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Ramasawmy P, Gamboa Arana OL, Mai TT, Heim LC, Schumann SE, Fechner E, Jiang Y, Moschner O, Chakalov I, Bähr M, Petzke F, Antal A. No add-on therapeutic benefit of at-home anodal tDCS of the primary motor cortex to mindfulness meditation in patients with fibromyalgia. Clin Neurophysiol 2024; 164:168-179. [PMID: 38901112 DOI: 10.1016/j.clinph.2024.05.018] [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: 03/27/2024] [Revised: 05/25/2024] [Accepted: 05/28/2024] [Indexed: 06/22/2024]
Abstract
OBJECTIVE This study investigated the efficacy of combining at-home anodal transcranial direct current stimulation (tDCS) of the left primary motor cortex (M1) with mindfulness meditation (MM) in fibromyalgia patients trained in mindfulness. METHODS Thirty-seven patients were allocated to receive ten daily sessions of MM paired with either anodal or sham tDCS over the primary motor cortex. Primary outcomes were pain intensity and quality of life. Secondary outcomes were psychological impairment, sleep quality, mood, affective pain, mindfulness level, and transcranial magnetic stimulation (TMS) measures of cortical excitability. Outcomes were analyzed pre- and post-treatment, with a one-month follow-up. RESULTS We found post-tDCS improvement in all clinical outcomes, including mindfulness level, except for positive affect and stress, in both groups without significant difference between active and sham conditions. No significant group*time interaction was found for all clinical and TMS outcomes. CONCLUSIONS Our findings demonstrate no synergistic or add-on efffect of anodal tDCS of the left M1 compared to the proper effect of MM in patients with fibromyalgia. SIGNIFICANCE Our findings challenge the potential of combining anodal tDCS of the left M1 and MM in fibromyalgia.
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Affiliation(s)
- Perianen Ramasawmy
- Department of Neurology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany.
| | | | - Thuy Tien Mai
- Department of Neurology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Luise Charlotte Heim
- Department of Neurology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Samuel Enrico Schumann
- Department of Neurology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Elisabeth Fechner
- Department of Neurology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Yong Jiang
- Department of Neurology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Oscar Moschner
- Institute of Computer and Communication Technology, Technische Hochschule Köln, Köln, Germany
| | - Ivan Chakalov
- Department of Neurology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany; Department of Anesthesiology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Frank Petzke
- Department of Anesthesiology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - Andrea Antal
- Department of Neurology, University Medical Center Göttingen, Georg-August University, Göttingen, Germany
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Dehghani A, Bango C, Murphy EK, Halter RJ, Wager TD. Independent effects of transcranial direct current stimulation and social influence on pain. Pain 2024:00006396-990000000-00657. [PMID: 39167466 DOI: 10.1097/j.pain.0000000000003338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 05/28/2024] [Indexed: 08/23/2024]
Abstract
ABSTRACT Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulatory technique with the potential to provide pain relief. However, tDCS effects on pain are variable across existing studies, possibly related to differences in stimulation protocols and expectancy effects. We investigated the independent and joint effects of contralateral motor cortex tDCS (anodal vs cathodal) and socially induced expectations (analgesia vs hyperalgesia) about tDCS on thermal pain. We employed a double-blind, randomized 2 × 2 factorial cross-over design, with 5 sessions per participant on separate days. After calibration in Session 1, Sessions 2 to 5 crossed anodal or cathodal tDCS (20 minutes 2 mA) with socially induced analgesic or hyperalgesic expectations, with 6 to 7 days between the sessions. The social manipulation involved videos of previous "participants" (confederates) describing tDCS as inducing a low-pain state ("analgesic expectancy") or hypersensitivity to sensation ("hyperalgesic expectancy"). Anodal tDCS reduced pain compared with cathodal stimulation (F(1,19.9) = 19.53, P < 0.001, Cohen d = 0.86) and analgesic expectancy reduced pain compared with hyperalgesic expectancy (F(1,19.8) = 5.62, P = 0.027, Cohen d = 0.56). There was no significant interaction between tDCS and social expectations. Effects of social suggestions were related to expectations, whereas tDCS effects were unrelated to expectancies. The observed additive effects provide novel evidence that tDCS and socially induced expectations operate through independent processes. They extend clinical tDCS studies by showing tDCS effects on controlled nociceptive pain independent of expectancy effects. In addition, they show that social suggestions about neurostimulation effects can elicit potent placebo effects.
