Transcranial Direct Current Stimulation (tDCS) has shown potential in modulating cortical activity and treating depression. Despite its promise, variability in electrode montage configurations and electric field strength across studies has resulted in inconsistent outcomes. Traditional meta-analytic methods assessing the effect of tDCS in depression typically do not compare tDCS montage and the anatomical distribution of electric field, which is a major source of inter-experimental variability.
View Article and Find Full Text PDFTranscranial magnetic stimulation (TMS) is a noninvasive brain stimulation method that modulates brain activity by inducing electric fields in the brain. Real-time, state-dependent stimulation with TMS has shown that neural oscillation phase modulates corticospinal excitability. However, such motor evoked potentials (MEPs) only indirectly reflect motor cortex activation and are unavailable at other brain regions of interest.
View Article and Find Full Text PDFBackground: Low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) protocols targeting primary motor cortex (M1) are used in rehabilitation of neurological diseases for their therapeutic potential, safety, and tolerability. Although lower intensity LF-rTMS can modulate M1 neurophysiology, results are variable, and a systematic assessment of its dose effect is lacking.
Objectives: To determine the dose-response of LF-rTMS on stimulated and non-stimulated M1.
Transcranial magnetic stimulation (TMS) modulates neuronal activity, but the efficacy of an open-loop approach is limited due to the brain state's dynamic nature. Real-time integration with electroencephalography (EEG) increases experimental reliability and offers personalized neuromodulation therapy by using immediate brain states as biomarkers. Here, we review brain state-controlled TMS-EEG studies since the first publication several years ago.
View Article and Find Full Text PDFVariability in brain structure is associated with the capacity for behavioral change. However, a causal link between specific brain areas and behavioral change (such as motor learning) has not been demonstrated. We hypothesized that greater gray matter volume of a primary motor cortex (M1) area active during a hand motor learning task is positively correlated with subsequent learning of the task, and that the disruption of this area blocks learning of the task.
View Article and Find Full Text PDFSocial information can be used to optimize decision-making. However, the simultaneous presentation of multiple sources of advice can lead to a distinction bias in judging the validity of the information. While the involvement of event-related potential (ERP) components in social information processing has been studied, how they are modulated by (mis)judging an advisor's information validity remains unknown.
View Article and Find Full Text PDFHuman working memory is a key cognitive process that engages multiple functional anatomical nodes across the brain. Despite a plethora of correlative neuroimaging evidence regarding the working memory architecture, our understanding of critical hubs causally controlling overall performance is incomplete. Causal interpretation requires cognitive testing following safe, temporal, and controllable neuromodulation of specific functional anatomical nodes.
View Article and Find Full Text PDF. Transcranial alternating current stimulation (tACS) can be used to non-invasively entrain neural activity and thereby cause changes in local neural oscillatory power. Despite its increased use in cognitive and clinical neuroscience, the fundamental mechanisms of tACS are still not fully understood.
View Article and Find Full Text PDFThe gradual shifting of preferred neural spiking relative to local field potentials (LFPs), known as phase precession, plays a prominent role in neural coding. Correlations between the phase precession and behavior have been observed throughout various brain regions. As such, phase precession is suggested to be a global neural mechanism that promotes local neuroplasticity.
View Article and Find Full Text PDFTranscranial magnetic stimulation (TMS) is a noninvasive brain stimulation method that is rapidly growing in popularity for studying causal brain-behavior relationships. However, its dose-dependent centrally induced neural mechanisms and peripherally induced sensory costimulation effects remain debated. Understanding how TMS stimulation parameters affect brain responses is vital for the rational design of TMS protocols.
View Article and Find Full Text PDFObjective: Transcranial direct current stimulation (tDCS) has mixed effects for major depressive disorder (MDD) symptoms, partially owing to large inter-experimental variability in tDCS protocols and their correlated induced electric fields (E-fields). We investigated whether the E-field strength of distinct tDCS parameters was associated with antidepressant effect.
Methods: A meta-analysis was performed with placebo-controlled clinical trials of tDCS enrolling MDD patients.
