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Mattioli F, Maglianella V, D'Antonio S, Trimarco E, Caligiore D. Non-invasive brain stimulation for patients and healthy subjects: Current challenges and future perspectives. J Neurol Sci 2024; 456:122825. [PMID: 38103417 DOI: 10.1016/j.jns.2023.122825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 11/22/2023] [Accepted: 11/28/2023] [Indexed: 12/19/2023]
Abstract
Non-invasive brain stimulation (NIBS) techniques have a rich historical background, yet their utilization has witnessed significant growth only recently. These techniques encompass transcranial electrical stimulation and transcranial magnetic stimulation, which were initially employed in neuroscience to explore the intricate relationship between the brain and behaviour. However, they are increasingly finding application in research contexts as a means to address various neurological, psychiatric, and neurodegenerative disorders. This article aims to fulfill two primary objectives. Firstly, it seeks to showcase the current state of the art in the clinical application of NIBS, highlighting how it can improve and complement existing treatments. Secondly, it provides a comprehensive overview of the utilization of NIBS in augmenting the brain function of healthy individuals, thereby enhancing their performance. Furthermore, the article delves into the points of convergence and divergence between these two techniques. It also addresses the existing challenges and future prospects associated with NIBS from ethical and research standpoints.
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Affiliation(s)
- Francesco Mattioli
- AI2Life s.r.l., Innovative Start-Up, ISTC-CNR Spin-Off, Via Sebino 32, 00199 Rome, Italy; School of Computing, Electronics and Mathematics, University of Plymouth, Drake Circus, Plymouth PL4 8AA, United Kingdom
| | - Valerio Maglianella
- Computational and Translational Neuroscience Laboratory, Institute of Cognitive Sciences and Technologies, National Research Council (CTNLab-ISTC-CNR), Via San Martino della Battaglia 44, 00185 Rome, Italy
| | - Sara D'Antonio
- Computational and Translational Neuroscience Laboratory, Institute of Cognitive Sciences and Technologies, National Research Council (CTNLab-ISTC-CNR), Via San Martino della Battaglia 44, 00185 Rome, Italy
| | - Emiliano Trimarco
- Computational and Translational Neuroscience Laboratory, Institute of Cognitive Sciences and Technologies, National Research Council (CTNLab-ISTC-CNR), Via San Martino della Battaglia 44, 00185 Rome, Italy
| | - Daniele Caligiore
- AI2Life s.r.l., Innovative Start-Up, ISTC-CNR Spin-Off, Via Sebino 32, 00199 Rome, Italy; Computational and Translational Neuroscience Laboratory, Institute of Cognitive Sciences and Technologies, National Research Council (CTNLab-ISTC-CNR), Via San Martino della Battaglia 44, 00185 Rome, Italy.
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Narmashiri A, Akbari F. The Effects of Transcranial Direct Current Stimulation (tDCS) on the Cognitive Functions: A Systematic Review and Meta-analysis. Neuropsychol Rev 2023:10.1007/s11065-023-09627-x. [PMID: 38060075 DOI: 10.1007/s11065-023-09627-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 10/24/2023] [Indexed: 12/08/2023]
Abstract
Previous studies have investigated the effect of transcranial direct current stimulation (tDCS) on cognitive functions. However, these studies reported inconsistent results due to differences in experiment design, measurements, and stimulation parameters. Nonetheless, there is a lack of meta-analyses and review studies on tDCS and its impact on cognitive functions, including working memory, inhibition, flexibility, and theory of mind. We performed a systematic review and meta-analysis of tDCS studies published from the earliest available data up to October 2021, including studies reporting the effects of tDCS on cognitive functions in human populations. Therefore, these systematic review and meta-analysis aim to comprehensively analyze the effects of anodal and cathodal tDCS on cognitive functions by investigating 69 articles with a total of 5545 participants. Our study reveals significant anodal tDCS effects on various cognitive functions. Specifically, we observed improvements in working memory reaction time (RT), inhibition RT, flexibility RT, theory of mind RT, working memory accuracy, theory of mind accuracy and flexibility accuracy. Furthermore, our findings demonstrate noteworthy cathodal tDCS effects, enhancing working memory accuracy, inhibition accuracy, flexibility RT, flexibility accuracy, theory of mind RT, and theory of mind accuracy. Notably, regarding the influence of stimulation parameters of tDCS on cognitive functions, the results indicated significant differences across various aspects, including the timing of stimulation (online vs. offline studies), population type (clinical vs. healthy studies), stimulation duration (< 15 min vs. > 15 min), electrical current intensities (1-1.5 m.A vs. > 1.5 m.A), stimulation sites (right frontal vs. left frontal studies), age groups (young vs. older studies), and different cognitive tasks in each cognitive functioning aspect. In conclusion, our results demonstrate that tDCS can effectively enhance cognitive task performance, offering valuable insights into the potential benefits of this method for cognitive improvement.
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Affiliation(s)
- Abdolvahed Narmashiri
- School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran.
- Electrical Engineering Department, Bio-Intelligence Research Unit, Sharif Brain Center, Sharif University of Technology, Tehran, Iran.
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Garcia-Larrea L. Non-invasive cortical stimulation for drug-resistant pain. Curr Opin Support Palliat Care 2023; 17:142-149. [PMID: 37339516 DOI: 10.1097/spc.0000000000000654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
PURPOSE OF REVIEW Neuromodulation techniques are being increasingly used to alleviate pain and enhance quality of life. Non-invasive cortical stimulation was originally intended to predict the efficacy of invasive (neurosurgical) techniques, but has now gained a place as an analgesic procedure in its own right. RECENT FINDINGS Repetitive transcranial magnetic stimulation (rTMS): Evidence from 14 randomised, placebo-controlled trials (~750 patients) supports a significant analgesic effect of high-frequency motor cortex rTMS in neuropathic pain. Dorsolateral frontal stimulation has not proven efficacious so far. The posterior operculo-insular cortex is an attractive target but evidence remains insufficient. Short-term efficacy can be achieved with NNT (numbers needed to treat) ~2-3, but long-lasting efficacy remains a challenge.Like rTMS, transcranial direct-current stimulation (tDCS) induces activity changes in distributed brain networks and can influence various aspects of pain. Lower cost relative to rTMS, few safety issues and availability of home-based protocols are practical advantages. The limited quality of many published reports lowers the level of evidence, which will remain uncertain until more prospective controlled studies are available. SUMMARY Both rTMS and tDCS act preferentially upon abnormal hyperexcitable states of pain, rather than acute or experimental pain. For both techniques, M1 appears to be the best target for chronic pain relief, and repeated sessions over relatively long periods of time may be required to obtain clinically significant benefits. Patients responsive to tDCS may differ from those improved by rTMS.
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Affiliation(s)
- Luis Garcia-Larrea
- Central Integration of Pain (NeuroPain) Lab, Lyon Centre for Neuroscience (CRNL), INSERM U1028, University Claude Bernard Lyon 1, Villeurbanne
- University Hospital Pain Centre (CETD), Neurological Hospital, Hospices Civils de Lyon, Lyon, France
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Gordon MS, Seeto JXW, Dux PE, Filmer HL. Intervention is a better predictor of tDCS mind-wandering effects than subjective beliefs about experimental results. Sci Rep 2022; 12:13110. [PMID: 35908042 PMCID: PMC9338927 DOI: 10.1038/s41598-022-16545-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 07/12/2022] [Indexed: 11/29/2022] Open
Abstract
Blinding in non-invasive brain stimulation research is a topic of intense debate, especially regarding the efficacy of sham-controlled methods for transcranial direct current stimulation (tDCS). A common approach to assess blinding success is the inclusion of correct guess rate. However, this method cannot provide insight into the effect of unblinding on observed stimulation outcomes. Thus, the implementation of measures to systematically evaluate subjective expectation regarding stimulation is needed. Previous work evaluated subjective effects in an earlier study which reported a mind-wandering and tDCS data set and concluded that subjective belief drove the pattern of results observed. Here we consider the subjective and objective intervention effects in a key contrast from that data set-2 mA vs. sham-which was not examined in the reanalysis. In addition, we examine another key contrast from a different tDCS mind-wandering study that employed similar methodology. Our findings support objective intervention as the strongest predictor of the observed effects of mind-wandering in both re-analyses, over and above that of subjective intervention. However, it is important to control for and understand the possible inadequacies of sham-controlled methods.
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Affiliation(s)
- Matilda S Gordon
- School of Psychology, The University of Queensland, McElwain Building (24A), St Lucia, QLD, 4072, Australia.
| | - Jennifer X W Seeto
- School of Psychology, The University of Queensland, McElwain Building (24A), St Lucia, QLD, 4072, Australia
| | - Paul E Dux
- School of Psychology, The University of Queensland, McElwain Building (24A), St Lucia, QLD, 4072, Australia
| | - Hannah L Filmer
- School of Psychology, The University of Queensland, McElwain Building (24A), St Lucia, QLD, 4072, Australia
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Caulfield KA, Indahlastari A, Nissim NR, Lopez JW, Fleischmann HH, Woods AJ, George MS. Electric Field Strength From Prefrontal Transcranial Direct Current Stimulation Determines Degree of Working Memory Response: A Potential Application of Reverse-Calculation Modeling? Neuromodulation 2022; 25:578-587. [PMID: 35670064 DOI: 10.1111/ner.13342] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/24/2020] [Accepted: 11/30/2020] [Indexed: 12/26/2022]
Abstract
BACKGROUND Transcranial direct current stimulation (tDCS) for working memory is an enticing treatment, but there is mixed evidence to date. OBJECTIVES We tested the effects of electric field strength from uniform 2 mA dosing on working memory change from prestimulation to poststimulation. Second, we statistically evaluated a reverse-calculation method of individualizing tDCS dose and its effect on normalizing electric field at the cortex. MATERIALS AND METHODS We performed electric field modeling on a data set of 28 healthy older adults (15 women, mean age = 73.7, SD = 7.3) who received ten sessions of active 2 mA tDCS (N = 14) or sham tDCS (N = 14) applied over bilateral dorsolateral prefrontal cortices (DLPFC) in a triple-blind design. We evaluated the relationship between electric field strength and working memory change on an N-back task in conditions of above-median, high electric field from active 2 mA (N = 7), below-median, low electric field from active 2 mA (N = 7), and sham (N = 14) at regions of interest (ROI) at the left and right DLPFC. We then determined the individualized reverse-calculation dose to produce the group average electric field and measured the electric field variance between uniform 2 mA doses vs individualized reverse-calculation doses at the same ROIs. RESULTS Working memory improvements from pre- to post-tDCS were significant for the above-median electric field from active 2 mA condition at the left DLPFC (mixed ANOVA, p = 0.013). Furthermore, reverse-calculation modeling significantly reduced electric field variance at both ROIs (Levene's test; p < 0.001). CONCLUSIONS Higher electric fields at the left DLPFC from uniform 2 mA doses appear to drive working memory improvements from tDCS. Individualized doses from reverse-calculation modeling significantly reduce electric field variance at the cortex. Taken together, using reverse-calculation modeling to produce the same, high electric fields at the cortex across participants may produce more effective future tDCS treatments for working memory.
