When I relive a positive me: Vivid autobiographical memories facilitate autonoetic brain activation and enhance mood

Autobiographical Cerebral Network Activation in Older Adults Before and After Reminiscence Therapy: A Preliminary Report

INTRODUCTION

Reminiscence therapy (RT), which engages individuals to evoke positive memories, has been shown to be effective in improving psychological well-being in older adults suffering from PTSD, depression, and anxiety. However, its impact on brain function has yet to be determined. This paper presents functional magnetic resonance imaging (fMRI) data to describe changes in autobiographical memory networks (AMN) in community-dwelling older adults.

METHODS

This pilot study used a within-subject design to measure changes in AMN activation in 11 older adults who underwent 6 weeks of RT. In the scanner, participants retrieved autobiographical memories which were either recent or remote, rehearsed or unrehearsed. Participants also underwent a clinical interview to assess changes in memory, quality of life, mental health, and affect.

FINDINGS

Compared to pretreatment, anxiety decreased (z = -2.014, p = .040) and activated significant areas within the AMN, including bilateral medial prefrontal cortex, left precuneus, right occipital cortex, and left anterior hippocampus.

CONCLUSION

Although RT had subtle effects on psychological function in this sample with no evidence of impairments, including depression at baseline, the fMRI data support current thinking of the effect RT has on the AMN. Increased activation of right posterior hippocampus following RT is compatible with the Multiple Trace Theory Theory (Nadel & Moscovitch, 1997).

The Functional Neuroimaging of Autobiographical Memory for Happy Events: A Coordinate-Based Meta-Analysis

Neuroimaging studies using autobiographical recall methods investigated the neural correlates of happy autobiographical memories (AMs). The scope of the present activation likelihood estimation (ALE) meta-analysis was to quantitatively analyze neuroimaging studies of happy AMs conducted with autobiographical recall paradigms. A total of 17 studies (12 fMRI; 5 PET) on healthy individuals were included in this meta-analysis. During recall of happy life events, consistent activation foci were found in the frontal gyrus, the cingulate cortex, the basal ganglia, the parahippocampus/hippocampus, the hypothalamus, and the thalamus. The result of this quantitative coordinate-based ALE meta-analysis provides an objective view of brain responses associated with AM recollection of happy events, thus identifying brain areas consistently activated across studies. This extended brain network included frontal and limbic regions involved in remembering emotionally relevant positive events. The frontal gyrus and the cingulate cortex may be responsible for cognitive appraisal processes during recollection of happy AMs, while the subthalamic nucleus and globus pallidus may be involved in pleasure reactions associated with recollection of happy life events. These findings shed light on the neural network involved in recalling positive AMs in healthy individuals, opening further avenues for future research in clinical populations with mood disorders.

Bayesian evaluation of diverging theories of episodic and affective memory distortions in dysphoria

People suffering from dysphoria retrieve autobiographical memories distorted in content and affect, which may contribute to the aetiology and maintenance of depression. However, key memory difficulties in dysphoria remain elusive because theories disagree how memories of different valence are altered. Here, we assessed the psychophysiological expression of affect and retrieved episodic detail while participants with dysphoria (but without a diagnosed mental illness) and participants without dysphoria relived positive, negative, and neutral memories. We show that participants with dysphoria retrieve positive memories with diminished episodic detail and negative memories with enhanced detail, compared to participants without dysphoria. This is in line with negativity bias but not overgeneral memory bias theories. According to confirmatory analyses, participants with dysphoria also express diminished positive affect and enhanced negative affect when retrieving happy memories, but exploratory analyses suggest that this increase in negative affect may not be robust. Further confirmatory analyses showed that affective responses to memories are not related to episodic detail and already present during the experience of new emotional events. Our results indicate that affective memory distortions may not emerge from mnemonic processes but from general distortions in positive affect, which challenges assumptions of memory theories and therapeutics. Protocol registration: The Stage 1 protocol for this Registered Report was accepted in principle on the 18rd of March 2021. The protocol, as accepted by the journal, can be found at https://doi.org/10.6084/m9.figshare.14605374.v1 .

Aberrant neural network activation during reliving of autobiographical memories in adolescent depression

BACKGROUND

Adolescents with depression exhibit negative biases in autobiographical memory with detrimental consequences for their self-concept and well-being. Investigating how adolescents relive positive autobiographical memories and activate the underlying neural networks could reveal mechanisms that drive such biases. This study investigated neural networks when reliving positive and neutral memories, and how neural activity is modulated by valence and vividness in adolescents with and without depression.

METHODS

Adolescents (N = 69; n = 17 with depression) retrieved positive and neutral autobiographical memories. On a separate day, they relived these memories during fMRI scanning, and reported on pleasantness and vividness after reliving each memory. We used a multivariate, data-driven approach - event-related independent component analysis (eICA) - to characterize neural networks supporting autobiographical recollection.

