion and importance. Early AD seems to compromise many phenomenological features, especially visual imagery, but also seems to preserve some other features.