Transcranial direct current stimulation of the right dorsolateral prefrontal cortex improves response inhibition

Asymmetric Modulation of Brain Connectivity by Anodal Transcranial Direct Current Stimulation in Healthy Individuals: A Single-Blind, Randomized Sham-Controlled Trial

Transcranial direct current stimulation (tDCS) applied to the dorsolateral prefrontal cortex (DLPFC) has shown asymmetric behavioral effects, though the underlying neurophysiological mechanisms remain unclear. In this preliminary study with 34 healthy individuals, tDCS was applied to either the left or right DLPFC or a sham group. Behavioral and neurophysiological changes were examined by the Stroop test and resting-state fMRI, respectively, which were measured before and after a 15-min tDCS session. Seed-to-voxel connectivity analysis with seeds placed under the tDCS target regions (F3 and F4) showed no significant changes, but voxel-to-voxel whole-brain intrinsic connectivity (IC) analysis revealed significant 3 × 2 interaction effects (stimulation site × time) in the right DLPFC (18 mm off from the F4). Post hoc analysis showed that only the right DLPFC stimulation led to an increase in IC from pre- to post-stimulation. Consistent with this finding, right DLPFC stimulation improved Stroop task performance measured by increased interference score, which represents better inhibition of irrelevant information. These findings provide further insights into the hemispheric difference of tDCS effects and its underlying neurophysiological mechanisms. However, the small sample size limits the generalizability of the results and necessitates further research with a larger cohort for confirmation.

Intermittent theta burst stimulation (iTBS) and inhibitory control training for excess weight treatment: study protocol for a randomized controlled trial (InhibE)

BACKGROUND

The prevalence of excess weight has increased globally. Despite interventions include targeted goals on essential aspects such as physical activity and diet, their long-term effectiveness remains limited. Research highlights that eating behaviour is influenced by impulsive processes, especially in the context of a food-rich environment. Inhibitory control has been identified as a key factor in regulating eating behaviour. Neuroscience approaches, including inhibitory control training and non-invasive neuromodulation of brain regions such as the dorsolateral prefrontal cortex, show promise in improving eating behaviour when used in addition to conventional intervention for weight management. This parallel group, randomized, controlled trial aims to study the efficacy of neuromodulation with iTBS as an add-on to the weight loss treatment as usual (TAU: diet and exercise), alone and in combination with inhibitory control training, for excess weight treatment.

METHODS AND ANALYSIS

141 people with excess weight will be randomized into three groups: combined intervention (inhibitory control training + iTBS), iTBS and sham iTBS. The three groups will receive individualized diet and physical exercise guidelines (TAU). The interventions will comprehend ten sessions along two weeks. The main outcome measure will be the Body Mass Index change. Secondary outcomes include changes in brain connectivity and activation using fMRI, cognitive measures, eating and physical exercise behaviours, anthropometric and biological measures. Assessments will be carried out before the intervention, after the intervention and 3 months after the intervention. In addition, data on the use of the health system will be collected to analyse the cost-effectiveness and the cost-utility of the intervention.

DISCUSSION

Findings of this study will expand the available evidence on cognitive interventions to improve eating behaviour in people with excess weight.

TRIAL REGISTRATION

The trial has been registered at www.

CLINICALTRIALS

gov under the number NCT06668077 on the 11th of February 2025 named Inhibitory Control Training and iTBS for Excess Weight Behavioral and Brain Changes (InhibE). Any relevant modification to the protocol will be reflected in the clinical trial registry in www.

CLINICALTRIALS

gov.

Role of right dorsolateral prefrontal cortex-left primary motor cortex interaction in motor inhibition in Parkinson's disease

Background

Impaired motor inhibition in Parkinson's disease (PD) is associated with functional alterations in the frontal-basal ganglia (BG) neural circuits. The right dorsolateral prefrontal cortex (DLPFC), pre-supplementary motor area (pre-SMA), and primary motor cortex (M1) play key roles in regulating this inhibition. However, the changes in interhemispheric interactions during motor inhibition in PD have not been clearly defined.

Methods

We used dual-site paired-pulse transcranial magnetic stimulation (ppTMS) to examine the interactions between the right DLPFC and pre-SMA and the left M1 in 30 patients with early-stage PD and 30 age-matched healthy controls (HC) during both resting and active conditions, specifically while performing a stop-signal task (SST).

Results

Stop-signal reaction times (SSRT) were significantly longer in PD patients compared to HC. The right DLPFC-left M1 interaction, at both short- and long-latency intervals, showed enhanced inhibition in PD following the stop-signal. In PD patients, SSRT was correlated with the inhibition of the right DLPFC-left M1 interaction, with stronger inhibition associated with shorter SSRT.

Conclusion

The deficit in reactive inhibition observed in PD is linked to an abnormal modulation of the right DLPFC-left M1 interaction during the stopping process.

Exploring social impairment in those with opioid use disorder: linking impulsivity, childhood trauma, and the prefrontal cortex

BACKGROUND

Challenges with social functioning, which is a hallmark of opioid use disorder (OUD), are a drawback in treatment adherence and maintenance. Yet, little research has explored the underlying mechanisms of this impairment. Impulsivity and corresponding neural alterations may be at the center of this issue. Childhood adversity, which has been linked to both impulsivity and poorer treatment outcomes, could also affect this relationship. This study explores the relationship between impulsivity, social functioning, and their neural correlates in the prefrontal cortex, while examining the potential moderating effects of childhood trauma in individuals recovering from OUD.

METHODS

Participants with (N = 16) and without (N = 19) social impairment completed a survey (e.g., social functioning, Barrat's Impulsivity Scale, Adverse Childhood Experiences (ACEs) and cognitive tasks while undergoing neuroimaging. Functional near infrared spectroscopy (fNIRS), a modern, portable, wearable and low-cost neuroimaging technology, was used to measure prefrontal cortex activity during a behavioral inhibition task (Go/No-Go task).

