Effects of transcranial alternating current stimulation on cognitive function in people with multiple sclerosis: A randomized controlled trial.

Background: Cognitive impairment is a core symptom that profoundly impacts the lives of people with multiple sclerosis (PwMS). Since the existing disease modifying therapies can only stabilize, but not actively treat, cognition in PwMS, there is an unmet need to expand approaches to treat these cognitive symptoms. Transcranial alternating current stimulation (tACS) permits frequency-specific entrainment of neural oscillations intrinsic to cognitive activity.

Intensity-dependent gamma electrical stimulation regulates microglial activation, reduces beta-amyloid load, and facilitates memory in a mouse model of Alzheimer's disease.

Background: Gamma sensory stimulation may reduce AD-specific pathology. Yet, the efficacy of alternating electrical current stimulation in animal models of AD is unknown, and prior research has not addressed intensity-dependent effects.

Methods: The intensity-dependent effect of gamma electrical stimulation (GES) with a sinusoidal alternating current at 40 Hz on Aβ clearance and microglia modulation were assessed in 5xFAD mouse hippocampus and cortex, as well as the behavioral performance of the animals with the Morris Water Maze.

Gamma neuromodulation improves episodic memory and its associated network in amnestic mild cognitive impairment: a pilot study.

Amnestic mild cognitive impairment (aMCI) is a predementia stage of Alzheimer's disease associated with dysfunctional episodic memory and limited treatment options. We aimed to characterize feasibility, clinical, and biomarker effects of noninvasive neurostimulation for aMCI. 13 individuals with aMCI received eight 60-minute sessions of 40-Hz (gamma) transcranial alternating current stimulation (tACS) targeting regions related to episodic memory processing.

Stimulus specific cortical activity associated with ignoring distraction during working memory encoding and maintenance.

Distraction disrupts Working Memory (WM) performance, but how the brain filters distraction is not known. One possibility is that neural activity associated with distractions is suppressed relative to a baseline/passive task (biased competition). Alternatively, distraction may be denied access to WM, with no suppression.

Enhancing cognitive control in amnestic mild cognitive impairment via at-home non-invasive neuromodulation in a randomized trial.

Individuals with multi-domain amnestic mild cognitive impairment (md-aMCI) have an elevated risk of dementia and need interventions that may retain or remediate cognitive function. In a feasibility pilot study, 30 older adults aged 60-80 years with md-aMCI were randomized to 8 sessions of transcranial alternating current stimulation (tACS) with simultaneous cognitive control training (CCT). The intervention took place within the participant's home without direct researcher assistance.

Musical Training Facilitates Exogenous Temporal Attention via Delta Phase Entrainment within a Sensorimotor Network.

Temporal orienting of attention plays an important role in our day-to-day lives and can use timing information from exogenous or endogenous sources. Yet, it is unclear what neural mechanisms give rise to temporal attention, and it is debated whether both exogenous and endogenous forms of temporal attention share a common neural source. Here, older adult nonmusicians ( = 47, 24 female) were randomized to undergo 8 weeks of either rhythm training, which places demands on exogenous temporal attention, or word search training as a control.

How musical rhythm training improves short-term memory for faces.

Playing a musical instrument engages numerous cognitive abilities, including sensory perception, selective attention, and short-term memory. Mounting evidence indicates that engaging these cognitive functions during musical training will improve performance of these same functions. Yet, it remains unclear the extent these benefits may extend to nonmusical tasks, and what neural mechanisms may enable such transfer.

Structural and functional network mechanisms of rescuing cognitive control in aging.

Age-related declines in cognitive control, an ability critical in most daily tasks, threaten individual independence. We previously showed in both older and younger adults that transcranial alternating current stimulation (tACS) can improve cognitive control, with effects observed across neural regions distant from the stimulated site and frequencies outside the stimulated range. Here, we assess network-level changes in neural activity that extend beyond the stimulated site and evaluate anatomical pathways that subserve these effects.

Research outside the laboratory: Longitudinal at-home neurostimulation.

The use of noninvasive transcranial electrical stimulation (tES) has rapidly increased over the past two decades. Yet, tES continues to be largely implemented in laboratory and rehabilitation settings, thereby limiting accessibility to the broader population. We have previously demonstrated that transcranial alternating current stimulation (tACS) in the theta (4-7 Hz) band improves cognitive control, such as multitasking, in younger adults following a single tACS session, as well as in older adults following three tACS sessions.

Individual differences in neuroanatomy and neurophysiology predict effects of transcranial alternating current stimulation.

Background: Noninvasive transcranial electrical stimulation (tES) research has been plagued with inconsistent effects. Recent work has suggested neuroanatomical and neurophysiological variability may alter tES efficacy. However, direct evidence is limited.

Effects of Transcranial Direct Current Stimulation on Cognition, Mood, Pain, and Fatigue in Multiple Sclerosis: A Systematic Review and Meta-Analysis.

The study aimed to evaluate the effects of transcranial direct current stimulation (tDCS) on cognition, mood disturbance, pain, and fatigue in people with multiple sclerosis (PwMS). A literature search was performed on articles published between January 1990 and May 2020 in Pubmed, Medline, and Web of Science using the following keywords and their abbreviation in combinations: multiple sclerosis and transcranial direct current stimulation. Mean effect size (ES) and 95% confidence interval were calculated for each domain of interest.