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Affiliation(s)
- Kevin A Caulfield
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, Charleston, SC, USA.
| | - Aprinda Indahlastari
- Center for Cognitive Aging and Memory Clinical Translational Research, McKnight Brain Institute, Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Nicole R Nissim
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - James W Lopez
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, Charleston, SC, USA
| | - Holly H Fleischmann
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, Charleston, SC, USA
| | - Adam J Woods
- Center for Cognitive Aging and Memory Clinical Translational Research, McKnight Brain Institute, Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Mark S George
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson VA Medical Center, Charleston, SC, USA
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Antal A, Luber B, Brem AK, Bikson M, Brunoni AR, Cohen Kadosh R, Dubljević V, Fecteau S, Ferreri F, Flöel A, Hallett M, Hamilton RH, Herrmann CS, Lavidor M, Loo C, Lustenberger C, Machado S, Miniussi C, Moliadze V, Nitsche MA, Rossi S, Rossini PM, Santarnecchi E, Seeck M, Thut G, Turi Z, Ugawa Y, Venkatasubramanian G, Wenderoth N, Wexler A, Ziemann U, Paulus W. Non-invasive brain stimulation and neuroenhancement. Clin Neurophysiol Pract 2022; 7:146-165. [PMID: 35734582 PMCID: PMC9207555 DOI: 10.1016/j.cnp.2022.05.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/19/2022] [Accepted: 05/18/2022] [Indexed: 12/15/2022] Open
Abstract
Attempts to enhance human memory and learning ability have a long tradition in science. This topic has recently gained substantial attention because of the increasing percentage of older individuals worldwide and the predicted rise of age-associated cognitive decline in brain functions. Transcranial brain stimulation methods, such as transcranial magnetic (TMS) and transcranial electric (tES) stimulation, have been extensively used in an effort to improve cognitive functions in humans. Here we summarize the available data on low-intensity tES for this purpose, in comparison to repetitive TMS and some pharmacological agents, such as caffeine and nicotine. There is no single area in the brain stimulation field in which only positive outcomes have been reported. For self-directed tES devices, how to restrict variability with regard to efficacy is an essential aspect of device design and function. As with any technique, reproducible outcomes depend on the equipment and how well this is matched to the experience and skill of the operator. For self-administered non-invasive brain stimulation, this requires device designs that rigorously incorporate human operator factors. The wide parameter space of non-invasive brain stimulation, including dose (e.g., duration, intensity (current density), number of repetitions), inclusion/exclusion (e.g., subject's age), and homeostatic effects, administration of tasks before and during stimulation, and, most importantly, placebo or nocebo effects, have to be taken into account. The outcomes of stimulation are expected to depend on these parameters and should be strictly controlled. The consensus among experts is that low-intensity tES is safe as long as tested and accepted protocols (including, for example, dose, inclusion/exclusion) are followed and devices are used which follow established engineering risk-management procedures. Devices and protocols that allow stimulation outside these parameters cannot claim to be "safe" where they are applying stimulation beyond that examined in published studies that also investigated potential side effects. Brain stimulation devices marketed for consumer use are distinct from medical devices because they do not make medical claims and are therefore not necessarily subject to the same level of regulation as medical devices (i.e., by government agencies tasked with regulating medical devices). Manufacturers must follow ethical and best practices in marketing tES stimulators, including not misleading users by referencing effects from human trials using devices and protocols not similar to theirs.
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Key Words
- AD, Alzheimer’s Disease
- BDNF, brain derived neurotrophic factor
- Cognitive enhancement
- DARPA, Defense Advanced Research Projects Agency
- DIY stimulation
- DIY, Do-It-Yourself
- DLPFC, dorsolateral prefrontal cortex
- EEG, electroencephalography
- EMG, electromyography
- FCC, Federal Communications Commission
- FDA, (U.S.) Food and Drug Administration
- Home-stimulation
- IFCN, International Federation of Clinical Neurophysiology
- LTD, long-term depression
- LTP, long-term potentiation
- MCI, mild cognitive impairment
- MDD, Medical Device Directive
- MDR, Medical Device Regulation
- MEP, motor evoked potential
- MRI, magnetic resonance imaging
- NIBS, noninvasive brain stimulation
- Neuroenhancement
- OTC, Over-The-Counter
- PAS, paired associative stimulation
- PET, positron emission tomography
- PPC, posterior parietal cortex
- QPS, quadripulse stimulation
- RMT, resting motor threshold
- SAE, serious adverse event
- SMA, supplementary motor cortex
- TBS, theta-burst stimulation
- TMS, transcranial magnetic stimulation
- Transcranial brain stimulation
- rTMS, repetitive transcranial magnetic stimulation
- tACS
- tACS, transcranial alternating current stimulation
- tDCS
- tDCS, transcranial direct current stimulation
- tES, transcranial electric stimulation
- tRNS, transcranial random noise stimulation
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Affiliation(s)
- Andrea Antal
- Department of Neurology, University Medical Center, Göttingen, Germany
| | - Bruce Luber
- Noninvasive Neuromodulation Unit, Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Anna-Katharine Brem
- University Hospital of Old Age Psychiatry, University of Bern, Bern, Switzerland
- Department of Old Age Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Marom Bikson
- Biomedical Engineering at the City College of New York (CCNY) of the City University of New York (CUNY), NY, USA
| | - Andre R. Brunoni
- Departamento de Clínica Médica e de Psiquiatria, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
- Service of Interdisciplinary Neuromodulation (SIN), Laboratory of Neurosciences (LIM-27), Institute of Psychiatry, Hospital das Clínicas da Faculdade de Medicina da USP, São Paulo, Brazil
| | - Roi Cohen Kadosh
- School of Psychology, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK
| | - Veljko Dubljević
- Science, Technology and Society Program, College of Humanities and Social Sciences, North Carolina State University, Raleigh, NC, USA
| | - Shirley Fecteau
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, CERVO Brain Research Centre, Centre intégré universitaire en santé et services sociaux de la Capitale-Nationale, Quebec City, Quebec, Canada
| | - Florinda Ferreri
- Unit of Neurology, Unit of Clinical Neurophysiology, Study Center of Neurodegeneration (CESNE), Department of Neuroscience, University of Padua, Padua, Italy
- Department of Clinical Neurophysiology, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland
| | - Agnes Flöel
- Department of Neurology, Universitätsmedizin Greifswald, 17475 Greifswald, Germany
- German Centre for Neurodegenerative Diseases (DZNE) Standort Greifswald, 17475 Greifswald, Germany
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Roy H. Hamilton
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Christoph S. Herrmann
- Experimental Psychology Lab, Department of Psychology, Carl von Ossietzky Universität, Oldenburg, Germany
| | - Michal Lavidor
- Department of Psychology and the Gonda Brain Research Center, Bar Ilan University, Israel
| | - Collen Loo
- School of Psychiatry and Black Dog Institute, University of New South Wales; The George Institute; Sydney, Australia
| | - Caroline Lustenberger
- Neural Control of Movement Lab, Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Sergio Machado
- Department of Sports Methods and Techniques, Federal University of Santa Maria, Santa Maria, Brazil
- Laboratory of Physical Activity Neuroscience, Neurodiversity Institute, Queimados-RJ, Brazil
| | - Carlo Miniussi
- Center for Mind/Brain Sciences – CIMeC and Centre for Medical Sciences - CISMed, University of Trento, Rovereto, Italy
| | - Vera Moliadze
- Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany
| | - Michael A Nitsche
- Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors at TU, Dortmund, Germany
- Dept. Neurology, University Medical Hospital Bergmannsheil, Bochum, Germany
| | - Simone Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Unit of Neurology and Clinical Neurophysiology, Department of Medicine, Surgery and Neuroscience, University of Siena, Italy
| | - Paolo M. Rossini
- Department of Neuroscience and Neurorehabilitation, Brain Connectivity Lab, IRCCS-San Raffaele-Pisana, Rome, Italy
| | - Emiliano Santarnecchi
- Precision Neuroscience and Neuromodulation Program, Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Margitta Seeck
- Department of Clinical Neurosciences, Hôpitaux Universitaires de Genève, Switzerland
| | - Gregor Thut
- Centre for Cognitive Neuroimaging, School of Psychology and Neuroscience, EEG & Epolepsy Unit, University of Glasgow, United Kingdom
| | - Zsolt Turi
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Yoshikazu Ugawa
- Department of Human Neurophysiology, Fukushima Medical University, Fukushima, Japan
| | | | - Nicole Wenderoth
- Neural Control of Movement Lab, Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
- Future Health Technologies, Singapore-ETH Centre, Campus for Research Excellence And Technological Enterprise (CREATE), Singapore
| | - Anna Wexler
- Department of Medical Ethics and Health Policy, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Ulf Ziemann
- Department of Neurology and Stroke, University of Tübingen, Germany
- Hertie Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Walter Paulus
- Department of of Neurology, Ludwig Maximilians University Munich, Germany
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Garcia-Larrea L, Quesada C. Cortical stimulation for chronic pain: from anecdote to evidence. Eur J Phys Rehabil Med 2022; 58:290-305. [PMID: 35343176 PMCID: PMC9980528 DOI: 10.23736/s1973-9087.22.07411-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Epidural stimulation of the motor cortex (eMCS) was devised in the 1990's, and has now largely supplanted thalamic stimulation for neuropathic pain relief. Its mechanisms of action involve activation of multiple cortico-subcortical areas initiated in the thalamus, with involvement of endogenous opioids and descending inhibition toward the spinal cord. Evidence for clinical efficacy is now supported by at least seven RCTs; benefits may persist up to 10 years, and can be reasonably predicted by preoperative use of non-invasive repetitive magnetic stimulation (rTMS). rTMS first developed as a means of predicting the efficacy of epidural procedures, then as an analgesic method on its own right. Reasonable evidence from at least six well-conducted RCTs favors a significant analgesic effect of high-frequency rTMS of the motor cortex in neuropathic pain (NP), and less consistently in widespread/fibromyalgic pain. Stimulation of the dorsolateral frontal cortex (DLPFC) has not proven efficacious for pain, so far. The posterior operculo-insular cortex is a new and attractive target but evidence remains inconsistent. Transcranial direct current stimulation (tDCS) is applied upon similar targets as rTMS and eMCS; it does not elicit action potentials but modulates the neuronal resting membrane state. tDCS presents practical advantages including low cost, few safety issues, and possibility of home-based protocols; however, the limited quality of most published reports entails a low level of evidence. Patients responsive to tDCS may differ from those improved by rTMS, and in both cases repeated sessions over a long time may be required to achieve clinically significant relief. Both invasive and non-invasive procedures exert their effects through multiple distributed brain networks influencing the sensory, affective and cognitive aspects of chronic pain. Their effects are mainly exerted upon abnormally sensitized pathways, rather than on acute physiological pain. Extending the duration of long-term benefits remains a challenge, for which different strategies are discussed in this review.
