Publications by authors named "LIGHT G"

Amygdala activation by emotional arousal during memory formation can prioritize events for long-term memory. Building upon our prior demonstration that brief electrical stimulation to the human amygdala reliably improved long-term recognition memory for images of neutral objects without eliciting an emotional response, our study aims to explore and describe individual differences and stimulation-related factors in amygdala-mediated memory modulation. Thirty-one patients undergoing intracranial monitoring for intractable epilepsy were shown neutral object images paired with direct amygdala stimulation during encoding with recognition memory tested immediately and one day later.

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  • Neurophysiological studies on psychosis often overlook how individual ERP scores vary over time, which might lead to missing important insights about the condition.
  • This study analyzed ERP data from 162 patients with psychosis and 178 non-psychotic individuals to assess differences in variability of specific ERPs.
  • Results indicated no significant differences in variability across most ERPs between the groups, but patients with schizophrenia showed greater MMN variability, particularly related to certain symptoms.
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Mismatch negativity (MMN) event-related potential (ERP) component reduction, indexing N-methyl-D-aspartate receptor (NMDAR)-dependent auditory echoic memory and short-term plasticity, is a well-established biomarker of schizophrenia that is sensitive to psychosis risk among individuals at clinical high-risk (CHR-P). Based on the NMDAR-hypofunction model of schizophrenia, NMDAR-dependent plasticity is predicted to contribute to aberrant neurodevelopmental processes involved in the pathogenesis of schizophrenia during late adolescence or young adulthood, including gray matter loss. Moreover, stress and inflammation disrupt plasticity.

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Background: Despite findings from translational and genetic studies in the event-related potential (ERP) literature, the validity and reliability of P50 suppression as a schizophrenia spectrum endophenotype has been questioned. Here, we aimed to examine sensory registration and gating measures derived from P50 and N100 amplitude, as well as N100 area-a novel approach proposed herein-in early psychosis versus health.

Methods: Individuals at clinical high risk for psychosis (CHR; n = 77), first-episode psychosis (FE; n = 52), and healthy controls (HC; n = 65) were assessed in a paired-click auditory ERP paradigm.

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Anhedonia, a transdiagnostic symptom present in many neuropsychiatric disorders, differs in males and females. Parietal EEG alpha asymmetry is associated with reduced arousal and low positive emotionality, and is, therefore, a promising neurophysiologic biomarker of anhedonia. To date, however, no prior studies have determined whether this measure captures sex differences in anhedonic expression.

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Background: Patient participation in treatment decision making is a pillar of recovery-oriented care and is associated with improvements in empowerment and well-being. Although demand for increased involvement in treatment decision-making is high among veterans with serious mental illness, rates of involvement are low. Collaborative decision skills training (CDST) is a recovery-oriented, skills-based intervention designed to support meaningful patient participation in treatment decision making.

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Background: Auditory system plasticity is a promising target for neuromodulation, cognitive rehabilitation and therapeutic development in schizophrenia (SZ). Auditory-based targeted cognitive training (TCT) is a 'bottom up' intervention designed to enhance the speed and accuracy of auditory information processing, which has been shown to improve neurocognition in certain SZ patients. However, the dynamics of TCT learning as a function of training exercises and their impact on neurocognitive functioning and therapeutic outcomes are unknown.

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This article describes the rationale, aims, and methodology of the Accelerating Medicines Partnership® Schizophrenia (AMP® SCZ). This is the largest international collaboration to date that will develop algorithms to predict trajectories and outcomes of individuals at clinical high risk (CHR) for psychosis and to advance the development and use of novel pharmacological interventions for CHR individuals. We present a description of the participating research networks and the data processing analysis and coordination center, their processes for data harmonization across 43 sites from 13 participating countries (recruitment across North America, Australia, Europe, Asia, and South America), data flow and quality assessment processes, data analyses, and the transfer of data to the National Institute of Mental Health (NIMH) Data Archive (NDA) for use by the research community.

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Background: Research using latent variable models demonstrates that pre-attentive measures of early auditory processing (EAP) and cognition may initiate a cascading effect on daily functioning in schizophrenia. However, such models fail to account for relationships among individual measures of cognition and EAP, thereby limiting their utility. Hence, EAP and cognition may function as complementary and interacting measures of brain function rather than independent stages of information processing.

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Article Synopsis
  • Scientists used tests that involve tasks to see how drugs work in mice and humans.
  • They found that when people took amphetamine, it made them want to work harder, while its effects on mice were a bit different.
  • They also discovered that a specific brain signal, called alpha power, increased when both mice and humans did the tasks, but amphetamine didn’t change this brain signal.
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Recent literature has shown, theoretically as well as experimentally, that while a beam splitter does not split a single photon, it nonetheless divides the electromagnetic wave into transmitted and reflected, with both containing energies. This implies the existence of a spacetime of pure electromagnetic waves of energies but without particles; also, it prompts the question on how much energy a photon loses after coming out of a beam splitter, which impacts on interferometry and hence quantum communication. This paper shows that, by Gauss divergence theorem, the gravitational force inside an electromagnetic wave ball results in a point energy that is three times as the wave energy; thus, a 50/50 beam splitter is to cause a photon to lose half of a quarter, or 1/8, of its initial wave energy.