RESULTS

Those who social functioning survey scores indicated social impairment (n = 16) scored significantly higher on impulsivity scale (t [33]= -3.4, p < 0.01) and reported more depressive symptoms (t [33] = -2.8, p < 0.01) than those reporting no social impairment (n = 19). Social functioning was negatively correlated with impulsivity (r=-0.7, p < 0.001), such that increased impulsivity corresponded to decreased social functioning. Childhood trauma emerged as a moderator of this relationship, but only when controlling for the effects of depression, B=-0.11, p = 0.023. Although both groups had comparable Go/No-Go task performance, the socially impaired group displayed greater activation in the dorsolateral (F(1,100.8) = 7.89, p < 0.01), ventrolateral (F(1,88.8) = 7.33, p < 0.01), and ventromedial (F(1,95.6) = 7.56, p < 0.01) prefrontal cortex duringthe behavioral inhibition task.

CONCLUSION

In addition to being more impulsive, individuals with social impairment exhibited greater activation in the prefrontal cortex during the Go/No-Go task. Furthermore, the impact of impulsivity on social functioning varies depending on ACEs, such that higher levels of ACEs corresponded to a stronger negative relationship between impulsivity and social functioning, highlighting its importance in treatment approaches. These findings have implications for addressing social needs and impulsivity of those in recovery, highlighting the importance of a more personalized, integrative, and trauma-informed approach to intervention.

Effects of Dual-Site Anodal Transcranial Direct Current Stimulation on Attention, Decision-Making, and Working Memory during Sports Fatigue in Elite Soccer Athletes

BACKGROUND

Sports fatigue in soccer athletes has been shown to decrease neural activity, impairing cognitive function and negatively affecting motor performance. Transcranial direct current stimulation (tDCS) can alter cortical excitability, augment synaptic plasticity, and enhance cognitive function. However, its potential to ameliorate cognitive impairment during sports fatigue remains largely unexplored. This study investigated the effect of dual-site tDCS targeting the dorsolateral prefrontal cortex (DLPFC) or primary motor cortex (M1) on attention, decision-making, and working memory in elite soccer athletes during sports fatigue.

METHODS

Sports fatigue was induced in 23 (non-goalkeeper) elite soccer athletes, who then participated in three counterbalanced intervention sessions: dual-site tDCS over the M1, dual-site tDCS over the DLPFC, and sham tDCS. Following tDCS, participants completed the Stroop, Iowa Gambling, and 2-back tasks.

RESULTS

We found a significant improvement in Stroop task accuracy following dual-site anodal tDCS over the M1 compared with the sham intervention in the incongruent condition (p = 0.036). Net scores in the Iowa Gambling task during blocks 4 (p = 0.019) and 5 (p = 0.014) significantly decreased under dual-site tDCS targeting the DLPFC compared with the sham intervention. No differences in 2-back task performance were observed between sessions (all p > 0.05).

CONCLUSIONS

We conclude that dual-site anodal tDCS applied to the M1 enhanced attention performance while tDCS targeting the DLPFC increased risk propensity in a decision-making task during sports fatigue in elite soccer athletes. However, dual-site anodal tDCS targeting either the M1 or DLPFC did not significantly influence working memory performance during sports fatigue in this population. These preliminary findings suggest that dual-site tDCS targeting the M1 has beneficial effects on attention performance, potentially informing future research on sports fatigue in athletes.

CLINICAL TRIAL REGISTRATION

No: NCT06594978. Registered 09 September, 2024; https://clinicaltrials.gov/search?cond=NCT06594978.

Effect of continuous theta burst stimulation on the glymphatic system, brain network and cognitive function in patients with cerebral small vessel disease

Objective

We aim to investigate the impact of continuous theta burst stimulation (cTBS) on glymphatic system (GS), brain network (BN) and cognition in cerebral small vessel disease (CSVD).

Methods

This exploratory study included a small cohort of 11 patients, divided into a cTBS group (6 patients) and a sham-cTBS group (5 patients). Over a period of 2 weeks, all participants underwent cTBS to the right dorsolateral prefrontal cortex (DLPFC). The efficiency of the GS was assessed by along the perivascular space (ALPS) index. BN was measured using global efficiency (GE), characteristic path length (CPL) and clustering coefficient (Cp ). Cognition was evaluated by Montreal Cognitive Assessment (MoCA).

Results

In the cTBS group, the ALPS index increased 4 out of 6 after treatment, compared to an increase in only 2 out of 5 in the control. Improvements in GE, CPL and Cp were observed in 4 out of 6 patients in the cTBS group, whereas no improvements were noted in the control group. The MoCA scores for all patients in the cTBS improved after treatment. Additionally, completion times of the Stroop color and word test C (Stroop C) were reduced for all individuals in the cTBS group, while the control saw an increase in one case. The Digital Span Test-backward (DST-backward) scores were significantly higher in the cTBS group than those in the control.

Conclusion

Applying cTBS to the DLPFC in CSVD may enhance the efficiency of brain glymphatic clearance, optimize network connectivity and improve cognitive function to a certain extent.

Effects of transcranial direct current stimulation on modulating executive functions in healthy populations: a systematic review and meta-analysis

Background

Conventional research has asserted that cognitive function, particularly, response inhibition, is closely related to the inferior frontal cortex (IFC), dorsolateral prefrontal cortex (DLPFC), or orbital frontal cortex (OFC), which belong to the prefrontal cortex (PFC). Different targets of anodal or cathodal transcranial direct current stimulation (a-tDCS or c-tDCS) would affect the experimental results, but the stimulation of the same brain target would produce inconsistent findings.

