scholarly journals When Brain Stimulation Backfires

2020 ◽  
Author(s):  
Sarah Beth Bell ◽  
Brian Turner ◽  
Lumy Sawaki ◽  
C. Nathan DeWall
Keyword(s):  
Prefrontal Cortex ◽  
Individual Differences ◽  
Direct Current ◽  
Brain Stimulation ◽  
Stop Signal Task ◽  
Impulsive Behavior ◽  
Trait Impulsivity ◽  
Behavior Scale ◽  
Healthy Participants ◽  
Intended Effect

Transcranial direct current stimulation can sometimes cause the opposite of its intended effect. These reverse effects may be related in part to individual differences in personality and neurochemistry. Previous studies have demonstrated that dopamine levels can impact the effects of tDCS. In the present study, 124 healthy participants took the UPPS Impulsive Behavior scale. Participants then underwent a single, randomized anodal or sham tDCS session on the prefrontal cortex. While the effects of tDCS were still active, they performed the Stop Signal Task, a measure of state impulsivity. tDCS was associated with increased errors on this task in people who had higher scores on the UPPS in two facets of impulsivity that correlate with dopamine levels. tDCS had no effects on people low in trait impulsivity. These results suggest that the reverse effects of tDCS could be associated with inter-individual differences in personality and neurochemistry.

scholarly journals When brain stimulation backfires: the effects of prefrontal cortex stimulation on impulsivity

2020 ◽  
Author(s):  
Sarah Beth Bell ◽  
Brian Turner ◽  
Lumy Sawaki ◽  
Nathan DeWall
Keyword(s):  
Prefrontal Cortex ◽  
Individual Differences ◽  
Direct Current ◽  
Brain Stimulation ◽  
Stop Signal Task ◽  
Impulsive Behavior ◽  
Trait Impulsivity ◽  
Behavior Scale ◽  
Healthy Participants ◽  
Intended Effect

Abstract Transcranial direct current stimulation (tDCS) can sometimes cause the opposite of its intended effect. These reverse effects may be related in part to individual differences in personality and neurochemistry. Previous studies have demonstrated that dopamine levels can impact the effects of tDCS. In the present study, 124 healthy participants took the UPPS impulsive behavior scale. Participants then underwent a single, randomized anodal or sham tDCS session on the prefrontal cortex. While the effects of tDCS were still active, they performed the Stop Signal Task, a measure of state impulsivity. tDCS was associated with increased errors on this task in people who had higher scores on the UPPS in two facets of impulsivity that correlate with dopamine levels. tDCS had no effects on people who are low in trait impulsivity. These results suggest that the reverse effects of tDCS could be associated with inter-individual differences in personality and neurochemistry.

Prefrontal Cortex Transcranial Direct Current Stimulation Treatment in Alcohol Dependence Syndrome (PreCoTTA): Study Protocol for a Double-Blind Randomized Sham-Controlled Trial

2021 ◽  
Vol 16 ◽  
Author(s):  
Anagha S. Deshmukh ◽  
Samir Kumar Praharaj ◽  
Shweta Rai ◽  
Asha Kamath ◽  
Dinesh Upadhya
Keyword(s):  
Prefrontal Cortex ◽  
Alcohol Dependence ◽  
Direct Current ◽  
Brain Stimulation ◽  
Transcranial Direct Current Stimulation ◽  
Public Health Problem ◽  
Comprehensive Treatment ◽  
Direct Current Stimulation ◽  
Non Invasive ◽  
Alcohol Dependence Syndrome