RESULTS

Adolescents with depression reported their positive memories as significantly less pleasant compared to healthy controls, while subjective vividness was unaffected. Using eICA, we identified a broad autobiographical memory network, and subnetworks related to reliving positive vs neutral memories. These subnetworks comprised a 'self-referential processing network' including medial prefrontal cortex, posterior cingulate cortex/precuneus, and temporoparietal junction, anti-correlating with parts of the central executive network and salience network. Adolescents with depression exhibited aberrant activation in this self-referential network, but only when reliving relatively 'low' pleasant memories.

CONCLUSIONS

Our findings provide first insights into how the quality of reliving autobiographical memories in adolescents with depression may relate to aberrant self-referential neural network activation, and underscore the potential of targeting memory reliving in therapeutic interventions to foster self-esteem and diminish depressive symptoms.

You are already dead: Case report of nihilistic delusions regarding others as one representation of Cotard's syndrome

Background

While the symptom of "I am already dead" is a hallmark of Cotard's syndrome, also known as nihilistic delusions, the symptom of "you are already dead" has been neglected.

Case presentation

A woman aged in her 60s diagnosed with schizophrenia was admitted to our hospital for psychotic symptoms, including delusions of reference, delusions of guilt, auditory hallucinations, cenesthetic hallucinations, agitation, depression, suicidal ideation, and catatonia. During hospitalization, her cenesthetic hallucinations progressed to include nihilistic delusions. She described cenesthetic hallucinations along with various delusional descriptions, including the belief that various objects, such as spoons, irons, nails, rulers, bins, and coins, were inside her body and that her body was being burned or in danger of exploding. She also claimed an altered sense of her own body, that her body was larger than normal or reversed. Moreover, she reported nihilistic delusions that her face and body did not exist, that her heart was not functioning, and that she was going to die soon or was already dead. She occasionally refused to eat because of the feeling of being dead. Notably, during a severe episode, she claimed that a doctor in front of her was dead. Clozapine was effective in improving her symptoms. Ultimately, the patient regained her sense of being alive and acknowledged that the doctor was alive.

Conclusion

We report the case of a patient presenting with nihilistic delusions regarding both self and others, along with prior cenesthetic hallucinations. Aberrant interoceptive processing could be a potential link between these two forms of nihilistic delusions.

Finding a positive me: Affective and neural insights into the challenges of positive autobiographical memory reliving in borderline personality disorder

BACKGROUND

This study aimed to investigate whether people with borderline personality disorder (BPD) can benefit from reliving positive autobiographical memories in terms of mood and state self-esteem and elucidate the neural processes supporting optimal memory reliving. Particularly the role of vividness and brain areas involved in autonoetic consciousness were studied, as key factors involved in improving mood and state self-esteem by positive memory reliving.

METHODS

Women with BPD (N = 25), Healthy Controls (HC, N = 33) and controls with Low Self-Esteem (LSE, N = 22) relived four neutral and four positive autobiographical memories in an MRI scanner. After reliving each memory mood and vividness was rated. State self-esteem was assessed before and after the Reliving Autobiographical Memories (RAM) task.

RESULTS

Overall, mood and state self-esteem were lower in participants with BPD compared to HC and LSE, but both the BPD and LSE group improved significantly after positive memory reliving. Moreover, participants with BPD indicated that they relived their memories with less vividness than HC but not LSE, regardless of valence. When reliving (vs reading) memories, participants with BPD showed increased precuneus and lingual gyrus activation compared to HC but not LSE, which was inversely related to vividness.

DISCUSSION

Women with BPD seem to experience more challenges in reliving neutral and positive autobiographical memories with lower vividness and less deactivated precuneus potentially indicating altered autonoetic consciousness. Nevertheless, participants with BPD do benefit in mood and self-esteem from reliving positive memories. These findings underline the potential of positive autobiographical memory reliving and suggest that interventions may be further shaped to improve mood and strengthen self-views in people with BPD.

Sad reflections of happy times: depression vulnerability and experiences of sadness and happiness upon retrieval of positive autobiographical memories

Instructed retrieval of positive autobiographical memories typically improves mood for healthy individuals, but not always for depressed individuals. No mood improvement may occur when depressed individuals retrieve positive memories that are self-incongruent, or when they ruminate upon positive memory retrieval. Mindfulness is associated with lower self-incongruency and rumination. The present study examined whether recurrent depression predicted emotional experience upon involuntary and voluntary retrieval of positive memories, and whether recurrent depression and trait mindfulness were associated with emotional experience upon positive memory retrieval through state rumination and self-incongruency. Recurrently and never-depressed individuals completed measures of depression, trait mindfulness, and a diary for reporting on everyday positive memories. Recurrently depressed individuals reported diminished happiness upon retrieving involuntary and voluntary positive memories compared to never-depressed individuals; and greater sadness upon involuntary positive memory retrieval, independent of current depression. Recurrent depression was associated with diminished happiness upon involuntary memory retrieval and greater sadness upon involuntary and voluntary positive memory retrieval, through state brooding, self-incongruency, or both. Higher trait mindfulness was associated with lower sadness upon involuntary and voluntary positive memory retrieval through state brooding and reflection. These findings highlight potential mechanisms in the relationship between depression vulnerability and emotional processing of positive autobiographical memories.