Purpose

This study aimed to investigate the effects of a-tDCS and c-tDCS applied over the PFC for healthy populations on reactive and proactive control process compared with sham or no tDCS conditions, as assessed using the Stop-signal task (SST) and Go/NoGo (GNG) task performance.

Methods

This systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Search was conducted on Web of Science, Google Scholar, PubMed, Elsevier, Scopus, and Science Direct until March 2024. Studies that assessed the inhibitory control in SST or/and GNG tasks were included to achieve a homogenous sample.

Results

Fourteen studies were included for meta-analyses, which were performed for two outcome measures, namely, stop-signal reaction time (SSRT) and commission error (CE) rate. A-tDCS and c-tDCS over the PFC had significant ergogenic effects on SST performance (mean difference = -17.03, 95% CI [-24.62, -9.43], p < 0.0001; mean difference = -15.19, 95% CI [-19.82, -10.55], p < 0.00001), and that of a-tDCS had a positive effect on GNG task performance (mean difference = -1.42, 95% CI [-2.71, -0.14], p = 0.03).

Conclusion

This review confirmed the engagement of PFC tDCS in reactive and proactive inhibitory processes. Future research should increase sample size and implement personalized stimulus protocols.

Unveiling the grip of mobile phone addiction: an in-depth review

Mobile Phone Addiction represents an emergent addictive disorder that gravely jeopardizes the physical and mental health of adolescents worldwide, necessitating exhaustive research. Current reviews of MPA are in dire need of updates and enhancements. Therefore, this review aggregates the extant research spanning the past two decades on the prevalence, pathogenesis, comorbidities, assessment, and treatment of MPA, aiming to furnish a reference for future investigations into this condition.

Greater weekly physical activity linked to left resting frontal alpha asymmetry in women: A study on gender differences in highly active young adults

Physical activity, beneficial for physical and psychological health, may facilitate affective mechanisms of positive emotion and approach-motivation. Greater resting frontal alpha asymmetry (FAA), an index of greater relative left than right frontal cortical activity, is a neural correlate of affective mechanisms possibly associated with active lifestyles. This study sought to amplify limited literature on the relationship between physical (in)activity, FAA, and gender differences. College students (n = 70) self-reported physical activity (Total PA) and sedentary activity (Total Sitting) via the International Physical Activity Questionnaire-Short Form (IPAQ-SF), followed by a resting electroencephalography session to record FAA. A Total PA × gender interaction (β = 0.462, t = 3.163, p = 0.002) identified a positive relationship between Total PA and FAA in women (β = 0.434, t = 2.221, p = 0.030) and a negative relationship for men (β = -0.338, t = -2.300, p = 0.025). Total Sitting was positively linked to FAA (β = 0.288, t = 2.228, p = 0.029; no gender effect). Results suggest affective mechanisms reflected by FAA (e.g., positive emotion, approach-motivation) are associated with physical activity for women, indicating a possible mechanism of the psychological benefits linked with physically active lifestyles. A positive relationship between sedentary behavior and greater left FAA may also reflect motivated mechanisms of behavior that aid in minimizing energy expenditure, particularly within the context of our highly active sample.

Single session and repeated anodal transcranial direct current stimulation over the right dorsolateral prefrontal cortex increases reflective thinking but not working memory updating performance

Background

Anodal transcranial direct current stimulation (tDCS) over the right dorsolateral prefrontal cortex (DLPFC) has shown to have effects on different domains of cognition yet there is a gap in the literature regarding effects on reflective thinking performance.

Objective

The current study investigated if single session and repeated anodal tDCS over the right DLPFC induces effects on judgment and decision-making performance and whether these are linked to working memory (updating) performance or cognitive inhibition.

Methods

Participants received anodal tDCS over the right DLPFC once (plus sham tDCS in a second session) or twice (24 h apart). In the third group participants received a single session of sham stimulation only. Cognitive characteristic measures were administered pre-stimulation (thinking disposition, impulsivity, cognitive ability). Experimental tasks included two versions of the Cognitive Reflection Test (numeric vs verbal-CRT), a set of incongruent base-rate vignettes, and two working memory tests (Sternberg task and n-back task). Forty-eight participants (mean age = 26.08 ± 0.54 years; 27 females) were recruited.

Results

Single sessions of tDCS were associated with an increase in reflective thinking performance compared to the sham conditions, with stimulation improving scores on incongruent base rate tasks as well as marginally improving numeric CRT scores (compared to sham), but not thinking tasks without a numeric component (verbal-CRT). Repeated anodal stimulation only improved numeric CRT scores. tDCS did not increase working memory (updating) performance. These findings could not be explained by a practice effect or a priori differences in cognitive characteristics or impulsivity across the experimental groups.

Conclusion

The current results demonstrate the involvement of the right DLPFC in reflective thinking performance which cannot be explained by working memory (updating) performance or general cognitive characteristics of participants.

Enhancing response inhibition behavior through tDCS intervention in college students with smartphone addiction

Smartphone addiction, emerging from excessive use of smartphones, poses a challenge to inhibitory control functions within society. This research employed transcranial direct current stimulation (tDCS) as an intervention alongside the stop signal task (SST) to explore behavioral distinctions between individuals with smartphone addiction and a non-addicted control group, focusing on the efficacy of tDCS intervention. The participant cohort comprised 80 individuals, divided into an addiction group (39 participants, with 19 receiving active tDCS and 20 receiving sham tDCS) and a control group (41 participants, with 20 receiving active tDCS and 21 receiving sham tDCS), with anodal stimulation applied over the right dorsolateral prefrontal cortex (dlPFC) and cathodal placement over the left arm. The findings indicate that university students struggling with smartphone addiction exhibit reduced inhibitory control compared to their non-addicted peers, while maintaining similar levels of general cognitive control. Remarkably, tDCS interventions were observed to enhance inhibitory control in both groups. Although the improvement in the addiction group appeared more pronounced numerically than in the control group, no significant interaction with group was noted. However, a higher percentage of participants in the smartphone addiction (SA) group exhibited enhanced response inhibition under active tDCS. This study demonstrates the inhibitory control deficits in individuals addicted to smartphones and underscores the potential of tDCS in enhancing response inhibition. It provides a valuable reference for future tDCS research targeting smartphone addiction and highlights the importance of developing healthier smartphone usage habits.

