The Effect of Retrieval Focus and Emotional Valence on the Inferior Frontal Cortex Activity during Autobiographical Recollection

Brain connectivity changes associated with episodic recollection decline in aging: A review of fMRI studies

With advancing age, individuals experience a gradual decline in recollection, the ability to retrieve personal experiences accompanied by details, such as temporal and spatial contextual information. Numerous studies have identified several brain regions that exhibit age-related activation differences during recollection tasks. More recently, an increasing number of studies have provided evidence regarding how brain connectivity among the regions supporting recollection contributes to the explanation of recollection deficits in aging. However, brain connectivity evidence has not been examined jointly to provide an integrative view of how these new findings have improved our knowledge of the neurofunctional changes underlying the recollection deficits associated with aging. Therefore, the aim of the present study was to examine functional magnetic resonance imaging (fMRI) studies that employed one of the numerous methods available for analyzing brain connectivity in older adults. Only studies that applied connectivity analysis to data recorded during episodic recollection tasks, either during encoding or retrieval, were assessed. First, the different brain connectivity analysis methods and the information conveyed were briefly described. Then, the brain connectivity findings from the different studies were described and discussed to provide an integrative point of view of how these findings explain the decline in recollection associated with aging. The studies reviewed provide evidence that the hippocampus consistently decreased its connectivity with the parahippocampal gyrus and the posterior cingulate cortex, essential regions of the recollection network, in older adults relative to young adults. In addition, older adults exhibited increased connectivity between the hippocampus and several widespread regions compared to young adults. The increased connectivity was interpreted as brain intensification recourse to overcome recollection decay. Additionally, suggestions for future research in the field are outlined.

How shifting visual perspective during autobiographical memory retrieval influences emotion: A change in retrieval orientation

Visual perspective during autobiographical memory (AM) retrieval influences how people remember the emotional aspects of memories. Prior research in emotion regulation has also shown that shifting from an own eyes to an observer-like perspective is an efficient way of regulating the affect elicited by emotional AMs. However, the impact of shifting visual perspective is also dependent on the nature of the emotion associated with the event. The current review synthesizes behavioral and functional neuroimaging findings from the event memory and emotion regulation literature that examine how adopting particular visual perspectives and actively shifting across them during retrieval alters emotional experience, by primarily focusing on emotional intensity. We review current theories explaining why shifts in perspectives may or may not change the emotional characteristics of memories, then propose a new theory, suggesting that the own eyes and observer-like perspectives are two different retrieval orientations supported by differential neural activations that lead episodic details to be reconstructed in specific ways.

Differences in topological properties of functional brain networks between menstrually-related and non-menstrual migraine without aura

Menstrually-related migraine without aura refers to a specific type of migraine that is associated with the female ovarian cycle. Compared with non-menstrual migraine without aura, in menstrually-related migraine without aura, there are additional attacks of migraine outside of the menstrual period. Menstrually-related migraine without aura tends to be less responsive to acute treatment and more prone to relapse than non-menstrual migraine without aura. Currently menstrually-related migraine without aura is treated no differently from any other migraine but, the differences in the central mechanisms underlying menstrually-related migraine without aura and non-menstrual migraine without aura remain poorly understood. Here, using resting-state functional magnetic resonance imaging and graph theory approaches, we aimed to explore the differences in topological properties of functional networks in 51 menstrually-related migraine without aura patients and 47 non-menstrual migraine without aura patients. The major finding of our study was that significant differences in topological properties between the two groups were mainly evident in the nodal centrality of the inferior frontal gyrus and the thalamus. Nodal centrality in inferior frontal gyrus was negatively correlated with Headache Impact Test questionnaire scores in the menstrually-related migraine without aura patients. Partial least squares correlation analysis revealed enhanced correlations of inferior frontal gyrus to pain-related behavior in the non-menstrual migraine without aura group, while within the menstrually-related migraine without aura group these effects were non-significant. These results indicate that the regulatory mechanisms in the central nervous system may differ between the two subtypes of migraine. The results provide novel insights into the pathophysiology of different subtypes of migraine, and could help us to enhance their clinical diagnosis and treatment.

Cultivating Affective Resilience: Proof-of-Principle Evidence of Translational Benefits From a Novel Cognitive-Emotional Training Intervention

Available evidence highlights the importance of emotion regulation (ER) in psychological well-being. However, translation of the beneficial effects of ER from laboratory to real-life remains scarce. Here, we present proof-of-principle evidence from a novel cognitive-emotional training intervention targeting the development of ER skills aimed at increasing resilience against emotional distress. This pilot intervention involved training military veterans over 5-8 weeks in applying two effective ER strategies [Focused Attention (FA) and Cognitive Reappraisal (CR)] to scenarios presenting emotional conflicts (constructed with both external and internal cues). Training was preceded and followed by neuropsychological, personality, and clinical assessments, and resting-state functional MRI data were also collected from a subsample of the participants. Results show enhanced executive function and psychological well-being following training, reflected in increased working memory (WM), post-traumatic growth (PTG), and general self-efficacy (GSE). Brain imaging results showed evidence of diminished bottom-up influences from emotional and perceptual brain regions, along with evidence of normalized functional connectivity in the large-scale functional networks following training. The latter was reflected in increased connectivity among cognitive and emotion control regions and across regions of self-referential and control networks. Overall, our results provide proof-of-concept evidence that resilience and well-being can be learned through ER training, and that training-related improvements manifested in both behavioral change and neuroplasticity can translate into real-life benefits.

