Effector-independent reduction in choice reaction time following bi-hemispheric transcranial direct current stimulation over motor cortex

Abstract

Increased reaction times (RT) during choice-RT tasks stem from a requirement for additional processing as well as reduced motor-specific preparatory activation. Transcranial direct current stimulation (tDCS) can modulate primary motor cortex excitability, increasing (anodal stimulation) or decreasing (cathodal stimulation) excitability in underlying cortical tissue. The present study investigated whether lateralized differences in choice-RT would result from the concurrent modulation of left and right motor cortices using bi-hemispheric tDCS. Participants completed a choice-RT task requiring either a left or right wrist extension. In forced-choice trials an illuminated target indicated the required response, whereas in free-choice trials participants freely selected either response upon illumination of a central fixation. Following a pre-test trial block, offline bi-hemispheric tDCS (1 mA) was applied over the left and right motor cortices for 10 minutes, which was followed by a post-tDCS block of RT trials. Twelve participants completed three experimental sessions, two with real tDCS (anode right, anode left), as well as a sham tDCS session. Post-tDCS results showed faster RTs for both right and left responses irrespective of tDCS polarity during forced-choice trials, while sham tDCS had no effect. In contrast, no stimulation-related RT or response selection differences were observed in free-choice trials. The present study shows evidence of an effector-independent speeding of response initiation in a forced-choice RT task following bi-hemispheric tDCS and yields novel information regarding the functional effect of bi-hemispheric tDCS.

Poststimulation time interval-dependent effects of motor cortex anodal tDCS on reaction-time task performance

“…The results of the present study are in principle accordance with those of others, which showed an impact of tDCS on RT tasks. For example, when RT was evaluated before and after 10 min of tDCS application, faster RTs were found after stimulation (Drummond et al, 2017). Other studies showed a similar impact of tDCS on motor performance in RT tasks (Müller et al, 2008;Nitsche, Schauenburg, et al, 2003).…”

“…Sixty right-handed volunteers, 31 women and 29 men (mean age = 25.9 ± 3.03 years), participated in the study. Sample size was determined based on previous studies about the effect of tDCS on RT tasks (Drummond et al, 2017;Verissimo, Barradas, Santos, Miranda, & Ferreira, 2016). All subjects were healthy and without evidence of neurological or psychiatric disorders, and none of them was under central nervous system active medication.…”

“…The functional effects of tDCS on motor performance and coordination so far have been tested primarily during stimulation (Cuypers et al, 2013;Foerster et al, 2013; Andrés Molero-Chamizo, José R. Alameda Bailén and Guadalupe N. Rivera-Urbina contributed equally to this work. Cuypers, Vanvlijmen, & Meesen, 2015;Nitsche, Schauenburg, et al, 2003;Pavlova, Kuo, Nitsche, & Borg, 2014) or immediately thereafter (Drummond, Hayduk-Costa, Leguerrier, & Carlsen, 2017;Leite, Carvalho, Fregni, & Gonçalves, 2011). Since the neurophysiological effects of motor cortex tDCS can remain for a considerable period after stimulation (Nitsche & Paulus, 2000, also the impact on motor performance might outlast the stimulation itself.…”

Transcranial Direct current stimulation does not modulate performance on a tongue twister task

“…2). In addition, bi-hemispheric montages are at least as effective as uni-hemispheric ones [19][20][21] or can even improve the effects on task performance [22][23][24]. Secondly, we reduced the current amplitude from 2mA to 1mA and the duration of stimulation from 20 minutes to 13 minutes.…”

Neurodiagnostics in Sports: Investigating the Athlete’s Brain to Augment Performance and Sport-Specific Skills

“…For example, a single tDCS session has been shown to increase motor performance or skill learning (Nitsche et al, 2003b;Vollmann et al, 2013;Ammann et al, 2016;Kaminski et al, 2016;Jackson et al, 2019;Kumari et al, 2019). tDCS-induced performance enhancement has not only been described for simple motor tasks such as tapping (Saimpont et al, 2016) and reaction time tasks (Nitsche et al, 2003b;Drummond et al, 2017;Hupfeld et al, 2017), but also for complex whole-body tasks such as balancing (Dutta et al, 2014;Kaminski et al, 2016). Moreover, further studies demonstrated that tDCS is capable of increasing endurance performance during cycling (Okano et al, 2015;Vitor-Costa et al, 2015;Angius et al, 2018a;Park et al, 2019) and running (Park et al, 2019) as well as leg muscle power (Tanaka et al, 2009).…”