Two fundamentally different mechanisms by which unconscious information impairs behavioral performance: Evidence from fMRI and computational modeling

It is increasingly clear that unconscious information impairs the performance of the corresponding action when the instruction to act is delayed. However, whether this impairment occurs at the response level or at the perceptual level remains controversial. This study used fMRI and a computational model with a pre-post design to address this elusive issue. The fMRI results showed that when the unconscious information containing strong stimulus-response associations was irrelevant to subsequent stimuli, the precuneus in the parietal lobe, which is thought to be involved in sensorimotor processing, was activated. In contrast, when the unconscious information was relevant to subsequent stimuli, regardless of the strength of the stimulus-response associations, some regions in the occipital and temporal cortices, which are thought to be involved in visual perceptual processing, were activated. In addition, the percent signal change in the regions of interest associated with motor inhibition was modulated by compatibility in the irrelevant but not in the relevant stimuli conditions. Modeling of behavioral data further supported that the irrelevant and relevant stimuli conditions involved fundamentally different mechanisms. Our finding reconciles the debate about the mechanism by which unconscious information impairs action performance and has important implications for understanding of unconscious cognition.

Effects of high-intensity interval training combined with dual-site transcranial direct current stimulation on inhibitory control and working memory in healthy adults

Transcranial direct current stimulation (tDCS) and high-intensity interval training (HIIT) have been demonstrated to enhance inhibitory control and working memory (WM) performance in healthy adults. However, the potential benefits of combining these two interventions have been rarely explored and remain largely speculative. This study aimed to explore the effects of acute HIIT combined with dual-site tDCS over the dorsolateral prefrontal cortex (DLPFC, F3 and F4) on inhibitory control and WM in healthy young adults. Twenty-five healthy college students (20.5 ± 1.3 years; 11 females) were recruited to complete HIIT + tDCS, HIIT + sham-tDCS, rest + tDCS, and rest + sham-tDCS (CON) sessions in a randomized crossover design. tDCS or sham-tDCS was conducted after completing HIIT or a rest condition of the same duration. The Stroop and 2-back tasks were used to evaluate the influence of this combined intervention on cognitive tasks involving inhibitory control and WM performance in post-trials, respectively. Response times (RTs) of the Stroop task significantly improved in the HIIT + tDCS session compared to the CON session across all conditions (all p values <0.05), in the HIIT + tDCS session compared to the rest + tDCS session in the congruent and neutral conditions (all p values <0.05), in the HIIT + sham-tDCS session compared to the CON session in the congruent and neutral conditions (all p values <0.05), in the HIIT + sham-tDCS session compared to the rest + tDCS session in the congruent condition (p = 0.015). No differences were found between sessions in composite score of RT and accuracy in the Stroop task (all p values >0.05) and in the 2-back task reaction time and accuracy (all p values >0.05). We conclude that acute HIIT combined with tDCS effectively improved inhibitory control but it failed to yield cumulative benefits on inhibitory control and WM in healthy adults. These preliminary findings help to identify beneficial effects of combined interventions on cognitive performance and might guide future research with clinical populations.

Modulation of movement-related oscillatory signatures by cognitive interference in healthy aging

Age-related changes in the neurophysiology underlying motor control are well documented, but whether these changes are specific to motor function or more broadly reflect age-related alterations in fronto-parietal circuitry serving attention and other higher-level processes remains unknown. Herein, we collected high-density magnetoencephalography (MEG) in 72 healthy adults (age 28-63 years) as they completed an adapted version of the multi-source interference task that involved two subtypes of cognitive interference (i.e., flanker and Simon) and their integration (i.e., multi-source). All MEG data were examined for age-related changes in neural oscillatory activity using a whole-brain beamforming approach. Our primary findings indicated robust behavioral differences in task performance based on the type of interference, as well as stronger beta oscillations with increasing age in the right dorsolateral prefrontal cortices (flanker and multi-source conditions), left parietal (flanker and Simon), and medial parietal regions (multi-source). Overall, these data indicate that healthy aging is associated with alterations in higher-order association cortices that are critical for attention and motor control in the context of cognitive interference.

Exploring Social Impairment in Those with Opioid Use Disorder: Linking Impulsivity, Childhood Trauma, and the Prefrontal Cortex

Background

Challenges with social functioning, which is a hallmark of opioid use disorder (OUD), are a drawback in treatment adherence and maintenance. Yet, little research has explored the underlying mechanisms of this impairment. Impulsivity, a known risk factor for OUD, and corresponding neural alterations may be at the center of this issue. Childhood adversity, which has been linked to both impulsivity and poorer treatment outcomes, could also affect this relationship. This study aims to understand the relationship between impulsivity and social functioning in those recovering from OUD. Differences in the prefrontal cortex will be analyzed, as well as potential moderating effects of childhood trauma.

Methods

Participants with (N = 16) and without (N = 19) social impairment completed a survey (e.g., social functioning, Barrat's Impulsivity Scale, Adverse Childhood Experiences (ACEs) and cognitive tasks while undergoing neuroimaging. Functional near infrared spectroscopy (fNIRS), a modern, portable, wearable and low-cost neuroimaging technology, was used to measure prefrontal cortex activity during a behavioral inhibition task (Go/No-Go task).