Background: Alcohol dependence is a significant public health problem, contributing to the global health burden. Due to its immense socio-economic burden, various psychosocial, psychological, and pharmacological approaches have attempted to alter the behaviour of the patient misusing or abusing alcohol, but their efficacy is modest at best. Therefore, there is a search for newer treatment approaches, including noninvasive brain stimulation in the management of alcohol dependence. We plan to study the efficacy of Prefrontal Cortex Transcranial direct current stimulation Treatment in Alcohol dependence syndrome (PreCoTTA). Methods: Two hundred twenty-five male patients with alcohol dependence syndrome will be randomized into the three study arms (2 active, left dorsolateral prefrontal cortex and left orbitofrontal cortex, and 1 sham) to receive a total of 14 tDCS sessions (10 continuous and 4 booster sessions). Data will be collected from them at five different time points on clinical, neuropsychological and biochemical parameters. In addition, 225 healthy age and education matched controls will be administered the neuropsychological test battery at baseline for comparison with the patient group. Discussion: The proposed study aims to explore the use of non-invasive brain stimulation; tDCS as a treatment alternative. We also aim to overcome the methodological gaps of limited sample sizes, fewer tDCS intervention sessions, lack of long term follow ups to measure the sustainability of gains and lack comprehensive measures to track changes in functioning and abstinence after tDCS intervention. The main outcomes include clinical (reduction in cue-induced craving, time to first drink and QFI); neuropsychological (risk-taking, impulsivity, and other neuropsychological domains) and biochemical markers (BDNF, leptin and adiponectin). The findings of the study will have translational value as it may help to improve the clinician’s ability to effectively manage craving in patients with alcohol dependence syndrome. Furthermore, we will have a better understanding of the neuropsychological and biochemical effects of non-invasive brain stimulation techniques which are of interest in the comprehensive treatment of addiction disorders. Trial registration: The study has been registered with the Clinical Trials Registry-India (CTRI/2020/09/027582) on September 03rd 2020.

Modulation of complex multitask performance by tDCS depends on individual differences in baseline task ability

2016 ◽  
Vol 60 (1) ◽  
pp. 42-46 ◽  
Author(s):  
Melissa R. Scheldrup ◽  
Pritty Dwivedy ◽  
Jennifer Fisher ◽  
Julianne Holmbald ◽  
Pamela Greenwood
Keyword(s):  
Prefrontal Cortex ◽  
Individual Differences ◽  
Direct Current ◽  
Dual Task ◽  
Transcranial Direct Current Stimulation ◽  
Cognitive Interventions ◽  
High Performers ◽  
Baseline Task ◽  
And Training ◽  
Cathodal Stimulation

The ability to multitask is central to many important occupations. Individual differences in multitasking ability have been linked with differential activation within the prefrontal cortex (PFC), but causal evidence is lacking. In this study we applied transcranial direct current stimulation (tDCS) to the PFC during performance of the dual-task videogame Warship Commander (WSC). For low performers- cathodal stimulation, regardless of hemisphere, decreased performance in a subtask of WSC during stimulation, with effects persisting 24hours later. Anodal stimulation to right PFC also decreased performance in the same subtask, but this effect was limited to performance during stimulation. Stimulation did not significantly affect performance for high performers. The results of this study are the first to provide causal evidence for differential recruitment of the PFC for low and high performers. These findings indicate the need for assessment of individual differences in development of cognitive interventions and training protocols.

No Effect of Transcranial Direct Current Stimulation over Left Dorsolateral Prefrontal Cortex on Temporal Attention

2021 ◽  
pp. 1-13
Author(s):  
Raquel E. London ◽  
Heleen A. Slagter
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Individual Differences ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Cortical Excitability ◽  
Activity Levels ◽  
Direct Current Stimulation ◽  
Dorsolateral Prefrontal

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 transcranial direct current stimulation (tDCS) over left dorsolateral prefrontal cortex (lDLPFC)—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 “attentional blink” (AB), a deficit in identifying the second of two targets presented in rapid succession. Thirty-four participants performed an 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 the basis of suggestions that effects of tDCS depend on baseline brain activity levels, we hypothesized that anodal tDCS over lDLPFC would modulate the magnitude of the AB as a function of individual baseline AB magnitude. Behavioral results did not provide support for this hypothesis. At the group level, we also did not observe any significant effects of tDCS, and a Bayesian analysis revealed strong evidence that tDCS to lDLPFC did not affect AB performance. Together, these findings do not support the idea that there is an optimal level of prefrontal cortical excitability for cognitive function. More generally, they add to a growing body of work that challenges the idea that the effects of tDCS can be predicted from baseline levels of behavior.

Transcranialis egyenáram-stimuláció a kognitív idegtudományban – buktatók és megoldások

2021 ◽  
Vol 74 (5-6) ◽  
pp. 171-182
Author(s):  
Orsolya Pesthy ◽  
Karolina Janacsek ◽  
Dezső Németh
Keyword(s):  
Clinical Practice ◽  
Individual Differences ◽  
Mechanism Of Action ◽  
Direct Current ◽  
Brain Stimulation ◽  
Brain Activity ◽  
Noisy Data ◽  
Full Understanding ◽  
Non Invasive ◽  
Potential Problems

Transcranial direct current stimulation (tDCS) is a promising brain stimulation tool which is non-invasive, easy to use and relatively cheap. Since it can change brain activity in a temporal manner, it can contribute to both clinical practice and neuroscientific research. However, the effectiveness of tDCS has been questioned considering the lack of full understanding of its mechanism of action and the seemingly contradictory results. In this review, we aim to provide a summary of potential problems and possible solutions. Our main focus is on the inter-individual differences in the effect of tDCS which can explain the noisy data, thus, controlling for them is important in order to show reliable results. This review is hoped to contribute to maximizing the potential of tDCS by helping future researchers to design replicable studies.

