Neuromodulation of inhibitory control using phase-lagged transcranial alternating current stimulation.

Background: Transcranial alternating current stimulation (tACS) is a prominent non-invasive brain stimulation method for modulating neural oscillations and enhancing human cognitive function. This study aimed to investigate the effects of individualized theta tACS delivered in-phase and out-of-phase between the dorsal anterior cingulate cortex (dACC) and left dorsolateral prefrontal cortex (lDLPFC) during inhibitory control performance.

Methods: The participants engaged in a Stroop task with phase-lagged theta tACS over individually optimized high-density electrode montages targeting the dACC and lDLPFC.

Non-invasive electrical brain stimulation modulates human conscious perception of mental representation.

Mental representation is a key concept in cognitive science; nevertheless, its neural foundations remain elusive. We employed non-invasive electrical brain stimulation and functional magnetic resonance imaging to address this. During this process, participants perceived flickering red and green visual stimuli, discerning them either as distinct, non-fused colours or as a mentally generated, fused colour (orange).

Out-of-phase transcranial alternating current stimulation modulates the neurodynamics of inhibitory control.

Transcranial alternating current stimulation (tACS) is an efficient neuromodulation technique that enhances cognitive function in a non-invasive manner. Using functional magnetic resonance imaging, we investigated whether tACS with different phase lags (0° and 180°) between the dorsal anterior cingulate and left dorsolateral prefrontal cortices modulated inhibitory control performance during the Stroop task. We found out-of-phase tACS mediated improvements in task performance, which was neurodynamically reflected as putamen, dorsolateral prefrontal, and primary motor cortical activation as well as prefrontal-based top-down functional connectivity.

The influence of sleep on fear extinction in trauma-related disorders.

In Posttraumatic Stress Disorder (PTSD), fear and anxiety become dysregulated following psychologically traumatic events. Regulation of fear and anxiety involves both high-level cognitive processes such as cognitive reattribution and low-level, partially automatic memory processes such as fear extinction, safety learning and habituation. These latter processes are believed to be deficient in PTSD.

Rapid eye movement sleep parasympathetic activity predicts wake hyperarousal symptoms following a traumatic event.

Heart rate variability (HRV) can be used to assess changes in output of the parasympathetic nervous system (PNS). Considering that patients with post-traumatic stress disorder (PTSD) often experience disturbances in sleep, arousal, and autonomic functioning, we sought to explore the association of PNS activity during sleep with hyperarousal symptoms of PTSD. Because a broad literature supports the importance of rapid eye movement (REM) sleep in PTSD, REM-sleep features were specifically examined as predictors of PTSD symptom severity.

Abnormal dynamic functional connectivity during fear extinction learning in PTSD and anxiety disorders.

Examining the neural circuits of fear/threat extinction advanced our mechanistic understanding of several psychiatric disorders, including anxiety disorders (AX) and posttraumatic stress disorder (PTSD). More is needed to understand the interplay of large-scale neural networks during fear extinction in these disorders. We used dynamic functional connectivity (FC) to study how FC might be perturbed during conditioned fear extinction in individuals with AX or PTSD.

Aging-Related Changes in Cortical Sources of Sleep Oscillatory Neural Activity Following Motor Learning Reflect Contributions of Cortical Thickness and Pre-sleep Functional Activity.

Oscillatory neural activity during sleep, such as that in the delta and sigma bands, is important for motor learning consolidation. This activity is reduced with typical aging, and this reduction may contribute to aging-related declines in motor learning consolidation. Evidence suggests that brain regions involved in motor learning contribute to oscillatory neural activity during subsequent sleep.

Associations of sleep measures with neural activations accompanying fear conditioning and extinction learning and memory in trauma-exposed individuals.

Study Objectives: Sleep disturbances increase risk of posttraumatic stress disorder (PTSD). Sleep effects on extinction may contribute to such risk. Neural activations to fear extinction were examined in trauma-exposed participants and associated with sleep variables.

Encoding and consolidation of motor sequence learning in young and older adults.

Sleep benefits motor memory consolidation in young adults, but this benefit is reduced in older adults. Here we sought to understand whether differences in the neural bases of encoding between young and older adults contribute to aging-related differences in sleep-dependent consolidation of an explicit variant of the serial reaction time task (SRTT). Seventeen young and 18 older adults completed two sessions (nap, wake) one week apart.

Autonomic activity, posttraumatic and nontraumatic nightmares, and PTSD after trauma exposure.

Background: Nightmares are a hallmark symptom of posttraumatic stress disorder (PTSD). This strong association may reflect a shared pathophysiology in the form of altered autonomic activity and increased reactivity. Using an acoustic startle paradigm, we investigated the interrelationships of psychophysiological measures during wakefulness and PTSD diagnosis, posttraumatic nightmares, and nontraumatic nightmares.

Partial and Total Sleep Deprivation Interferes With Neural Correlates of Consolidation of Fear Extinction Memory.

Background: We assessed the impact of total and partial sleep loss on neural correlates of fear conditioning, extinction learning, and extinction recall in healthy young adults.

Methods: Participants (56.3% female, age 24.

Fear extinction memory is negatively associated with REM sleep in insomnia disorder.

Study Objectives: Formation and maintenance of fear-extinction memories are disrupted in post-traumatic stress disorder (PTSD) and anxiety disorders. Sleep contributes to emotional memory consolidation and emotion regulation. Insomnia disorder (ID) is characterized by persistent sleep disturbance as well as rapid eye movement (REM) sleep abnormalities and often precedes or develops in parallel with PTSD and anxiety disorders.