Results

Those who social functioning survey scores indicated social impairment (n = 16) scored significantly higher on impulsivity scale (t(33)= -3.4, p < 0.01) and reported more depressive symptoms (t(33) = -2.8, p < 0.01) than those reporting no social impairment (n = 19). Social functioning was negatively correlated with impulsivity (r=-0.7, p < 0.001), such that increased impulsivity corresponded to decreased social functioning. Childhood trauma emerged as a moderator of this relationship, but only when controlling for the effects of depression, B=-0.11, p = 0.023. Although both groups had comparable Go/No-Go task performance, the socially impaired group displayed greater activation in the dorsolateral (F(1,100.8) = 7.89, p < 0.01), ventrolateral (F(1,88.8) = 7.33, p < 0.01), and ventromedial (F(1,95.6) = 7.56, p < 0.01) prefrontal cortex during impulse control.

Conclusion

In addition to being more impulsive, individuals with social impairment exhibited differential activation in the prefrontal cortex when controlling responses. Furthermore, the impact of impulsivity on social functioning varies depending on ACEs demonstrating that it must be considered in treatment approaches. These findings have implications for addressing social needs and impulsivity of those in recovery, highlighting the importance of a more personalized, integrative, and trauma-informed approach to intervention.

Impact of transcranial direct current stimulation combined with motor-cognitive intervention on post-stroke cognitive impairment

OBJECTIVE

In this study, it was explored whether the efficacy on applying transcranial direct current stimulation (tDCS) combined with motor-cognitive intervention for post-stroke cognitive impairment (PSCI) was greater than that on applying each method alone.

METHODS

A total of 90 patients with PSCI admitted to Zhejiang Provincial People's Hospital, China, from April 2021 to June 2022 were randomly divided into a tDCS group (n = 30), a motor-cognitive intervention group (n = 30), and a combination group (n = 30). All three groups received conventional rehabilitation therapy. The tDCS group was given tDCS therapy. The motor-cognitive intervention group received motor-cognitive intervention, whereas the combination group received tDCS combined with motor-cognitive intervention. The treatment duration was 4 weeks. The general data of patients were recorded before treatment. The Montreal Cognitive Assessment (MoCA) Scale and the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) Scale were used to evaluate the cognitive function of patients in three groups before and after treatment. Further, within- and between-groups comparisons were performed to determine differences in cognitive function.

RESULTS

Before treatment, there was no significant difference between the baseline scores of the three groups (P > 0.05). After 4 weeks of treatment, except for the score for the LOTCA motor praxis subtest of the tDCS group, the MoCA and LOTCA scores of the three groups significantly improved compared with the corresponding scores before treatment (P < 0.05), and there was no drop-out case. After treatment, the MoCA and LOTCA scores of the three groups were compared in pairs. The results showed that except for the attention domain in MoCA, the method used for the combination group had more efficacy than those used for the other two groups (P < 0.05). Further, there was no statistical difference in efficacy between the tDCS and the motor-cognitive intervention groups (P > 0.05).

CONCLUSION

The combination of tDCS and motor-cognitive intervention is safe and can help improve the cognitive function of patients with PSCI.

Cortical activity and spatiotemporal parameters during gait termination and walking: A preliminary study

Gait termination requires an interaction between the biomechanical and neuromuscular systems to arrest forward momentum. Currently, the biomechanical characteristics of gait termination have been demonstrated; however, the neural mechanism of gait termination remains unclear. This study aimed to investigate cortical activity during gait termination using functional near-infrared spectroscopy (fNIRS). Thirteen healthy younger adults (mean age:24.0 ± 1.7) participated in this study. All participants performed three experimental sessions: planned gait termination (PGT), unplanned gait termination (UGT), and walking. Each experimental session comprised a block paradigm design (three cycles; 20 s resting, 45 s task). Cortical activity in the dorsolateral prefrontal cortex (DLPFC), supplementary motor area (SMA), and primary motor cortex (M1) and spatiotemporal parameters were measured. We compared the cortical activities and spatiotemporal parameters among PGT, UGT, and walking sessions. In addition, we performed Pearson correlations between hemodynamic responses and spatiotemporal parameters. The PGT was activated in the right DLPFC, whereas the UGT and walking were activated in the left SMA (p < 0.05). Comparing cortical activation between sessions, both the PGT and UGT showed significantly higher activation in the right DLPFC than during walking (p < 0.05). There were no significant differences in cortical activity between PGT and UGT (p > 0.05). In addition, the gait termination time revealed moderate positive correlation with hemodynamic responses in the right DLPFC (p < 0.05). Our results indicate that the right DLPFC is associated with gait termination, regardless of gait termination type. Our findings provide the potential implication that the hemodynamic response in the right DLPFC would be a biomarker to evaluate the ability of gait termination.

The Effect of Continuous Theta Burst Stimulation over the Right Dorsolateral Prefrontal Cortex on Cognitive Function and Emotional Regulation in Patients with Cerebral Small Vessel Disease

OBJECTIVES

Cognitive impairment in cerebral small vessel disease (CSVD) is a common cause of vascular dementia and is often accompanied by mental disorders. The purpose of this study was to investigate the effect of continuous theta burst stimulation (cTBS) over the right dorsolateral prefrontal cortex (DLPFC) on the cognitive function and Hamilton depression (HAMD) scores in patients with CSVD.

