Publications by authors named "Casey S Gilmore"

Background: Brain-based interventions are needed to address persistent relapse in alcohol use disorder (AUD). Neuroimaging evidence suggests higher frontal connectivity as well as higher within-network connectivity of theoretically defined addiction networks are associated with reduced relapse rates and extended abstinence during follow-up periods.

Objective: /Hypothesis: A longitudinal randomized double-blind sham-controlled clinical trial investigated whether a non-invasive neuromodulation intervention delivered during early abstinence can (i) modulate connectivity of addiction networks supporting abstinence and (ii) improve relapse rates.

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There is a public health need to understand mental health vulnerabilities to COVID-19 pandemic-related stressors and promote resilience among high-risk populations with preexisting psychiatric conditions. Recent cross-sectional studies suggest increases in mental health distress (e.g.

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Background: In mild traumatic brain injury (mTBI), diffuse axonal injury results in disruption of functional networks in the brain and is thought to be a major contributor to cognitive dysfunction even years after trauma.

Objective: Few studies have assessed longitudinal changes in network topology in chronic mTBI. We utilized a graph theoretical approach to investigate alterations in global network topology based on resting-state functional connectivity in veterans with chronic mTBI.

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Article Synopsis
  • Mild traumatic brain injury (TBI) may increase the risk of progressive neurodegeneration, so this study aimed to assess changes in retinal layer thickness in veterans with a history of mild TBI.
  • The research included 139 veterans, comparing 69 with mild TBI to 70 controls with no TBI history, and excluded those with any retinal or optic nerve diseases.
  • Results showed that veterans with mild TBI experienced significantly greater thinning of the retinal nerve fiber layer and declines in visual function compared to the control group.
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Background: Impulsivity is a multidimensional personality trait observed across a variety of psychiatric disorders. Transcranial direct current stimulation (tDCS) applied over dorsolateral prefrontal cortex (DLPFC) has shown promise as an intervention to reduce impulsivity.

Objective: To investigate the effects of tDCS paired with a decision-making task on risk-taking in Veterans with a clinical history of impulsive behavior.

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Approximately 275,000 American service members deployed to Iraq or Afghanistan have sustained a mild traumatic brain injury (mTBI), with 75% of these incidents involving an explosive blast. Combat-related mTBI is frequently associated with comorbid mental health disorders, especially posttraumatic stress disorder (PTSD). Attention problems, including sustained attention, are common cognitive complaints of veterans with TBI and PTSD.

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Article Synopsis
  • Around 275,000 American service members have experienced mild traumatic brain injuries (mTBI) after blasts in Iraq and Afghanistan, leading to common issues like visual processing problems and cognitive dysfunction.
  • A study of 127 veterans utilized resting fMRI to assess functional connectivity in key visual brain regions and correlated this with the severity of blast-related mTBI and executive functioning performance.
  • Results indicated that higher mTBI severity scores were linked to decreased functional connectivity in various brain regions, ultimately predicting poorer performance on tasks measuring executive function, emphasizing the impact of blast-related injuries on visual and cognitive integration.
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Analyzing the induced (non-stimulus-phase-locked) EEG activity elicited by targets in a three-condition visual oddball task, Fein and colleagues have shown increased theta band event-related synchronization (ERS) in two different samples of long-term abstinent alcoholics (LTAA) compared with age- and gender-comparable controls. The theta ERS effect in alcoholics was also shown to be independent of, and opposite in direction to, the reduced amplitude evoked (stimulus-phase-locked) activity typically found in alcoholics and those at genetic risk of developing alcoholism. This study extends these findings by applying time-frequency analysis to target stimulus event-related EEG to compare evoked and induced theta activity in 43 LTAA and 72 nonalcoholic controls with a group of 31 alcoholics who just recently initiated abstinence from alcohol (between 6- and 15-week abstinent; referred to as short-term abstinent alcoholics, STAA).

