Mind matters: A narrative review on affective state-dependency in non-invasive brain stimulation

International Journal of Clinical and Health Psychology, Journal Year: 2023, Volume and Issue: 23(3), P. 100378 - 100378

Published: Feb. 16, 2023

Variability in findings related to non-invasive brain stimulation (NIBS) have increasingly been described as a result of differences neurophysiological state. Additionally, there is some evidence suggesting that individual psychological states may correlate with the magnitude and directionality effects NIBS on neural behavioural level. In this narrative review, it proposed assessment baseline affective can quantify non-reductive properties which are not readily accessible neuroscientific methods. Particularly, affective-related theorized physiological, phenomenological NIBS. While further systematic research needed, suggested provide complementary cost-effective source information for understanding variability outcomes. Implementing measures state potentially contribute increasing sensitivity specificity results experimental clinical studies.

Language: Английский

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Why Temporal Inference Stimulation May Fail in the Human Brain: A Pilot Research Study

Biomedicines, Journal Year: 2023, Volume and Issue: 11(7), P. 1813 - 1813

Published: June 24, 2023

Temporal interference stimulation (TIS) aims at targeting deep brain areas during transcranial electrical alternating current (tACS) by generating fields depth. Although its modulatory effects have been demonstrated in animal and human models studies, direct experimental evidence is lacking for utility humans (in vivo). Herein, we directly test compare three different structures: firstly, perform peripheral nerve muscle quantifying twitches as readout, secondly, stimulate peri-orbitally with phosphene perception a surrogate marker, thirdly, attempt to modulate the mean power of alpha oscillations occipital area measured electroencephalography (EEG). We found strong efficacy on modulated frequency PNS, but no CNS. Possible reasons failing activate CNS targets could be comparatively higher activation thresholds here or inhibitory components carrier interfering signal.

Language: Английский

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Alpha modulation via transcranial alternating current stimulation in adults with attention-deficit hyperactivity disorder

Frontiers in Psychology, Journal Year: 2024, Volume and Issue: 14

Published: Jan. 12, 2024

One potential therapy treating attention-deficit/hyperactivity disorder (ADHD) is to modulate dysfunctional brain activations using stimulation techniques. While the number of studies investigating effect transcranial direct current on ADHD symptoms continues increase, alternating (tACS) poorly examined. Previous reported impaired alpha oscillation (8-12 Hz) that may be associated with increased attention deficits in ADHD. Our aim was enhance power adult patients via tACS, different methods explore therapeutic effects. Undergoing a crossover design, adults received active and sham distinct days. Before after each intervention, mean power, performance, subjective symptom ratings, as well head gaze movement were Frequency analyses revealed significant increase band both interventions. Despite trend toward an interaction effect, this was, however, not significantly higher compared stimulation. For other measures, some additional pre-post effects found, which intervention-related. study cannot provide clear evidence for tACS-induced patients, thus no related improvement parameters. We further recommendations future investigation tACS treatment.

Language: Английский

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Neuroplastic effects of transcranial alternating current stimulation (tACS): from mechanisms to clinical trials

Frontiers in Human Neuroscience, Journal Year: 2025, Volume and Issue: 19

Published: March 12, 2025

Transcranial alternating current stimulation (tACS) is a promising non-invasive neuromodulation technique with the potential for inducing neuroplasticity and enhancing cognitive clinical outcomes. A unique feature of tACS, compared to other modalities, that it modulates brain activity by entraining neural oscillations an externally applied current. While many studies have focused on online effects during stimulation, growing evidence suggests tACS can induce sustained after-effects, which emphasizes long-term neurophysiological changes, essential therapeutic applications. In first part this review, we discuss how after-effects could be mediated four non-mutually exclusive mechanisms. First, spike-timing-dependent plasticity (STDP), where timing pre- postsynaptic spikes strengthens or weakens synaptic connections. Second, spike-phase coupling oscillation phase as mediators plasticity. Third, homeostatic plasticity, emphasizing importance operate within dynamic physiological ranges. Fourth, state-dependent highlights state in modulatory tACS. second applications trials targeting neurological psychiatric disorders, including major depressive disorder, schizophrenia, Parkinson’s disease, Alzheimer’s disease. Evidence repeated sessions, optimized individual oscillatory frequencies combined behavioral interventions, may result lasting enhance However, critical challenges remain, need personalized dosing, improved modeling, systematic investigation effects. conclusion, review mechanisms translational bridging basic neuroscience research optimize its use tool.

