Anodal transcranial direct current stimulation over left inferior frontal gyrus enhances sentence comprehension

2018 ◽  
Vol 176 ◽  
pp. 36-41 ◽  
Author(s):  
Beatrice Giustolisi ◽  
Alessandra Vergallito ◽  
Carlo Cecchetto ◽  
Erica Varoli ◽  
Leonor J. Romero Lauro
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Sentence Comprehension ◽  
Inferior Frontal Gyrus ◽  
Left Inferior Frontal Gyrus ◽  
Direct Current Stimulation

scholarly journals Transcranial direct current stimulation over the left inferior frontal gyrus improves sentence comprehension

2020 ◽  
Author(s):  
Eleni Peristeri ◽  
Zeyi Wang ◽  
Olivia Herrmann ◽  
Brian Caffo ◽  
Constantine Frangakis ◽  
...  
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Sentence Comprehension ◽  
Inferior Frontal Gyrus ◽  
Post Treatment ◽  
Lexical Retrieval ◽  
Transfer Effects ◽  
Far Transfer ◽  
Left Inferior Frontal Gyrus ◽  
Direct Current Stimulation

Background. The left inferior frontal gyrus (IFG) has been shown to be involved in sentence comprehension in many studies through its involvement in both semantic and syntactic computations. However, causal evidence for its involvement in sentence comprehension is scarce. We used transcranial direct current stimulation (tDCS) to test the causal involvement of the left IFG in sentence comprehension in a group of individuals with primary progressive aphasia (PPA). These individuals participated in a tDCS study targeting lexical retrieval only, not sentence comprehension, therefore in the present study we report on far-transfer effects of tDCS in sentence comprehension. Objective. We sought to determine whether tDCS over the left inferior frontal gyrus (IFG) coupled with lexical retrieval treatment may improve sentence comprehension in PPA. Method. Within a sham-controlled, double-blind design, we tested whether 15 daily sessions of anodal tDCS over the left IFG may improve sentence comprehension in 27 people with PPA, and whether the tDCS effects were sustained up to two months post-treatment. Results. We found that immediately post-treatment, and up to 2-months post-treatment, there was significantly larger improvement of sentence comprehension in the tDCS condition compared to sham. There were, however, differential effects of tDCS in each PPA variant and sentence-type. Importantly, participants with the epicenter of atrophy over the stimulated area (non-fluent PPA) benefited most from tDCS. Conclusion. TDCS over the left IFG induces far-transfer effects and may improve sentence comprehension in PPA. We provide causal evidence that left IFG is a critical area for sentence comprehension.

Effects of Anodal Transcranial Direct Current Stimulation (atDCS) on Sentence Comprehension

2019 ◽  
Vol 25 (3) ◽  
pp. 331-335
Author(s):  
Jarrad A. G. Lum ◽  
Gillian M. Clark ◽  
Caitlyn M. Rogers ◽  
James D. Skalkos ◽  
Ian Fuelscher ◽  
...  
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Sentence Comprehension ◽  
Inferior Frontal Gyrus ◽  
Reaction Times ◽  
Healthy Adults ◽  
Word Comprehension ◽  
Sham Stimulation ◽  
Direct Current Stimulation ◽  
Comprehension Task

AbstractObjectives: This study examined the effects of anodal transcranial direct current stimulation (a-tDCS) on sentence and word comprehension in healthy adults. Methods: Healthy adult participants, aged between 19 and 30 years, received either a-tDCS over the left inferior frontal gyrus (n=18) or sham stimulation (n=18). Participants completed sentence comprehension and word comprehension tasks before and during stimulation. Accuracy and reaction times (RTs) were recorded as participants completed both tasks. Results: a-tDCS was found to significantly decrease RT on the sentence comprehension task compared to baseline. There was no change in RT following sham stimulation. a-tDCS was not found to have a significant effect on accuracy. Also, a-tDCS did not affect accuracy or RTs on the word comprehension task. Conclusions: The study provides evidence that non-invasive anodal electrical stimulation can modulate sentence comprehension in healthy adults, at least compared to their baseline performance. (JINS, 2019, 25, 331–335)

scholarly journals Brain state and polarity dependent modulation of brain networks by transcranial direct current stimulation

2017 ◽  
Author(s):  
Lucia M. Li ◽  
Ines R. Violante ◽  
Rob Leech ◽  
Ewan Ross ◽  
Adam Hampshire ◽  
...  
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Large Scale ◽  
Inferior Frontal Gyrus ◽  
Brain Networks ◽  
Cognitive Networks ◽  
Network Activity ◽  
Brain State ◽  
Direct Current Stimulation ◽  
Network Activation

AbstractTranscranial direct current stimulation (TDCS) has been widely used to improve cognitive function. However, current deficiencies in mechanistic understanding hinders wider applicability. To clarify its physiological effects, we acquired fMRI whilst simultaneously acquiring TDCS to the right inferior frontal gyrus (rIFG) of healthy human participants, a region involved in coordinating activity within brain networks. TDCS caused widespread modulation of network activity depending on brain state (‘rest’ or choice reaction time task) and polarity (anodal or cathodal). During task, TDCS increased salience network activation and default mode network deactivation, but had the opposite effect during ‘rest’. Furthermore, there was an interaction between brain state and TDCS polarity, with cathodal effects more pronounced during task performance and anodal effects more pronounced during ‘rest’. Overall, we show that rIFG TDCS produces brain state and polarity dependent effects within large-scale cognitive networks, in a manner that goes beyond predictions from the current literature.