The Role of the Parietal Cortex in Multisensory and Response Integration: Evidence from Transcranial Direct Current Stimulation (tDCS)

2014 ◽  
Vol 27 (2) ◽  
pp. 161-172 ◽  
Author(s):  
Sharon Zmigrod
Keyword(s):  
Multisensory Integration ◽  
Parietal Cortex ◽  
Direct Current ◽  
Brain Stimulation ◽  
Transcranial Direct Current Stimulation ◽  
Brain Regions ◽  
The Right ◽  
The Brain ◽  
Healthy Participants

The question of how the brain forms unified representations from multisensory data that are processed in distinct cortical regions is known in the literature as ‘the binding problem’. In the last decade, several studies have suggested possible neural mechanisms and brain regions that might be involved in integration processes. One of the brain regions that is implicated with multisensory perception is the posterior parietal cortex (PPC). Evidence from patients with parietal lesions suggests the involvement of the PPC in coherent perception. Here, we investigated the role of the PPC in multisensory feature integration through experimental manipulation of non-invasive brain stimulation with healthy participants using transcranial direct current stimulation (tDCS). In different sessions, healthy participants received anodal, cathodal, or sham stimulation (2 mA, 20 min) over the right PPC while performing an audio-visual event-file task. The results underscore two interesting observations. Firstly, there was a significant difference in integration effects between features from different modalities in the anodal stimulation compared to sham, suggesting interference of the multisensory integration processes during the brain stimulation. And secondly, after anodal stimulation, the unattended feature became more likely to be integrated with the response feature compared to the other conditions, presumably through an interference of attentional processes. Hence, these findings emphasize the role of the right PPC in multisensory integration. Furthermore, from a methodological perspective, tDCS can be used as an experimental tool by creating a temporary, reversible disruption in cognitive processes in order to explore the mechanisms underlying cognitive functions.

Activation of Inhibition: Diminishing Impulsive Behavior by Direct Current Stimulation over the Inferior Frontal Gyrus

2011 ◽  
Vol 23 (11) ◽  
pp. 3380-3387 ◽  
Author(s):  
Liron Jacobson ◽  
Daniel C. Javitt ◽  
Michal Lavidor
Keyword(s):  
Cognitive Control ◽  
Direct Current ◽  
Brain Stimulation ◽  
Response Inhibition ◽  
Inferior Frontal Gyrus ◽  
Brain Lesion ◽  
Angular Gyrus ◽  
Stop Signal Task ◽  
Direct Current Stimulation ◽  
The Right

A common feature of human existence is the ability to reverse decisions after they are made but before they are implemented. This cognitive control process, termed response inhibition, refers to the ability to inhibit an action once initiated and has been localized to the right inferior frontal gyrus (rIFG) based on functional imaging and brain lesion studies. Transcranial direct current stimulation (tDCS) is a brain stimulation technique that can facilitate as well as impair cortical function. To explore whether response inhibition can be improved through rIFG electrical stimulation, we administered focal tDCS before subjects performed the stop signal task (SST), which measures response inhibition. Notably, activation of the rIFG by unilateral anodal stimulation significantly improved response inhibition, relative to a sham condition, whereas the same tDCS protocol did not affect response time in the go trials of the SST and in a control task. Furthermore, the SST was not affected by tDCS at a control site, the right angular gyrus. Our results are the first demonstration of response inhibition improvement with brain stimulation over rIFG and further confirm the rIFG involvement in this task. Although this study was conducted in healthy subjects, present findings with anodal rIFG stimulation support the use of similar paradigms for the treatment of cognitive control impairments in pathological conditions.

scholarly journals A meta-analysis of the effects of transcranial direct current brain stimulation on multiple realms of social behavior

2017 ◽  
Author(s):  
Sarah Beth Bell
Keyword(s):  
Prefrontal Cortex ◽  
Publication Bias ◽  
Direct Current ◽  
Brain Stimulation ◽  
Risk Taking ◽  
Meta Analysis ◽  
Region Of Interest ◽  
Social Behaviors ◽  
High Likelihood ◽  
Significant Publication Bias