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Affiliation(s)
- Amin Dehghani
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, United States
| | - Carmen Bango
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, United States
| | - Ethan K Murphy
- Thayer School of Engineering and Geisel School of Medicine, Dartmouth College, Hanover, NH, United States
| | - Ryan J Halter
- Thayer School of Engineering and Geisel School of Medicine, Dartmouth College, Hanover, NH, United States
| | - Tor D Wager
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, United States
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Mollica A, Ng E, Burke MJ, Nestor SM, Lee H, Rabin JS, Hamani C, Lipsman N, Giacobbe P. Treatment expectations and clinical outcomes following repetitive transcranial magnetic stimulation for treatment-resistant depression. Brain Stimul 2024; 17:752-759. [PMID: 38901565 DOI: 10.1016/j.brs.2024.06.006] [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: 12/20/2023] [Revised: 05/28/2024] [Accepted: 06/05/2024] [Indexed: 06/22/2024] Open
Abstract
BACKGROUND Patient expectations, including both positive (placebo) and negative (nocebo) effects, influence treatment outcomes, yet their impact on acute repetitive transcranial magnetic stimulation (rTMS) for treatment-resistant depression (TRD) is unclear. METHODS In this single-center retrospective chart review, 208 TRD patients completed the Stanford Expectation of Treatment Scale (SETS) before starting open-label rTMS treatment. Patients were offered two excitatory rTMS protocols (deep TMS or intermittent theta-burst stimulation), which stimulated the left dorsolateral prefrontal cortex. A minimum of 20 once daily treatments were provided, delivered over 4-6 weeks. Primary outcomes were 1) remission, measured by a post-treatment score of <8 on the Hamilton Depression Rating Scale (HAMD-17), and 2) premature discontinuation. The change in HAMD-17 scores over time was used as a secondary outcome. Physicians were blinded to SETS scores. Logistic and linear regression, adjusting for covariates, assessed SETS and HAMD-17 relationships. RESULTS Of 208 patients, 177 had baseline and covariate data available. The mean positivity bias score (positive expectancy minus negative expectancy subscale averages) was 0.48 ± 2.21, indicating the cohort was neutral regarding the expectations of their treatment on average. Higher positive expectancy scores were significantly associated with greater odds of remission (OR = 1.90, p = 0.003) and greater reduction in HAMD-17 scores (β = 1.30, p = 0.005) at the end of acute treatment, after adjusting for covariates. Negative expectancy was not associated with decreased odds of remission (p = 0.2) or treatment discontinuation (p = 0.8). CONCLUSIONS Higher pre-treatment positive expectations were associated with greater remission rates with open-label rTMS in a naturalistic cohort of patients with TRD.
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Affiliation(s)
- Adriano Mollica
- Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Enoch Ng
- Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Matthew J Burke
- Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada; Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Sean M Nestor
- Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Hyewon Lee
- Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Jennifer S Rabin
- Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada; Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada; Rehabilitation Sciences Institute, University of Toronto, Canada
| | - Clement Hamani
- Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada; Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Nir Lipsman
- Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada; Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada
| | - Peter Giacobbe
- Harquail Centre for Neuromodulation and Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Psychiatry, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada.