Temporal attention is not affected by working memory load.

Temporal attention refers to the ability to orient attention in time, which serves to enhance performance such as target detection and discrimination and is a fundamental component of cognitive function. Although some research indicates that temporal attention ability is affected by working memory updating, it is unclear whether temporal attention is also affected by the availability of working memory stores. To address this, participants were presented a dual-task paradigm requiring zero, three, or six digits to be held in working memory while engaged in a temporally cued visual discrimination task.

Multimodal sensory integration: Diminishing returns in rhythmic synchronization.

Synchronizing movements with events in the surrounding environment is a ubiquitous aspect of behavior. Experiments studying multimodal integration and rhythmic synchronization tend to focus on how bimodal (e.g.

Intracranial alternating current stimulation facilitates neurogenesis in a mouse model of Alzheimer's disease.

Background: Neurogenesis is significantly impaired in the brains of both human patients and experimental animal models of Alzheimer's disease (AD). Although deep brain stimulation promotes neurogenesis, it is an invasive technique that may damage neural circuitry along the path of the electrode. To circumvent this problem, we assessed whether intracranial electrical stimulation to the brain affects neurogenesis in a mouse model of Alzheimer's disease (5xFAD).

Neural Correlates Underlying the Precision of Visual Working Memory.

The neural mechanisms associated with the limited capacity of working memory (WM) has long been studied, but it is still unclear which neural regions are associated with the precision of visual WM. Here, an orientation recall task for estimating the trial-wise precision of visual WM was performed and then repeated two weeks later in an fMRI scanner. Results showed that activity in frontal and parietal regions during WM maintenance scaled with WM load, but not with the precision of WM (i.

A Tablet-Based Assessment of Rhythmic Ability.

The exponential rise in use of mobile consumer electronics has presented a great potential for research to be conducted remotely, with participants numbering several orders of magnitude greater than a typical research paradigm. Here, we attempt to demonstrate the validity and reliability of using a consumer game-engine to create software presented on a mobile tablet to assess sensorimotor synchronization, a proxy of rhythmic ability. Our goal was to ascertain whether previously observed research results can be replicated, rather than assess whether a mobile tablet achieves comparable performance to a desktop computer.

Aging of the frontal lobe.

Healthy aging is associated with numerous deficits in cognitive function, which have been attributed to changes within the prefrontal cortex (PFC). This chapter summarizes some of the most prominent cognitive changes associated with age-related alterations in the anatomy and physiology of the PFC. Specifically, aging of the PFC results in deficient aspects of cognitive control, including sustained attention, selective attention, inhibitory control, working memory, and multitasking abilities.

Gyrification abnormalities in presymptomatic expansion carriers.

Objective: To investigate in-vivo cortical gyrification patterns measured by the local gyrification index (lGI) in presymptomatic expansion carriers compared with healthy controls, and investigate relationships between lGI and cortical thickness, an established morphometric measure of neurodegeneration.

Methods: We assessed cortical gyrification and thickness patterns in a cohort of 15 presymptomatic expansion carriers (age 43.7 ± 10.

Parametric effects of transcranial alternating current stimulation on multitasking performance.

Background: We have previously demonstrated that transcranial alternating current stimulation (tACS) can generate positive effects on multitasking performance and associated neurophysiological measures when it is applied with anti-phase theta band stimulation across bilateral prefrontal cortex (PFC) and a short (1-min) inter-session interval (ISI). However, it is unclear how altering the phase of stimulation and the duration of the ISI might impact positive tACS effects. Here, we investigated the role of tACS parameters in engendering performance improvements by manipulating these two stimulation parameters (i.

Enhancement of multitasking performance and neural oscillations by transcranial alternating current stimulation.

Multitasking is associated with the generation of stimulus-locked theta (4-7 Hz) oscillations arising from prefrontal cortex (PFC). Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that influences endogenous brain oscillations. Here, we investigate whether applying alternating current stimulation within the theta frequency band would affect multitasking performance, and explore tACS effects on neurophysiological measures.

Spatial Attention and the Effects of Frontoparietal Alpha Band Stimulation.

A frontoparietal network has long been implicated in top-down control of attention. Recent studies have suggested that this network might communicate through coherence in the alpha band. Here we aimed to test the effect of coherent alpha (8-12 Hz) stimulation on the frontoparietal network.

Dance Experience and Associations with Cortical Gray Matter Thickness in the Aging Population.

Introduction: We investigated the effect dance experience may have on cortical gray matter thickness and cognitive performance in elderly participants with and without mild cognitive impairment (MCI).

Methods: 39 cognitively normal and 48 MCI elderly participants completed a questionnaire regarding their lifetime experience with music, dance, and song. Participants identified themselves as either dancers or nondancers.

Predictive cues and age-related declines in working memory performance.

Older adults, compared to younger adults, do not benefit from predictive information regarding either what type of stimuli they will see or when to expect them, yet it is unclear whether older adults benefit when given both types of predictive information. Here, electroencephalogram recordings of older (aged 62-87 years) and younger (aged 20-32 years) adults were recorded during a working memory task. Each trial contained 2 faces and 2 scenes presented sequentially, followed by a 5-second delay and a probe stimulus.