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Affiliation(s)
- Luis Garcia-Larrea
- Central Integration of Pain (NeuroPain) Lab, Lyon Center for Neuroscience (CRNL), INSERM U1028, University Claude Bernard Lyon 1, Villeurbanne, France - .,University Hospital Pain Center (CETD), Neurological Hospital, Hospices Civils de Lyon, Lyon, France -
| | - Charles Quesada
- Central Integration of Pain (NeuroPain) Lab, Lyon Center for Neuroscience (CRNL), INSERM U1028, University Claude Bernard Lyon 1, Villeurbanne, France.,Department of Physiotherapy, Sciences of Rehabilitation Institute (ISTR), University Claude Bernard Lyon 1, Villeurbanne, France
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8
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Zanto TP, Jones KT, Ostrand AE, Hsu WY, Campusano R, Gazzaley A. Individual differences in neuroanatomy and neurophysiology predict effects of transcranial alternating current stimulation. Brain Stimul 2021; 14:1317-1329. [PMID: 34481095 DOI: 10.1016/j.brs.2021.08.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 08/11/2021] [Accepted: 08/19/2021] [Indexed: 10/20/2022] Open
Abstract
BACKGROUND Noninvasive transcranial electrical stimulation (tES) research has been plagued with inconsistent effects. Recent work has suggested neuroanatomical and neurophysiological variability may alter tES efficacy. However, direct evidence is limited. OBJECTIVE We have previously replicated effects of transcranial alternating current stimulation (tACS) on improving multitasking ability in young adults. Here, we attempt to assess whether these stimulation parameters have comparable effects in older adults (aged 60-80 years), which is a population known to have greater variability in neuroanatomy and neurophysiology. It is hypothesized that this variability in neuroanatomy and neurophysiology will be predictive of tACS efficacy. METHODS We conducted a pre-registered study where tACS was applied above the prefrontal cortex (between electrodes F3-F4) while participants were engaged in multitasking. Participants were randomized to receive either 6-Hz (theta) tACS for 26.67 min daily for three days (80 min total; Long Exposure Theta group), 6-Hz tACS for 5.33 min daily (16-min total; Short Exposure Theta group), or 1-Hz tACS for 26.67 min (80 min total; Control group). To account for neuroanatomy, magnetic resonance imaging data was used to form individualized models of the tACS-induced electric field (EF) within the brain. To account for neurophysiology, electroencephalography data was used to identify individual peak theta frequency. RESULTS Results indicated that only in the Long Theta group, performance change was correlated with modeled EF and peak theta frequency. Together, modeled EF and peak theta frequency accounted for 54%-65% of the variance in tACS-related performance improvements, which sustained for a month. CONCLUSION These results demonstrate the importance of individual differences in neuroanatomy and neurophysiology in tACS research and help account for inconsistent effects across studies.
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Affiliation(s)
- Theodore P Zanto
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA; Neuroscape, University of California-San Francisco, San Francisco, CA, USA.
| | - Kevin T Jones
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA; Neuroscape, University of California-San Francisco, San Francisco, CA, USA
| | - Avery E Ostrand
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA; Neuroscape, University of California-San Francisco, San Francisco, CA, USA
| | - Wan-Yu Hsu
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA
| | - Richard Campusano
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA; Neuroscape, University of California-San Francisco, San Francisco, CA, USA
| | - Adam Gazzaley
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA; Neuroscape, University of California-San Francisco, San Francisco, CA, USA; Departments of Physiology and Psychiatry, University of California-San Francisco, San Francisco, CA, USA
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9
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Feltman KA, Hayes AM, Bernhardt KA, Nwala E, Kelley AM. Viability of tDCS in Military Environments for Performance Enhancement: A Systematic Review. Mil Med 2021; 185:e53-e60. [PMID: 31735955 DOI: 10.1093/milmed/usz189] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/23/2019] [Indexed: 12/30/2022] Open
Abstract
INTRODUCTION Transcranial electrical stimulation (tES) as a method of cognitive enhancement in both diseased and healthy individuals has gained popularity. Its potential for enhancing cognition in healthy individuals has gained the interest of the military. However, before it being implemented into military training or operational settings, further work is needed to determine its efficacy and safety. Although a considerable amount of literature exists, few studies have specifically evaluated its use in enhancing cognition relative to operational, military tasks. Therefore, in a first step to evaluate its efficacy, we completed a systematic literature review of studies using transcranial direct current stimulation (tDCS), a type of tES, to enhance cognitive processes in healthy individuals. METHODS A systematic literature review was conducted to identify literature published between 2008 and 2018 that used a method of tES for cognitive enhancement. As part of a larger literature review effort, 282 articles were initially retrieved. These were then screened to identify articles meeting predetermined criteria, to include those using various methods of tES, resulting in 44 articles. Next, the articles were screened for those using tDCS or high-definition tDCS, resulting in 34 articles for review and information extraction. RESULTS Of the 34 articles reviewed, 28 reported some degree of enhancement (eg, improved accuracy on tasks and reduced reaction times). Areas of cognitive enhancements included executive functioning, creativity/cognitive flexibility, attention/perception, decision-making, memory, and working memory. However, the precise outcomes of enhancement varied given the range in tasks that were used to assess the constructs. Additionally, the stimulation parameters in terms of intensity applied, duration of stimulation, and brain region targeted for stimulation varied. CONCLUSIONS The conclusions to be drawn from this systematic literature review include the identification of a brain region for targeting with stimulation to enhance a broad range of cognitive constructs applicable to military tasks, as well as stimulation parameters for duration and intensity. The dorsolateral prefrontal cortex was most frequently targeted in the studies that found enhanced performance across several cognitive constructs. Stimulation intensities of 2 mA and durations of 20 minutes or longer appeared frequently as well. Although several parameters were identified, further work is required before this type of technology can be recommended for operational use.
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Affiliation(s)
- Kathryn A Feltman
- U.S. Army Aeromedical Research Laboratory, 6901 Farrel Road, Fort Rucker, AL 36362
| | - Amanda M Hayes
- U.S. Army Aeromedical Research Laboratory, 6901 Farrel Road, Fort Rucker, AL 36362.,Oak Ridge Institute for Science and Education, 100 ORAU Way, Oak Ridge, TN 37830
| | - Kyle A Bernhardt
- U.S. Army Aeromedical Research Laboratory, 6901 Farrel Road, Fort Rucker, AL 36362.,Oak Ridge Institute for Science and Education, 100 ORAU Way, Oak Ridge, TN 37830
| | - Emmanuel Nwala
- U.S. Army Aeromedical Research Laboratory, 6901 Farrel Road, Fort Rucker, AL 36362
| | - Amanda M Kelley
- U.S. Army Aeromedical Research Laboratory, 6901 Farrel Road, Fort Rucker, AL 36362
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The effect of non-invasive brain stimulation on executive functioning in healthy controls: A systematic review and meta-analysis. Neurosci Biobehav Rev 2021; 125:122-147. [PMID: 33503477 DOI: 10.1016/j.neubiorev.2021.01.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 12/07/2020] [Accepted: 01/11/2021] [Indexed: 01/01/2023]
Abstract
In recent years, there has been a heightened interest in the effect of non-invasive brain stimulation on executive functioning. However, there is no comprehensive overview of its effects on different executive functioning domains in healthy individuals. Here, we assessed the state of the field by conducting a systematic review and meta-analysis on the effectiveness of non-invasive brain stimulation (i.e. repetitive transcranial magnetic stimulation and transcranial direct current stimulation) over prefrontal regions on tasks assessing working memory, inhibition, flexibility, planning and initiation performance. Our search yielded 63 studies (n = 1537), and the effectiveness of excitatory and inhibitory non-invasive brain stimulation were assessed per executive functioning task. Our analyses showed that excitatory non-invasive brain stimulation had a small but positive effect on Stop Signal Task and Go/No-Go Task performance, and that inhibitory stimulation had a small negative effect on Flanker Task performance. Non-invasive brain stimulation did not affect performance on working memory and flexibility tasks, and effects on planning tasks were inconclusive.