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Bisio A, Panascì M, Ferrando V, Albergoni A, Ruggeri P, Faelli E. Warm-up plus verbal communications administered as placebo procedure during the training session improves running performance. PSYCHOLOGY OF SPORT AND EXERCISE 2024; 73:102633. [PMID: 38548005 DOI: 10.1016/j.psychsport.2024.102633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 12/10/2023] [Accepted: 03/25/2024] [Indexed: 04/06/2024]
Abstract
The aim of this study was to investigate the effects on running performance of a within-session placebo procedure consisting of a conditioning treatment plus verbal communications. Twenty-six subjects were assigned to PLACEBO and CONTROL groups. Participants performed three sessions: Session 1-Cooper Test, Session 2-Baseline session and Session 3-Experimental session. During Session 2, participants performed a sprint-interval-training (SIT)-until-exhaustion preceded by a general warm-up, while in Session3 the SIT was preceded by a conditioning treatment (FIFA11+ warm-up), known to be effective in preventing injuries but not improving performance. Moreover, in Session3, only the PLACEBO group received verbal suggestions (before the warm-up) to influence participants' expectations about FIFA11+ effectiveness in improving performance, and deceptive feedback (during each SIT recovery bout) to increase the conditioning effect. To evaluate performance improvements, Running Time was chosen as a main outcome while to ensure participants reached exhaustion, physiological and metabolic responses were monitored. Total running distance (TRD) was also measured. Results showed that, Running Time and TRD significantly increased in the PLACEBO group whilst no differences in the CONTROL group were observed thus, suggesting the effectiveness of the within-session-placebo procedure in improving running performance. These findings shed a new light on the interaction between cognitive domain and performance, thus encouraging coaches to adopt this innovative method during the training protocol to enhance athletes' performance. Moreover, this placebo procedure, not requiring additional time, tools or resources, could represent a more ecological approach that can be easily adopted in the field.
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Affiliation(s)
- Ambra Bisio
- Section of Human Physiology, Department of Experimental Medicine, Università Degli Studi di Genova, 16132, Genoa, Italy; Centro Polifunzionale di Scienze Motorie, Università Degli Studi di Genova, 16132, Genoa, Italy
| | - Marco Panascì
- Section of Human Physiology, Department of Experimental Medicine, Università Degli Studi di Genova, 16132, Genoa, Italy; Centro Polifunzionale di Scienze Motorie, Università Degli Studi di Genova, 16132, Genoa, Italy
| | - Vittoria Ferrando
- Section of Human Physiology, Department of Experimental Medicine, Università Degli Studi di Genova, 16132, Genoa, Italy; Centro Polifunzionale di Scienze Motorie, Università Degli Studi di Genova, 16132, Genoa, Italy.
| | - Andrea Albergoni
- Centro Polifunzionale di Scienze Motorie, Università Degli Studi di Genova, 16132, Genoa, Italy; Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal Child Health, Università Degli Studi di Genova, 16132, Genoa, Italy
| | - Piero Ruggeri
- Section of Human Physiology, Department of Experimental Medicine, Università Degli Studi di Genova, 16132, Genoa, Italy; Centro Polifunzionale di Scienze Motorie, Università Degli Studi di Genova, 16132, Genoa, Italy
| | - Emanuela Faelli
- Section of Human Physiology, Department of Experimental Medicine, Università Degli Studi di Genova, 16132, Genoa, Italy; Centro Polifunzionale di Scienze Motorie, Università Degli Studi di Genova, 16132, Genoa, Italy
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Hooyman A, Haikalis NK, Wang P, Schambra HM, Lohse KR, Schaefer SY. Evidence and sources of placebo effects in transcranial direct current stimulation during a single session of visuospatial working memory practice. Sci Rep 2024; 14:9094. [PMID: 38643299 PMCID: PMC11032394 DOI: 10.1038/s41598-024-59927-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 04/16/2024] [Indexed: 04/22/2024] Open
Abstract
Transcranial direct current stimulation (tDCS) can be used to non-invasively augment cognitive training. However, the benefits of tDCS may be due in part to placebo effects, which have not been well-characterized. The purpose of this study was to determine whether tDCS can have a measurable placebo effect on cognitive training and to identify potential sources of this effect. Eighty-three right-handed adults were randomly assigned to one of three groups: control (no exposure to tDCS), sham tDCS, or active tDCS. The sham and active tDCS groups were double-blinded. Each group performed 20 min of an adapted Corsi Block Tapping Task (CBTT), a visuospatial working memory task. Anodal or sham tDCS was applied during CBTT training in a right parietal-left supraorbital montage. After training, active and sham tDCS groups were surveyed on expectations about tDCS efficacy. Linear mixed effects models showed that the tDCS groups (active and sham combined) improved more on the CBTT with training than the control group, suggesting a placebo effect of tDCS. Participants' tDCS expectations were significantly related to the placebo effect, as was the belief of receiving active stimulation. This placebo effect shows that the benefits of tDCS on cognitive training can occur even in absence of active stimulation. Future tDCS studies should consider how treatment expectations may be a source of the placebo effect in tDCS research, and identify ways to potentially leverage them to maximize treatment benefit.
