scholarly journals Opposite effects of transcranial direct current stimulation (tDCS) on sustained attention in individuals with high and low levels of dispositional mindfulness

2020 ◽  
Author(s):  
Enrique Molina ◽  
Irune Fernandez-Prieto ◽  
Pilar Andres ◽  
Fabrice B. R. Parmentier

Objective: Some studies suggest a link between mindfulness and attentional functioning. Using transcranial direct-current stimulation (tDCS), we tested the hypothesis that mindfulness might improve vigilance through enhanced prefrontal functioning. Methods: We compared the performance of individuals with low versus high dispositional mindfulness (LDM vs HDM) under anodal tDCS of the right prefrontal region and in a sham condition. Results: The stimulation improved vigilance performance in the LDM group and reduced it in the HDM group. No difference was found between the groups in the sham condition. Conclusions: The results fit with the view that lower mindfulness is associated with lower attentional functioning, such that individuals with low mindfulness benefit from the anodal stimulation of the right prefrontal region in a vigilance task. We tentatively suggest that individuals with high dispositional mindfulness might have directed more attention to the physical discomfort produced by the stimulation (e.g., itching), thereby reducing the attention directed to the task (and, consequently, performance in this task). In sum, our results suggest a positive link between dispositional mindfulness, prefrontal functioning and vigilance performance.

2020 ◽  
Author(s):  
Jin-xiang Cheng ◽  
Xianchao Zhao ◽  
Jian Qiu ◽  
Yingcong Jiang ◽  
Jiafeng Ren ◽  
...  

Abstract Background: Previous studies have claimed that transcranial direct current stimulation (tDCS) on the left dorsolateral prefrontal cortex (dlPFC) improves cognition in patients, but few studies that have evaluated the effects of tDCS on cognition improvement during sleep deprivation. To determine whether tDCS (anodal on the left DLPFC and cathodal on the right DLPFC at 2mA current for 30 minutes) can be an effective fatigue countermeasure. Methods: Seven participants and 8 participants underwent active or sham tDCS on the time participants’ cognition declined, respectively. All participants completed the psychomotor vigilance task, the trail making test A and B, the digit cancellation test, the stroop color word test, the brief visuospatial memory test-revised and a procedural game every two hours during the sleep deprivation and after recovery sleep. Results: The active tDCS had beneficial effects on attention, memory, executive function, processing speed, and the ability to inhibit cognitive interference, as well as improvements of subjective drowsiness and fatigue during sleep deprivation. The lasting effect of single tDCS on cognition during sleep deprivation can extend to more than 2 hours. All participants after tDCS gained no disturbed recovery sleep and recovered to baseline cognitive level after the recovery sleep. Conclusions: The study indicated that tDCS is an effective fatigue countermeasure during sleep deprivation, and doesn’t disturb the recovery sleep and performance postrecovery sleep.


2016 ◽  
Vol 28 (5) ◽  
pp. 724-738 ◽  
Author(s):  
Paola Marangolo ◽  
Valentina Fiori ◽  
Umberto Sabatini ◽  
Giada De Pasquale ◽  
Carmela Razzano ◽  
...  

Several studies have already shown that transcranial direct current stimulation (tDCS) is a useful tool for enhancing recovery in aphasia. However, no reports to date have investigated functional connectivity changes on cortical activity because of tDCS language treatment. Here, nine aphasic persons with articulatory disorders underwent an intensive language therapy in two different conditions: bilateral anodic stimulation over the left Broca's area and cathodic contralesional stimulation over the right homologue of Broca's area and a sham condition. The language treatment lasted 3 weeks (Monday to Friday, 15 sessions). In all patients, language measures were collected before (T0) and at the end of treatment (T15). Before and after each treatment condition (real vs. sham), each participant underwent a resting-state fMRI study. Results showed that, after real stimulation, patients exhibited the greatest recovery not only in terms of better accuracy in articulating the treated stimuli but also for untreated items on different tasks of the language test. Moreover, although after the sham condition connectivity changes were confined to the right brain hemisphere, real stimulation yielded to stronger functional connectivity increase in the left hemisphere. In conclusion, our data provide converging evidence from behavioral and functional imaging data that bilateral tDCS determines functional connectivity changes within the lesioned hemisphere, enhancing the language recovery process in stroke patients.


