Episodic Autobiographical Memory Research Articles

Compromised future thinking: another cognitive cost of temporal lobe epilepsy.

The ability to mentally travel forward through time allows humans to envisage a diverse array of possible events taking place in the future, helping us to choose which pathway to take in life. In epilepsy, we assume that patients use this cognitive ability when deciding between various treatment options, but this assumption has not been robustly tested. The temporal lobes are key contributors to this ‘future thinking’ and its building blocks include cognitive functions commonly impaired in temporal lobe epilepsy such as memory and language, giving rise to a hypothesis that ‘future thinking’ is impaired in this patient cohort. Participants were 68 adults: 37 with neurosurgically-naïve, unilateral temporal lobe epilepsy (51% right lateralized) and 31 healthy controls of similar age, sex and intellectual ability to the participants with epilepsy. Future thinking was measured using an imagined experiences task validated in other neurological populations. Tools well-established in temporal lobe epilepsy were used to measure potential cognitive correlates of future thinking. Analysis of variance revealed significantly impoverished future thinking in both left and right temporal lobe epilepsy relative to controls (P = 0.001, ηp2=0.206), with no difference between temporal lobe epilepsy groups (P > 0.05). Future thinking deficits in left temporal lobe epilepsy were paralleled by deficits in scene construction, whereas impoverished future thinking in right temporal lobe epilepsy occurred in the setting of intact scene construction. Deficits in future thinking were associated with reductions in lexical access and episodic autobiographic memory in both epilepsy groups. In sum, future thinking is compromised in both left and right temporal lobe epilepsy. The deficit in left temporal lobe epilepsy is largely explainable by dysfunction in verbal cognitive processes including scene construction. While the basis of the deficits observed with right temporal foci shares features with that of left temporal lobe epilepsy, their intact scene construction raises questions about the role of the left and right temporal lobes in future thinking and scene construction and the relationship between these two constructs, including whether right temporal lobe might play a specific role in future thinking in terms of creative processing. Clinicians should take impaired future thinking into account when counselling temporal lobe epilepsy patients about various treatment options, as they may struggle to vividly imagine what different outcomes might mean for their future selves.

Neuropsychological Performance in Autoimmune Limbic Encephalitis: Evidence from an Immunotherapy-Naïve Cohort.

ObjectiveAutoimmune limbic encephalitis (ALE) is characterized by memory impairment, psychiatric symptoms, and epileptic seizures. Though, the neuropsychological profile of ALE is not yet well defined. However, there is some evidence that neuropsychological impairments might exceed those related to the limbic system and that different autoantibodies (AABs) are associated with distinguishable pattern of neuropsychological impairments. We provide a comprehensive presentation of neuropsychological performance of ALE in an immune therapy-naïve sample.MethodsWe retrospectively analyzed 69 immunotherapy-naïve ALE-patients (26 seropositive—[8 LGI1-, 4 CASPR2-, 2 GABAB-R-, 3 Hu-, 4 GAD65-, 2 Ma2-, 2 unknown antigen, and 1 Yo-AABs] and 43 seronegative patients, mean age 56.0 years [21.9–78.2], mean disease duration 88 weeks [0–572]). Neuropsychological evaluations comprised of the domains memory, attention, praxis, executive functions, language, social cognition, and psychological symptoms. We compared these functions between seronegative −, seropositive patients with AABs against intracellular neural antigens and seropositive patients with AABs against surface membrane neural antigens.ResultsNo effect of AAB group on neuropsychological performance could be detected. Overall, ALE predominantly presents with deficits in long-term memory and memory recognition, autobiographical-episodic memory loss, impairment of emotion recognition, and depressed mood. Furthermore, deficits in praxis of pantomimes and imitations, visuo-construction, and flexibility may occur.ConclusionALE shows a wide spectrum of neuropsychological impairments, which might exceed the limbic system, with no evidence of differences between AAB groups. Neuropsychological assessment for diagnosing ALE should include long-term memory, memory recognition, autobiographical-episodic memory, emotion recognition, and a detailed investigation of depression.