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Affiliation(s)
- Andrew Hooyman
- School of Biological and Health Systems Engineering, Arizona State University, 501 E. Tyler Mall, MC 9709, Tempe, AZ, 85287, USA
| | - Nicole K Haikalis
- School of Biological and Health Systems Engineering, Arizona State University, 501 E. Tyler Mall, MC 9709, Tempe, AZ, 85287, USA
| | - Peiyuan Wang
- School of Biological and Health Systems Engineering, Arizona State University, 501 E. Tyler Mall, MC 9709, Tempe, AZ, 85287, USA
| | - Heidi M Schambra
- Department of Neurology and Department of Physical Medicine and Rehabilitation, Grossman School of Medicine, New York University, New York, NY, USA
| | - Keith R Lohse
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO, USA
| | - Sydney Y Schaefer
- School of Biological and Health Systems Engineering, Arizona State University, 501 E. Tyler Mall, MC 9709, Tempe, AZ, 85287, USA.
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Fassi L, Hochman S, Daskalakis ZJ, Blumberger DM, Cohen Kadosh R. The importance of individual beliefs in assessing treatment efficacy. eLife 2024; 12:RP88889. [PMID: 38547008 PMCID: PMC10977967 DOI: 10.7554/elife.88889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024] Open
Abstract
In recent years, there has been debate about the effectiveness of treatments from different fields, such as neurostimulation, neurofeedback, brain training, and pharmacotherapy. This debate has been fuelled by contradictory and nuanced experimental findings. Notably, the effectiveness of a given treatment is commonly evaluated by comparing the effect of the active treatment versus the placebo on human health and/or behaviour. However, this approach neglects the individual's subjective experience of the type of treatment she or he received in establishing treatment efficacy. Here, we show that individual differences in subjective treatment - the thought of receiving the active or placebo condition during an experiment - can explain variability in outcomes better than the actual treatment. We analysed four independent datasets (N = 387 participants), including clinical patients and healthy adults from different age groups who were exposed to different neurostimulation treatments (transcranial magnetic stimulation: Studies 1 and 2; transcranial direct current stimulation: Studies 3 and 4). Our findings show that the inclusion of subjective treatment can provide a better model fit either alone or in interaction with objective treatment (defined as the condition to which participants are assigned in the experiment). These results demonstrate the significant contribution of subjective experience in explaining the variability of clinical, cognitive, and behavioural outcomes. We advocate for existing and future studies in clinical and non-clinical research to start accounting for participants' subjective beliefs and their interplay with objective treatment when assessing the efficacy of treatments. This approach will be crucial in providing a more accurate estimation of the treatment effect and its source, allowing the development of effective and reproducible interventions.