Transcranial Direct Current Stimulation Combined With Cognitive Training Induces Response Inhibition Facilitation Through Distinct Neural Responses According to the Stimulation Site: A Follow-up Event-Related Potentials Study

2020 ◽  
pp. 155005942095896
Author(s):  
Clémence Dousset ◽  
Anaïs Ingels ◽  
Elisa Schröder ◽  
Laura Angioletti ◽  
Michela Balconi ◽  
...  
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Cognitive Rehabilitation ◽  
Response Times ◽  
Inferior Frontal Gyrus ◽  
Training Session ◽  
Event Related Potentials ◽  
Stimulation Site ◽  
Direct Current Stimulation ◽  
Related Potentials

Objective We investigated whether the mid-term impact (1 week posttraining) of a “combined cognitive rehabilitation (CRP)/transcranial direct current stimulation (tDCS) program” on the performance of a Go/No-go task was enhanced compared with isolated CRP and whether it varied according to the stimulation site (right inferior frontal gyrus [rIFG] vs right dorsolateral prefrontal cortex [rDLPFC]). Methods A total of 150 healthy participants were assigned to (1) an Inhibition Training (IT) group, (2) a group receiving active tDCS over the rIFG in combination with IT (IT + IF), (3) a group receiving active tDCS over the rDLPFC in combination with IT (IT + DL), (4) a group receiving IT with sham tDCS (ITsham), and (5) a No-Training (NT) group to control for test-retest effects. Each group undertook 3 sessions of a Go/No-go task concomitant with the recording of event-related potentials (T0, before training; T1, at the end of a 4-day training session [20 minutes each day]; T2, 1 week after T1). Results With the exception of the NT participants, all the groups exhibited improved performances at T2. The IT + DL group exhibited the best improvement profile, indexed by faster response times (RTs) (T0 > T1 = T2), with a reduced rate of errors at the posttraining sessions compared with both T0 and T1. This “inhibitory learning effect” was neurophysiologically indexed by shorter No-go N2d latencies and enhanced No-go P3d amplitudes. Conclusion CRP combined with active tDCS over the rDLPFC appears to be optimal for boosting long-term (one week) inhibitory skills as it induced specific and robust neural changes.

Modulating Brain Mechanisms Resolving Lexico-semantic Interference during Word Production: A Transcranial Direct Current Stimulation Study

2014 ◽  
Vol 26 (7) ◽  
pp. 1403-1417 ◽  
Author(s):  
Ilona Henseler ◽  
Andreas Mädebach ◽  
Sonja A. Kotz ◽  
Jörg D. Jescheniak
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Inferior Frontal Gyrus ◽  
Cortical Activation ◽  
Middle Temporal Gyrus ◽  
Semantic Interference ◽  
Facilitation Effect ◽  
Direct Current Stimulation ◽  
Response Reversal ◽  
Naming Latencies

The aim of the current study was to shed further light on control processes that shape semantic access and selection during speech production. These processes have been linked to differential cortical activation in the left inferior frontal gyrus (IFG) and the left middle temporal gyrus (MTG); however, the particular function of these regions is not yet completely elucidated. We applied transcranial direct current stimulation to the left IFG and the left MTG (or sham stimulation) while participants named pictures in the presence of associatively related, categorically related, or unrelated distractor words. This direct modulation of target regions can help to better delineate the functional role of these regions in lexico-semantic selection. Independent of stimulation, the data show interference (i.e., longer naming latencies) with categorically related distractors and facilitation (i.e., shorter naming latencies) with associatively related distractors. Importantly, stimulation location interacted with the associative effect. Whereas the semantic interference effect did not differ between IFG, MTG, and sham stimulations, the associative facilitation effect was diminished under MTG stimulation. Analyses of latency distributions suggest this pattern to result from a response reversal. Associative facilitation occurred for faster responses, whereas associative interference resulted in slower responses under MTG stimulation. This reduction of the associative facilitation effect under transcranial direct current stimulation may be caused by an unspecific overactivation in the lexicon or by promoting competition among associatively related representations. Taken together, the results suggest that the MTG is especially involved in the processes underlying associative facilitation and that semantic interference and associative facilitation are linked to differential activation in the brain.

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