We aimed to evaluate the effects of prefrontal tDCS on mood and mood-related cognitive processing in healthy humans. In a first study, we administered excitability-enhancing anodal, excitability-diminishing cathodal and placebo tDCS to the left dorsolateral prefrontal cortex, combined with antagonistic stimulation of the right frontopolar cortex, and tested acute mood changes by an adjective checklist. Subjective mood was not influenced by tDCS. Emotional face identification, however, which was explored in a second experiment, was subtly improved by a tDCS-driven excitability modulation of the prefrontal cortex, markedly by anodal tDCS of the left dorsolateral prefrontal cortex for positive emotional content. We conclude that tDCS of the prefrontal cortex improves mood processing in healthy subjects, but does not influence subjective mood state.
Category Archives: Paper
ScienceDirect.com – Progress in Neuro-Psychopharmacology and Biological Psychiatry – Transcranial direct current stimulation for the treatment of Major Depressive Disorder: A summary of preclinical, clinical and translational findings
Major depressive disorder (MDD) is a common psychiatric illness, with 6-12% lifetime prevalence. It is also among the five most disabling diseases worldwide. Current pharmacological treatments, although relatively effective, present important side effects that lead to treatment discontinuation. Therefore, novel treatment options for MDD are needed. Here, we discuss the recent advancements of one new neuromodulatory technique – transcranial direct current stimulation (tDCS) – that has undergone intensive research over the past decade with promising results. tDCS is based on the application of weak, direct electric current over the scalp, leading to cortical hypo- or hyper-polarization according to the specified parameters. Recent studies have shown that tDCS is able to induce potent changes in cortical excitability as well as to elicit long-lasting changes in brain activity. Moreover, tDCS is a technique with a low rate of reported side effects, relatively easy to apply and less expensive than other neuromodulatory techniques – appealing characteristics for clinical use. In the past years, 4 of 6 phase II clinical trials and one recent meta-analysis have shown positive results in ameliorating depression symptoms. tDCS has some interesting, unique aspects such as noninvasiveness and low rate of adverse effects, being a putative substitutive/augmentative agent for antidepressant drugs, and low-cost and portability, making it suitable for use in clinical practice. Still, further phase II and phase III trials are needed as to better clarify tDCS role in the therapeutic arsenal of MDD.
Fig. 2. Montage of transcranial direct current stimulation.The figures show the main montages used for major depression: in both, the anode is positioned over the left dorsolateral prefrontal cortex. The cathode can be either placed over the right dorsolateral prefrontal cortex (Figure A) or the right supraorbital area (Figure B).
Frontiers | USING TRANSCRANIAL DIRECT CURRENT STIMULATION TDCS TO TREAT DEPRESSION IN HIV-INFECTED PERSONS: THE OUTCOMES OF A FEASIBILITY STUDY | Frontiers in Neuropsychiatric Imaging and Stimulation
Depression scores significantly decreased p<.0005 after the treatment. No serious adverse events occurred. Several transient minor AEs and occasional changes of blood pressure and heart rate were noted. Mini-mental status scores remained unchanged or increased after the treatment. All subjects were highly satisfied with the protocol and treatment results and described the desire to find new treatments for HIV-MDD as motivating participation. Conclusions: F indings support feasibility and clinical potential of tDCS for HIV-MDD patients, and justify larger-sample, sham-controlled trials.
tDCS Update: Recent Trends and Applications – Roy Hamilton, 2010/11
Modulation of Training by Single-Session Transcranial Direct Current Stimulation to the Intact Motor Cortex Enhances Motor Skill Acquisition of the Paretic Hand
Method—Twelve well-recovered chronic patients with subcortical stroke attended 2 training sessions during which either cathodal tDCS or a sham intervention were applied to the contralesional motor cortex in a double-blind, crossover design. Two different motor sequences, matched for their degree of complexity, were tested in a counterbalanced order during as well as 90 minutes and 24 hours after the intervention. Potential underlying mechanisms were evaluated with transcranial magnetic stimulation.
Results—tDCS facilitated the acquisition of a new motor skill compared with sham stimulation (P=0.04) yielding better task retention results. A significant correlation was observed between the tDCS-induced improvement during training and the tDCS-induced changes of intracortical inhibition (R2=0.63).
Conclusions—These results indicate that tDCS is a promising tool to improve not only motor behavior, but also procedural learning. They further underline the potential of noninvasive brain stimulation as an adjuvant treatment for long-term recovery, at least in patients with mild functional impairment after stroke.