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Background: Click trains elicit an auditory steady-state response (ASSR) at the driving frequency (1F) and its integer multiple frequencies (2F, 3F, etc.) called harmonics; we call this harmonic response the steady-state harmonic response (SSHR). We describe the 40 Hz ASSR (1F) and 80 Hz SSHR (2F) in humans and rats and their sensitivity to the uncompetitive NMDA antagonist memantine.

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Sensory networks naturally entrain to rhythmic stimuli like a click train delivered at a particular frequency. Such synchronization is integral to information processing, can be measured by electroencephalography (EEG) and is an accessible index of neural network function. Click trains evoke neural entrainment not only at the driving frequency (F), referred to as the auditory steady state response (ASSR), but also at its higher multiples called the steady state harmonic response (SSHR).

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Auditory-based targeted cognitive training (ATCT) programs are emerging pro-cognitive therapeutic interventions which aim to improve auditory processing to attenuate cognitive impairment in a "bottom up" manner. Biomarkers of early auditory information processing (EAIP) like mismatch negativity (MMN) and P3a have been used successfully to predict gains from a full 40 h course of ATCT in schizophrenia (SZ). Here we investigated the ability of EAIP biomarkers to predict ATCT performance in a group of subjects (n = 26) across SZ, MDD, PTSD and GAD diagnoses.

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Background: Adaptation of interventions is inevitable during translation to new populations or settings. Systematic approach to adaptation can ensure that fidelity to core functions of the intervention are preserved while optimizing implementation feasibility and effectiveness for the local context. In this study, we used an iterative, mixed methods, and stakeholder-engaged process to systematically adapt Collaborative Decision Skills Training for Veterans with psychosis currently participating in VA Psychosocial Rehabilitation and Recovery Centers.

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Background: The uncompetitive NMDA antagonist, memantine (MEM), enhances prepulse inhibition of startle (PPI) across species. MEM is used to treat Alzheimer's disease (AD); conceivably, its acute impact on PPI might be used to predict a patient's sensitivity to MEM's therapeutic effects.

Objective: To begin to test this possibility, we studied MEM effects on PPI and related measures in AD patients.

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Background: The auditory N100 is an event related potential (ERP) that is reduced in schizophrenia, but its status in individuals at clinical high risk for psychosis (CHR) and its ability to predict conversion to psychosis remains unclear. We examined whether N100 amplitudes are reduced in CHR subjects relative to healthy controls (HC), and this reduction predicts conversion to psychosis in CHR.

Methods: Subjects included CHR individuals (n = 552) and demographically similar HC subjects (n = 236) from the North American Prodrome Longitudinal Study.

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Importance: Improved understanding of the boundaries and connections between positive symptoms, negative symptoms, and role functioning in schizophrenia is critical, given limited empirical support for clear distinctions among these clinical areas. This study's use of network psychometrics to investigate differential associations and structural overlap between positive symptoms, negative symptoms, and functional domains in schizophrenia may contribute to such understanding.

Objective: To apply network analysis and community detection methods to examine the interplay and structure of positive symptoms, negative symptoms, and functional domains in individuals with schizophrenia.

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Measuring polarisation, spectrum, temporal dynamics, and spatial complex amplitude of optical beams is essential to studying phenomena in laser dynamics, telecommunications and nonlinear optics. Current characterisation techniques apply in limited contexts. Non-interferometric methods struggle to distinguish spatial phase, while phase-sensitive approaches necessitate either an auxiliary reference source or a self-reference, neither of which is universally available.

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Importance: Although clinical criteria for identifying youth at risk for psychosis have been validated, they are not sufficiently accurate for predicting outcomes to inform major treatment decisions. The identification of biomarkers may improve outcome prediction among individuals at clinical high risk for psychosis (CHR-P).

Objective: To examine whether mismatch negativity (MMN) event-related potential amplitude, which is deficient in schizophrenia, is reduced in young people with the CHR-P syndrome and associated with outcomes, accounting for effects of antipsychotic medication use.

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Article Synopsis
  • * Researchers discovered 287 genomic regions associated with schizophrenia, emphasizing genes specifically active in excitatory and inhibitory neurons, and identified 120 key genes potentially responsible for these associations.
  • * The findings highlight important biological processes related to neuronal function, suggesting overlaps between common and rare genetic variants in both schizophrenia and neurodevelopmental disorders, ultimately aiding future research on these conditions.
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