In Trauma-Exposed Individuals, Self-reported Hyperarousal and Sleep Architecture Predict Resting-State Functional Connectivity in Frontocortical and Paralimbic Regions.

Background: Symptoms of posttraumatic stress disorder (PTSD) reflect abnormalities in large-scale brain networks. In individuals with recent trauma exposure, we examined associations of seed-based resting-state functional connectivity (rs-FC) with posttraumatic symptoms and sleep. We hypothesized that more severe PTSD symptoms and poorer sleep quality would predict 1) greater rs-FC between fear-related seeds and other fear-related regions and 2) lesser rs-FC between fear-related seeds and emotion-regulatory regions.

Delayed fear extinction in individuals with insomnia disorder.

Study Objectives: Insomnia increases the risk for anxiety disorders that are also associated with fear-extinction deficits. We compared activation of fear and extinction networks between insomnia disorder (ID) without comorbidity and good sleepers (GS).

Methods: Twenty-three ID participants age- and sex-matched to 23 GS participants completed 14 days of actigraphy and diaries, three nights of ambulatory polysomnography and a 2-day fear conditioning and extinction paradigm.

Altered power spectral density in the resting-state sensorimotor network in patients with myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) is a multisystemic disease that involves the brain with several neurological symptoms. Although there were few imaging studies on DM1, no studies have investigated functional alterations in the sensorimotor network at rest in patients with DM1. In the current study, a power spectral density (PSD) analysis of resting-state fMRI data was performed to assess possible alteration in spontaneous neural activity of the sensorimotor network in patients with DM1.

Altered executive function in the welders: A functional magnetic resonance imaging study.

Chronic exposure to manganese (Mn) can lead to impairments in motor and cognitive functions. Several recent studies reported Mn-induced executive dysfunction. The present study compared the neural correlates of ongoing executive function of welders and healthy controls.

Altered executive function in the lead-exposed brain: A functional magnetic resonance imaging study.

Introduction: It is well known that lead exposure induces neurotoxic effects, which can result in dysfunction in a variety of cognitive capacities including executive function. However, few studies have used fMRI to examine the direct neural correlates of executive function in participants with past lead exposure. Therefore, this study aimed to investigate possible alterations in the neural correlates of executive function in the previously lead-exposed brain.

An fMRI study of differences in brain activity among elite, expert, and novice archers at the moment of optimal aiming.

Objective: We investigated brain activity in elite, expert, and novice archers during a simulated archery aiming task to determine whether neural correlates of performance differ by skill level.

Background: Success in shooting sports depends on complex mental routines just before the shot, when the brain prepares to execute the movement.

Methods: During functional magnetic resonance imaging, 40 elite, expert, or novice archers aimed at a simulated 70-meter-distant target and pushed a button when they mentally released the bowstring.

Lead-induced impairments in the neural processes related to working memory function.

Background: It is well known that lead exposure induces neurotoxic effects, which can result in a variety of neurocognitive dysfunction. Especially, occupational lead exposures in adults are associated with decreases in cognitive performance including working memory. Despite recent advances in human neuroimaging techniques, the neural correlates of lead-exposed cognitive impairment remain unclear.

Increased power spectral density in resting-state pain-related brain networks in fibromyalgia.

Fibromyalgia (FM), characterized by chronic widespread pain, is known to be associated with heightened responses to painful stimuli and atypical resting-state functional connectivity among pain-related regions of the brain. Previous studies of FM using resting-state functional magnetic resonance imaging (rs-fMRI) have focused on intrinsic functional connectivity, which maps the spatial distribution of temporal correlations among spontaneous low-frequency fluctuation in functional MRI (fMRI) resting-state data. In the current study, using rs-fMRI data in the frequency domain, we investigated the possible alteration of power spectral density (PSD) of low-frequency fluctuation in brain regions associated with central pain processing in patients with FM.

Combined information from resting-state functional connectivity and passive movements with functional magnetic resonance imaging differentiates fast late-onset motor recovery from progressive recovery in hemiplegic stroke patients: a pilot study.

Objective: To investigate the value of combining information from resting-state functional connectivity and passive movements, measured with functional magnetic resonance imaging (fMRI), in acute stroke patients with severe motor impairment.

Subjects: Eight patients with severe left upper limb motor impairment underwent a passive movement task with fMRI and resting-state fMRI, 3 weeks following stroke onset. According to the patterns of motor recovery, patients were divided into groups with, respectively, good or poor motor recovery.

Do patients with fibromyalgia show abnormal neural responses to the observation of pain in others?

Chronic widespread pain is a hallmark of fibromyalgia (FM). Previous neuroimaging studies have reported that the pain neuro-matrix in patients with FM showed augmented activation in response to actual pain. However, the effect of observing pain in others among patients with FM remains poorly understood.

Working memory impairment in fibromyalgia patients associated with altered frontoparietal memory network.

Background: Fibromyalgia (FM) is a disorder characterized by chronic widespread pain and frequently associated with other symptoms. Patients with FM commonly report cognitive complaints, including memory problem. The objective of this study was to investigate the differences in neural correlates of working memory between FM patients and healthy subjects, using functional magnetic resonance imaging (MRI).

Brain activation patterns of motor imagery reflect plastic changes associated with intensive shooting training.

Evidence from previous studies has suggested that motor imagery and motor action engage overlapping brain systems. As a result of this observation that motor imagery can activate brain regions associated with actual motor movement, motor imagery is expected to enhance motor skill performance and become an underlying principle for physical training in sports and physical rehabilitation. However, few studies have examined the effects of physical training on motor imagery in beginners.