Language: Английский

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A new perspective for evaluating the efficacy of tACS and tDCS in improving executive functions: A combined tES and fNIRS study

Human Brain Mapping, Journal Year: 2023, Volume and Issue: 45(1)

Published: Dec. 11, 2023

Abstract Background Executive function enhancement is considered necessary for improving the quality of life patients with neurological or psychiatric disorders, such as attention‐deficit/hyperactivity disorder, obsessive‐compulsive disorder and Alzheimer's disease. Transcranial electrical stimulation (tES) has been shown to have some beneficial effects on executive functioning, but quantification these improvements remains controversial. We aimed explore potential functioning induced by use transcranial alternating current (tACS)/transcranial direct (tDCS) right inferior frontal gyrus (IFG) accompanying brain variations in resting state. Methods recruited 229 healthy adults participate Experiments 1 (105 participants) 2 (124 participants). The participants each experiment were randomly divided into tACS, tDCS, sham groups. completed cognitive tasks assess behavior related three core components functions. Functional near‐infrared spectroscopy (fNIRS) was used monitor hemodynamic changes crucial cortical regions Results Inhibition flexibility (excluding working memory) significantly increased after tACS/tDCS, there no significant behavioral differences between tACS tDCS fNIRS revealed that decreases functional connectivity (increased neural efficiency) relevant cortices. Conclusions Enhancement observed tES, tACS/tDCS may need be precisely evaluated via imaging indicators at rest. better benefits than during phase. These findings might provide new insights selecting intervention methods future studies evaluating clinical efficacy tES.

Language: Английский

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Working memory enhancement using real-time phase-tuned transcranial alternating current stimulation

Brain stimulation, Journal Year: 2024, Volume and Issue: 17(4), P. 850 - 859

Published: July 1, 2024

Language: Английский

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The phase of tACS-entrained pre-SMA beta oscillations modulates motor inhibition

NeuroImage, Journal Year: 2024, Volume and Issue: 290, P. 120572 - 120572

Published: March 13, 2024

Inhibitory control has been linked to beta oscillations in the fronto-basal ganglia network. Here we aim investigate functional role of phase this oscillatory rhythm for successful motor inhibition. We applied 20Hz transcranial alternating current stimulation (tACS) pre-supplementary area (pre-SMA) while presenting stop signals at 4 (Experiment 1) and 8 2) equidistant phases tACS entrained oscillations. Participants showed better inhibitory performance when were presented trough oscillation whereas their decreased with being peak. These results are consistent communication through coherence theory, which postsynaptic effects thought be greater an input arrives optimal within cycle target neuronal population. The study provides mechanistic insights into neural principles underlying inhibition may have implications phase-specific interventions aimed treating disorders such as PD or OCD.

Language: Английский

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Decomposing the effects of α-tACS on brain oscillations and aperiodic 1/f activity

Brain stimulation, Journal Year: 2024, Volume and Issue: 17(3), P. 721 - 723

Published: May 1, 2024

Language: Английский

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Alpha transcranial alternating current stimulation as add-on to neglect training: a randomised trial

Brain Communications, Journal Year: 2024, Volume and Issue: 6(5)

Published: Jan. 1, 2024

Abstract Visuospatial neglect is a common and debilitating condition following unilateral stroke, significantly impacting cognitive functioning daily life. There an urgent need for effective treatments that can provide clinically relevant sustained benefits. In addition to traditional stroke treatment, non-invasive brain stimulation, such as transcranial alternating current shows promise complementary approach enhance recovery. the study, we aimed evaluate additive effects of multi-session stimulation at alpha frequency when combined with visual scanning training in chronic patients visuospatial neglect. this double-blind randomized controlled trial, compared active sham (placebo) both training. Both groups received eighteen 40-minute sessions over 6-week period. A total 22 participated study (active group n = 12, 10). The median age was 61.0 years, time since 36.1 months. We assessed six time-points: baseline, after first, ninth eighteenth sessions, well 1 week 3 months completion neuromodulation intervention. primary outcome measure change performance on search task, specifically star cancellation task. Secondary outcomes included detection two line bisection tasks three evaluating living. found improved (primary outcome) neglected side group, group. did not observe nor Time were observed all but one measures. Multi-session may be more treatment than alone. These findings valuable insights into novel strategies recovery, even long injury, aim enhancing rehabilitation improving overall quality life individuals affected by condition. Trial registration: ClinicalTrials.gov; registration number: NCT05466487; https://clinicaltrials.gov/ct2/show/NCT05466487

Language: Английский

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Right frontal gamma transcranial alternating current stimulation modulates optimism biases

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: March 12, 2024

Background When forecasting the future, people often underestimate likelihood of adverse life events, a phenomenon known as optimism bias. While transcranial alternating current stimulation (tACS) over frontal regions has been employed to modulate various cognitive and emotional functions, its potential impact on bias remains unexplored. Results Using single-blind, sham-controlled, between-subjects design, we investigated effects alpha- gamma-tACS Three groups participants received 15-min either individualized alpha frequency (IAF)-tACS, 40 Hz-tACS, or sham right cortex during rest. To assess how tACS impacted bias, completed belief update task before immediately after tACS. delayed effect tACS, delay estimation 24 hours later. We found that across all three groups, showed classic such they were more likely their beliefs toward desirable than undesirable feedback. Notably, compared IAF-tACS Hz-tACS further enhanced biases hours. Conclusion These findings suggest gamma- but not alpha-tACS could effectively long-term optimistic updating. Our study highlights non-invasive brain promising tool for altering biases, which may benefit individuals with pessimistic outlooks.

Language: Английский

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