The effects of transcranial direct current stimulation with visual illusion in neuropathic pain due to spinal cord injury: An evoked potentials and quantitative thermal testing study – Kumru – 2012 – European Journal of Pain – Wiley Online Library
Abstract
Background
Neuropathic pain NP is common in spinal cord injury SCI patients. One of its manifestations is a lowering of pain perception threshold in quantitative thermal testing QTT in dermatomes rostral to the injury level. Transcranial direct current stimulation tDCS combined with visual illusion VI improves pain in SCI patients. We studied whether pain relief with tDCS + VI intervention is accompanied by a change in contact heat- evoked potentials CHEPs or in QTT.
Methods
We examined 18 patients with SCI and NP before and after 2 weeks of daily tDCS + VI intervention. Twenty SCI patients without NP and 14 healthy subjects served as controls. We assessed NP intensity using a numerical rating scale NRS and determined heat and pain thresholds with thermal probes. CHEPs were recorded to stimuli applied at C4 level, and subjects rated their perception of evoked pain using NRS during CHEPs.
Results
Thirteen patients reported a mean decrease of 50% in the NRS for NP after tDCS + VI. Evoked pain perception was significantly higher than in the other two groups, and reduced significantly together with CHEPs amplitude after tDCS + VI with respect to baseline. Pain perception threshold was significantly lower than in the other two groups before tDCS + VI intervention, and increased significantly afterwards.
Conclusion
Two weeks of tDCS + VI induced significant changes in CHEPs, evoked pain and heat pain threshold in SCI patients with NP. These neurophysiological tests might be objective biomarkers of treatment effects for NP in patients with SCI.
U of Penn [Unverified] Seeks Input From DIYtDCS Community.
This just came in as a comment, I’m reposting as a post. I don’t know the author and have not corresponded with them as of yet. I can confirm that the originating email address has a upen.edu footprint.
Hi, You are being invited to participate in a research study conducted by the University of Pennsylvania. Your participation is voluntary which means you can choose whether or not you want to participate. The Laboratory of Cognition and Neural Stimulation at the University of Pennsylvania is involved in research using transcranial direct current stimulation (tDCS). In recent years this technology has increased in popularity, and evidence suggests that some individuals may be constructing their own stimulators for personal use. We are interested in examining the reasons behind this. Please answer the questions below, and email them to braintdcs@gmail.com to give us insight into why people make their own tDCS machines. Questions 1. Where did you first learn about tDCS? 2. Have you built your own tDCS machine? 3. Where did you get the information to build the machine? 4. Why did you want to try brain stimulation? 5. How long have you been using tDCS? 6. What were your experiences with this technology? 7. Did you ever experience any side-effects? The research team may use information about you collected from your responses. By completing the questionnaire, you are giving your consent to participate in this study. Once you email us, your responses are not considered confidential since emails do not protect confidentiality. Thanks, Research Specialist Laboratory of Cognition and Neural Stimulation University of Pennsylvania
Transcranial Direct Current Stimulation for the Reduction of… : The Clinical Journal of Pain
Results: Trials investigating experimental pain in healthy participants (n=6) used a wide variety of stimulation and outcome parameters that did not allow a synthesis across outcome parameters. Trials investigating chronic pain (n=8) used anodal motor cortex stimulation of 1 or 2 mA intensity, either as a single dose or on a maximum of 10 consecutive days. Four trials on chronic pain were excluded due to a high risk of bias. A meta-analysis of 4 trials on chronic pain found a pooled effect size of −2.29 with a 95% confidence interval of −3.5 to −1.08. This effect does just reach minimal clinically important difference recommendations.
Discussion: The level of evidence for the efficacy of transcranial direct current stimulation in experimental and chronic pain reduction is low. Evidence from high quality randomized controlled trials is required before this treatment should be recommended.
via Transcranial Direct Current Stimulation for the Reduction of… : The Clinical Journal of Pain.
Effects of transcranial direct curren… [Restor Neurol Neurosci. 2012] – PubMed – NCBI
Conclusions: Anodal tDCS applied over the affected pharyngeal motor cortex can enhance the outcome of swallowing training in post-stroke dysphagia. Our results suggest that non-invasive cortical stimulation has a potential role as an adjuvant strategy during swallowing training in patients with post-stroke dysphagia.
via Effects of transcranial direct curren… [Restor Neurol Neurosci. 2012] – PubMed – NCBI.