METHODS

A total of 30 CSVD patients who met the inclusion criteria were randomly assigned to either the sham or cTBS group. The patients in both groups received routine cognitive function training. All the patients were under treatment for 14 sessions, with one session per day (each cTBS conditioning session consisted of three-pulse bursts at 50 Hz repeated at 5 Hz, 80% MT, and 600 pulses). Before and after the treatment, the patients in both groups were evaluated using the Montreal Cognitive Assessment (MoCA), Stroop Color-Word Test (SCWT), Trail Marking Test (TMT), Digital Span Test (DST), and HAMD test. The time to complete the SCWT and TMT were recorded. The scores of the MoCA, DST and HAMD test were recorded.

RESULTS

The HAMD scores in the cTBS group decreased significantly compared to the control (p < 0.05). There were no significant differences in the MoCA (including the MoCA subitems) or DST scores or in the SCWT or TMT completion times between the two groups (p > 0.05). For the HAMD scores and the MoCA subitem visuospatial/executive scores, the SCWT-B and SCWT-C completion times in the two groups both improved significantly before and after treatment (p < 0.05). For the MoCA scores, the DST-backward scores and the TMT-B completion times in the cTBS group improved significantly before and after treatment (p < 0.05). There was no significant difference in the SCWT-A, TMT-A completion times and MoCA subitems naming, attention, language, abstraction, delayed recall, and orientation scores either before or after treatment in the two groups or between the two groups (p > 0.05).

CONCLUSIONS

In this study, cTBS over the right DLPFC decreased the HAMD scores significantly in patients with CSVD but had no significant improvement or impairment effects on cognitive function. cTBS over the right DLPFC could be used to treat CSVD patients with depression symptoms.

The impact of sensation seeking personality trait on acute alcohol-induced disinhibition

BACKGROUND

Acute alcohol-related behavioral disinhibition has been well studied. But whether individual differences in the personality trait sensation seeking affect alcohol-induced behavioral disinhibition remains uncertain.

METHODS

The present study used functional near-infrared spectroscopy (fNIRS) technique and a response inhibition task (i.e., Go/No-Go) to determine the impact of the sensation seeking trait on the relationship between acute alcohol administration and inhibitory control capacity, and further investigate the neural mechanisms underlying this behavioral effect. Twenty-five high-sensation seekers and twenty-six low-sensation seekers were enrolled in this study. These participants attended two sessions: once for alcohol intake (0.5g/kg) and once for placebo intake (0g/kg).

RESULTS

Our results showed that high-sensation seekers relative to low-sensation seekers showed a significant decrease in inhibition accuracy under alcohol versus the placebo condition. Moreover, reduced prefrontal activity following acute alcohol consumption was more pronounced in high-sensation seekers compared with low-sensation seekers.

CONCLUSIONS

These findings showed that alcohol-induced behavioral disinhibition was affected by the personality trait sensation seeking and that recruitment of the prefrontal cortex contributed to the observed behavioral effect.

High-definition transcranial direct current stimulation over right dorsolateral prefrontal cortex differentially modulates inhibitory mechanisms for speech vs. limb movement

Evidence suggests that planning and execution of speech and limb movement are subserved by common neural substrates. However, less is known about whether they are supported by a common inhibitory mechanism. P3 event-related potentials (ERPs) is a neural signature of motor inhibition, which are found to be generated by several brain regions including the right dorsolateral prefrontal cortex (rDLPFC). However, the relative contribution of rDLPFC to the P3 response associated with speech versus limb inhibition remains elusive. We investigated the contribution of rDLPFC to the P3 underlying speech versus limb movement inhibition. Twenty-one neurotypical adults received both cathodal and sham high-definition transcranial direct current stimulation (HD-tDCS) over rDLPFC. ERPs were subsequently recorded while subjects were performing speech and limb Go/No-Go tasks. Cathodal HD-tDCS decreased accuracy for speech versus limb No-Go. Both speech and limb No-Go elicited a similar topographical distribution of P3, with significantly larger amplitudes for speech versus limb at a frontocentral location following cathodal HD-tDCS. Moreover, results showed stronger activation in cingulate cortex and rDLPFC for speech versus limb No-Go following cathodal HD-tDCS. These results indicate (1) P3 is an ERP marker of amodal inhibitory mechanisms that support both speech and limb inhibition, (2) larger P3 for speech versus limb No-Go following cathodal HD-tDCS may reflect the recruitment of additional neural resources-particularly within rDLPFC and cingulate cortex-as compensatory mechanisms to counteract the temporary stimulation-induced decline in speech inhibitory process. These findings have translational implications for neurological conditions that concurrently affect speech and limb movement.

tDCS Anodal Stimulation of the Right Dorsolateral Prefrontal Cortex Improves Creative Performance in Real-World Problem Solving

Brain regions associated with creativity is a focal point in research related to the field of cognitive neuroscience. Previous studies have paid more attention to the role of activation of the left dorsolateral prefrontal cortex in creativity tasks, which are mostly abstract conceptual tasks, and less attention to real-world creativity tasks. The right dorsolateral prefrontal cortex is involved in functions such as visuospatial processing, which may have a positive impact on innovative solutions to real-world problems. In this study, tDCS technology was used to explore the effect of anodal stimulation of the right dorsolateral prefrontal cortex on design creativity performance in a real-word problem-solving task related to product design. The experimental task comprised three stages, of which the first two were idea generation stages based on divergent thinking using text and graphics, respectively, whereas the third was the creative evaluation stage based on convergent thinking. Thirty-six design students were recruited to partake in the experiment. They were randomly assigned into anodal stimulation and sham stimulation groups. The results showed that anodal stimulation of the right dorsolateral prefrontal cortex produced a significant positive effect during the creative evaluation stage, promoting the usefulness of ideas (p = 0.009); thus, improving product creativity scores. However, there was no significant impact on the idea generation stage (p > 0.05), which is dominated by divergent thinking. The results suggest that activating the right dorsolateral prefrontal cortex with tDCS can improve people’s performance in creative activities by promoting convergent thinking rather than divergent thinking. It also provides further evidence that the right hemisphere of the brain has an advantage in solving complex problems that require the participation of visuospatial information.