Exploring the role of interoception in autobiographical memory recollection

The way we perceive signals coming from the inside of the body (i.e., interoception) may influence the processing of information related to the self. In this study, we investigated whether interoceptive sensibility may play a role in autobiographical memory processes. We evaluated 41 healthy participants with a modified version of the Autobiographical Memory Test, also assessing specificity, vividness, emotional valence, and intensity for autobiographical and public memories. Participants completed a self-report questionnaire measuring interoceptive sensibility. Results showed that autobiographical memories were recalled with higher specificity, vividness, and emotional intensity than public memories. Interestingly, we found that participants with (self-reported) high interoceptive sensibility recalled more positive events in the autobiographical compared to the public condition. Our findings provided new evidence on the selective role of physiological aspects of bodily self-awareness in autobiographical memory, suggesting that interoception is fundamental for supporting adaptive emotion regulation processes when recollecting engrams related to the self.

Patterns of brain activity associated with nostalgia: a social-cognitive neuroscience perspective

Nostalgia arises from tender and yearnful reflection on meaningful life events or important persons from one's past. In the last two decades, the literature has documented a variety of ways in which nostalgia benefits psychological well-being. Only a handful of studies, however, have addressed the neural basis of the emotion. In this prospective review, we postulate a neural model of nostalgia. Self-reflection, autobiographical memory, regulatory capacity and reward are core components of the emotion. Thus, nostalgia involves brain activities implicated in self-reflection processing (medial prefrontal cortex, posterior cingulate cortex and precuneus), autobiographical memory processing (hippocampus, medial prefrontal cortex, posterior cingulate cortex and precuneus), emotion regulation processing (anterior cingulate cortex and medial prefrontal cortex) and reward processing (striatum, substantia nigra, ventral tegmental area and ventromedial prefrontal cortex). Nostalgia's potential to modulate activity in these core neural substrates has both theoretical and applied implications.

Insights from a Bibliometric Analysis of Vividness and Its Links with Consciousness and Mental Imagery

We performed a bibliometric analysis of the peer-reviewed literature on vividness between 1900 and 2019 indexed by the Web of Science and compared it with the same analysis of publications on consciousness and mental imagery. While we observed a similarity between the citation growth rates for publications about each of these three subjects, our analysis shows that these concepts rarely overlap (co-occur) in the literature, revealing a surprising paucity of research about these concepts taken together. A disciplinary analysis shows that the field of Psychology dominates the topic of vividness, even though the total number of publications containing that term is small and the concept occurs in several other disciplines such as Computer Science and Artificial Intelligence. The present findings suggest that without a coherent unitary framework for the use of vividness in research, important opportunities for advancing the field might be missed. In contrast, we suggest that an evidence-based framework (such as the bibliometric analytic methods as exemplified here) will help to guide research from all disciplines that are concerned with vividness and help to resolve the challenge of epistemic incommensurability amongst published research in multidisciplinary fields.

When I relive a positive me: Vivid autobiographical memories facilitate autonoetic brain activation and enhance mood

Autobiographical memory is vital for our well‐being and therefore used in therapeutic interventions. However, not much is known about the (neural) processes by which reliving memories can have beneficial effects. This study investigates what brain activation patterns and memory characteristics facilitate the effectiveness of reliving positive autobiographical memories for mood and sense of self. Particularly, the role of vividness and autonoetic consciousness is studied. Participants (N = 47) with a wide range of trait self‐esteem relived neutral and positive memories while their bold responses, experienced vividness of the memory, mood, and state self‐esteem were recorded. More vivid memories related to better mood and activation in amygdala, hippocampus and insula, indicative of increased awareness of oneself (i.e., prereflective aspect of autonoetic consciousness). Lower vividness was associated with increased activation in the occipital lobe, PCC, and precuneus, indicative of a more distant mode of reliving. While individuals with lower trait self‐esteem increased in state self‐esteem, they showed less deactivation of the lateral occipital cortex during positive memories. In sum, the vividness of the memory seemingly distinguished a more immersed and more distant manner of memory reliving. In particular, when reliving positive memories higher vividness facilitated increased prereflective autonoetic consciousness, which likely is instrumental in boosting mood.