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11
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Westwood SJ, Radua J, Rubia K. Noninvasive brain stimulation in children and adults with attention-deficit/hyperactivity disorder: a systematic review and meta-analysis. J Psychiatry Neurosci 2021; 46:E14-E33. [PMID: 33009906 PMCID: PMC7955851 DOI: 10.1503/jpn.190179] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) could provide treatment alternatives to stimulant medication for attention-deficit/hyperactivity disorder (ADHD), given some evidence for improvements in cognition and clinical symptoms. However, despite a lack of solid evidence for their use, rTMS and tDCS are already offered clinically and commercially in ADHD. This systematic review and meta-analysis aimed to critically appraise rTMS and tDCS studies in ADHD to inform good research and clinical practice. METHODS A systematic search (up to February 2019) identified 18 studies (rTMS 4, tDCS 14; 311 children and adults with ADHD) stimulating mainly the dorsolateral prefrontal cortex (dlPFC). We included 12 anodal tDCS studies (232 children and adults with ADHD) in 3 random-effects meta-analyses of cognitive measures of attention, inhibition and processing speed. RESULTS The review of rTMS and tDCS showed positive effects in some functions but not others, and little evidence for clinical improvement. The meta-analyses of 1 to 5 sessions of anodal tDCS over mainly the left or bilateral dlPFC showed trend-level improvements in inhibition and processing speed, but not in attention. LIMITATIONS Heterogeneity in stimulation parameters, patient age and outcome measures limited the interpretation of findings. CONCLUSION The review and meta-analysis showed limited evidence that 1 to 5 sessions of rTMS and tDCS, mostly of the dlPFC, improved clinical or cognitive measures of ADHD. These findings did not support using rTMS or tDCS of the dlPFC as an alternative neurotherapy for ADHD as yet. Larger, multi-session stimulation studies identifying more optimal sites and stimulation parameters in combination with cognitive training could achieve larger effects.
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Affiliation(s)
- Samuel J Westwood
- From the Department of Child & Adolescent Psychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom (Westwood, Rubia); the Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain (Radua); the Mental Health Research Networking Centre (CIBERSAM), Madrid, Spain (Radua); the Department of Clinical Neuroscience, Centre for Psychiatric Research and Education, Karolinska Institutet, Tomtebodavägen 18A, Stockholm, Sweden (Radua); and the Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London, United Kingdom (Radua)
| | - Joaquim Radua
- From the Department of Child & Adolescent Psychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom (Westwood, Rubia); the Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain (Radua); the Mental Health Research Networking Centre (CIBERSAM), Madrid, Spain (Radua); the Department of Clinical Neuroscience, Centre for Psychiatric Research and Education, Karolinska Institutet, Tomtebodavägen 18A, Stockholm, Sweden (Radua); and the Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London, United Kingdom (Radua)
| | - Katya Rubia
- From the Department of Child & Adolescent Psychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom (Westwood, Rubia); the Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain (Radua); the Mental Health Research Networking Centre (CIBERSAM), Madrid, Spain (Radua); the Department of Clinical Neuroscience, Centre for Psychiatric Research and Education, Karolinska Institutet, Tomtebodavägen 18A, Stockholm, Sweden (Radua); and the Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, De Crespigny Park, London, United Kingdom (Radua)
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Solomons CD, Shanmugasundaram V. Transcranial direct current stimulation: A review of electrode characteristics and materials. Med Eng Phys 2020; 85:63-74. [PMID: 33081965 DOI: 10.1016/j.medengphy.2020.09.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 09/10/2020] [Accepted: 09/25/2020] [Indexed: 12/15/2022]
Abstract
Electrode characteristics are crucial in transcranial direct current stimulation (tDCS) since electrode design and placement determine the cortical area being modulated, current density and spatial resolution of stimulation. Early research on tDCS sought to determine optimal parameters for stimulation by specifying maximum current, duration and sizes of electrodes. Further research focused on determining efficient ways to deliver stimulation to targeted regions on the cortex with minimal discomfort to the user by altering electrode size, placement, shape and material. This review aims to give an insight on the main characteristics of electrodes used in tDCS and on the variability found in electrode parameters and placements from tDCS to high definition tDCS (HD-tDCS) applications and beyond.
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Affiliation(s)
- Cassandra D Solomons
- School of Electrical Engineering, Vellore Institute of Technology, Vellore 632014, India
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Abstract
Technological advancements have provided militaries with the possibility to enhance human performance and to provide soldiers with better warfighting capabilities. Though these technologies hold significant potential, their use is not without cost to the individual. This paper explores the complexities associated with using human cognitive enhancements in the military, focusing on how the purpose and context of these technologies could potentially undermine a soldier’s ability to say no to these interventions. We focus on cognitive enhancements and their ability to also enhance a soldier’s autonomy (i.e., autonomy-enhancing technologies). Through this lens, we explore situations that could potentially compel a soldier to accept such technologies and how this acceptance could impact rights to individual autonomy and informed consent within the military. In this examination, we highlight the contextual elements of vulnerability—institutional and differential vulnerability. In addition, we focus on scenarios in which a soldier’s right to say no to such enhancements can be diminished given the special nature of their work and the significance of making better moral decisions. We propose that though in some situations, a soldier may be compelled to accept said enhancements; with their right to say no diminished, it is not a blanket rule, and safeguards ought to be in place to ensure that autonomy and informed consent are not overridden.
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Abstract
The direct-to-consumer (DTC) neurotechnology market, which includes some brain-computer interfaces, neurostimulation devices, virtual reality systems, wearables, and smartphone apps is rapidly growing. Given this technology's intimate relationship with the brain, a number of ethical dimensions must be addressed so that the technology can achieve the goal of contributing to human flourishing. This paper identifies safety, transparency, privacy, epistemic appropriateness, existential authenticity, just distribution, and oversight as such dimensions. After an initial exploration of the relevant ethical foundations for DTC neurotechnologies, this paper lays out each dimension and uses examples to justify its inclusion.
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Placebo Brain Stimulation Affects Subjective but Not Neurocognitive Measures of Error Processing. JOURNAL OF COGNITIVE ENHANCEMENT 2020. [DOI: 10.1007/s41465-020-00172-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
AbstractThe aim of this preregistered EEG study was to show how expectations about enhanced or impaired performance through transcranial stimulation affect feelings of agency and error processing. Using a single-blind experimental design, participants (N = 57) were attached to a transcranial direct current stimulation (tDCS) device, and in different blocks, they were verbally instructed to expect enhanced or impaired cognitive performance, or no effects of the brain stimulation. In all cases, but unbeknownst to the participants, we used an inert sham tDCS protocol. Subsequently, we measured their response to errors on a cognitive control task. Our expectancy manipulation was successful: participants reported improved subjective performance in the enhancement compared with the impairment condition—even though objective performance was kept at a constant level across conditions. Participants reported the highest feelings of agency over their task performance in the control condition, and lowest feelings of agency in the impairment condition. The expectancy manipulation did not affect the error-related negativity (ERN) in association with incorrect responses. During the induction phase, expecting impaired versus enhanced performance increased frontal theta power, potentially reflecting a process of increased cognitive control allocation. Our findings show that verbally induced manipulations can affect subjective performance on a cognitive control task, but that stronger manipulations (e.g., through conditioning) are necessary to induce top-down effects on neural error processing.
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16
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Brühl AB, d'Angelo C, Sahakian BJ. Neuroethical issues in cognitive enhancement: Modafinil as the example of a workplace drug? Brain Neurosci Adv 2020; 3:2398212818816018. [PMID: 32166175 PMCID: PMC7058249 DOI: 10.1177/2398212818816018] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Indexed: 12/01/2022] Open
Abstract
The use of cognitive-enhancing drugs by healthy individuals has been a feature for much of recorded history. Cocaine and amphetamine are modern cases of drugs initially enthusiastically acclaimed for enhancing cognition and mood. Today, an increasing number of healthy people are reported to use cognitive-enhancing drugs, as well as other interventions, such as non-invasive brain stimulation, to maintain or improve work performance. Cognitive-enhancing drugs, such as methylphenidate and modafinil, which were developed as treatments, are increasingly being used by healthy people. Modafinil not only affects ‘cold’ cognition, but also improves ‘hot’ cognition, such as emotion recognition and task-related motivation. The lifestyle use of ‘smart drugs’ raises both safety concerns as well as ethical issues, including coercion and increasing disparity in society. As a society, we need to consider which forms of cognitive enhancement (e.g. pharmacological, exercise, lifelong learning) are acceptable and for which groups under what conditions and by what methods we would wish to improve and flourish.
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Affiliation(s)
- Annette B Brühl
- Department of Psychiatry, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.,Department of Psychiatry, Psychotherapy, and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Camilla d'Angelo
- Department of Psychiatry, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Barbara J Sahakian
- Department of Psychiatry, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
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Zandvakili A, Berlow YA, Carpenter LL, Philip NS. Transcranial Direct Current Stimulation in Psychiatry: What Psychiatrists Need to Know. FOCUS: JOURNAL OF LIFE LONG LEARNING IN PSYCHIATRY 2020; 17:44-49. [PMID: 31975960 DOI: 10.1176/appi.focus.20180029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Transcranial direct current stimulation (tDCS) is emerging as a potential treatment for a host of neuropsychiatric disorders. Data appear to indicate that tDCS applied over frontal or prefrontal brain regions may reduce symptoms of major depression, yet results have been mixed. Early studies showed promise, but recent work failed to replicate earlier results. The decision whether to use tDCS is further affected by the complex regulatory environment; no tDCS devices are cleared by the U.S. Food and Drug Administration for clinical use. Older systems have grandfathered regulatory approval for treating mood, anxiety, and insomnia, although they have not demonstrated efficacy in rigorous trials. Furthermore, as the field of noninvasive brain stimulation advances, various side effects and contraindications are increasingly recognized. Over the last few years, research and consumer use of tDCS have outpaced education, thus providing little guidance for clinicians and trainees about how to understand tDCS. Therefore, this focused review includes those items psychiatric clinicians and trainees most need to understand tDCS, including basic electrical and neurophysiological principles, a brief review of efficacy data in major depressive disorder, and suggested guidelines about how to manage patients using tDCS.
