scholarly journals Anodal Transcranial Direct Current Stimulation (tDCS) of hMT+ Does Not Affect Motion Perception Learning

2018 ◽  
Author(s):  
Stephanie J. Larcombe ◽  
Christopher Kennard ◽  
Jacinta O’Shea ◽  
Holly Bridge
Keyword(s):  
Task Performance ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Visual Motion ◽  
Training Session ◽  
Macaque Monkey ◽  
Anodal Tdcs ◽  
Motion Direction ◽  
Direct Current Stimulation ◽  
Direction Discrimination

AbstractBackgroundHuman visual cortical area hMT+, like its homologue MT in the macaque monkey, has been shown to be particularly selective to visual motion. After damage to the primary visual cortex (V1), patients often exhibit preserved ability to detect moving stimuli, which is associated with neural activity in area hMT+. As an anatomical substrate underlying residual function in the absence of V1, promoting functional plasticity in hMT+ could potentially boost visual performance despite cortical damage.ObjectiveTo establish in healthy participants whether it is possible to use transcranial direct current stimulation (tDCS) over hMT+ to potentiate learning of visual motion direction discrimination.MethodsParticipants were trained daily for five days on a visual motion direction discrimination task. Task difficulty was increased as performance improved, by decreasing the proportion of coherently moving dots, such that participants were always performing at psychophysical threshold. tDCS, either anodal or sham, was applied daily during the 20-minute training session. Task performance was assessed at baseline and at the end of the training period.ResultsAll participants showed improved task performance both during and after training. Contrary to our hypothesis, anodal tDCS did not further improve performance compared to sham stimulation. Bayesian statistics indicated significant evidence in favour of the null hypothesis.ConclusionAnodal tDCS to hMT+ does not enhance visual motion direction discrimination learning in the young healthy visual system.

Effect of Transcranial Direct Current Stimulation on Professional Female Soccer Players’ Recovery Following Official Matches

2021 ◽  
pp. 003151252110212
Author(s):  
Alexandre Moreira ◽  
Daniel Gomes da Silva Machado ◽  
Marom Bikson ◽  
Gozde Unal ◽  
Paul S. Bradley ◽  
...  
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Repeated Measures ◽  
Training Session ◽  
Well Being ◽  
Soccer Players ◽  
Total Quality ◽  
Direct Current Stimulation ◽  
Sham Condition ◽  
World Class

This study investigated the effect of transcranial direct current stimulation (tDCS) combined with a recovery training session on the well-being and self-perceived recovery of professional female soccer players after official matches. Data from 13 world-class players were analyzed after participating in four official soccer matches of the first division of the Brazilian Women’s Soccer Championship (7-, 10-, and 13-day intervals). We applied anodal tDCS (a-tDCS) over the left dorsolateral prefrontal cortex with 2 mA for 20 minutes (+F3/−F4 montage) the day after each match. Participants underwent two randomly ordered sessions of a-tDCS or sham. Players completed the Well-Being Questionnaire (WBQ) and the Total Quality Recovery (TQR) scale before each experimental condition and again the following morning. A two-way repeated-measures ANOVA showed a significant time x condition interaction on the WBQ (F(1,11)=5.21; p=0.043; ηp2=0.32), but not on the TQR (F(1,12) = 0.552; p = 0.47; ηp2 = 0.044). There was a large effect size (ES) for a-tDCS for the WBQ score (ES = 1.02; 95%CI = 0.17;1.88), and there was a moderate WBQ score increase (ES = 0.53; 95%CI = −0.29;1.34) for the sham condition. We found similar increases in the TQR score for a-tDCS (ES = 1.50; 95%CI = 0.63–2.37) and the sham condition (ES = 1.36; 95%CI = 0.51–2.22). These results suggest that a-tDCS (+F3/−F4 montage) combined with a recovery training session may slightly improve perceived well-being beyond the level of improvement after only the recovery training session among world-class female soccer players. Prior to widely adopting this recovery approach, further study is needed with larger and more diverse samples, including for female teams of different performance levels.

scholarly journals Tagging motor memories with transcranial direct current stimulation allows later artificially-controlled retrieval

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Daichi Nozaki ◽  
Atsushi Yokoi ◽  
Takahiro Kimura ◽  
Masaya Hirashima ◽  
Jean-Jacques Orban de Xivry
Keyword(s):  
Direct Current ◽  
Sensorimotor Cortex ◽  
Transcranial Direct Current Stimulation ◽  
Background Activity ◽  
Training Session ◽  
Motor Memory ◽  
Activity Levels ◽  
Direct Current Stimulation ◽  
Cathodal Tdcs ◽  
Human Motor