The Impact of Focused Attention on Emotional Experience: A Functional MRI Investigation

Emotional well-being depends on the ability to adaptively cope with various emotional challenges. Most studies have investigated the neural mechanisms of emotion regulation strategies deployed relatively later in the timing of processing that leads to full emotional experiences. However, less is known about strategies that are engaged in earlier stages of emotion processing, such as those involving attentional deployment. We investigated the neural mechanisms associated with self-guided Focused Attention (FA) in mitigating subjective negative emotional experiences. Functional magnetic resonance imaging (fMRI) data were recorded while participants viewed a series of composite negative and neutral images with distinguishable foreground (FG) and background (BG) areas. Participants were instructed to focus either on the FG or BG components of the images, and then rated their emotional experiences. Behavioral results showed that FA was successful in decreasing emotional ratings for negative images viewed in BG Focus condition. At the neural level, the BG Focus was associated with increased activity in regions typically implicated in top-down executive control (dorsolateral prefrontal cortex and lateral parietal cortex) and decreased activity in regions linked to affective processing (amygdala and ventrolateral prefrontal cortex). Dissociable brain activity linked to FA also was identified in visual cortices, including between the parahippocampal and fusiform gyri, showing increased versus decreased activity, respectively, during the BG Focus. These findings complement the evidence from prior FA studies with recollected emotional memories as internal stimuli and further demonstrate the effectiveness of self-guided FA in mitigating negative emotional experiences associated with processing of external unpleasant stimuli.

Emerging Directions in Emotional Episodic Memory

Building upon the existing literature on emotional memory, the present review examines emerging evidence from brain imaging investigations regarding four research directions: (1) Social Emotional Memory, (2) The Role of Emotion Regulation in the Impact of Emotion on Memory, (3) The Impact of Emotion on Associative or Relational Memory, and (4) The Role of Individual Differences in Emotional Memory. Across these four domains, available evidence demonstrates that emotion- and memory-related medial temporal lobe brain regions (amygdala and hippocampus, respectively), together with prefrontal cortical regions, play a pivotal role during both encoding and retrieval of emotional episodic memories. This evidence sheds light on the neural mechanisms of emotional memories in healthy functioning, and has important implications for understanding clinical conditions that are associated with negative affective biases in encoding and retrieving emotional memories.

FMRI contributions to addressing autobiographical memory impairment in temporal lobe pathology

Episodic autobiographical memory (AM) allows one, through the recollection of sensory-perceptual details, thoughts and feelings, to become aware of an event as belonging to one’s own past as well as being able to project into one’s future. Because AM provides a sense of self-continuity, contributes to the integrity of the self, and helps predicting future experiences, any deficit of AM may have debilitating consequences for everyday life functioning. Understanding AM failure and the underlying neural mechanisms has the potential to shed light on brain reorganization mechanisms and engagement of compensatory processes. Functional magnetic resonance imaging (fMRI) provides the most promising imaging method to tackle these issues. We reviewed evidence from the few studies that used fMRI to investigate the functionality of the residual tissue, the neural reorganization and compensatory mechanisms in patients with neurological conditions due to impaired medial temporal lobe. Overall, these studies highlight the importance of the left hippocampus, which when atrophied and not functional leads to AM deficits but its residual functionality may support relatively normal AM recollection. When damaged hippocampal tissue is not functional, other brain regions (e.g., the medial prefrontal cortex) may be involved to compensate impairment, but they appear generally ineffective to support detailed episodic recollection.

Neural correlates of 'distracting' from emotion during autobiographical recollection

Remembering emotional autobiographical memories (AMs) is important for emotional well-being, and investigation of the role of emotion regulation (ER) during AM recollection has relevance for understanding mental health issues. Although significant progress has been made in understanding the brain mechanisms underlying ER and AM, less is known about the role of ER during AM recollection. The present study investigated how focusing away (or 'distracting') from the emotional content during AM recollection influences the subjective re-experiencing of emotions and the associated neural correlates, by manipulating the retrieval focus of participants who remembered emotional AMs while fMRI data were recorded. First, focusing away from emotion led to decreased self-reported emotional responses, along with increased engagement of ER-related regions (ventro-medial prefrontal cortex, vmPFC), and reduced activity in emotion-related regions (amygdala, AMY). Second, increased vmPFC activity was linked to reduced emotional ratings, during the non-emotional focus. Third, mediation analysis identified vmPFC as a functional hub integrating affective signals from AMY and mediating their impact on the subjective re-experiencing of emotion, according to the current retrieval focus. Collectively, these findings shed light on the neural mechanisms underlying the ability to effectively switch attentional focus away from emotions during AM recollections and have direct relevance for understanding, preventing and treating affective disorders, characterised by reduced ability to regulate emotions.