From the Laboratory to the Real-World: The Role of Mismatch Negativity in Psychosis.

Mismatch negativity (MMN) has gained attention as a biomarker for psychosis and a translational intermediate phenotype in animal models of psychosis, including rodents and non-human primates. MMN has been linked to global functioning (Global Assessment of Functioning [GAF] score) and prognosis (psychosis onset or remission), suggesting that MMN reflects activities beyond auditory processing alone. This review examines the 45-year history of MMN from the perspective of psychiatric researchers and discusses current advances in computational and translational research on MMN, summarizing the current understanding of the MMN generation mechanism.

Frontal pole-precuneus connectivity is associated with a discrepancy between self-rated and observer-rated depression severity in mood disorders: a resting-state functional magnetic resonance imaging study.

Discrepancies in self-rated and observer-rated depression severity may underlie the basis for biological heterogeneity in depressive disorders and be an important predictor of outcomes and indicators to optimize intervention strategies. However, the neural mechanisms underlying this discrepancy have been understudied. This study aimed to examine the brain networks that represent the neural basis of the discrepancy between self-rated and observer-rated depression severity using resting-state functional MRI.

Longitudinal trajectories of anterior cingulate glutamate and subclinical psychotic experiences in early adolescence: the impact of bullying victimization.

Previous studies reported decreased glutamate levels in the anterior cingulate cortex (ACC) in non-treatment-resistant schizophrenia and first-episode psychosis. However, ACC glutamatergic changes in subjects at high-risk for psychosis, and the effects of commonly experienced environmental emotional/social stressors on glutamatergic function in adolescents remain unclear. In this study, adolescents recruited from the general population underwent proton magnetic resonance spectroscopy (MRS) of the pregenual ACC using a 3-Tesla scanner.

Longitudinal change in mismatch negativity (MMN) but not in gamma-band auditory steady-state response (ASSR) is associated with psychological difficulties in adolescence.

Adolescence is a critical period for psychological difficulties. Auditory mismatch negativity (MMN) and gamma-band auditory steady-state response (ASSR) are representative electrophysiological indices that mature during adolescence. However, the longitudinal association between MMN/ASSR and psychological difficulties among adolescents remains unclear.

Cerebral cortical structural alteration patterns across four major psychiatric disorders in 5549 individuals.

According to the operational diagnostic criteria, psychiatric disorders such as schizophrenia (SZ), bipolar disorder (BD), major depressive disorder (MDD), and autism spectrum disorder (ASD) are classified based on symptoms. While its cluster of symptoms defines each of these psychiatric disorders, there is also an overlap in symptoms between the disorders. We hypothesized that there are also similarities and differences in cortical structural neuroimaging features among these psychiatric disorders.

Subcortical volumetric alterations in four major psychiatric disorders: a mega-analysis study of 5604 subjects and a volumetric data-driven approach for classification.

Differential diagnosis is sometimes difficult in practical psychiatric settings, in terms of using the current diagnostic system based on presenting symptoms and signs. The creation of a novel diagnostic system using objective biomarkers is expected to take place. Neuroimaging studies and others reported that subcortical brain structures are the hubs for various psycho-behavioral functions, while there are so far no neuroimaging data-driven clinical criteria overcoming limitations of the current diagnostic system, which would reflect cognitive/social functioning.

Alterations of auditory-evoked gamma oscillations are more pronounced than alterations of spontaneous power of gamma oscillation in early stages of schizophrenia.

Several animal models of schizophrenia and patients with chronic schizophrenia have shown increased spontaneous power of gamma oscillations. However, the most robust alterations of gamma oscillations in patients with schizophrenia are reduced auditory-oscillatory responses. We hypothesized that patients with early-stage schizophrenia would have increased spontaneous power of gamma oscillations and reduced auditory-oscillatory responses.

Criticality in the Healthy Brain.

The excellence of the brain is its robustness under various types of noise and its flexibility under various environments. However, how the brain works is still a mystery. The critical brain hypothesis proposes a possible mechanism and states that criticality plays an important role in the healthy brain.

High-power gamma-related delta phase alteration in schizophrenia patients at rest.

Aim: Information processing is supported by the cortico-cortical transmission of neural oscillations across brain regions. Recent studies have demonstrated that the rhythmic firing of neural populations is not random but is governed by interactions with other frequency bands. Specifically, the amplitude of gamma-band oscillations is associated with the phase of lower frequency oscillations in support of short and long-range communications among networks.