PsychiatryOnline | American Journal of Psychiatry | Examining Transcranial Direct-Current Stimulation tDCS as a Treatment for Hallucinations in Schizophrenia
Results: Auditory verbal hallucinations were robustly reduced by tDCS relative to sham stimulation, with a mean diminution of 31% SD=14; d=1.58, 95% CI=0.76–2.40. The beneficial effect on hallucinations lasted for up to 3 months. The authors also observed an amelioration with tDCS of other symptoms as measured by the Positive and Negative Syndrome Scale d=0.98, 95% CI=0.22–1.73, especially for the negative and positive dimensions. No effect was observed on the dimensions of disorganization or grandiosity/excitement.
Conclusions: Although this study is limited by the small sample size, the results show promise for treating refractory auditory verbal hallucinations and other selected manifestations of schizophrenia.
tDCS Info resource
Is there anybody willing to help with writing tDCS info resource ?
I started here https://brmlab.cz/project/brain_hacking/tdcs but is a task for comunity no one person , i planed to copy this info to GoFlow wiki when it started.
Almoust everyone underestimate the complexicity of tDCS and posible risk from long term use.
Frontiers | Transcranial Alternating Current Stimulation affects decision making | Frontiers in Systems Neuroscience
In a recent paper in Frontiers in Decision Neuroscience, Sela and colleagues 2012 used tACS to investigate the effects of oscillatory prefrontal theta stimulation, a frequency involved in regulatory control during decision-making processes Sela et al., 2012. Subjects performed a modified version of the Balloon Analog Risk Task BART, Lejuez et al., 2004. In this task, volunteers pump a balloon without knowing when it will explode. The more the pump button is pressed, the more points accumulate while at the same time the risk of losing points with a balloon explosion increases. Subjects are thus pressured to decide whether to adopt a risky behavior and keep pumping, or to use a more conservative strategy and stop. tACS was delivered to three groups of healthy volunteers. One group received stimulation over the left prefrontal cortex lPFC, one over the right prefrontal cortex rPFC, and the other received sham stimulation. tACS was delivered online during the task. Stimulation started 5 minutes before the task began and lasted for approximately 10 minutes until the BART was completed. Crucially, active tACS was only delivered at a theta frequency of 6.5 Hz. Sham stimulation involved the same parameters, but was only delivered for 30 s. Results showed a striking effect of lPFC stimulation, whereas rPFC and sham stimulations failed to produce any considerable effect on task performance. More specifically, the increase of sequential losses during tACS stimulation over lPFC suggested that volunteers lost the ability to adjust their actions based on negative feedback. Sela et al. 2012 hypothesized that theta stimulation of the lPFC interfered with volunteers’ performance during the task, making them more inclined to adopt a risky behavior.
Investigation of visual dream reports after transcranial direct current stimulation (tDCS) during REM sleep
This is one of the applications of tDCS I’ve been waiting to hear about. I was hoping tDCS might help facilitate an active dreaming state or even lucid dreaming.
Conclusions
In summary, using two different methodologies it appears that tDCS had no effect on the presence of dream reports with visual imagery or measures of dream quality. However, this may be due to methodological limitations of these stud- ies, as the delivery methods employed allowed only low levels of tDCS to be delivered without waking participants. Improvements allowing higher levels of stimulation during sleep and stimulation of other cortical regions could poten- tially provide more definitive conclusions regarding the ef- fectiveness of tDCS on dream imagery reported from REM sleep.
Abstract
Investigation of visual dream reports after tran- scranial direct current stimulation (tDCS) during REM sleep (pdf)
Effects of sham-controlled double blind transcranial direct current stimulation in patients with disorders of consciousness
Assessing the effect of transcranial direct current stimulation (tDCS) on cognition in patients with disorder of consciousness.
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PLoS ONE: Anodal Transcranial Direct Current Stimulation Reduces Psychophysically Measured Surround Suppression in the Human Visual Cortex
The aim of this study was to assess whether anodal tDCS could reduce inhibitory interactions within the human visual cortex. Psychophysical measures of surround suppression were used as an index of inhibition within V1. Overlay suppression, which is thought to originate within the lateral geniculate nucleus LGN, was also measured as a control. Anodal stimulation of the occipital poles significantly reduced psychophysical surround suppression, but had no effect on overlay suppression. This effect was specific to anodal stimulation as cathodal stimulation had no effect on either measure. These psychophysical results provide the first evidence for tDCS-induced reductions of intracortical inhibition within the human visual cortex.