Autobiographical and episodic memory deficits in schizophrenia: A narrative review and proposed agenda for research

Improving autobiographical memory in schizophrenia using wearable cameras: A single-case experimental study

Autobiographical memory (AM) impairments influence both sense of identity and social functioning of patients with schizophrenia. However, cognitive remediation methods addressing these difficulties do not sufficiently consider the heterogeneity of this disorder and frequently face methodological limitations. The aim of the present study was to evaluate the efficacy of a method using a wearable camera (NarrativeClip®), through an alternating treatments design across two types of AM training. In parallel, repeated measures were used to appreciate the efficacy, specificity, and generalizability of the programme's benefits. Three patients were invited to wear the camera during 24 personal events. Ten of these events memories were trained by visual cueing (wearable camera condition), 10 others by verbal cueing (written diary condition) and 4 were not trained (control condition). Using pictures collected by the wearable camera seemed particularly relevant, since it promoted more detailed recalls than the diary method, from the first training session and until the end of a one-year follow-up. In addition, the repeated measures performed revealed (1) the efficacy (improvement in AM capacities after participating in the programme), (2) specificity (persistence of working memory deficits), and (3) generalizability (improvement in measures of episodic memory) of our cognitive remediation programme's effects.

Spurious Autobiographical Memory of Psychosis: A Mechanistic Hypothesis for the Resolution, Persistence, and Recurrence of Positive Symptoms in Psychotic Disorders

Psychotic disorders are complex disorders with multiple etiologies. While increased dopamine synthesis capacity has been proposed to underlie psychotic episodes, dopamine-independent processes are also involved (less responsive to dopamine receptor-blocking medications). The underlying mechanism(s) of the reduction in antipsychotic responsiveness over time, especially after repeated relapses, remain unclear. Despite the consistent evidence of dopamine overactivity and hippocampal volume loss in schizophrenia, few accounts have been provided based on the interactive effect of dopamine on hippocampal synapse plasticity mediating autobiographical memory processes. The present hypothesis builds upon previous works showing the potential effects of dopamine overactivity on hippocampal-mediated neuroplasticity underlying autobiographical memory, alongside known patterns of autobiographical memory dysfunction in psychosis. We propose that spurious autobiographical memory of psychosis (SAMP) produced during active psychosis may be a key mechanism mediating relapses and treatment non-responsiveness. In a hyperdopaminergic state, SAMP is expected to be generated at an increased rate during active psychosis. Similar to other memories, it will undergo assimilation, accommodation, and extinction processes. However, if SAMP fails to integrate with existing memory, a discontinuity in autobiographical memory may result. Inadequate exposure to normalizing experiences and hyposalience due to overmedication or negative symptoms may also impede the resolution of SAMP. Residual SAMP is hypothesized to increase the propensity for relapse and treatment non-responsiveness. Based on recent findings on the role of dopamine in facilitating hippocampal synapse plasticity and autobiographical memory formation, the SAMP hypothesis is consistent with clinical observations of DUP effects, including the repetition of contents in psychotic relapses as well as the emergence of treatment non-responsiveness after repeated relapses. Clinical implications of the hypothesis highlight the importance of minimizing active psychosis, integrating psychosis memory, avoiding over-medication, and fostering normalizing experiences.

Potential Anti-Amnesic Activity of a Novel Multimodal Derivative of Salicylamide, JJGW08, in Mice

Memory impairments constitute a significant problem worldwide, and the COVID-19 pandemic dramatically increased the prevalence of cognitive deficits. Patients with cognitive deficits, specifically memory disturbances, have underlying comorbid conditions such as schizophrenia, anxiety, or depression. Moreover, the available treatment options have unsatisfactory effectiveness. Therefore, there is a need to search for novel procognitive and anti-amnesic drugs with additional pharmacological activity. One of the important therapeutic targets involved in the modulation of learning and memory processes are serotonin receptors, including 5-HT1A, 5-HT6, and 5-HT7, which also play a role in the pathophysiology of depression. Therefore, this study aimed to assess the anti-amnesic and antidepressant-like potential of JJGW08, a novel arylpiperazine alkyl derivative of salicylamide with strong antagonistic properties at 5-HT1A and D2 receptors and weak at 5-HT2A and 5-HT7 receptors in rodents. First, we investigated the compound’s affinity for 5-HT6 receptors using the radioligand assays. Next, we assessed the influence of the compound on long-term emotional and recognition memory. Further, we evaluated whether the compound could protect against MK-801-induced cognitive impairments. Finally, we determined the potential antidepressant-like activity of the tested compound. We found that JJGW08 possessed no affinity for 5-HT6 receptors. Furthermore, JJGW08 protected mice against MK-801-induced recognition and emotional memory deficits but showed no antidepressant-like effects in rodents. Therefore, our preliminary study may suggest that blocking serotonin receptors, especially 5-HT1A and 5-HT7, might be beneficial in treating cognitive impairments, but it requires further investigation.