Association Study Between White Matter Microstructure and Intelligence Decline in Schizophrenia.

Patients with schizophrenia can exhibit intelligence decline, which is an important element of cognitive impairment. Previous magnetic resonance imaging (MRI) studies have demonstrated that patients with schizophrenia have altered gray matter structures and functional connectivity associated with intelligence decline defined by a difference between premorbid and current intelligence quotients (IQs). However, it has remained unclear whether white matter microstructures are related to intelligence decline.

Birth order and prosociality in the early adolescent brain.

Birth order is a crucial environmental factor for child development. For example, later-born children are relatively unlikely to feel secure due to sibling competition or diluted parental resources. The positive effect of being earlier-born on cognitive intelligence is well-established.

Trends in big data analyses by multicenter collaborative translational research in psychiatry.

The underlying pathologies of psychiatric disorders, which cause substantial personal and social losses, remain unknown, and their elucidation is an urgent issue. To clarify the core pathological mechanisms underlying psychiatric disorders, in addition to laboratory-based research that incorporates the latest findings, it is necessary to conduct large-sample-size research and verify reproducibility. For this purpose, it is critical to conduct multicenter collaborative research across various fields, such as psychiatry, neuroscience, molecular biology, genomics, neuroimaging, cognitive science, neurophysiology, psychology, and pharmacology.

Intergenerational transmission of the patterns of functional and structural brain networks.

There is clear evidence of intergenerational transmission of life values, cognitive traits, psychiatric disorders, and even aspects of daily decision making. To investigate biological substrates of this phenomenon, the brain has received increasing attention as a measurable biomarker and potential target for intervention. However, no previous study has quantitatively and comprehensively investigated the effects of intergenerational transmission on functional and structural brain networks.

Abnormal phase discontinuity of alpha- and theta-frequency oscillations in schizophrenia.

Background: Schizophrenia patients have abnormal electroencephalographic (EEG) power over multiple frequency bands, even at rest, though the primary neural generators and spatiotemporal dynamics of these abnormalities are largely unknown. Disturbances in the precise synchronization of oscillations within and across cortical sources may underlie abnormal resting-state EEG activity in schizophrenia patients.

Methods: A novel assessment method was applied to identify the independent contributing sources of resting-state EEG and assess the phase discontinuity in schizophrenia patients (N = 148) and healthy subjects (N = 143).

Unique contributions of sensory discrimination and gamma synchronization deficits to cognitive, clinical, and psychosocial functional impairments in schizophrenia.

Background: Schizophrenia patients show widespread deficits in neurocognitive, clinical, and psychosocial functioning. Mismatch negativity (MMN) and gamma-band auditory steady-state response (ASSR) are robust translational biomarkers associated with schizophrenia and associated with cognitive dysfunction, negative symptom severity, and psychosocial disability. Although these biomarkers are conceptually linked as measures of early auditory information processing, it is unclear whether MMN and gamma-band ASSR account for shared vs.

Sources of the frontocentral mismatch negativity and P3a responses in schizophrenia patients and healthy comparison subjects.

Background: Mismatch negativity (MMN) and P3a are event-related potential measures of early auditory information processing that are increasingly used as translational biomarkers in the development of treatments for neuropsychiatric disorders. These responses are reduced in schizophrenia patients over the frontocentral scalp electrodes and are associated with important domains of cognitive and psychosocial functioning. While MMN and P3a responses are generated by a dynamic network of cortical sources distributed across the temporal and frontal brain regions, it is not clear how these sources independently contribute to MMN and P3a at the primary frontocentral scalp electrode or to abnormalities observed in schizophrenia.

Neural network dynamics underlying gamma synchronization deficits in schizophrenia.

Gamma-band (40-Hz) activity is critical for cortico-cortical transmission and the integration of information across neural networks during sensory and cognitive processing. Patients with schizophrenia show selective reductions in the capacity to support synchronized gamma-band oscillations in response to auditory stimulation presented 40-Hz. Despite widespread application of this 40-Hz auditory steady-state response (ASSR) as a translational electroencephalographic biomarker for therapeutic development for neuropsychiatric disorders, the spatiotemporal dynamics underlying the ASSR have not been fully characterized.