Phase-Amplitude Coupling and Phase Synchronization Between Medial Temporal, Frontal and Posterior Brain Regions Support Episodic Autobiographical Memory Recall

Episodic autobiographical memory (EAM) is a complex cognitive function that emerges from the coordination of specific and distant brain regions. Specific brain rhythms, namely theta and gamma oscillations and their synchronization, are thought of as putative mechanisms enabling EAM. Yet, the mechanisms of inter-regional interaction in the EAM network remain unclear in humans at the whole brain level. To investigate this, we analyzed EEG recordings of participants instructed to retrieve autobiographical episodes. EEG recordings were projected in the source space, and time-courses of atlas-based brain regions-of-interest (ROIs) were derived. Directed phase synchrony in high theta (7–10 Hz) and gamma (30–80 Hz) bands and high theta-gamma phase-amplitude coupling were computed between each pair of ROIs. Using network-based statistics, a graph-theory method, we found statistically significant networks for each investigated mechanism. In the gamma band, two sub-networks were found, one between the posterior cingulate cortex (PCC) and the medial temporal lobe (MTL) and another within the medial frontal areas. In the high theta band, we found a PCC to ventromedial prefrontal cortex (vmPFC) network. In phase-amplitude coupling, we found the high theta phase of the left MTL biasing the gamma amplitude of posterior regions and the vmPFC. Other regions of the temporal lobe and the insula were also phase biasing the vmPFC. These findings suggest that EAM, rather than emerging from a single mechanism at a single frequency, involves precise spatio-temporal signatures mapping on distinct memory processes. We propose that the MTL orchestrates activity in vmPFC and PCC via precise phase-amplitude coupling, with vmPFC and PCC interaction via high theta phase synchrony and gamma synchronization contributing to bind information within the PCC-MTL sub-network or valuate the candidate memory within the medial frontal sub-network.

ATTACHMENT AND MEMORY STABILITY

ABSTRACT Previous studies confirm that attachment representations are very stable and are rooted in semantic and episodic autobiographic memory systems. The Adult Attachment Interview (AAI) provides a means to assess secure, insecure, and disorganized (U) states of mind; it incorporates a fine-grained analysis of attachment-related memories. The AAI is not a measure to determine false versus true memories or to claim it can identify veridical truth; however, longitudinal research studies demonstrate that the AAI is highly stable in how (degree of coherence) the speaker discusses past events. This IRB approved study (n = 130) examined a non-clinical sample of active individuals. The results indicated that passive states of mind was a predictor variable for unresolved loss and unresolved childhood abuse and both passive states of mind and more Adverse Childhood Experiences (ACEs) predicted overall lack of resolution (U). Lack of memory and dissociative amnesia were not significant predictors. This study and previous studies demonstrate that retrospective reporting of ACEs remain stable over time. These findings suggest that clinical focus should follow the attachment protocol of examining the state of mind of the speaker. Autobiographical memory systems reveal enduring Internal Working Models (IWMs) that influence how memories are stored and recounted.

Episodic Past, Future, and counterfactual thinking in Relapsing-Remitting Multiple sclerosis