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Affiliation(s)
- Luisa Fassi
- MRC Cognition and Brain Sciences Unit, University of CambridgeCambridgeUnited Kingdom
- Department of Psychiatry, University of CambridgeCambridgeUnited Kingdom
- Department of Experimental Psychology, University of OxfordOxfordUnited Kingdom
| | - Shachar Hochman
- School of Psychology, University of SurreySurreyUnited Kingdom
| | - Zafiris J Daskalakis
- Department of Psychiatry, University of California, San DiegoSan DiegoUnited States
| | - Daniel M Blumberger
- Temerty Centre for Therapeutic Brain Intervention at the Centre for Addiction and Mental Health and Department of Psychiatry, Temerty Faculty of Medicine, University of TorontoTorontoCanada
| | - Roi Cohen Kadosh
- Department of Experimental Psychology, University of OxfordOxfordUnited Kingdom
- School of Psychology, University of SurreySurreyUnited Kingdom
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7
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Hervik JA, Vika KS, Stub T. Transcranial direct current stimulation for chronic headaches, a randomized, controlled trial. FRONTIERS IN PAIN RESEARCH 2024; 5:1353987. [PMID: 38476353 PMCID: PMC10927820 DOI: 10.3389/fpain.2024.1353987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 02/15/2024] [Indexed: 03/14/2024] Open
Abstract
Background and objectives Chronic headaches are a frequent cause of pain and disability. The purpose of this randomized trial was to examine whether transcranial direct current stimulation (tDCS) applied to the primary motor cortex, reduces pain and increases daily function in individuals suffering from primary chronic headache. Materials and methods A prospective, randomized, controlled trial, where participants and assessors were blinded, investigated the effect of active tDCS vs. sham tDCS in chronic headache sufferers. Forty subjects between 18 and 70 years of age, with a diagnosis of primary chronic headache were randomized to either active tDCS or sham tDCS treatment groups. All patients received eight treatments over four consecutive weeks. Anodal stimulation (2 mA) directed at the primary motor cortex (M1), was applied for 30 min in the active tDCS group. Participants in the sham tDCS group received 30 s of M1 stimulation at the start and end of the 30-minute procedure; for the remaining 29 min, they did not receive any stimulation. Outcome measures based on data collected at baseline, after eight treatments and three months later included changes in daily function, pain levels, and medication. Results Significant improvements in both daily function and pain levels were observed in participants treated with active tDCS, compared to sham tDCS. Effects lasted up to 12 weeks post-treatment. Medication use remained unchanged in both groups throughout the trial with no serious adverse effects reported. Conclusion These results suggest that tDCS has the potential to improve daily function and reduce pain in patients suffering from chronic headaches. Larger randomized, controlled trials are needed to confirm these findings. Trial registration The study was approved by the local ethics committee (2018/2514) and by the Norwegian Centre for Research Data (54483).
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Affiliation(s)
- Jill Angela Hervik
- Department of Anaesthesiology, Vestfold Hospital Trust, Tonsberg, Norway
| | - Karl Solbue Vika
- Department of School and Nursery, NIFU Nordic Institute for Studies in Innovation, Research and Education, Oslo, Norway
| | - Trine Stub
- Department of Community Medicine, National Research Center in Complementary and Alternative Medicine, NAFKAM, UiT The Arctic University of Norway, Tromsø, Norway
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Haikalis NK, Hooyman A, Wang P, Daliri A, Schaefer SY. Placebo effects of transcranial direct current stimulation on motor skill acquisition. Neurosci Lett 2023; 814:137442. [PMID: 37591359 PMCID: PMC11101143 DOI: 10.1016/j.neulet.2023.137442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/21/2023] [Accepted: 08/14/2023] [Indexed: 08/19/2023]
Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique used in neurorehabilitation to enhance motor training. However, its benefits to motor training can be difficult to reproduce across research studies. It is possible that the observed benefits of tDCS are not directly related to the intervention itself but rather to the brain-mind responses elicited by the treatment context, commonly known as a placebo effect. This study investigated the presence of a placebo effect of tDCS on motor training and explored potential underlying factors. Sixty-eight participants who were right-handed were randomly assigned to active tDCS, sham tDCS, or a no-stimulation control group. Double-blind active or sham tDCS was applied to the right primary motor cortex, while the unblinded control group received no stimulation. All participants completed 30 training trials of a functional upper-extremity motor task. Participants' beliefs of tDCS, along with their prior knowledge of tDCS, were also collected. There was no significant difference in the amount of improvement on the motor task between the active and sham tDCS groups; however, both active and sham tDCS groups improved more than the control group, indicating a placebo effect. More motor task improvement was also associated with higher beliefs of tDCS (regardless of whether active or sham tDCS was received). This demonstrates a measurable placebo effect of tDCS on motor training, driven at least in part by treatment expectations or beliefs. Future tDCS studies should control for beliefs and other placebo-related factors.