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Affiliation(s)
- Amin Zandvakili
- Center for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, Rhode Island (Zandvakili, Berlow, Philip); Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence (Zandvakili, Berlow, Carpenter, Philip); Butler Hospital, Neuromodulation Research Facility, Providence (Carpenter)
| | - Yosef Alfred Berlow
- Center for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, Rhode Island (Zandvakili, Berlow, Philip); Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence (Zandvakili, Berlow, Carpenter, Philip); Butler Hospital, Neuromodulation Research Facility, Providence (Carpenter)
| | - Linda Leigh Carpenter
- Center for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, Rhode Island (Zandvakili, Berlow, Philip); Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence (Zandvakili, Berlow, Carpenter, Philip); Butler Hospital, Neuromodulation Research Facility, Providence (Carpenter)
| | - Noah Stephen Philip
- Center for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, Rhode Island (Zandvakili, Berlow, Philip); Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, Providence (Zandvakili, Berlow, Carpenter, Philip); Butler Hospital, Neuromodulation Research Facility, Providence (Carpenter)
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19
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Garcia-Larrea L, Perchet C, Hagiwara K, André-Obadia N. At-Home Cortical Stimulation for Neuropathic Pain: a Feasibility Study with Initial Clinical Results. Neurotherapeutics 2019; 16:1198-1209. [PMID: 31062295 PMCID: PMC6985395 DOI: 10.1007/s13311-019-00734-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The clinical use of noninvasive cortical stimulation procedures is hampered by the limited duration of the analgesic effects and the need to perform stimulation in hospital settings. Here, we tested the feasibility and pilot efficacy of an internet-based system for at-home, long-duration, medically controlled transcranial motor cortex stimulation (H-tDCS), via a double-blinded, sham-controlled trial in patients with neuropathic pain refractory to standard-of-care drug therapy. Each patient was first trained at hospital, received a stimulation kit, allotted a password-protected Web space, and completed daily tDCS sessions during 5 weeks, via a Bluetooth connection between stimulator and a minilaptop. Each session was validated and internet-controlled by hospital personnel. Daily pain ratings were obtained during 11 consecutive weeks, and afterwards via iterative visits/phone contacts. Twenty full procedures were completed in 12 consecutive patients (500 daily tDCS sessions, including 20% sham). No serious adverse effects were recorded. Superficial burning at electrode position occurred in 2 patients, and nausea/headache in two others, all of whom wished to pursue stimulation. Six out of the 12 patients achieved satisfactory relief on a scale combining pain scores, drug intake, and quality of life. Daily pain reports correlated with such combined assessment, and differentiated responders from nonresponders without overlap. Clinical improvement in responders could last up to 6 months. Five patients asked to repeat the whole procedure when pain resumed again, with comparable results. At-home, long-duration tDCS proved safe and technically feasible, and provided long-lasting relief in 50% of a small sample of patients with drug-resistant neuropathic pain.
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Affiliation(s)
- Luis Garcia-Larrea
- Central Integration of Pain (NeuroPain) Lab-Lyon Neuroscience Research Center, INSERM U1028, CNRS, UMR5292, Université Claude Bernard Lyon 1, F-69677, Bron, France.
- Centre D'évaluation et de Traitement de la Douleur (CETD), Hôpital Neurologique, F-69000, Lyon, France.
| | - Caroline Perchet
- Central Integration of Pain (NeuroPain) Lab-Lyon Neuroscience Research Center, INSERM U1028, CNRS, UMR5292, Université Claude Bernard Lyon 1, F-69677, Bron, France
| | - Koichi Hagiwara
- Central Integration of Pain (NeuroPain) Lab-Lyon Neuroscience Research Center, INSERM U1028, CNRS, UMR5292, Université Claude Bernard Lyon 1, F-69677, Bron, France
| | - Nathalie André-Obadia
- Central Integration of Pain (NeuroPain) Lab-Lyon Neuroscience Research Center, INSERM U1028, CNRS, UMR5292, Université Claude Bernard Lyon 1, F-69677, Bron, France
- Service de Neurologie Fonctionnelle et d'Epileptologie, Hôpital Neurologique, Hospices Civils de Lyon, F-69677, Bron, France
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20
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Lefaucheur JP. Boosting physical exercise with cortical stimulation or brain doping using tDCS: Fact or myth? Neurophysiol Clin 2019; 49:95-98. [DOI: 10.1016/j.neucli.2019.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 01/08/2019] [Indexed: 11/26/2022] Open
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21
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Hypothesis of the optimal therapeutic effect of transcranial direct current stimulation (tDCS) for psychiatric disorders: Integration of positive cognitive tasks during the neuroplastic process. Med Hypotheses 2019; 125:1-4. [DOI: 10.1016/j.mehy.2019.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 02/01/2019] [Accepted: 02/02/2019] [Indexed: 11/18/2022]
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22
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Dresler M, Sandberg A, Bublitz C, Ohla K, Trenado C, Mroczko-Wąsowicz A, Kühn S, Repantis D. Hacking the Brain: Dimensions of Cognitive Enhancement. ACS Chem Neurosci 2019; 10:1137-1148. [PMID: 30550256 PMCID: PMC6429408 DOI: 10.1021/acschemneuro.8b00571] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 12/14/2018] [Indexed: 12/11/2022] Open
Abstract
In an increasingly complex information society, demands for cognitive functioning are growing steadily. In recent years, numerous strategies to augment brain function have been proposed. Evidence for their efficacy (or lack thereof) and side effects has prompted discussions about ethical, societal, and medical implications. In the public debate, cognitive enhancement is often seen as a monolithic phenomenon. On a closer look, however, cognitive enhancement turns out to be a multifaceted concept: There is not one cognitive enhancer that augments brain function per se, but a great variety of interventions that can be clustered into biochemical, physical, and behavioral enhancement strategies. These cognitive enhancers differ in their mode of action, the cognitive domain they target, the time scale they work on, their availability and side effects, and how they differentially affect different groups of subjects. Here we disentangle the dimensions of cognitive enhancement, review prominent examples of cognitive enhancers that differ across these dimensions, and thereby provide a framework for both theoretical discussions and empirical research.
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Affiliation(s)
- Martin Dresler
- Donders Institute for Brain, Cognition and Behaviour , Radboud University Medical Centre , Nijmegen 6525 EN , The Netherlands
| | - Anders Sandberg
- Future of Humanity Institute , Oxford University , Oxford OX1 1PT , United Kingdom
| | | | - Kathrin Ohla
- Institute of Neuroscience and Medicine, Cognitive Neuroscience (INM3) , Forschungszentrum Jülich , Jülich 52428 , Germany
| | - Carlos Trenado
- Institute of Clinical Neuroscience and Medical Psychology , Heinrich Heine University Düsseldorf , Düsseldorf 40225 , Germany
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors , TU Dortmund , Dortmund 44139 , Germany
| | | | - Simone Kühn
- Max Planck Institute for Human Development , Berlin 14195 , Germany
- Department of Psychiatry and Psychotherapy , University Clinic Hamburg Eppendorf , Hamburg 20246 , Germany
| | - Dimitris Repantis
- Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin 12203 , Germany
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Amico G, Schaefer S. No Evidence for Performance Improvements in Episodic Memory Due to Fidgeting, Doodling or a “Neuro-Enhancing” Drink. JOURNAL OF COGNITIVE ENHANCEMENT 2019. [DOI: 10.1007/s41465-019-00124-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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24
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Mind-Reading or Misleading? Assessing Direct-to-Consumer Electroencephalography (EEG) Devices Marketed for Wellness and Their Ethical and Regulatory Implications. JOURNAL OF COGNITIVE ENHANCEMENT 2018. [DOI: 10.1007/s41465-018-0091-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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25
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Colzato LS. Responsible Cognitive Enhancement: Neuroethical Considerations. JOURNAL OF COGNITIVE ENHANCEMENT 2018. [DOI: 10.1007/s41465-018-0090-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Abstract
Transcranial direct current stimulation (tDCS) is a neuromodulatory approach that is affordable, safe, and well tolerated. This review article summarizes the research and clinically relevant findings from meta-analyses and studies investigating the cognitive effects of tDCS in healthy and clinical populations. We recapitulate findings from recent studies where cognitive performance paired with tDCS was compared with performance under placebo (sham stimulation) in single sessions and longitudinal designs where cognitive effects were evaluated following repeated sessions. In summary, the tDCS literature currently indicates that the effects of tDCS on cognitive measures are less robust and less predictable compared with the more consistent effects on motor outcomes. There is also a notable difference in the consistency of single-session and longitudinal designs. In single-session tDCS designs, there are small effects amid high variability confounded by individual differences and potential sham stimulation effects. In contrast, longitudinal studies provide more consistent benefits in healthy and clinical populations, particularly when tDCS is paired with a concurrent task. Yet, these studies are few in number, thereby impeding design optimization. While there is good evidence that tDCS can modulate cognitive functioning and potentially produce longer-term benefits, a major challenge to widespread translation of tDCS is the absence of a complete mechanistic account for observed effects. Significant future work is needed to identify a priori responders from nonresponders for every cognitive task and tDCS protocol.