Intrinsic neural timescales mediate the cognitive bias of self - temporal integration as key mechanism

Our perceptions and decisions are not always objectively correct as they are featured by a bias related to our self. What are the behavioral, neural, and computational mechanisms of such cognitive bias? Addressing this yet unresolved question, we here investigate whether the cognitive bias is related to temporal integration and segregation as mediated by the brain's Intrinsic neural timescales (INT). Using Signal Detection Theory (SDT), we operationalize the cognitive bias by the Criterion C as distinguished from the sensitivity index d'. This was probed in a self-task based on morphed self- and other faces. Behavioral data demonstrate clear cognitive bias, i.e., Criterion C. That was related to the EEG-based INT as measured by the autocorrelation window (ACW) in especially the transmodal regions dorsolateral prefrontal cortex (dlPFC) and default-mode network (DMN) as distinct from unimodal visual cortex. Finally, simulation of the same paradigm in a large-scale network model shows high degrees of temporal integration of temporally distinct inputs in CMS/DMN and dlPFC while temporal segregation predominates in visual cortex. Together, we demonstrate a key role of INT-based temporal integration in CMS/DMN and dlPFC including its relation to the brain's uni-transmodal topographical organization in mediating the cognitive bias of our self.

Probing the Promises of Noninvasive Transcranial Electrical Stimulation for Boosting Mental Performance in Sports

While the importance of physical abilities is noncontested to perform in elite sport, more focus has recently been turned toward cognitive processes involved in sport performance. Practicing any sport requires a high demand of cognitive functioning including, but not limited to, decision-making, processing speed, working memory, perceptual processing, motor functioning, and attention. Noninvasive transcranial electrical stimulation (tES) has recently attracted considerable scientific interest due to its ability to modulate brain functioning. Neuromodulation apparently improves cognitive functions engaged in sports performance. This opinion manuscript aimed to reveal that tES is likely an adjunct ergogenic resource for improving cognitive processes, counteracting mental fatigue, and managing anxiety in elite athletes. Nevertheless, the first evidence is insufficient to guarantee its real effectiveness and benefits. All tES techniques could be add-ons to make performance-related cognitive functions more efficient and obtain better results. Modulating inhibitory control through tES over the frontal cortex might largely contribute to the improvement of mental performance. Nevertheless, studies in elite athletes are required to assess the long-term effects of tES application as an ergogenic aid in conjunction with other training methods (e.g., neurofeedback, mental imagery) where cognitive abilities are trainable.

Transcranial direct current stimulation over the right intraparietal sulcus improves response inhibition

Various situations in our everyday life call for response inhibition, mechanisms deputed to outright stop an ongoing course of action. This function reportedly involves the activity of the right intraparietal sulcus (rIPS). This study aimed to determine whether transcranial direct current stimulation (tDCS) intervention to the rIPS alters response inhibition. We investigated 15 healthy adults performing a stop signal task before and after tDCS intervention. We applied tDCS with 1.5 mA to the rIPS directly above (P4) and the left supraorbital area for 20 min. The stimulation conditions involved Anodal, cathodal, and pseudo-stimulation. Each participant performed a stop signal task under all stimulation conditions. The changes in response inhibition function were evaluated by comparing the stop signal reaction times (SSRT) before and after the tDCS intervention. Under the Anodal condition, SSRT was significantly shorter after than before the intervention (p = 0.014). Under the Anodal and Cathodal conditions, we could observe a significantly positive correlation between the SSRT before the tDCS intervention and the difference in SSRT before and after tDCS intervention (Anodal condition: r = 0.823, p < 0.001; Cathodal condition: r = 0.831, p < 0.001). No such correlation could be found under the Sham condition. In summary, this study demonstrated that Anodal-tDCS intervention for rIPS improves response-inhibitory function and the stimulus effect depends on the response-inhibitory function of the participant prior to stimulation.

Bibliometric and visual analysis of transcranial direct current stimulation in the web of science database from 2000 to 2022 via CiteSpace

Objective

This study aimed to evaluate the current research hotspots and development tendency of Transcranial Direct Current Stimulation (tDCS) in the field of neurobiology from a bibliometric perspective by providing visualized information to scientists and clinicians.

Materials and methods

Publications related to tDCS published between 2000 and 2022 were retrieved from the Web of Science Core Collection (WOSCC) on May 5, 2022. Bibliometric features including the number of publications and citations, citation frequency, H-index, journal impact factors, and journal citation reports were summarized using Microsoft Office Excel. Co-authorship, citation, co-citation, and co-occurrence analyses among countries, institutions, authors, co-authors, journals, publications, references, and keywords were analyzed and visualized using CiteSpace (version 6.1.R3).

Results

A total of 4,756 publications on tDCS fulfilled the criteria we designed and then were extracted from the WOSCC. The United States (1,190 publications, 25.02%) and Harvard University (185 publications, 3.89%) were the leading contributors among all the countries and institutions, respectively. NITSCHE MA and FREGNI F, two key researchers, have made great achievements in tDCS. Brain Stimulation (306 publications) had the highest number of publications relevant to tDCS and the highest number of citations (4,042 times). In terms of potential hotspots, we observed through reference co-citation analysis timeline viewer related to tDCS that "depression"#0, "Sensorimotor network"#10, "working memory"#11, and "Transcranial magnetic stimulation"#9 might be the future research hotspots, while keywords with the strong burst and still ongoing were "intensity" (2018-2022), "impairment" (2020-2022), "efficacy" (2020-2022), and "guideline" (2020-2022).