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Individuals with schizophrenia (SZ) have deviations in auditory perception perhaps attributable to altered neural oscillatory response properties in thalamo-cortical and/or local cortico-cortical circuits. Previous EEG studies of auditory steady-state responses (aSSRs; a measure of sustained neuronal entrainment to repetitive stimulation) in SZ have indicated attenuated gamma range (≈40 Hz) neural entrainment. Stimuli in most such studies have been relatively brief (500-1000 ms) trains of 1 ms clicks or amplitude modulated pure tones (1000 Hz) with short, fixed interstimulus intervals (200-1000 ms).

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P3 amplitude reduction (P3-AR) is associated with biological vulnerability to a spectrum of externalizing (EXT) disorders, such as conduct disorder, antisocial behavior, and substance use disorders. P3 amplitude, however, can be affected by the context within which it is measured, for example, by the position of the target in the sequence of stimuli during an oddball task. We hypothesized that EXT-related P3-AR may be due to attention or working memory deficits in EXT that would weaken these stimulus sequence effects.

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Background: Electroencephalography and magnetoencephalography studies indicate among schizophrenia patients (SZ) abnormal, often reduced, entrained steady-state (aSSR) and transient (N100/M100) neural responses to auditory stimuli. We complement this literature by focusing analyses on auditory cortices, assessing a wide range of stimulation frequencies with long driving periods and evaluating relationships between aSSR and M100 reductions in SZ.

Methods: Seventeen SZ and 17 healthy subjects (H) participated.

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Abnormalities in electrophysiological measures of stimulus-evoked brain activity (including the P3 event-related potential (ERP) and its associated delta and theta time-frequency (TF) components), and intrinsic, resting state brain activity (including EEG in the beta frequency band) have each been associated with biological vulnerability to a variety of externalizing (EXT) spectrum disorders, such as substance use disorders, conduct disorder, and antisocial behavior. While each of these individual measures has shown promise as an endophenotype for one or more aspects of EXT, we proposed that the power to identify EXT-related genes may be enhanced by using these measures collectively. Thus, we sought to explore a multivariate approach to identifying electrophysiological endophenotypes related to EXT, using measures identified in the literature as promising individual endophenotypes for EXT.

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P3 amplitude reduction (P3-AR) is associated with biological vulnerability to a spectrum of externalizing disorders, such as ADHD, conduct disorder, and substance use disorders. P3, however, is generally characterized as a broad activation involving multiple neurophysiological processes. One approach to separating P3-related processes is time-frequency (TF) analysis.

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Hemispheric lateralization of early event-related potentials (ERPs; e.g. N1) is largely based on anatomy of the afferent pathway; lateralization of later auditory ERPs (P2/N2, P250, P3b) is less clear.

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Research on the neural correlates of decision making in gambling tasks may be informative for understanding problem gambling. The present study explored confidence and overconfidence using magnetoencephalography (MEG) to measure brain activity during a judgment task. Nineteen undergraduates who self-identified as frequent gamblers (average age 19.

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Schizophrenia patients have difficulty distinguishing relevant from irrelevant auditory information. Auditory oddball paradigms are commonly used to investigate the processing of stimulus relevance. The present study used dense-array EEG and distributed source reconstructions to examine schizophrenia-normal differences in the processing of targets and standards as a function of the temporal sequence of stimuli.

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Four monkeys and 6 humans representing five different native languages were compared in the ability to categorize natural CV tokens of /b/ versus /d/ produced by 4 talkers of American English (2 male, 2 female) in four vowel contexts (/i, e, a, u/). A two-choice "left/right" procedure was used in which both percentage correct and response time data were compared between species. Both measures indicated striking context effects for monkeys, in that they performed better for the back vowels /a/ and /u/ than for the front vowels /i/ and /e/.

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The present study examined how increasing the rate of steady-state stimulation affects schizophrenia-normal differences on the N1 auditory-evoked potential, an index of auditory integration. Dense-array EEG was recorded while schizophrenia and normal subjects heard 1 kHz tones amplitude modulated at 10, 20, 40, or 80 Hz. Spectral power across frequency and time was calculated.

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