This meta-analysis examines the effects of transcranial direct current brain stimulation (tDCS) applied to the prefrontal cortex on a variety of social behaviors including aggression, overeating, impulsivity, bias, honesty, and risk-taking. 48 studies were included in this meta-analysis, N=2,196. tDCS was found to have an overall effect size of d=-0.2, which means tDCS reduced the undesirable behavior by a small but significant amount. tDCS was most effective at reducing risk-taking behavior, bias, and overeating. tDCS was not significantly effective at reducing aggression, impulsivity, or dishonesty. Moderators such as brain region of interest, online versus offline stimulation, within versus between subjects designs, dose, and duration were examined. Publication bias was also examined with three different tools, and significant publication bias was found in the literature in this meta-analysis. These findings indicate high likelihood that many tDCS studies with null findings exist and have not been added to our published literature. Taken together, these results suggest that tDCS works better on some social behaviors than others, but overall, can reduce antisocial behavior by a small but significant amount.Keywords: transcranial direct current stimulation, meta-analysis, social psychology, prefrontal cortex, prosocial behavior

Subthalamic Nucleus Activation Occurs Early during Stopping and Is Associated with Trait Impulsivity

2019 ◽  
Vol 31 (4) ◽  
pp. 510-521
Author(s):  
Jong H. Yoon ◽  
Edward Dong Bo Cui ◽  
Michael J. Minzenberg ◽  
Cameron S. Carter
Keyword(s):  
Individual Differences ◽  
Subthalamic Nucleus ◽  
Time Course ◽  
Stop Signal ◽  
Stop Signal Task ◽  
Native Space ◽  
Novel Approach ◽  
Range Function ◽  
Trait Impulsivity ◽  
Time Required

The subthalamic nucleus (STN) is thought to be a central regulator of behavioral inhibition, which is thought to be a major determinant of impulsivity. Thus, it would be reasonable to hypothesize that STN function is related to impulsivity. However, it has been difficult to test this hypothesis because of the challenges in noninvasively and accurately measuring this structure's signal in humans. We utilized a novel approach for STN signal localization that entails identifying this structure directly on fMRI images for each individual participant in native space. Using this approach, we measured STN responses during the stop signal task in a sample of healthy adult participants. We confirmed that the STN exhibited selective activation during “Stop” trials. Furthermore, the magnitude of STN activation during successful Stop trials inversely correlated with individual differences in trait impulsivity as measured by a personality inventory. Time course analysis revealed that early STN activation differentiated successful from unsuccessful Stop trials, and individual differences in the magnitude of STN activation inversely correlated with stop signal RT, an estimate of time required to stop. These results are consistent with the STN playing a central role in inhibition and related behavioral proclivities, with implications for both normal range function and clinical syndromes of inhibitory dyscontrol. Moreover, the methods utilized in this study for measuring STN fMRI signal in humans may be gainfully applied in future studies to further our understanding of the role of the STN in regulating behavior and neuropsychiatric conditions.

Noninvasive Brain Stimulation of the Dorsolateral Prefrontal Cortex During Aesthetic Appreciation

2021 ◽  
pp. 97-101
Author(s):  
Marcos Nadal ◽  
Zaira Cattaneo ◽  
Camilo J. Cela-Conde
Keyword(s):  
Prefrontal Cortex ◽  
Direct Current ◽  
Brain Stimulation ◽  
Transcranial Direct Current Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Aesthetic Appreciation ◽  
Causal Association ◽  
Noninvasive Brain Stimulation ◽  
Dorsolateral Prefrontal ◽  
Stimulation Of

Several neuroimaging studies had shown that activity in the left dorsolateral prefrontal cortex (lDLPFC) was associated with aesthetic appreciation. But, was this a causal association? In the article under discussion, the authors used transcranial direct current stimulation (tDCS) to determine whether lDLPFC activity actually caused increased aesthetic appreciation. Their results showed that tDCS over lDLPFC caused liking for artworks and photographs to increase. They therefore concluded that the lDLPFC plays a causal role in visual aesthetic appreciation. The authors suggested that lDLPFC activity contributes to disengaging from a pragmatic orientation to stimuli, consisting mainly in identifying objects, adopting an aesthetic orientation, and focusing on those objects’ aesthetic qualities.

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