Multiple sclerosis (MS) is a progressive disease characterized by widespread white matter lesions in the brain and spinal cord. In addition to well-characterized motor deficits, MS results in cognitive impairments in several domains, notably in episodic autobiographical memory. Recent studies have also revealed that patients with MS exhibit deficits in episodic future thinking, i.e., our capacity to imagine possible events that may occur in our personal future. Both episodic memory and episodic future thinking have been shown to share cognitive and neural mechanisms with a related kind of hypothetical simulation known as episodic counterfactual thinking: our capacity to imagine alternative ways in which past personal events could have occurred but did not. However, the extent to which episodic counterfactual thinking is affected in MS is still unknown. The current study sought to explore this issue by comparing performance in mental simulation tasks involving either past, future or counterfactual thoughts in relapsing-remitting MS. Diffusion weighted imaging (DWI) measures were also extracted to determine whether changes in structural pathways connecting the brain’s default mode network (DMN) would be associated with group differences in task performance. Relative to controls, patients showed marked reductions in the number of internal details across all mental simulations, but no differences in the number of external and semantic-based details. It was also found that, relative to controls, patients with relapsing-remitting MS reported reduced composition ratings for episodic simulations depicting counterfactual events, but not so for actual past or possible future episodes. Additionally, three DWI measures of white matter integrity—fractional anisotropy, radial diffusivity and streamline counts—showed reliable differences between patients with relapsing-remitting MS and matched healthy controls. Importantly, DWI measures associated with reduced white matter integrity in three association tracts on the DMN—the right superior longitudinal fasciculus, the left hippocampal portion of the cingulum and the left inferior longitudinal fasciculus—predicted reductions in the number of internal details during episodic counterfactual simulations. Taken together, these results help to illuminate impairments in episodic simulation in relapsing-remitting MS and show, for the first time, a differential association between white matter integrity and deficits in episodic counterfactual thinking in individuals with relapsing-remitting MS.

Reminiscence groupwork and autobiographical memory as part of meaningful activities

The current paper describes a reminiscence group activity session held as part of meaningful activities engagement for older adults. Topics of reminiscence included both autobiographical memories and memories of broader historical events from the past. Participants included those with memory impairment and those without, and participants with healthy memory were helpful in prompting memories in participants with memory impairment. Semantic and episodic autobiographical memory were assessed at baseline and following the end of both group activities, using the Episodic Autobiographical Memory Interview (EAMI) and quality of life was assessed using the Quality of Life AD-scale (QOL-AD). The reminiscence intervention did not significantly affect autobiographical memory recall or quality of life. However, oral reminiscence was reported to have increased outside of the reminiscence sessions.

Effects of familiar olfactory stimulation on self‐consciousness

AbstractBackgroundAutobiographical memory involves self‐life episodes and generic knowledge that enables the meaning attributed to a lifetime story. The semantic autobiographical memory is related to a general knowledge and the episodic autobiographical memory is associated to the personal experiences at specific time and place related to past experiences among a long period of life (Allen, et al., 2018; Eustache et al., 2013, 2016). Autobiographical events activate an autonomic consciousness related to recovers the past memories, while autobiographical semantic knowledge comprises a noetic familiar awareness and a consciousness of past limited (Markowitsch , & Staniloiu, 2011; Piolino et al., 2003; Tulving, 2002). Progressive loss of self‐consciousness presented in Alzheimer Disease (A.D) is connected to the decline of autobiographical episodic memory. Some studies validate positive effects of olfactory stimulation on autobiographical memory (El Haj et al., 2015; Gachet & El Haj, 2020) but no research has evaluated the influence of familiar olfactory stimulation on A.D related to improve self‐consciousness in Colombia. This study aims to assess if the evoked autobiographical memories from familiar olfactory stimulation has an enforcement or facilitator effect on self‐consciousness.MethodFifty people will participate, 25 at the control group and 25 at the experimental group. The control group will have an olfactory stimulation without familiar smells, and the experimental grouo, will have it with familiar smells. There will be three phases: 1) After intervention: Evaluation of autobiographical episodic memory; 2) During intervention: Placebo olfactory stimulation with control group, and olfactory familiar stimulation with experimental group. Then there will be an evaluation of autobiographical episodic memory; 3) Before intervention: Post olfactory stimulation of self‐consciousness.ResultsMore autobiographical memories evoked are expected with the positive valiance of familiar olfactory intervention than the placebo olfactory stimulation in people with A.D. We expect that autobiographical episodic involuntary memories evoked will be more elevated than the voluntary ones on subjective content. We also contemplate that the group of patients with familiar olfactory stimulation will improve their level of self‐consciousness and evoke autobiographical episodic memory.ConclusionThis research will be an important framework for future clinical trials with familiar olfactory intervention in Latin America. Also, for non‐pharmacologic interventions.