Conclusion

This was the first-ever study of peer-reviewed publications relative to tDCS using several scientometric and visual analytic methods to quantitatively and qualitatively reveal the current research status and trends in the field of tDCS. Through the bibliometric method, we gained an in-depth understanding of the current research status and development trend on tDCS. Our research and analysis results might provide some practical sources for academic scholars and clinicians.

Improved food Go/No-Go scores after transcranial direct current stimulation (tDCS) to prefrontal cortex in a randomized trial

OBJECTIVE

Reduced dorsolateral prefrontal cortex (dlPFC) activity and inhibitory control may contribute to obesity. The study objective was to assess effects of repeated transcranial direct current stimulation (tDCS) on food Go/No-Go (GNG), food Stroop performance, and snack food intake.

METHODS

Twenty-nine individuals with obesity (12 male; mean [SD], age 42 [11] years; BMI 39 [8]) participated in a combined inpatient/outpatient randomized parallel-design trial and received 15 sessions of anodal or sham tDCS to the left dlPFC. Food-related inhibitory control (GNG), attentional bias (Stroop), and snack food intake were assessed at baseline, completion of inpatient sessions (day 7), and follow-up (day 31).

RESULTS

GNG performance improved in the anodal group by day 31, compared with sham (p = 0.01), but Stroop scores did not differ by intervention. Greater snack food intake was associated with lower GNG scores (p = 0.01), driven by the sham group (p < 0.001) and higher food and palatable bias scores on the Stroop (all p = 0.02) across both groups. Changes on tasks were not associated with changes in intake.

CONCLUSIONS

Anodal tDCS to the left dlPFC improved performance on a food-related inhibitory control task, providing evidence of potential for therapeutic benefit of neuromodulation in areas controlling executive function. Results showed that tDCS to the dlPFC reduced snack food intake and hunger; however, underlying neurocognitive mechanisms remain uncertain.

Does Executive Function Training Impact on Communication? A Randomized Controlled tDCS Study on Post-Stroke Aphasia

New approaches in aphasia rehabilitation have recently identified the crucial role of executive functions (EFs) in language recovery, especially for people with severe aphasia (PWSA). Indeed, EFs include high-order cognitive abilities such as planning and problem solving, which enable humans to adapt to novel situations and are essential for everyday functional communication. In a randomized double-blind crossover design, twenty chronic Italian PWSA underwent ten days of transcranial direct current stimulation (tDCS) (20 min, 2 mA) over the right dorsolateral prefrontal cortex (DLPFC). Two conditions were considered, i.e., anodal and sham, while performing four types of cognitive training (alertness, selective attention, visuo-spatial working memory, and planning), all of which were related to executive functions. After anodal tDCS, a greater improvement in selective attention, visuospatial working memory and planning abilities was found compared to the sham condition; this improvement persisted one month after the intervention. Importantly, a significant improvement was also observed in functional communication, as measured through the Communication Activities of Daily Living Scale, in noun and verb naming, in auditory and written language comprehension tasks and in executive function abilities. This evidence emphasizes, for the first time, that tDCS over the right DLPFC combined with executive training enhances functional communication in severe aphasia.

Multitarget high-definition transcranial direct current stimulation improves response inhibition more than single-target high-definition transcranial direct current stimulation in healthy participants

Prior studies have focused on single-target anodal transcranial direct current stimulation (tDCS) over the right inferior frontal gyrus (rIFG) or pre-supplementary motor area (pre-SMA) to improve response inhibition in healthy individuals. However, the results are contradictory and the effect of multitarget anodal stimulation over both brain regions has never been investigated. The present study aimed to investigate the behavioral and neurophysiological effects of different forms of anodal high-definition tDCS (HD-tDCS) on improving response inhibition, including HD-tDCS over the rIFG or pre-SMA and multitarget HD-tDCS over both areas. Ninety-two healthy participants were randomly assigned to receive single-session (20 min) anodal HD-tDCS over rIFG + pre-SMA, rIFG, pre-SMA, or sham stimulation. Before and immediately after tDCS intervention, participants completed a stop-signal task (SST) and a go/nogo task (GNG). Their cortical activity was recorded using functional near-infrared spectroscopy (fNIRS) during the go/nogo task. The results showed multitarget stimulation produced a significant reduction in stop-signal reaction time (SSRT) relative to baseline. The pre-to-post SSRT change was not significant for rIFG, pre-SMA, or sham stimulation. Further analyses revealed multitarget HD-tDCS significantly decreased SSRT in both the high-performance and low-performance subgroups compared with the rIFG condition which decreased SSRT only in the low-performance subgroup. Only the multitarget condition significantly improved neural efficiency as indexed by lower △oxy-Hb after stimulation. In conclusion, the present study provides important preliminary evidence that multitarget HD-tDCS is a promising avenue to improve stimulation efficacy, establishing a more effective montage to enhance response inhibition relative to the commonly used single-target stimulation.

Frontal Asymmetry as a Neural Correlate of Motivational Conflict

Motivational systems of approach, avoidance, and inhibition are fundamental to human behavior. While past research has linked approach motivation with greater relative left frontal asymmetry, many attempts to link avoidance motivation with greater relative right frontal asymmetry have been mixed. These mixed effects could be due to coactivation of the avoidance and behavioral inhibition system (BIS). Much recent evidence indicates that the behavioral inhibition system may be associated with greater relative right frontal activation. The current review examines evidence linking traits associated with the behavioral inhibition system with resting right frontal asymmetry. Other research links individual differences associated with the behavioral inhibition system with state changes in relative right frontal asymmetry. Moreover, activation of the behavioral inhibition system, but not activation of withdrawal motivation, increases greater relative right frontal asymmetry. Together, this work highlights the role of relative frontal asymmetry as a neural correlate in motivational conflict and helps to disentangle behavioral inhibition from avoidance motivation.