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Affiliation(s)
- Nicole K Haikalis
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Andrew Hooyman
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Peiyuan Wang
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Ayoub Daliri
- Department of Speech and Hearing Science, Arizona State University, Tempe, AZ, USA
| | - Sydney Y Schaefer
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA.
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Teymoori H, Amiri E, Tahmasebi W, Hoseini R, Grospretre S, Machado DGDS. Effect of tDCS targeting the M1 or left DLPFC on physical performance, psychophysiological responses, and cognitive function in repeated all-out cycling: a randomized controlled trial. J Neuroeng Rehabil 2023; 20:97. [PMID: 37496055 PMCID: PMC10373277 DOI: 10.1186/s12984-023-01221-9] [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: 02/01/2023] [Accepted: 07/19/2023] [Indexed: 07/28/2023] Open
Abstract
BACKGROUND Despite reporting the positive effects of transcranial direct current stimulation (tDCS) on endurance performance, very few studies have investigated its efficacy in anaerobic short all-out activities. Moreover, there is still no consensus on which brain areas could provide the most favorable effects on different performance modalities. Accordingly, this study aimed to investigate the effects of anodal tDCS (a-tDCS) targeting the primary motor cortex (M1) or left dorsolateral prefrontal cortex (DLPFC) on physical performance, psychophysiological responses, and cognitive function in repeated all-out cycling. METHODS In this randomized, crossover, and double-blind study, 15 healthy physically active men underwent a-tDCS targeting M1 or the left DLPFC or sham tDCS in separate days before performing three bouts of all-out 30s cycling anaerobic test. a-tDCS was applied using 2 mA for 20 min. Peak power, mean power, fatigue index, and EMG of the quadriceps muscles were measured during each bout. Heart rate, perceived exertion, affective valence, and arousal were recorded two minutes after each bout. Color-word Stroop test and choice reaction time were measured at baseline and after the whole anaerobic test. RESULTS Neither tDCS montage significantly changed peak power, mean power, fatigue index, heart rate, affective valence, arousal, and choice reaction time (p> 0.05). a-tDCS over DLPFC significantly lowered RPE of the first bout (compared to sham; p=0.048, Δ=-12.5%) and third bout compared to the M1 (p=0.047, Δ=-12.38%) and sham (p=0.003, Δ=-10.5%), increased EMG of the Vastus Lateralis muscle during the second (p=0.016, Δ= +40.3%) and third bout (p=0.016, Δ= +42.1%) compared to sham, and improved the score of color-word Stroop test after the repeated all-out task (p=0.04, Δ= +147%). The qualitative affective response (valence and arousal) was also higher under the M1 and DLPFC compared to the sham. CONCLUSION We concluded that tDCS targeting M1 or DLPFC does not improve repeated anaerobic performance. However, the positive effect of DLPFC montage on RPE, EMG, qualitative affective responses, and cognitive function is promising and paves the path for future research using different tDCS montages to see any possible effects on anaerobic performance. TRIAL REGISTRATION This study was approved by the Ethics Committee of Razi University (IR.RAZI.REC.1400.023) and registered in the Iranian Registry of Clinical Trials (IRCT id: IRCT20210617051606N5; Registration Date: 04/02/2022).
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Affiliation(s)
- Hafez Teymoori
- Exercise Metabolism and Performance Lab (EMPL), Department of Exercise Physiology, Faculty of Sport Sciences, Razi University, Kermanshah, Iran
| | - Ehsan Amiri
- Exercise Metabolism and Performance Lab (EMPL), Department of Exercise Physiology, Faculty of Sport Sciences, Razi University, Kermanshah, Iran.