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Wurzman R, Hamilton RH, Pascual-Leone A, Fox MD. An open letter concerning do-it-yourself users of transcranial direct current stimulation. Ann Neurol 2018; 80:1-4. [PMID: 27216434 DOI: 10.1002/ana.24689] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 05/16/2016] [Accepted: 05/16/2016] [Indexed: 02/02/2023]
Affiliation(s)
- Rachel Wurzman
- Department of Neurology, University of Pennsylvania, Philadelphia, PA
| | - Roy H Hamilton
- Department of Neurology and Physical Medicine & Rehabilitation, University of Pennsylvania, Philadelphia, PA
| | | | - Michael D Fox
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA.,Department of Neurology, Massachusetts General Hospital, Boston, MA.,Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA
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Hoogeveen S, Schjoedt U, van Elk M. Did I Do That? Expectancy Effects of Brain Stimulation on Error-related Negativity and Sense of Agency. J Cogn Neurosci 2018; 30:1720-1733. [PMID: 29916787 DOI: 10.1162/jocn_a_01297] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This study examines the effects of expected transcranial stimulation on the error(-related) negativity (Ne or ERN) and the sense of agency in participants who perform a cognitive control task. Placebo transcranial direct current stimulation was used to elicit expectations of transcranially induced cognitive improvement or impairment. The improvement/impairment manipulation affected both the Ne/ERN and the sense of agency (i.e., whether participants attributed errors to oneself or the brain stimulation device): Expected improvement increased the ERN in response to errors compared with both impairment and control conditions. Expected impairment made participants falsely attribute errors to the transcranial stimulation. This decrease in sense of agency was correlated with a reduced ERN amplitude. These results show that expectations about transcranial stimulation impact users' neural response to self-generated errors and the attribution of responsibility-especially when actions lead to negative outcomes. We discuss our findings in relation to predictive processing theory according to which the effect of prior expectations on the ERN reflects the brain's attempt to generate predictive models of incoming information. By demonstrating that induced expectations about transcranial stimulation can have effects at a neural level, that is, beyond mere demand characteristics, our findings highlight the potential for placebo brain stimulation as a promising tool for research.
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Wexler A. Who Uses Direct-to-Consumer Brain Stimulation Products, and Why? A Study of Home Users of tDCS Devices. JOURNAL OF COGNITIVE ENHANCEMENT 2017. [DOI: 10.1007/s41465-017-0062-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Borrione L, Brunoni AR. Primum non nocere or primum facere meliorem? Hacking the brain in the 21st century. TRENDS IN PSYCHIATRY AND PSYCHOTHERAPY 2017; 39:232-238. [DOI: 10.1590/2237-6089-2017-0075] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 08/16/2017] [Indexed: 11/21/2022]
Abstract
Abstract Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that modulates cortical excitability. It is devoid of serious adverse events and exerts variable effects on cognition, with several research findings suggesting that it can improve memory, verbal and mathematical skills. Because tDCS devices are low-cost, portable and relatively easy to assemble, they have become available outside of the medical setting and used for non-medical (“cosmetic”) purposes by laypersons. In this sense, tDCS has become a popular technique aiming to improve cognition and the achievement of a better performance not only at work, but also in other fields such as sports, leisure activities (video games) and even the military. In spite of these unforeseen developments, there has been a general paralysis of the medical and regulatory agencies to develop guidelines for the use of tDCS for cosmetic purposes. Several challenges are present, most importantly, how to restrict tDCS use outside of the medical setting in face of variable and sometimes conflicting results from scientific research. This article aims to describe the popular use of tDCS, in light of the pillars of neuroethics, a branch of bioethics relative to brain research. Between two possible but extreme solutions – total release or total restriction of tDCS – it is paramount to develop a spectrum of alternatives, which may vary over time and in different cultural backgrounds.
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Affiliation(s)
| | - Andre R. Brunoni
- Universidade de São Paulo, Brazil; Ludwig-Maximilians-University, Germany
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Rabipour S, Andringa R, Boot WR, Davidson PSR. What Do People Expect of Cognitive Enhancement? JOURNAL OF COGNITIVE ENHANCEMENT 2017; 2:70-77. [DOI: 10.1007/s41465-017-0050-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Santarnecchi E, Pascual-Leone A. The Illusion of the Perfect Brain Enhancer. CEREBRUM : THE DANA FORUM ON BRAIN SCIENCE 2017; 2017:cer-11-17. [PMID: 30210662 PMCID: PMC6132045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Many questions loom over transcranial direct current stimulation (tDCS), a non-invasive form of neurostimulation in which constant, low current is delivered directly to areas of the brain using small electrodes. It was first established in neuroscience research in the 1950s and 60s, but has seen rapid growth, particularly in the last five years. Originally developed to help patients with brain injuries such as strokes, tDCS is now also used to enhance language and mathematical ability, attention span, problem solving, memory, coordination, and even gaming skills. The authors examine its potential and pitfalls.
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Antal A, Alekseichuk I, Bikson M, Brockmöller J, Brunoni AR, Chen R, Cohen LG, Dowthwaite G, Ellrich J, Flöel A, Fregni F, George MS, Hamilton R, Haueisen J, Herrmann CS, Hummel FC, Lefaucheur JP, Liebetanz D, Loo CK, McCaig CD, Miniussi C, Miranda PC, Moliadze V, Nitsche MA, Nowak R, Padberg F, Pascual-Leone A, Poppendieck W, Priori A, Rossi S, Rossini PM, Rothwell J, Rueger MA, Ruffini G, Schellhorn K, Siebner HR, Ugawa Y, Wexler A, Ziemann U, Hallett M, Paulus W. Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines. Clin Neurophysiol 2017; 128:1774-1809. [PMID: 28709880 PMCID: PMC5985830 DOI: 10.1016/j.clinph.2017.06.001] [Citation(s) in RCA: 670] [Impact Index Per Article: 95.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/29/2017] [Accepted: 06/06/2017] [Indexed: 12/11/2022]
Abstract
Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears to be safe. No serious adverse events (SAEs) have been reported so far in over 18,000 sessions administered to healthy subjects, neurological and psychiatric patients, as summarized here. Moderate adverse events (AEs), as defined by the necessity to intervene, are rare, and include skin burns with tDCS due to suboptimal electrode-skin contact. Very rarely mania or hypomania was induced in patients with depression (11 documented cases), yet a causal relationship is difficult to prove because of the low incidence rate and limited numbers of subjects in controlled trials. Mild AEs (MAEs) include headache and fatigue following stimulation as well as prickling and burning sensations occurring during tDCS at peak-to-baseline intensities of 1-2mA and during tACS at higher peak-to-peak intensities above 2mA. The prevalence of published AEs is different in studies specifically assessing AEs vs. those not assessing them, being higher in the former. AEs are frequently reported by individuals receiving placebo stimulation. The profile of AEs in terms of frequency, magnitude and type is comparable in healthy and clinical populations, and this is also the case for more vulnerable populations, such as children, elderly persons, or pregnant women. Combined interventions (e.g., co-application of drugs, electrophysiological measurements, neuroimaging) were not associated with further safety issues. Safety is established for low-intensity 'conventional' TES defined as <4mA, up to 60min duration per day. Animal studies and modeling evidence indicate that brain injury could occur at predicted current densities in the brain of 6.3-13A/m2 that are over an order of magnitude above those produced by tDCS in humans. Using AC stimulation fewer AEs were reported compared to DC. In specific paradigms with amplitudes of up to 10mA, frequencies in the kHz range appear to be safe. In this paper we provide structured interviews and recommend their use in future controlled studies, in particular when trying to extend the parameters applied. We also discuss recent regulatory issues, reporting practices and ethical issues. These recommendations achieved consensus in a meeting, which took place in Göttingen, Germany, on September 6-7, 2016 and were refined thereafter by email correspondence.
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Affiliation(s)
- A Antal
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg August University, Göttingen, Germany.
| | - I Alekseichuk
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg August University, Göttingen, Germany
| | - M Bikson
- Department of Biomedical Engineering, The City College of New York, New York, USA
| | - J Brockmöller
- Department of Clinical Pharmacology, University Medical Center Goettingen, Germany
| | - A R Brunoni
- Service of Interdisciplinary Neuromodulation, Department and Institute of Psychiatry, Laboratory of Neurosciences (LIM-27) and Interdisciplinary Center for Applied Neuromodulation University Hospital, University of São Paulo, São Paulo, Brazil
| | - R Chen
- Division of Neurology, Department of Medicine, University of Toronto and Krembil Research Institute, Toronto, Ontario, Canada
| | - L G Cohen
- Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke NIH, Bethesda, USA
| | | | - J Ellrich
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark; Institute of Physiology and Pathophysiology, University of Erlangen-Nürnberg, Erlangen, Germany; EBS Technologies GmbH, Europarc Dreilinden, Germany
| | - A Flöel
- Universitätsmedizin Greifswald, Klinik und Poliklinik für Neurologie, Greifswald, Germany
| | - F Fregni
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA
| | - M S George
- Brain Stimulation Division, Medical University of South Carolina, and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, USA
| | - R Hamilton
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - J Haueisen
- Institute of Biomedical Engineering and Informatics, Technische Universität Ilmenau, Germany
| | - C S Herrmann
- Experimental Psychology Lab, Department of Psychology, European Medical School, Carl von Ossietzky Universität, Oldenburg, Germany
| | - F C Hummel
- Defitech Chair of Clinical Neuroengineering, Centre of Neuroprosthetics (CNP) and Brain Mind Institute, Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland; Defitech Chair of Clinical Neuroengineering, Clinique Romande de Réadaptation, Swiss Federal Institute of Technology (EPFL Valais), Sion, Switzerland
| | - J P Lefaucheur
- Department of Physiology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, and EA 4391, Nerve Excitability and Therapeutic Team (ENT), Faculty of Medicine, Paris Est Créteil University, Créteil, France
| | - D Liebetanz
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg August University, Göttingen, Germany
| | - C K Loo
- School of Psychiatry & Black Dog Institute, University of New South Wales, Sydney, Australia
| | - C D McCaig
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - C Miniussi
- Center for Mind/Brain Sciences CIMeC, University of Trento, Rovereto, Italy; Cognitive Neuroscience Section, IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - P C Miranda
- Institute of Biophysics and Biomedical Engineering, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - V Moliadze
- Institute of Medical Psychology and Medical Sociology, University Hospital of Schleswig-Holstein (UKSH), Campus Kiel, Christian-Albrechts-University, Kiel, Germany
| | - M A Nitsche
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; Department of Neurology, University Hospital Bergmannsheil, Bochum, Germany
| | - R Nowak
- Neuroelectrics, Barcelona, Spain
| | - F Padberg
- Department of Psychiatry and Psychotherapy, Munich Center for Brain Stimulation, Ludwig-Maximilian University Munich, Germany
| | - A Pascual-Leone
- Division of Cognitive Neurology, Harvard Medical Center and Berenson-Allen Center for Noninvasive Brain Stimulation at Beth Israel Deaconess Medical Center, Boston, USA
| | - W Poppendieck
- Department of Information Technology, Mannheim University of Applied Sciences, Mannheim, Germany
| | - A Priori
- Center for Neurotechnology and Experimental Brain Therapeutich, Department of Health Sciences, University of Milan Italy; Deparment of Clinical Neurology, University Hospital Asst Santi Paolo E Carlo, Milan, Italy
| | - S Rossi
- Department of Medicine, Surgery and Neuroscience, Human Physiology Section and Neurology and Clinical Neurophysiology Section, Brain Investigation & Neuromodulation Lab, University of Siena, Italy
| | - P M Rossini
- Area of Neuroscience, Institute of Neurology, University Clinic A. Gemelli, Catholic University, Rome, Italy
| | | | - M A Rueger
- Department of Neurology, University Hospital of Cologne, Germany
| | | | | | - H R Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
| | - Y Ugawa
- Department of Neurology, Fukushima Medical University, Fukushima, Japan; Fukushima Global Medical Science Center, Advanced Clinical Research Center, Fukushima Medical University, Japan
| | - A Wexler
- Department of Science, Technology & Society, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - U Ziemann
- Department of Neurology & Stroke, and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - M Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - W Paulus
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg August University, Göttingen, Germany
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Philip NS, Nelson BG, Frohlich F, Lim KO, Widge AS, Carpenter LL. Low-Intensity Transcranial Current Stimulation in Psychiatry. Am J Psychiatry 2017; 174:628-639. [PMID: 28231716 PMCID: PMC5495602 DOI: 10.1176/appi.ajp.2017.16090996] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Neurostimulation is rapidly emerging as an important treatment modality for psychiatric disorders. One of the fastest-growing and least-regulated approaches to noninvasive therapeutic stimulation involves the application of weak electrical currents. Widespread enthusiasm for low-intensity transcranial electrical current stimulation (tCS) is reflected by the recent surge in direct-to-consumer device marketing, do-it-yourself enthusiasm, and an escalating number of clinical trials. In the wake of this rapid growth, clinicians may lack sufficient information about tCS to inform their clinical practices. Interpretation of tCS clinical trial data is aided by familiarity with basic neurophysiological principles, potential mechanisms of action of tCS, and the complicated regulatory history governing tCS devices. A growing literature includes randomized controlled trials of tCS for major depression, schizophrenia, cognitive disorders, and substance use disorders. The relative ease of use and abundant access to tCS may represent a broad-reaching and important advance for future mental health care. Evidence supports application of one type of tCS, transcranial direct current stimulation (tDCS), for major depression. However, tDCS devices do not have regulatory approval for treating medical disorders, evidence is largely inconclusive for other therapeutic areas, and their use is associated with some physical and psychiatric risks. One unexpected finding to arise from this review is that the use of cranial electrotherapy stimulation devices-the only category of tCS devices cleared for use in psychiatric disorders-is supported by low-quality evidence.
