Effects of transcranial direct current stimulation over the Broca’s area on tongue twister production

Wong, Min Ney; Chan, Yanky; Ng, Manwa L.; Zhu, Frank

doi:10.1080/17549507.2017.1417480

Cited by 8 publications

(11 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Participants showed an improvement in performance and this was greater for the tongue twisters than for the simple sentences but these changes did not differ among the three groups. These results align with a recent study that also failed to replicate the original behavioural finding [11]. The effect of tDCS on behaviour in neurotypical populations has been difficult to replicate [13], [18].…”

Section: Discussionsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

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

Wiltshire

Watkins

2019

Preprint

View full text Add to dashboard Cite

Background: TDCS modulates cortical excitability in a polarity-specific way. When used in combination with a behavioural task, it can also alter performance. Previously, tDCS modulated the performance of older adults on a complex speech motor learning task, which involved repetition of tongue twisters [1].Objective: We aimed to replicate this finding in healthy young participants and to extend it by measuring tDCS-induced changes in motor excitability using transcranial magnetic stimulation and motor-evoked potentials elicited in the lips.Method: In a double-blind randomized sham-controlled study, three groups of 20 participants received: 1) anodal tDCS to the left IFG/LipM1 and cathodal tDCS to the right hemisphere homologue; or 2) cathodal tDCS over the left and anodal over the right; or 3) sham stimulation. Participants heard and repeated tongue twisters and matched simple sentences before, during and 10 minutes after the stimulation. Motor excitability was measured before and immediately after the tDCS.Results: The improvement in performance of tongue twister repetition from baseline to after stimulation was significantly greater than for the simple sentences but did not differ among the three groups. Motor excitability significantly decreased to a small but similar extent across the three groups.Conclusions: TDCS did not modulate performance on a complex articulation task in healthy young adults. TDCS applied concurrently with task learning also failed to modulate motor excitability in expected ways. TDCS may be most effective in brains where brain function is sub-optimal due to age-related declines or pathology.

show abstract

Section: Discussionsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 97%

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

Wiltshire

Watkins

2019

Preprint

View full text Add to dashboard Cite

show abstract

“…A further possible confound for tDCS studies is practice or training effects following repeated attempts at a task which could mask, interfere, or interact with tDCS (Eddy et al 2017;Furuya et al 2014;Hsu et al 2015;Peters et al 2013;Thair et al 2017;Wong et al 2018). Fortunately, the ODT is quite resilient to repeated attempts as no robust performance improvement could be observed without extensive training (Song et al 2010;Vogels and Orban 1985).…”

Section: Introductionmentioning

confidence: 99%

Investigating the Effects of tDCS on Visual Orientation Discrimination Task Performance: “the Possible Influence of Placebo”

et al. 2019

View full text Add to dashboard Cite

The non-invasive neuromodulation technique tDCS offers the promise of a low-cost tool for both research and clinical applications in psychology, psychiatry, and neuroscience. However, findings regarding its efficacy are often equivocal. A key issue is that the clinical and cognitive applications studied are often complex and thus effects of tDCS are difficult to predict given its known effects on the basic underlying neurophysiology, namely alterations in cortical inhibition-excitation balance. As such, it may be beneficial to assess the effects of tDCS in tasks whose performance has a clear link to cortical inhibition-excitation balance such as the visual orientation discrimination task (ODT). In prior studies in our laboratory, no practice effects were found during 2 consecutive runs of the ODT, thus in the current investigation, to examine the effects of tDCS, subjects received 10 min of 2 mA occipital tDCS (sham, anode, cathode) between a first and second run of ODT. Surprisingly, subjects' performance significantly improved in the second run of ODT compared to the first one regardless of the tDCS stimulation type they received (anodal, cathodal, or sham-tDCS). Possible causes for such an improvement could have been due to either a generic "placebo" effect of tDCS (as all subjects received some form of tDCS) or an increased delay period between the two runs of ODT of the current study compared to our previous work (10-min duration required to administer tDCS as opposed to~2 min in previous studies as a "break"). As such, we tested these two possibilities with a subsequent experiment in which subjects received 2-min or 10-min delay between the 2 runs (with no tDCS) or 10 min of sham-tDCS. Only sham-tDCS resulted in improved performance thus these data add to a growing literature suggesting that tDCS has powerful placebo effect that may occur even in the absence of active cortical modulation.