| | - Worya Tahmasebi
- Exercise Metabolism and Performance Lab (EMPL), Department of Exercise Physiology, Faculty of Sport Sciences, Razi University, Kermanshah, Iran
| | - Rastegar Hoseini
- Exercise Metabolism and Performance Lab (EMPL), Department of Exercise Physiology, Faculty of Sport Sciences, Razi University, Kermanshah, Iran
| | - Sidney Grospretre
- EA4660-C3S Laboratory - Culture, Sports, Health and Society, University Bourgogne France- Comte, Besancon, France
| | - Daniel Gomes da Silva Machado
- Research Group in Neuroscience of the Human Movement (NeuroMove), Department of Physical Education, Federal University of Rio Grande do Norte, Natal, RN, Brazil
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Klichowski M, Wicher A, Kruszwicka A, Golebiewski R. Reverse effect of home-use binaural beats brain stimulation. Sci Rep 2023; 13:11079. [PMID: 37422545 PMCID: PMC10329717 DOI: 10.1038/s41598-023-38313-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 07/06/2023] [Indexed: 07/10/2023] Open
Abstract
Binaural beats brain stimulation is a popular strategy for supporting home-use cognitive tasks. However, such home-use brain stimulation may be neutral to cognitive processes, and any intellectual improvement may be only a placebo effect. Thus, without belief in it, it may bring no benefits. Here we test 1000 individuals at their homes as they perform a two-part fluid intelligence test. Some took the second part listening to binaural beats, while others took it in silence or listening to other sounds. The binaural beats group was divided into three subgroups. The first one was informed that they would listen to sounds that improve the brain's work, the second that neutral sounds, and the third that some sounds the nature of which was not defined. We found that listening to binaural beats was not neutral, as it dramatically deteriorated the score irrespective of the condition. Silence or other sounds had no effect. Thus, home-use binaural beats brain stimulation brings reverse effects to those assumed: instead of supporting the effectiveness of cognitive activities, it may weaken them.
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Affiliation(s)
- Michal Klichowski
- Cognitive Neuroscience Center, Adam Mickiewicz University, Poznan, Poland.
- Learning Laboratory, Faculty of Educational Studies, Adam Mickiewicz University, Poznan, Poland.
| | - Andrzej Wicher
- Cognitive Neuroscience Center, Adam Mickiewicz University, Poznan, Poland
- Department of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland
| | - Agnieszka Kruszwicka
- Cognitive Neuroscience Center, Adam Mickiewicz University, Poznan, Poland
- Learning Laboratory, Faculty of Educational Studies, Adam Mickiewicz University, Poznan, Poland
| | - Roman Golebiewski
- Cognitive Neuroscience Center, Adam Mickiewicz University, Poznan, Poland
- Department of Acoustics, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland
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11
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Schutter DJ, Smits F, Klaus J. Mind matters: A narrative review on affective state-dependency in non-invasive brain stimulation. Int J Clin Health Psychol 2023; 23:100378. [PMID: 36866122 PMCID: PMC9971283 DOI: 10.1016/j.ijchp.2023.100378] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/03/2023] [Indexed: 02/18/2023] Open
Abstract
Variability in findings related to non-invasive brain stimulation (NIBS) have increasingly been described as a result of differences in neurophysiological state. Additionally, there is some evidence suggesting that individual differences in psychological states may correlate with the magnitude and directionality of effects of NIBS on the neural and behavioural level. In this narrative review, it is proposed that the assessment of baseline affective states can quantify non-reductive properties which are not readily accessible to neuroscientific methods. Particularly, affective-related states are theorized to correlate with physiological, behavioural and phenomenological effects of NIBS. While further systematic research is needed, baseline psychological states are suggested to provide a complementary cost-effective source of information for understanding variability in NIBS outcomes. Implementing measures of psychological state may potentially contribute to increasing the sensitivity and specificity of results in experimental and clinical NIBS studies.