Autobiographical memory impairment in chronic schizophrenia: Significance and clinical correlates

Previous studies of autobiographical memory (AM) in schizophrenia yielded a reduction of specificity, richness of details and conscious recollection, which indicate both, quantitative and qualitative AM changes. However, their associations with psychopathological symptoms and neuropsychological deficits were not resolved. Therefore, we sought to investigate AM with respect to psychopathology and neuropsychology in patients with chronic schizophrenia to rule out the influence of different courses of the disease. AM of four lifetime periods was examined in 75 patients and 50 healthy controls by using a semi-structured interview. The recalled episodes were rated for memory specificity. Subsequently, one single event of each period of life was rated for details and experiential aspects of reliving (originality, vividness/visual imagery, emotional re-experiencing and emotional valence). When contrasted with healthy controls, patients recalled a significantly reduced number of episodes and personal semantic facts; moreover, memory specificity of AM was significantly lower in patients than controls. While the richness of details calculated for single events showed only minor, non-significant group differences, vividness and emotional re-experiencing were significantly less pronounced in the patient group. Along with this, AM performance correlated significantly with negative symptoms including apathy as well as verbal memory and executive functions. Our results underline the significance of overgenerality as a key feature of AM in schizophrenia as well as a dissociation between intact number of details of single events and reduced vividness and emotional re-experiencing. The extent of negative symptoms including apathy and impairments of verbal memory/executive functions may explain AM deficits in chronic schizophrenia.

Neurocognitive Deficits in First-Episode and Chronic Psychotic Disorders: A Systematic Review from 2009 to 2022

Cognitive impairment in patients suffering from schizophrenia spectrum disorders has been discussed as a strong predictor for multiple disease outcome variables, such as response to psychotherapy, stable relationships, employment, and longevity. However, the consistency and severity of cognitive deficits across multiple domains in individuals with first-episode and chronic psychotic disorders is still undetermined. We provide a comprehensive overview of primary research from the years 2009 to 2022. Based on a Cochrane risk assessment, a systematic synthesis of 51 out of 3669 original studies was performed. Impairment of cognitive functioning in patients diagnosed with first-episode psychotic disorders compared with healthy controls was predicted to occur in all assessed cognitive domains. Few overall changes were predicted for chronically affected patients relative to those in the first-episode stage, in line with previous longitudinal studies. Our research outcomes support the hypothesis of a global decrease in cognitive functioning in patients diagnosed with psychotic disorders, i.e., the occurrence of cognitive deficits in multiple cognitive domains including executive functioning, memory, working memory, psychomotor speed, and attention. Only mild increases in the frequency of cognitive impairment across studies were observed at the chronically affected stage relative to the first-episode stage. Our results confirm and extend the outcomes from prior reviews and meta-analyses. Recommendations for psychotherapeutic interventions are provided, considering the broad cognitive impairment already observed at the stage of the first episode. Based on the risk of bias assessment, we also make specific suggestions concerning the quality of future original studies.

Autobiographical memory and the self on the psychosis continuum: investigating their relationship with positive- and negative-like symptoms

Autobiographical memory is severely impaired in schizophrenia, but previous work has largely treated both as unitary concepts. Here, we examined how various dimensions of autobiographical memory relate to different aspects of psychosis. Participants were recruited from the general population (Study 1, N = 264) and a university subject pool (Study 2, N = 305). We examined different measures of autobiographical memory and self (i.e., involuntary memory, autobiographical recollection, self-knowledge and self-awareness), at the trait level in Study 1 and both trait and state levels in Study 2, as a function of positive-and negative-like symptoms of psychosis. Across both studies, positive and negative dimensions of psychosis were found to be related to an increase in involuntary memories (i.e., the spontaneous recall of personal memories), and to lower self-concept clarity and insight. Positive and negative dimensions of psychosis correlated differently with autobiographical recollection characteristics, measured at both trait (Studies 1 and 2) and state levels (Study 2). Positive-like symptoms (in particular hallucination-proneness) showed a stronger and more consistent pattern of correlations than negative-like symptoms. These findings call for a dimensional approach to the relationship between autobiographical memory and psychosis symptoms in clinical and non-clinical individuals, to better understand the breakdown of autobiographical memory in the psychopathology of psychosis.