Self, insula and dementia with Lewy bodies

AbstractBackgroundThe objective is to review in the literature evidence of the relationship between the Self, the insular cortex, and Dementia with Lewy bodies (DLB). The notion of “Self” encompasses a subjective part that integrates the most internal bodily phenomena of self‐awareness, and an objective part that sustains autobiographical memory and its most specific details. Modifications of the Self, such as anosognosia and personal identity, or autobiographical memory deterioration, are frequently reported by relatives and noticed by clinicians, jointly with insular atrophy, which occurs early in the course of the disease.MethodWe performed research on PubMed and Google Scholar, using MeSH subheadings and keywords, limited to papers in English; 226 publications contributed to the review. The terms “Lewy bodies”, “Insula”, “Self” and different aspects related to the self, such as “subjective sense of self”, “self‐concept” and “autobiographical memory” were used to denote the themes of interest.ResultThe evidence suggest that insula is a multiconnected brain region involved in processing varied aspects of the self. On the one hand, insula’s posterior part integrates primary interoceptive representations through sensorimotor processes, and on the other hand insula’s anterior part sustains and integrates viscerosensory responses, socio‐emotional processing and cognitive functions, allowing the emergence of self‐awareness. In addition, changes in personal tastes resulting from insular atrophy have been highlighted in DLB. However, there is, to date, little work exploring the different components of the self (i.e. subjective sense of self; self‐concept; autobiographical memory) in DLB.ConclusionBased on our literature review, it seems that no experimental work have ever been performed on the Self in DLB. Numerous aspects related to the Self, from the most primitive to more elaborated ones are worthy of being studied in this affection, whose anatomic peculiarity sets in early insular damage. We intend to investigate these questionings in DLB, compared to Alzheimer disease – which is characterized by an early deterioration of episodic autobiographical memory – and healthy elderly population, by combining behavioral measures and multimodal neuroimaging, with a particular interest for the insular cortex.

Episodic Memory Reliving and Personality

Abstract. There are considerable individual differences in remembering past episodes. The current study aimed to examine the link between episodic memory reliving and the Five-Factor Model personality traits. Altogether 422 participants (67% women) described an autobiographical episode and rated the vividness and clarity of that recollection. Next, they assessed their general tendencies of autobiographical recollections, which resulted in two autobiographical episodic memory scores (AEMS) for each participant – episodic and general. Participants also filled in the Estonian version of the International Personality Item Pool NEO questionnaire. Findings from partial correlation analysis (controlling for age and gender) revealed distinguishable patterns of associations for the episodic and general-level reports of memory reliving: the episodic AEMS was positively associated with E4: Activity Level and E1: Friendliness, whereas the general AEMS was negatively correlated with N4: Self-Consciousness, and positively with E1: Friendliness, E6: Cheerfulness, O1: Imagination, O5: Intellect, C2: Orderliness, and C3: Dutifulness (all significant at p < .005). The associations between the general (but not the episodic) AEMS and personality facets were significantly correlated with the average social desirability ratings of the respective facets. We conclude that greater social adaptation together with the motivation of positive self-perception are plausible explanations of the links between personality traits and reporting the quality of reliving personal memories.

Episodic Autobiographical Memory Impairment and Differences in Pronoun Use: Study of Self-Awareness in Functional Amnesia and Transient Global Amnesia.