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Affiliation(s)
- Noah S. Philip
- From the Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, and the Center of Excellence for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, R.I.; the Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Mass., and the Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Mass.; the Department of Psychiatry, the Department of Biomedical Engineering, the
| | - Brent G. Nelson
- From the Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, and the Center of Excellence for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, R.I.; the Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Mass., and the Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Mass.; the Department of Psychiatry, the Department of Biomedical Engineering, the
| | - Flavio Frohlich
- From the Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, and the Center of Excellence for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, R.I.; the Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Mass., and the Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Mass.; the Department of Psychiatry, the Department of Biomedical Engineering, the
| | - Kelvin O. Lim
- From the Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, and the Center of Excellence for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, R.I.; the Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Mass., and the Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Mass.; the Department of Psychiatry, the Department of Biomedical Engineering, the
| | - Alik S. Widge
- From the Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, and the Center of Excellence for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, R.I.; the Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Mass., and the Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Mass.; the Department of Psychiatry, the Department of Biomedical Engineering, the
| | - Linda L. Carpenter
- From the Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, and the Center of Excellence for Neurorestoration and Neurotechnology, Providence VA Medical Center, Providence, R.I.; the Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Mass., and the Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Mass.; the Department of Psychiatry, the Department of Biomedical Engineering, the
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Frontoparietal neurostimulation modulates working memory training benefits and oscillatory synchronization. Brain Res 2017; 1667:28-40. [PMID: 28502585 DOI: 10.1016/j.brainres.2017.05.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 05/01/2017] [Accepted: 05/03/2017] [Indexed: 11/24/2022]
Abstract
There is considerable interest in maintaining working memory (WM) because it is essential to accomplish most cognitive tasks, and it is correlated with fluid intelligence and ecologically valid measures of daily living. Toward this end, WM training protocols aim to improve WM capacity and extend improvements to unpracticed domains, yet success is limited. One emerging approach is to couple WM training with transcranial direct current stimulation (tDCS). This pairing of WM training with tDCS in longitudinal designs promotes behavioral improvement and evidence of transfer of performance gains to untrained WM tasks. However, the mechanism(s) underlying tDCS-linked training benefits remain unclear. Our goal was to gain purchase on this question by recording high-density EEG before and after a weeklong WM training+tDCS study. Participants completed four sessions of frontoparietal tDCS (active anodal or sham) during which they performed a visuospatial WM change detection task. Participants who received active anodal tDCS demonstrated significant improvement on the WM task, unlike those who received sham stimulation. Importantly, this pattern was mirrored by neural correlates in spectral and phase synchrony analyses of the HD-EEG data. Notably, the behavioral interaction was echoed by interactions in frontal-posterior alpha band power, and theta and low alpha oscillations. These findings indicate that one mechanism by which paired tDCS+WM training operates is to enhance cortical efficiency and connectivity in task-relevant networks.
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Voarino N, Dubljević V, Racine E. tDCS for Memory Enhancement: Analysis of the Speculative Aspects of Ethical Issues. Front Hum Neurosci 2017; 10:678. [PMID: 28123362 PMCID: PMC5225120 DOI: 10.3389/fnhum.2016.00678] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/20/2016] [Indexed: 11/26/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) is a promising technology to enhance cognitive and physical performance. One of the major areas of interest is the enhancement of memory function in healthy individuals. The early arrival of tDCS on the market for lifestyle uses and cognitive enhancement purposes lead to the voicing of some important ethical concerns, especially because, to date, there are no official guidelines or evaluation procedures to tackle these issues. The aim of this article is to review ethical issues related to uses of tDCS for memory enhancement found in the ethics and neuroscience literature and to evaluate how realistic and scientifically well-founded these concerns are? In order to evaluate how plausible or speculative each issue is, we applied the methodological framework described by Racine et al. (2014) for “informed and reflective” speculation in bioethics. This framework could be succinctly presented as requiring: (1) the explicit acknowledgment of factual assumptions and identification of the value attributed to them; (2) the validation of these assumptions with interdisciplinary literature; and (3) the adoption of a broad perspective to support more comprehensive reflection on normative issues. We identified four major considerations associated with the development of tDCS for memory enhancement: safety, autonomy, justice and authenticity. In order to assess the seriousness and likelihood of harm related to each of these concerns, we analyzed the assumptions underlying the ethical issues, and the level of evidence for each of them. We identified seven distinct assumptions: prevalence, social acceptance, efficacy, ideological stance (bioconservative vs. libertarian), potential for misuse, long term side effects, and the delivery of complete and clear information. We conclude that ethical discussion about memory enhancement via tDCS sometimes involves undue speculation, and closer attention to scientific and social facts would bring a more nuanced analysis. At this time, the most realistic concerns are related to safety and violation of users’ autonomy by a breach of informed consent, as potential immediate and long-term health risks to private users remain unknown or not well defined. Clear and complete information about these risks must be provided to research participants and consumers of tDCS products or related services. Broader public education initiatives and warnings would also be worthwhile to reach those who are constructing their own tDCS devices.
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Affiliation(s)
- Nathalie Voarino
- Institut de recherches cliniques de Montréal, Université de Montréal, McGill UniversityMontreal, QC, Canada; Bioethics Programme, Department of Social and Preventive Medicine, School of Public Health (ÉSPUM), Université de MontréalMontreal, QC, Canada
| | - Veljko Dubljević
- North Carolina State UniversityRaleigh, NC, USA; Neuroethics Research Unit, Institut de recherches cliniques de MontréalMontreal, QC, Canada
| | - Eric Racine
- Institut de recherches cliniques de Montréal, Université de Montréal, McGill University Montreal, QC, Canada
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Colzato LS, Nitsche MA, Kibele A. Noninvasive Brain Stimulation and Neural Entrainment Enhance Athletic Performance—a Review. JOURNAL OF COGNITIVE ENHANCEMENT 2016. [DOI: 10.1007/s41465-016-0003-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Evidence-based guidelines on the therapeutic use of transcranial direct current stimulation (tDCS). Clin Neurophysiol 2016; 128:56-92. [PMID: 27866120 DOI: 10.1016/j.clinph.2016.10.087] [Citation(s) in RCA: 1044] [Impact Index Per Article: 130.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 10/18/2016] [Accepted: 10/20/2016] [Indexed: 12/19/2022]
Abstract
A group of European experts was commissioned by the European Chapter of the International Federation of Clinical Neurophysiology to gather knowledge about the state of the art of the therapeutic use of transcranial direct current stimulation (tDCS) from studies published up until September 2016, regarding pain, Parkinson's disease, other movement disorders, motor stroke, poststroke aphasia, multiple sclerosis, epilepsy, consciousness disorders, Alzheimer's disease, tinnitus, depression, schizophrenia, and craving/addiction. The evidence-based analysis included only studies based on repeated tDCS sessions with sham tDCS control procedure; 25 patients or more having received active treatment was required for Class I, while a lower number of 10-24 patients was accepted for Class II studies. Current evidence does not allow making any recommendation of Level A (definite efficacy) for any indication. Level B recommendation (probable efficacy) is proposed for: (i) anodal tDCS of the left primary motor cortex (M1) (with right orbitofrontal cathode) in fibromyalgia; (ii) anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) (with right orbitofrontal cathode) in major depressive episode without drug resistance; (iii) anodal tDCS of the right DLPFC (with left DLPFC cathode) in addiction/craving. Level C recommendation (possible efficacy) is proposed for anodal tDCS of the left M1 (or contralateral to pain side, with right orbitofrontal cathode) in chronic lower limb neuropathic pain secondary to spinal cord lesion. Conversely, Level B recommendation (probable inefficacy) is conferred on the absence of clinical effects of: (i) anodal tDCS of the left temporal cortex (with right orbitofrontal cathode) in tinnitus; (ii) anodal tDCS of the left DLPFC (with right orbitofrontal cathode) in drug-resistant major depressive episode. It remains to be clarified whether the probable or possible therapeutic effects of tDCS are clinically meaningful and how to optimally perform tDCS in a therapeutic setting. In addition, the easy management and low cost of tDCS devices allow at home use by the patient, but this might raise ethical and legal concerns with regard to potential misuse or overuse. We must be careful to avoid inappropriate applications of this technique by ensuring rigorous training of the professionals and education of the patients.