Episodic Memory and Schizophrenia: From Characterization of Relational Memory Impairments to Neuroimaging Biomarkers

Episodic memory research in schizophrenia has a long history already which has clearly established significant impairments and strong associations with brain measures and functional outcome. The purpose of this chapter is not to make an exhaustive review of the recent literature but to highlight some relatively recent developments in the cognitive neuroscience field of episodic memory and schizophrenia. Hence, we present a contemporary view focusing specifically of relational memory which represents a form of episodic memory that refers to associations or binding among items or elements presented together. We describe the major tasks used and illustrate how their combination with brain imaging has: (1) favored the use of experimental memory tasks to isolate specific processes with specific neural correlates, (2) led to a distributed view of the neural correlates of memory impairments in schizophrenia where multiple regions are contributing, and (3) made possible the identification of fMRI biomarkers specific to episodic memory. We then briefly propose what we see as the next steps for memory research in schizophrenia so that the impact of this work can be maximized.

Clinical Manifestations of Body Memories: The Impact of Past Bodily Experiences on Mental Health

Bodily experiences such as the feeling of touch, pain or inner signals of the body are deeply emotional and activate brain networks that mediate their perception and higher-order processing. While the ad hoc perception of bodily signals and their influence on behavior is empirically well studied, there is a knowledge gap on how we store and retrieve bodily experiences that we perceived in the past, and how this influences our everyday life. Here, we explore the hypothesis that negative body memories, that is, negative bodily experiences of the past that are stored in memory and influence behavior, contribute to the development of somatic manifestations of mental health problems including somatic symptoms, traumatic re-experiences or dissociative symptoms. By combining knowledge from the areas of cognitive neuroscience and clinical neuroscience with insights from psychotherapy, we identify Clinical Body Memory (CBM) mechanisms that specify how mental health problems could be driven by corporeal experiences stored in memory. The major argument is that the investigation of the neuronal mechanisms that underlie the storage and retrieval of body memories provides us with empirical access to reduce the negative impact of body memories on mental health.

Emotional memory for facial expressions in schizophrenia spectrum disorders: The role of encoding method

Memory is better for emotional rather than neutral events or materials (emotional enhancement of memory; EEM). Evidence suggests that this memory benefit remains intact in schizophrenia, but conflicting findings present the need for further research to understand how and when this process occurs. Here, we examine whether different encoding methods for learning emotional faces may result in different EEM patterns in those with schizophrenia spectrum disorders (SSD). A patient group (n = 28) and healthy comparisons (n = 29) encoded faces in two conditions that manipulated attentional focus to promote direct (emotion judgements) or indirect (sex discrimination) processing of emotional content. Based on literature in schizophrenia showing selective emotion perception deficits on tasks of direct processing but relatively intact emotion perception on indirect processing tasks, we hypothesized that patients would show greater EEM effects when faces were encoded indirectly. This hypothesis was not supported, and the patient group instead showed a similar intact EEM for angry and fearful faces to healthy comparisons in both encoding conditions. Further, using the Remember/Know paradigm, we demonstrated that the EEM in SSD appears selective to recollection-based memory, which helps to explain inconsistencies in past literature that has not differentiated between recognition domains. These findings have important implications for improving emotional memory and functional outcomes in SSD; future research should establish how the EEM for facial expressions may relate to social functioning.

Atypical meta-memory evaluation strategy in schizophrenia patients

Background

Previous research has reported that patients with schizophrenia would regard false memories with higher confidence, and this meta-memory deficit was suggested as a neurocognitive marker of schizophrenia. However, how schizophrenia patients determine their memory decision confidence has received scant consideration. This study, therefore, aimed to characterize the extent to which meta-memory evaluation strategy differs between schizophrenia patients and healthy individuals, and how such difference contributes to the patients' meta-memory performance.

Methods

27 schizophrenia patients and 28 matched healthy controls performed a temporal-order judgement (TOJ) task, in which they judged which movie frame occurred earlier in an encoded video, and then made retrospective confidence rating. Mixed effect regression models were performed to assess the between-group metacognitive evaluation strategy difference and its relationship to clinical symptoms.

Results

Compared to the control group, the patients' confidence ratings were correlated more with the recent confidence history and less with the TOJ-related evidence. The degree of dependence on recent history of confidence was negatively correlated with the severity of positive symptoms. Furthermore, by controlling for the first-order TOJ performance, we observed that the patients discriminated correct memory decisions from the incorrect ones as accurately as the controls.