We demonstrate that human motor memories can be artificially tagged and later retrieved by noninvasive transcranial direct current stimulation (tDCS). Participants learned to adapt reaching movements to two conflicting dynamical environments that were each associated with a different tDCS polarity (anodal or cathodal tDCS) on the sensorimotor cortex. That is, we sought to determine whether divergent background activity levels within the sensorimotor cortex (anodal: higher activity; cathodal: lower activity) give rise to distinct motor memories. After a training session, application of each tDCS polarity automatically resulted in the retrieval of the motor memory corresponding to that polarity. These results reveal that artificial modulation of neural activity in the sensorimotor cortex through tDCS can act as a context for the formation and recollection of motor memories.

Effect of Different Intensities of Transcranial Direct Current Stimulation on Postural Response to External Perturbation in Patients With Parkinson’s Disease

2020 ◽  
Vol 34 (11) ◽  
pp. 1009-1019
Author(s):  
Victor Spiandor Beretta ◽  
Rodrigo Vitório ◽  
Priscila Nóbrega-Sousa ◽  
Núbia Ribeiro Conceição ◽  
Diego Orcioli-Silva ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
External Perturbation ◽  
Cortical Activity ◽  
Anodal Tdcs ◽  
Postural Response ◽  
Direct Current Stimulation ◽  
Sham Condition

Background Habituation of postural response to perturbations is impaired in people with Parkinson’s disease (PD) due to deficits in cortico-basal pathways. Although transcranial direct current stimulation (tDCS) modulate cortico-basal networks, it remains unclear if it can benefit postural control in PD. Objective To analyze the effect of different intensities of anodal tDCS on postural responses and prefrontal cortex (PFC) activity during the habituation to the external perturbation in patients with PD (n = 24). Methods Anodal tDCS was applied over the primary motor cortex (M1) with 1 mA, 2 mA, and sham stimulation in 3 different sessions (~2 weeks apart) during 20 minutes immediately before the postural assessment. External perturbation (7 trials) was applied by a support base posterior translation (20 cm/s and 5 cm). Primary outcome measures included lower limb electromyography and center of pressure parameters. Measures of PFC activity are reported as exploratory outcomes. Analyses of variance (Stimulation Condition × Trial) were performed. Results Habituation of perturbation was evidenced independent of the stimulation conditions. Both active stimulation intensities had shorter recovery time and a trend for lower cortical activity in the stimulated hemisphere when compared to sham condition. Shorter onset latency of the medial gastrocnemius as well as lower cortical activity in the nonstimulated hemisphere were only observed after 2 mA concerning the sham condition. Conclusions tDCS over M1 improved the postural response to external perturbation in PD, with better response observed for 2 mA compared with 1 mA. However, tDCS seems to be inefficient in modifying the habituation of perturbation.

scholarly journals Transcranial Direct Current Stimulation (tDCS) in Unilateral Cerebral Palsy: A Pilot Study of Motor Effect

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Emanuela Inguaggiato ◽  
Nadia Bolognini ◽  
Simona Fiori ◽  
Giovanni Cioni
Keyword(s):  
Cerebral Palsy ◽  
Pilot Study ◽  
Upper Limb ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Primary Motor Cortex ◽  
Controlled Study ◽  
Anodal Tdcs ◽  
Direct Current Stimulation ◽  
Unilateral Cerebral Palsy

Transcranial Direct Current Stimulation (tDCS) is an emerging tool to improve upper limb motor functions after stroke acquired in adulthood; however, there is a paucity of reports on its efficacy for upper limb motor rehabilitation in congenital or early-acquired stroke. In this pilot study we have explored, for the first time, the immediate effects, and their short-term persistence, of a single application of anodal tDCS on chronic upper limb motor disorders in children and young individuals with Unilateral Cerebral Palsy (UCP). To this aim, in a crossover sham-controlled study, eight subjects aged 10-28 years with UCP underwent two sessions of active and sham tDCS. Anodal tDCS (1.5 mA, 20 min) was delivered over the primary motor cortex (M1) of the ipsilesional hemisphere. Results showed, only following the active stimulation, an immediate improvement in unimanual gross motor dexterity of hemiplegic, but not of nonhemiplegic, hand in Box and Block test (BBT). Such improvement remained stable for at least 90 minutes. Performance of both hands in Hand Grip Strength test was not modified by anodal tDCS. Improvement in BBT was unrelated to participants’ age or lesion size, as revealed by MRI data analysis. No serious adverse effects occurred after tDCS; some mild and transient side effects (e.g., headache, tingling, and itchiness) were reported in a limited number of cases. This study provides an innovative contribution to scientific literature on the efficacy and safety of anodal tDCS in UCP. This trial is registered with NCT03137940.