Transcranial alternating current stimulation (tACS) can be used to non-invasively entrain neural activity, and thereby cause changes in local neural oscillatory power. Despite an increased use in cognitive and clinical neuroscience, the fundamental mechanisms of tACS are still not fully understood. Here, we develop a computational neuronal network model of two-compartment pyramidal neurons and inhibitory interneurons which mimic the local cortical circuits.
View Article and Find Full Text PDFThe gradual shifting of preferred neural spiking relative to local field potentials (LFPs), known as phase precession, plays a prominent role in neural coding. Correlations between the phase precession and behavior have been observed throughout various brain regions. As such, phase precession is suggested to be a global neural mechanism that promotes local neuroplasticity.
View Article and Find Full Text PDFTranscranial alternating current stimulation (tACS) can modulate human neural activity and behavior. Accordingly, tACS has vast potential for cognitive research and brain disorder therapies. The stimulation generates oscillating electric fields in the brain that can bias neural spike timing, causing changes in local neural oscillatory power and cross-frequency and cross-area coherence.
View Article and Find Full Text PDFBackground: Neural oscillations in the primary motor cortex (M1) shape corticospinal excitability. Power and phase of ongoing mu (8-13 Hz) and beta (14-30 Hz) activity may mediate motor cortical output. However, the functional dynamics of both mu and beta phase and power relationships and their interaction, are largely unknown.
View Article and Find Full Text PDFExploring ones surroundings may yield unexpected rewards, but is associated with uncertainty and risk. Alternatively, exploitation of certain outcomes is related to low risk, yet potentially better outcomes remain unexamined. As such, risk-taking behavior depends on perceived uncertainty and a trade-off between exploration-exploitation.
View Article and Find Full Text PDFAltering cortical activity using transcranial direct current stimulation (tDCS) has been shown to improve working memory (WM) performance. Due to large inter-experimental variability in the tDCS montage configuration and strength of induced electric fields, results have been mixed. Here, we present a novel meta-analytic method relating behavioral effect sizes to electric field strength to identify brain regions underlying largest tDCS-induced WM improvement.
View Article and Find Full Text PDFObjects can be recognized based on their intrinsic features, including shape, color, and texture. In daily life, however, such features are often not clearly visible, for example when objects appear in the periphery, in clutter, or at a distance. Interestingly, object recognition can still be highly accurate under these conditions when objects are seen within their typical scene context.
View Article and Find Full Text PDFCircadian rhythms have natural relative variations among humans known as chronotype. Chronotype or being a morning or evening person, has a specific physiological, behavioural, and also genetic manifestation. Whether and how chronotype modulates human brain physiology and cognition is, however, not well understood.
View Article and Find Full Text PDFRecognition of DNA is an evolutionarily highly conserved mechanism of immunity. In mammals, the cGAS-STING pathway plays a central role in coupling DNA sensing to the execution of innate immune mechanisms, both in contexts of infection as well as in noninfectious settings of cellular stress and injury. The indiscriminate ability of double-stranded DNA (dsDNA) to activate cGAS challenges our understanding on how engagement of this pathway is prevented on genomic self-DNA under homeostatic conditions.
View Article and Find Full Text PDFNatural scenes are characterized by individual objects as well as by global scene properties such as spatial layout. Functional neuroimaging research has shown that this distinction between object and scene processing is one of the main organizing principles of human high-level visual cortex. For example, object-selective regions, including the lateral occipital complex (LOC), were shown to represent object content (but not scene layout), while scene-selective regions, including the occipital place area (OPA), were shown to represent scene layout (but not object content).
View Article and Find Full Text PDFThe appearance of DNA in the cytosol is perceived as a danger signal that stimulates potent immune responses through cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS). How cells regulate the activity of cGAS toward self-DNA and guard against potentially damaging autoinflammatory responses is a fundamental biological question. Here, we identify barrier-to-autointegration factor 1 (BAF) as a natural opponent of cGAS activity on genomic self-DNA.
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