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Bikson M, Grossman P, Thomas C, Zannou AL, Jiang J, Adnan T, Mourdoukoutas AP, Kronberg G, Truong D, Boggio P, Brunoni AR, Charvet L, Fregni F, Fritsch B, Gillick B, Hamilton RH, Hampstead BM, Jankord R, Kirton A, Knotkova H, Liebetanz D, Liu A, Loo C, Nitsche MA, Reis J, Richardson JD, Rotenberg A, Turkeltaub PE, Woods AJ. Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016. Brain Stimul 2016; 9:641-661. [PMID: 27372845 PMCID: PMC5007190 DOI: 10.1016/j.brs.2016.06.004] [Citation(s) in RCA: 835] [Impact Index Per Article: 104.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 06/10/2016] [Accepted: 06/12/2016] [Indexed: 01/13/2023] Open
Abstract
This review updates and consolidates evidence on the safety of transcranial Direct Current Stimulation (tDCS). Safety is here operationally defined by, and limited to, the absence of evidence for a Serious Adverse Effect, the criteria for which are rigorously defined. This review adopts an evidence-based approach, based on an aggregation of experience from human trials, taking care not to confuse speculation on potential hazards or lack of data to refute such speculation with evidence for risk. Safety data from animal tests for tissue damage are reviewed with systematic consideration of translation to humans. Arbitrary safety considerations are avoided. Computational models are used to relate dose to brain exposure in humans and animals. We review relevant dose-response curves and dose metrics (e.g. current, duration, current density, charge, charge density) for meaningful safety standards. Special consideration is given to theoretically vulnerable populations including children and the elderly, subjects with mood disorders, epilepsy, stroke, implants, and home users. Evidence from relevant animal models indicates that brain injury by Direct Current Stimulation (DCS) occurs at predicted brain current densities (6.3-13 A/m(2)) that are over an order of magnitude above those produced by conventional tDCS. To date, the use of conventional tDCS protocols in human trials (≤40 min, ≤4 milliamperes, ≤7.2 Coulombs) has not produced any reports of a Serious Adverse Effect or irreversible injury across over 33,200 sessions and 1000 subjects with repeated sessions. This includes a wide variety of subjects, including persons from potentially vulnerable populations.
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Affiliation(s)
- Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA.
| | - Pnina Grossman
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Chris Thomas
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | | | - Jimmy Jiang
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Tatheer Adnan
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | | | - Greg Kronberg
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Dennis Truong
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Paulo Boggio
- Cognitive Neuroscience Laboratory and Developmental Disorders Program, Center for Health and Biological Sciences, Mackenzie Presbyterian University, Sao Paulo, Brazil
| | - André R Brunoni
- Service of Interdisciplinary Neuromodulation, Department and Institute of Psychiatry, Laboratory of Neurosciences (LIM-27), University of São Paulo, São Paulo, Brazil
| | - Leigh Charvet
- NYU MS Comprehensive Care Center, Department of Neurology, New York University School of Medicine, New York, NY, USA
| | - Felipe Fregni
- Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Brita Fritsch
- Department of Neurology, University Medical Center, Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Germany
| | - Bernadette Gillick
- Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis, MN
| | - Roy H Hamilton
- Laboratory for Cognition and Neural Stimulation, University of Pennsylvania, Philadelphia, PA, USA; Center for Cognitive Neuroscience, University of Pennsylvania, Philadelphia, PA, USA; Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Benjamin M Hampstead
- Mental Health Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, USA; Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Ryan Jankord
- Applied Neuroscience, 711th Human Performance Wing, Air Force Research Laboratory, WPAFB, OH, USA
| | - Adam Kirton
- Departments of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Helena Knotkova
- MJHS Institute for Innovation in Palliative Care, New York, NY, USA; Department of Social and Family Medicine, Albert Einstein College of Medicine, The Bronx, NY, USA
| | - David Liebetanz
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Goettingen 37075, Germany
| | - Anli Liu
- NYU Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, USA
| | - Colleen Loo
- Psychiatry, Black Dog Institute, Clinical Academic, St George Hospital, University of New South Wales, Sydney, Australia
| | - Michael A Nitsche
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Goettingen 37075, Germany; Leibniz Research Centre for Working Environment and Human Factors at the TU Dortmund, Dortmund, Germany; Department of Neurology, University Medical Hospital Bergmannsheil, Bochum, Germany
| | - Janine Reis
- Department of Neurology, University Medical Center, Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Germany
| | - Jessica D Richardson
- Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; Department of Communication Sciences & Disorders, The University of South Carolina, Columbia, SC, USA; Department of Speech and Hearing Sciences, The University of New Mexico, Albuquerque, NM, USA
| | - Alexander Rotenberg
- Berenson-Allen Center for Noninvasive Brain Stimulation, Division of Cognitive Neurology, Department of Neurology, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, MA, USA; Pediatric Neuromodulation Program, Division of Epilepsy and Neurophysiology, Department of Neurology, Children's Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - Peter E Turkeltaub
- Department of Neurology, Georgetown University, Washington, DC, USA; Research Division, MedStar National Rehabilitation Hospital, Washington, DC, USA
| | - Adam J Woods
- Center for Cognitive Aging and Memory, Institute on Aging, Department of Aging and Geriatric Research, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
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Brühl AB, Sahakian BJ. Drugs, games, and devices for enhancing cognition: implications for work and society. Ann N Y Acad Sci 2016; 1369:195-217. [PMID: 27043232 DOI: 10.1111/nyas.13040] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 02/15/2016] [Accepted: 02/18/2016] [Indexed: 12/11/2022]
Abstract
As work environments change, the demands on working people change. Cognitive abilities in particular are becoming progressively more important for work performance and successful competition in a global environment. However, work-related stress, performance over long hours, lack of sleep, shift work, and jet lag affect cognitive functions. Therefore, an increasing number of healthy people are reported to use cognitive-enhancing drugs, as well as other interventions, such as noninvasive brain stimulation, to maintain or improve work performance. This review summarizes research on pharmacological and technical methods as well as cognitive training, including game apps for the brain, in healthy people. In neuropsychiatric disorders, impairments in cognitive functions can drastically reduce the chances of returning to work; therefore, this review also summarizes findings from pharmacological and cognitive-training studies in neuropsychiatric disorders.
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Affiliation(s)
- Annette B Brühl
- Department of Psychiatry, and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom.,Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry Zurich, Zürich, Switzerland
| | - Barbara J Sahakian
- Department of Psychiatry, and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom
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Schroeder PA, Ehlis AC, Wolkenstein L, Fallgatter AJ, Plewnia C. Emotional Distraction and Bodily Reaction: Modulation of Autonomous Responses by Anodal tDCS to the Prefrontal Cortex. Front Cell Neurosci 2015; 9:482. [PMID: 26733808 PMCID: PMC4683355 DOI: 10.3389/fncel.2015.00482] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/30/2015] [Indexed: 11/28/2022] Open
Abstract
Prefrontal electric stimulation has been demonstrated to effectively modulate cognitive processing. Specifically, the amelioration of cognitive control (CC) over emotional distraction by transcranial direct current stimulation (tDCS) points toward targeted therapeutic applications in various psychiatric disorders. In addition to behavioral measures, autonomous nervous system (ANS) responses are fundamental bodily signatures of emotional information processing. However, interactions between the modulation of CC by tDCS and ANS responses have received limited attention. We here report on ANS data gathered in healthy subjects that performed an emotional CC task parallel to the modulation of left prefrontal cortical activity by 1 mA anodal or sham tDCS. Skin conductance responses (SCRs) to negative and neutral pictures of human scenes were reduced by anodal as compared to sham tDCS. Individual SCR amplitude variations were associated with the amount of distraction. Moreover, the stimulation-driven performance- and SCR-modulations were related in form of a quadratic, inverse-U function. Thus, our results indicate that non-invasive brain stimulation (i.e., anodal tDCS) can modulate autonomous responses synchronous to behavioral improvements, but the range of possible concurrent improvements from prefrontal stimulation is limited. Interactions between cognitive, affective, neurophysiological, and vegetative responses to emotional content can shape brain stimulation effectiveness and require theory-driven integration in potential treatment protocols.
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Affiliation(s)
- Philipp A. Schroeder
- Department of Psychiatry and Psychotherapy, Neurophysiology & Interventional Neuropsychiatry, University of TübingenTübingen, Germany
- Department of Psychology, University of TübingenTübingen, Germany
| | - Ann-Christine Ehlis
- Department of Psychiatry and Psychotherapy, Neurophysiology & Interventional Neuropsychiatry, University of TübingenTübingen, Germany
- LEAD Graduate School, University of TübingenTübingen, Germany
| | | | - Andreas J. Fallgatter
- Department of Psychiatry and Psychotherapy, Neurophysiology & Interventional Neuropsychiatry, University of TübingenTübingen, Germany
- LEAD Graduate School, University of TübingenTübingen, Germany
- Werner Reichardt Centre for Integrative NeuroscienceTübingen, Germany
| | - Christian Plewnia
- Department of Psychiatry and Psychotherapy, Neurophysiology & Interventional Neuropsychiatry, University of TübingenTübingen, Germany
- Werner Reichardt Centre for Integrative NeuroscienceTübingen, Germany
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