scholarly journals Effects of Transcranial Direct Current Stimulation over Left Dorsolateral pFC on the Attentional Blink Depend on Individual Baseline Performance

2015 ◽  
Vol 27 (12) ◽  
pp. 2382-2393 ◽  
Author(s):  
Raquel E. London ◽  
Heleen A. Slagter
Keyword(s):  
Working Memory ◽  
Individual Differences ◽  
Attentional Blink ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Critical Role ◽  
Anodal Tdcs ◽  
Direct Current Stimulation ◽  
Cathodal Tdcs ◽  
Left Dlpfc

Selection mechanisms that dynamically gate only relevant perceptual information for further processing and sustained representation in working memory are critical for goal-directed behavior. We examined whether this gating process can be modulated by anodal transcranial direct current stimulation (tDCS) over left dorsolateral pFC (DLPFC)—a region known to play a key role in working memory and conscious access. Specifically, we examined the effects of tDCS on the magnitude of the so-called “attentional blink” (AB), a deficit in identifying the second of two targets presented in rapid succession. Thirty-four participants performed a standard AB task before (baseline), during, and after 20 min of 1-mA anodal and cathodal tDCS in two separate sessions. On the basis of previous reports linking individual differences in AB magnitude to individual differences in DLPFC activity and on suggestions that effects of tDCS depend on baseline brain activity levels, we hypothesized that anodal tDCS over left DLPFC would modulate the magnitude of the AB as a function of individual baseline AB magnitude. Indeed, individual differences analyses revealed that anodal tDCS decreased the AB in participants with a large baseline AB but increased the AB in participants with a small baseline AB. This effect was only observed during (but not after) stimulation, was not found for cathodal tDCS, and could not be explained by regression to the mean. Notably, the effects of tDCS were not apparent at the group level, highlighting the importance of taking individual variability in performance into account when evaluating the effectiveness of tDCS. These findings support the idea that left DLPFC plays a critical role in the AB and in conscious access more generally. They are also in line with the notion that there is an optimal level of prefrontal activity for cognitive function, with both too little and too much activity hurting performance.

Anodal transcranial direct current stimulation of the motor cortex induces opposite modulation of reciprocal inhibition in wrist extensor and flexor

2014 ◽  
Vol 112 (6) ◽  
pp. 1505-1515 ◽  
Author(s):  
Alexandra Lackmy-Vallée ◽  
Wanalee Klomjai ◽  
Bernard Bussel ◽  
Rose Katz ◽  
Nicolas Roche
Keyword(s):  
Motor Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Reciprocal Inhibition ◽  
Anodal Tdcs ◽  
Direct Current Stimulation ◽  
Wrist Extensor ◽  
Hand Motor Area ◽  
Opposing Effects ◽  
Wrist Flexors

Transcranial direct current stimulation (tDCS) is used as a noninvasive tool to modulate brain excitability in humans. Recently, several studies have demonstrated that tDCS applied over the motor cortex also modulates spinal neural network excitability and therefore can be used to explore the corticospinal control acting on spinal neurons. Previously, we showed that reciprocal inhibition directed to wrist flexor motoneurons is enhanced during contralateral anodal tDCS, but it is likely that the corticospinal control acting on spinal networks controlling wrist flexors and extensors is not similar. The primary aim of the study was to explore the effects of anodal tDCS on reciprocal inhibition directed to wrist extensor motoneurons. To further examine the supraspinal control acting on the reciprocal inhibition between wrist flexors and extensors, we also explored the effects of the tDCS applied to the ipsilateral hand motor area. In healthy volunteers, we tested the effects induced by sham and anodal tDCS on reciprocal inhibition pathways innervating wrist muscles. Reciprocal inhibition directed from flexor to extensor muscles and the reverse situation, i.e., reciprocal inhibition, directed from extensors to flexors were studied in parallel with the H reflex technique. Our main finding was that contralateral anodal tDCS induces opposing effects on reciprocal inhibition: it decreases reciprocal inhibition directed from flexors to extensors, but it increases reciprocal inhibition directed from extensors to flexors. The functional result of these opposite effects on reciprocal inhibition seems to favor wrist extension excitability, suggesting an asymmetric descending control onto the interneurons that mediate reciprocal inhibition.

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