The subjective experience associated to memory processing is the core of the definition of episodic autobiographical memory (EAM). However, while it is widely known that amnesia affects the content of memories, few studies focused on the consequences of an impairment of EAM on the subjective self, also called the I-self. In the present study, we explored the I-self in two puzzling disorders that affect EAM: functional amnesia, which has an impact on autobiographical memory, and transient global amnesia (TGA), which only affects episodic memory. I-self was assessed through an original measure of self-integration in autobiographical narratives, namely the use of general or personal pronouns. Results showed that patients with functional amnesia tended to use general pronouns, whereas patients with TGA preferentially used the first person. The link between I-self and depersonalization-derealisation tendencies was also explored, showing dissociative tendencies in patients with functional amnesia but not in patients with TGA. We discuss these results from a combined neuropsychological and psychopathological perspective, with a view to proposing an explanatory model of the links between self-awareness and the episodic component of autobiographical memory.

Neural Correlates of Autobiographical Memory: Evidence From a Positron Emission Tomography Study in Patients With Mild Cognitive Impairment and Alzheimer's Disease.

Background: Autobiographical memory (AM) changes are the hallmark of Alzheimer's disease (AD) and mild cognitive impairment (MCI). In recent neuroimaging studies, AM changes have been associated with numerous cerebral sites, such as the frontal cortices, the mesial temporal lobe, or the posterior cingulum. Regional glucose uptake in these sites was investigated for underlying subdimensions using factor analysis. Subsequently, the factors were examined with respect to AM performance in a subgroup of patients.Methods: Data from 109 memory clinic referrals, who presented with MCI (n = 60), mild AD (n = 49), or were cognitively intact, were analyzed. The glucose metabolic rates determined by positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in 34 cerebral sites important for AM were investigated for underlying subdimensions by calculating factor analysis with varimax rotation. Subsequently, the respective factor scores were correlated with the episodic and semantic AM performance of 22 patients, which was measured with a semi-structured interview assessing episodic memories (characterized by event-related emotional, sensory, contextual, and spatial–temporal details) and personal semantic knowledge from three periods of life (primary school, early adulthood, and recent years).Results: Factor analysis identified seven factors explaining 69% of the variance. While patients with MCI and AD showed lower values than controls on the factors frontal cortex, mesial temporal substructures, and occipital cortex, patients with MCI presented with increased values on the factors posterior cingulum and left temporo-prefrontal areas. The factors anterior cingulum and right temporal cortex showed only minor, non-significant group differences. Solely, the factor mesial temporal substructures was significantly correlated with both episodic memories (r = 0.424, p < 0.05) and personal semantic knowledge (r = 0.547, p < 0.01) in patients with MCI/AD.Conclusions: The factor structure identified corresponds by large to the morphological and functional interrelations of the respective sites. While reduced glucose uptake on the factors frontal cortex, mesial temporal substructures, and occipital cortex in the patient group may correspond to neurodegenerative changes, increased values on the factors posterior cingulum and left temporo-prefrontal areas in MCI may result from compensatory efforts. Interestingly, changes of the mesial temporal substructures were correlated with both semantic and episodic AM. Our findings suggest that AM deficits do not only reflect neurodegenerative changes but also refer to compensatory mechanisms as they involve both quantitative losses of specific memories and qualitative changes with a semantization of memories.

Degree Centrality of a Brain Network Is Altered by Stereotype Threat: Evidences From a Resting-State Functional Magnetic Resonance Imaging Study.

Previous studies have found the effects of stereotype threat (ST) on cognitive processes, emotions, and motivations which could account for the underperformance in domain tasks. Efficient brain function does not require the function of different brain regions during specific tasks, but it does require the brain networks on which information is transported. Based on these, the effects of ST on the degree centrality under the resting state of brain regions related to these processes were investigated under math-related ST. The results showed that RSDC was decreased in the left hippocampus and left middle occipital gyrus (MOC), while RSDC was increased in the left precuneus, the right angular gyrus (AG), and the right superior parietal gyrus (SPG) under ST. Interestingly, we also found that the right-left anterior temporal lobe (ATL) and the right hippocampus were negatively correlated with manipulation check (MC) score in the ST group, while the right-left ATL and the right hippocampus were positively correlated with MC score in the control group. These results might reflect those individuals who attempted to inhibit the negative emotions induced by the negative stereotypes under ST conditions while increasing the self-relevant processes by retrieving episodic memory or autobiographical memory.