show abstract

“…Participants' response times and accuracy in repeating tongue twisters were successfully modulated during stimulation: a-tDCS significantly increased accuracy and reduced response times relative to baseline measures, whereas c-tDCS significantly reduced accuracy and increased response times from baseline; sham stimulation had no effect. The second study ( Wong et al, 2019 ) compared the effects of a-tDCS (2 mA for 20 min) over Broca's area and sham stimulation on reading of Cantonese tongue twisters in a younger population (mean age = 27 years; N = 30, 15 per group). Speech rate and accuracy improvements on the task were not modulated by a-tDCS, however.…”

Section: Introductionmentioning

confidence: 99%

“…We made a number of changes to the previous experimental designs ( Fiori et al, 2014 ; Wong et al, 2019 ) with the aim of optimizing the effects of stimulation and evaluating them with appropriate controls in a randomized double-blind sham-controlled study. The study design and analysis plan were pre-registered on the Open Science Framework ( https://osf.io/p84ys/ ).…”

Section: Introductionmentioning

confidence: 99%

Failure of tDCS to modulate motor excitability and speech motor learning

Wiltshire

Watkins

2020

Neuropsychologia

View full text Add to dashboard Cite

Transcranial direct current stimulation (tDCS) modulates cortical excitability in a polarity-specific way and, when used in combination with a behavioural task, it can alter performance. TDCS has the potential, therefore, for use as an adjunct to therapies designed to treat disorders affecting speech, including, but not limited to acquired aphasias and developmental stuttering. For this reason, it is important to conduct studies evaluating its effectiveness and the parameters optimal for stimulation. Here, we aimed to evaluate the effects of bi-hemispheric tDCS over speech motor cortex on performance of a complex speech motor learning task, namely the repetition of tongue twisters. A previous study in older participants showed that tDCS could modulate performance on a similar task. To further understand the effects of tDCS, we also measured the excitability of the speech motor cortex before and after stimulation. Three groups of 20 healthy young controls received: (i) anodal tDCS to the left IFG/LipM1 and cathodal tDCS to the right hemisphere homologue; or (ii) cathodal tDCS over the left and anodal over the right; or (iii) sham stimulation. Participants heard and repeated novel tongue twisters and matched simple sentences before, during and 10 min after the stimulation. One mA tDCS was delivered concurrent with task performance for 13 min. Motor excitability was measured using transcranial magnetic stimulation to elicit motor-evoked potentials in the lip before and immediately after tDCS. The study was double-blind, randomized, and sham-controlled; the design and analysis were pre-registered. Performance on the task improved from baseline to after stimulation but was not significantly modulated by tDCS. Similarly, a small decrease in motor excitability was seen in all three stimulation groups but did not differ among them and was unrelated to task performance. Bayesian analyses provide substantial evidence in support of the null hypotheses in both cases, namely that tongue twister performance and motor excitability were not affected by tDCS. We discuss our findings in the context of the previous positive results for a similar task. We conclude that tDCS may be most effective when brain function is sub-optimal due to age-related declines or pathology. Further study is required to determine why tDCS failed to modulate excitability in the speech motor cortex in the expected ways.

show abstract

Effects of transcranial direct current stimulation over the Broca’s area on tongue twister production

Abstract: The findings revealed that a single session of anodal tDCS over the Broca's area did not significantly improve speech production during tongue twister production.

Cited by 8 publications

References 29 publications

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

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

Investigating the Effects of tDCS on Visual Orientation Discrimination Task Performance: “the Possible Influence of Placebo”

Failure of tDCS to modulate motor excitability and speech motor learning

Contact Info

Product

Resources

About