2021 ◽  
pp. 003151252110212
Author(s):  
Alexandre Moreira ◽  
Daniel Gomes da Silva Machado ◽  
Marom Bikson ◽  
Gozde Unal ◽  
Paul S. Bradley ◽  
...  

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.


Author(s):  
Vincent Cabibel ◽  
Makii Muthalib ◽  
Jérôme Froger ◽  
Stéphane Perrey

Repeated transcranial magnetic stimulation (rTMS) is a well-known clinical neuromodulation technique, but transcranial direct-current stimulation (tDCS) is rapidly growing interest for neurorehabilitation applications. Both methods (contralesional hemisphere inhibitory low-frequency: LF-rTMS or lesional hemisphere excitatory anodal: a-tDCS) have been employed to modify the interhemispheric imbalance following stroke. The aim of this pilot study was to compare aHD-tDCS (anodal high-definition tDCS) of the left M1 (2 mA, 20 min) and LF-rTMS of the right M1 (1 Hz, 20 min) to enhance excitability and reduce inhibition of the left primary motor cortex (M1) in five healthy subjects. Single-pulse TMS was used to elicit resting and active (low level muscle contraction, 5% of maximal electromyographic signal) motor-evoked potentials (MEPs) and cortical silent periods (CSPs) from the right and left extensor carpi radialis muscles at Baseline, immediately and 20 min (Post-Stim-20) after the end of each stimulation protocol. LF-rTMS or aHD-tDCS significantly increased right M1 resting and active MEP amplitude at Post-Stim-20 without any CSP modulation and with no difference between methods. In conclusion, this pilot study reported unexpected M1 excitability changes, which most likely stems from variability, which is a major concern in the field to consider.


2019 ◽  
Vol 9 (5) ◽  
pp. 121 ◽  
Author(s):  
Fengxue Qi ◽  
Michael A. Nitsche ◽  
Volker R. Zschorlich

The aim of this randomized sham-controlled study was to examine the impact of cathodal transcranial direct current stimulation (ctDCS) of the primary motor cortex (M1) during movement observation on subsequent execution-related motor cortex activity. Thirty healthy participants received sham or real ctDCS (1 mA) over the left M1 for 10 minutes, respectively. The participants observed a video showing repeated button pressing tasks of the right hand during the sham or real ctDCS, followed by performance of these tasks by the right hand. Motor-evoked potentials (MEP) were recorded from the resting right first dorsal interosseous muscle before movement observation during the sham or real ctDCS, immediately after observation of actions, and after subsequent movement execution. The results of the ANOVA showed a significant main effect on the group (F1,28 = 4.60, p = 0.041) and a significant interaction between time and the group (F2,56 = 5.34, p = 0.008). As revealed by respective post hoc tests, ctDCS induced a significant reduction of MEP amplitudes in connection with movement observation (p = 0.026, Cohen’s d = 0.861) and after subsequent movement execution (p = 0.018, Cohen’s d = 0.914) in comparison with the sham stimulation. It is concluded that ctDCS during movement observation was effective in terms of modulating motor cortex excitability. Moreover, it subsequently influenced execution-related motor cortex activity. This indicates a possible application for rehabilitative treatment in syndromes with pathologically enhanced cortical activity.


2020 ◽  
Vol 34 (11) ◽  
pp. 1009-1019
Author(s):  
Victor Spiandor Beretta ◽  
Rodrigo Vitório ◽  
Priscila Nóbrega-Sousa ◽  
Núbia Ribeiro Conceição ◽  
Diego Orcioli-Silva ◽  
...  

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.


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