Conversational System as Assistant Tool in Reminiscence Therapy for People with Early-Stage of Alzheimer's.

Reminiscence therapy is a non-pharmacological intervention that helps mitigate unstable psychological and emotional states in patients with Alzheimer’s disease, where past experiences are evoked through conversations between the patients and their caregivers, stimulating autobiographical episodic memory. It is highly recommended that people with Alzheimer regularly receive this type of therapy. In this paper, we describe the development of a conversational system that can be used as a tool to provide reminiscence therapy to people with Alzheimer’s disease. The system has the ability to personalize the therapy according to the patients information related to their preferences, life history and lifestyle. An evaluation conducted with eleven people related to patient care (caregiver = 9, geriatric doctor = 1, care center assistant = 1) shows that the system is capable of carrying out a reminiscence therapy according to the patient information in a successful manner.

Supporting autistic adults' episodic memory recall in interviews: The role of executive functions, theory of mind, and language abilities.

Autistic people have difficulties recalling episodic memories, including retrieving fewer or less specific and detailed memories compared to typically developing people. However, the ability to effectively recall episodic memories is crucial in many real-world contexts, such as the criminal justice system, medical consultations, and employment interviews. Autistic people’s episodic memory difficulties are most apparent when open, unsupportive questions are used. The ‘Task Support Hypothesis’ posits that autistic people can recall as much information as typically developing people with more supportive questioning. Alongside problems retrieving episodic memories, autistic people also experience difficulties with executive functioning, theory of mind, and expressive language. The current study aimed to assess the impact of these abilities on recall in two previous studies by the authors that compared autistic and typically developing adults on recall specificity in police, healthcare, and employment interviews, and recall quality in employment interviews under unsupported and supported questioning. Under unsupported questioning only, autistic adults’ episodic autobiographical memory recall specificity was predicted by expressive language, whereas for the typically developing group, only theory of mind was a significant predictor. No other predictors were significant across the study. Implications for the task support hypothesis are discussed.Lay abstractAutistic people have difficulties recalling episodic memories (memories of specific events) compared to typically developing people. However, being able to effectively recall such memories is important in many real-world situations, for example, in police interviews, during medical consultations, and in employment interviews. Autistic people’s episodic memory difficulties are most noticeable when they are responding to open, unsupportive questions. However, the ‘Task Support Hypothesis’ indicates that autistic people are able to recall as much information as typically developing people, as long as they are asked more supportive questions. Autistic people also experience difficulties with executive functioning (cognitive abilities which allow us to plan, hold information in mind, inhibit interruptions, etc.), theory of mind (the ability to understand others’ perspectives and intentions), and spoken language. The current study aimed to investigate the impact of these cognitive abilities on memory recall in two previous studies which compared autistic and typically developing adults on how specific their recall was in police, healthcare, and employment interviews, and the quality of responses during an employment interview when both unsupportive and supportive questioning was used. The results show that while typically developing people may rely on theory of mind abilities, autistic people may rely more on language abilities when performing in interviews, potentially to compensate for their episodic memory difficulties, and that this effect is most apparent during more unsupportive recall (e.g. when a brief, open question is asked) compared to when open questions are followed by prompts (e.g. ‘tell me about who as there’, ‘what happened?’, etc.).

