Obliviate! Reviewing Neural Fundamentals of Intentional Forgetting from a Meta-Analytic Perspective

Emotional influences on remembering and forgetting explained by frontal and parietal dynamics

Based on item-method directed forgetting (DF) task, 60 participants were recruited to explore the influence of emotion (negative, neutral, and positive) on memory encoding processing, with all data referring to the encoding phase of the task. Behavioral results showed that participants were more successful at remembering negative pictures that needed to be forgotten, with both higher recognition rates and discrimination accuracy (Pr) compared with neutral pictures. In the brain, parietal activities reflected preferential processing during negative picture viewing through enhanced late parietal positive potentials (LPP) relative to neutral ones. In addition, "Remember" (R) instruction evoked a larger parietal P3 component, whereas "Forget" (F) instruction evoked a stronger frontal N2 component, each of which component was significantly associated with the DF effect (i.e., more recognized items of R-cue than that of F-cue), reflecting the fact that inhibitory control and selective rehearsal mechanisms were jointly responsible for the directed forgetting of emotional materials. Finally, we showed the presence of instruction-evoked low-frequency phase synchronization between frontal and parietal regions, and that these synchronization patterns differed between R-cue and F-cue in an emotion-dependent manner. Together, these findings reveal cognitive mechanisms and specific patterns of large-scale phase synchronization underlying active forgetting of emotional memories, deepening our comprehension of the interplay between cognition and emotion.NEW & NOTEWORTHY This study provides experimental evidence that emotional memories, especially negative ones, are more difficult to intentionally forget than neutral memories within the item-method directed forgetting paradigm. It explores the cognitive mechanisms underlying this process, highlighting the role of selective rehearsal and inhibitory control. In addition, it reveals emotion-dependent low-frequency phase synchronization between frontal and parietal regions, offering new insights into active forgetting of emotional memories.

A Decade of Dedication: Pioneering Perspectives on Neurological Diseases and Mental Illnesses

Welcome to Biomedicines' 10th Anniversary Special Issue, a journey through the human mind's labyrinth and complex neurological pathways [...].

Mitochondrial Impairment: A Common Motif in Neuropsychiatric Presentation? The Link to the Tryptophan-Kynurenine Metabolic System

Nearly half a century has passed since the discovery of cytoplasmic inheritance of human chloramphenicol resistance. The inheritance was then revealed to take place maternally by mitochondrial DNA (mtDNA). Later, a number of mutations in mtDNA were identified as a cause of severe inheritable metabolic diseases with neurological manifestation, and the impairment of mitochondrial functions has been probed in the pathogenesis of a wide range of illnesses including neurodegenerative diseases. Recently, a growing number of preclinical studies have revealed that animal behaviors are influenced by the impairment of mitochondrial functions and possibly by the loss of mitochondrial stress resilience. Indeed, as high as 54% of patients with one of the most common primary mitochondrial diseases, mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome, present psychiatric symptoms including cognitive impairment, mood disorder, anxiety, and psychosis. Mitochondria are multifunctional organelles which produce cellular energy and play a major role in other cellular functions including homeostasis, cellular signaling, and gene expression, among others. Mitochondrial functions are observed to be compromised and to become less resilient under continuous stress. Meanwhile, stress and inflammation have been linked to the activation of the tryptophan (Trp)-kynurenine (KYN) metabolic system, which observably contributes to the development of pathological conditions including neurological and psychiatric disorders. This review discusses the functions of mitochondria and the Trp-KYN system, the interaction of the Trp-KYN system with mitochondria, and the current understanding of the involvement of mitochondria and the Trp-KYN system in preclinical and clinical studies of major neurological and psychiatric diseases.