Conclusion

The present investigation revealed that schizophrenia patients tend to use more heuristics in making meta-memory evaluations, and such atypical strategy is related to their clinical symptoms. This study provides new insights into how schizophrenia patients perform meta-memory processes. Future research could consider examining such metacognitive deficits in light of other cognitive domains in psychosis.

How Local and Global Metacognition Shape Mental Health

Metacognition is the ability to reflect on our own cognition and mental states. It is a critical aspect of human subjective experience and operates across many hierarchical levels of abstraction-encompassing local confidence in isolated decisions and global self-beliefs about our abilities and skills. Alterations in metacognition are considered foundational to neurologic and psychiatric disorders, but research has mostly focused on local metacognitive computations, missing out on the role of global aspects of metacognition. Here, we first review current behavioral and neural metrics of local metacognition that lay the foundation for this research. We then address the neurocognitive underpinnings of global metacognition uncovered by recent studies. Finally, we outline a theoretical framework in which higher hierarchical levels of metacognition may help identify the role of maladaptive metacognitive evaluation in mental health conditions, particularly when combined with transdiagnostic methods.

Autobiographical memory in schizophrenia: The role of metacognition

BACKGROUND

Autobiographical memory is an important component of declarative memory, which refers to the ability to recall personal events that happened in the past. This requires that the person senses or experiences himself/herself in the past (i.e., conscious recollection). For people with schizophrenia, conscious recollection can be particularly difficult, resulting in difficulty accessing detailed, specific autobiographical information. Our hypothesis is that the ability to monitor and think about one's cognitive processes (metacognition) is a requisite for conscious recollection, and that it mediates the association between having schizophrenia and recalling fewer specific, personal memories.

METHODS

Participants were 30 adults with schizophrenia and 30 matched healthy controls. The main assessment instruments were the Metacognition Assessment Scale-Abbreviated (MAS-A) and the Autobiographical Memory Test (AMT). Severity of symptoms was assessed using the Positive and Negative Syndrome Scale (PANSS) for schizophrenia. Cognitive performance was measured with the Screen for Cognitive Impairment in Psychiatry (SCIP). Mediation analysis was conducted following Baron and Kenny's procedure.

RESULTS

People with schizophrenia had more semantic associations and fewer specific memories than controls in the AMT. Metacognition (MAS-A total score) partially mediated the association between having schizophrenia and recalling fewer specific past events, even after controlling for cognitive impairment as a potential confounding source.

CONCLUSIONS

Metacognitive ability, which can be improved with available programs, intervenes in the process of accessing autobiographical memories in people with schizophrenia. Practical implications of this finding are discussed.

Narrative identity in the psychosis spectrum: A systematic review and developmental model

Individuals with schizophrenia-spectrum disorders face profound challenges as they attempt to maintain identity through the course of illness. Narrative identity-the study of internalized, evolving life stories-provides a rich theoretical and empirical perspective on these challenges. Based on evidence from a systematic review of narrative identity in the psychosis spectrum (30 studies, combined N = 3859), we argue that the narrative identities of individuals with schizophrenia-spectrum disorders are distinguished by three features: disjointed structure, a focus on suffering, and detached narration. Psychotic disorders typically begin to emerge during adolescence and emerging adulthood, which are formative developmental stages for narrative identity, so it is particularly informative to understand identity disturbances from a developmental perspective. We propose a developmental model in which a focus on suffering emerges in childhood; disjointed structure emerges in middle and late adolescence; and detached narration emerges before or around the time of a first psychotic episode. Further research with imminent risk and early course psychosis populations would be needed to test these predictions. The disrupted life stories of individuals on the psychosis spectrum provide multiple rich avenues for further research to understand narrative self-disturbances.

Early life adversity and the specificity of autobiographical memory amongst people with schizophrenia

BACKGROUND

People with schizophrenia diagnoses are thought to have difficulty retrieving memories of specific autobiographical events because of attempts to avoid the negative affect associated with previous adversity. We provide the first investigation of the association between early adversity (e.g., childhood abuse) and autobiographical memory problems amongst people with and without schizophrenia.

METHOD

Participants with diagnoses of schizophrenia (n = 79) and participants without diagnoses (n = 41) completed the Maltreatment and Abuse Chronology of Exposure (MACE) interview schedule and a cued recall task.

RESULTS

Participants exposed to greater number of, and more severe, childhood adversity retrieved fewer specific autobiographical memories. However, participants with schizophrenia retrieved fewer specific memories than control participants without diagnoses irrespective of the presence, severity or number of adversities they experienced.

CONCLUSIONS

Adversity contributes towards autobiographical memory difficulty but adversity does not explain why people with schizophrenia differ from diagnoses-free people in their autobiographical memory abilities.