Mental representation of autobiographical memories along the sagittal mental timeline: Evidence from spatiotemporal interference

Time is usually conceived of in terms of space: many natural languages refer to time according to a back-to-front axis. Indeed, whereas the past is usually conceived to be “behind us”, the future is considered to be “in front of us.” Despite temporal coding is pivotal for the development of autonoetic consciousness, little is known about the organization of autobiographical memories along this axis. Here we developed a spatial compatibility task (SCT) to test the organization of autobiographical memories along the sagittal plane, using spatiotemporal interference. Twenty-one participants were asked to recall both episodic and semantic autobiographical memories (EAM and SAM, respectively) to be used in the SCT. Then, during the SCT, they were asked to decide whether each event occurred before or after the event presented right before, using a response code that could be compatible with the back-to-front axis (future in front) or not (future at back). We found that performance was significantly worse during the non-compatible condition, especially for EAM. The results are discussed in light of the evidence for spatiotemporal encoding of episodic autobiographical memories, taking into account possible mechanisms explaining compatibility effects.

Episodic Autobiographical Memory in Adults With Autism Spectrum Disorder: An Exploration With the Autobiographical Interview.

Introduction: The literature has provided contradictory results regarding the status of episodic memory in autism spectrum disorder (ASD). This might be explained by methodological differences across studies. In the present one, the well-recommended Autobiographical Interview was used in which important aspects of episodic memory were assessed, namely, the number and richness of phenomenological memory details, before and after a retrieval support.Method: Twenty-five well-documented adults with ASD without Intellectual Disability (nine women) and 25 control participants were included and asked to recall six specific autobiographical events. The number and richness of details were assessed globally and for five categories of details (perceptual/sensory, temporal, contextual, emotional, and cognitive), firstly before and then after a specific cueing phase consisting in a series of specific questions to elicit more precise memory details.Results: Cumulatively, from the spontaneous recall to the cueing phase, the number of internal details was lower in ASD individuals compared to controls, but this difference was relevant only after the specific cueing procedure and observed only for contextual details. In contrast, no relevant group difference was observed during spontaneous recall. The detail richness was not impaired in ASD throughout the Autobiographical Interview procedure.Conclusion: Our results speak against a clear impairment of episodicity of autobiographical memory in ASD individuals. They thus challenge previous ones showing both a reduced specificity and episodicity of autobiographical memory in this population and call for further studies to get a better understanding on the status of episodic autobiographical memory in ASD.

Electroconvulsive therapy related autobiographical amnesia: a review and case report

ABSTRACT Introduction: While short-term cognitive impairment following electroconvulsive therapy (ECT) is well described and acknowledged, the relationship between ECT and persistent memory impairment, particularly of autobiographical memory, has been controversial. Methods: We describe the case of a 70-year-old consultant neurophysiologist, AW, who developed prominent, selective autobiographical memory loss following two courses of ECT for treatment-resistant depression. Results: His performance on standard measures of IQ, semantic and episodic memory, executive function and mood was normal, while he performed significantly below controls on measures of episodic autobiographical memory. Conclusions: Explanations in terms of mood-related memory loss and somatoform disorder appear unlikely. We relate AW's autobiographical memory impairment, following his ECT, to reports of similar autobiographical memory impairment occurring in the context of epilepsy, and emphasise the importance of using sensitive approaches to AbM assessment.

Hippocampal gray matter volume in the long-term course after transient global amnesia

ObjectiveIn this retrospective, cross-sectional study we aimed to examine long-term memory deficits and gray matter volumes (GMV) in the hippocampus after transient global amnesia (TGA). Methods20 patients with a history of TGA (TGA+, mean 6.5 years after TGA) and 20 age-matched healthy controls (TGA-) underwent neurocognitive assessment (i.e. Mini-Mental State Examination (MMSE), visuospatial, verbal and episodic autobiographical memory and visuospatial learning/navigation [“human water maze”]) in combination with structural cerebral MRI. Voxel-based morphometry (VBM) was used to detect GMV in the hippocampus in TGA+ versus TGA-. ResultsBesides slight differences in MMSE and visuo-spatial learning/navigation measured with a human water maze in TGA+ vs. TGA-, no other tests of visuo-spatial, verbal and autobiographical long-term memory differed between groups. VBM analyses yielded a statistically significant difference in bilateral hippocampal GMV with TGA+ compared to TGA- showing greater GMV in a region corresponding to bilateral CA1. However, none of the hippocampus-dependent cognitive measures correlated with hippocampal GMV. ConclusionIn the long-term course after TGA, only subtle neurocognitive deficits without microstructural damage of the hippocampus could be detected. Greater GMV in bilateral hippocampus in TGA+ vs. TGA- may indicate that TGA triggers hippocampal GMV increase rather than atrophy.

Impact of familiar olfactory stimulation on self‐consciousness

AbstractBackgroundAutobiographical memory facilitates the construction and meaning attributed to a lifetime story. The episodic autobiographical memory involves the personal experiences related to a place and a specific time, and the semantic autobiographical memory is associated to a general knowledge related to repetitive events and past experiences over a long period of time (Allen, Doyle, Commins &amp; Roche, 2018). Autobiographical events trigger an autonomic consciousness in which it revives the past memories, while the autobiographical semantic knowledge involves a consciousness of past limited and noetic familiar sensation (Irish et al., 2018; El Haj, Nandrino &amp; Kapogiannis, 2015; Rathbone, Ellis, Ahmed, Moulin, Ernst, &amp; Butler, 2019). Decline of autobiographical episodic memory involves a progressive loss of self‐consciousness in Alzheimer’s disease (A.D). Some studies like Glachet, Gandolphe, Gallouj, Antonie, and El Haj (2018) demonstrate positive effects of olfactory stimulation on autobiographical memory. However, no research has evaluated the influence of familiar olfactory stimulation on A.D related to improve self‐consciousness in Dominican Republic. This study aims to evaluate the evoked autobiographical memories from familiar olfactory stimulation has an enforcement or facilitator effect on self‐consciousness.MethodFifty people with mild and moderate A.D will participate. The Control group, will have an olfactory stimulation without familiar smells and the experimental group, will have an olfactory stimulation with familiar smells. After intervention: Evaluation of autobiographical episodic memory (controlled process) and self‐consciousness. During Intervention: Olfactory familiar stimulation with experimental group and placebo olfactory stimulation with control group. Then there will be an evaluation of autobiographical episodic memory (automatic process). Before intervention: Post olfactory stimulation of self‐consciousness.ResultsWe expect that the positive valiance of familiar olfactory intervention will be evoked more in the autobiographical episodic memories than the placebo stimulation olfactory in patients with A.D; and that autobiographical episodic automatic or involuntary memories evoked will be more elevated about subjective content that the voluntary or explicit ones. We also hope that the group of patients with familiar olfactory stimulation evoke autobiographical episodic memory and improve their level of self‐consciousness.ConclusionThis study will be a framework for non‐pharmacologic interventions and future clinical trials with familiar olfactory intervention.

Vividness of recollection is supported by eye movements in individuals with high, but not low trait autobiographical memory

There are marked individual differences in the recollection of personal past events or autobiographical memory (AM). Theory concerning the relationship between mnemonic and visual systems suggests that eye movements promote retrieval of spatiotemporal details from memory, yet assessment of this prediction within naturalistic AM has been limited. We examined the relationship of eye movements to free recall of naturalistic AM and how this relationship is modulated by individual differences in AM capacity. Participants freely recalled past episodes while viewing a blank screen under free and fixed viewing conditions. Memory performance was quantified with the Autobiographical Interview, which separates internal (episodic) and external (non-episodic) details. In Study 1, as a proof of concept, fixation rate was predictive of the number of internal (but not external) details recalled across both free and fixed viewing. In Study 2, using an experimenter-controlled staged event (a museum-style tour) the effect of fixations on free recall of internal (but not external) details was again observed. In this second study, however, the fixation-recall relationship was modulated by individual differences in autobiographical memory, such that the coupling between fixations and internal details was greater for those endorsing higher than lower episodic AM. These results suggest that those with congenitally strong AM rely on the visual system to produce episodic details, whereas those with lower AM retrieve such details via other mechanisms.