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Affiliation(s)
- Dennis J.L.G. Schutter
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
| | - Fenne Smits
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
- Brain Research & Innovation Centre, Ministry of Defence, Utrecht, the Netherlands
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, The Netherlands
| | - Jana Klaus
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
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12
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Del Mauro L, Vergallito A, Gattavara G, Juris L, Gallucci A, Vedani A, Cappelletti L, Farneti PM, Romero Lauro LJ. Betting on Non-Invasive Brain Stimulation to Treat Gambling Disorder: A Systematic Review and Meta-Analysis. Brain Sci 2023; 13:698. [PMID: 37190663 PMCID: PMC10136786 DOI: 10.3390/brainsci13040698] [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: 03/18/2023] [Revised: 04/13/2023] [Accepted: 04/18/2023] [Indexed: 05/17/2023] Open
Abstract
Gambling disorder (GD) is a behavioral addiction that severely impacts individuals' functioning, leading to high socioeconomic costs. Non-invasive brain stimulation (NiBS) has received attention for treating psychiatric and neurological conditions in recent decades, but there is no recommendation for its use for GD. Therefore, this study aimed to systematically review and analyze the available literature to determine the effectiveness of NiBS in treating GD. Following the PRISMA guidelines, we screened four electronic databases up to July 2022 and selected relevant English-written original articles. We included ten papers in the systematic review and seven in the meta-analysis. As only two studies employed a sham-controlled design, the pre-post standardized mean change (SMCC) was computed as effect size only for real stimulation. The results showed a significant effect of NiBS in reducing craving scores (SMCC = -0.69; 95% CI = [-1.2, -0.2], p = 0.010). Moreover, considering the GD's frequent comorbidity with mood disorders, we ran an exploratory analysis of the effects of NiBS on depressive symptoms, which showed significant decreases in post-treatment scores (SMCC = -0.71; 95% CI = [-1.1, -0.3], p < 0.001). These results provide initial evidence for developing NiBS as a feasible therapy for GD symptoms but further comprehensive research is needed to validate these findings. The limitations of the available literature are critically discussed.
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Affiliation(s)
- Lilia Del Mauro
- Department of Psychology, University of Milano-Bicocca, 20126 Milano, Italy
- Fondazione Eris Onlus, 20134 Milano, Italy
| | - Alessandra Vergallito
- Department of Psychology & Neuromi, University of Milano-Bicocca, 20126 Milano, Italy
| | - Gaia Gattavara
- Department of Psychology, University of Milano-Bicocca, 20126 Milano, Italy
| | | | - Alessia Gallucci
- Ph.D. Program in Neuroscience, School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Anna Vedani
- Department of Psychology, University of Milano-Bicocca, 20126 Milano, Italy
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13
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Martin DM, Rushby JA, De Blasio FM, Wearne T, Osborne-Crowley K, Francis H, Xu M, Loo C, McDonald S. The effect of tDCS electrode montage on attention and working memory. Neuropsychologia 2023; 179:108462. [PMID: 36563998 DOI: 10.1016/j.neuropsychologia.2022.108462] [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: 09/06/2022] [Revised: 12/14/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022]
Abstract
The effects of transcranial direct current stimulation (tDCS) for improving attention and working memory have been generally mixed and small, potentially due to variability between studies with montages, stimulus parameters and outcome measures. The tDCS montage is an important parameter which determines the degree and intensity of stimulation in targeted brain regions. This study aimed to examine the effects of using three different montages for modulating attention and working memory performance: Bi-frontal, Broad-frontal and Broad-parietal. Ninety-three healthy adults participated in a counterbalanced cross-over study. Participants received both active and sham tDCS with either the Bi-frontal, Broad-frontal or Broad-parietal montage during performance of both a 1- and 2-back task. TDCS montage moderated 2-back working memory reaction time performance, though not accuracy, with faster reaction times observed for active compared to sham tDCS with the Broad-frontal montage only (F (1,90) = 5.26, p = .024, η2 = 0.06). TDCS montage did not significantly moderate performance on the 1-back task. The cognitive effects of tDCS varied according to montage, task, and outcome measure. TDCS administered with the cathode placed extracephalically in a Broad-frontal montage may be beneficial for improving working memory.
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Affiliation(s)
- Donel M Martin
- Discipline of Psychiatry and Mental Health, University of New South Wales, Sydney, NSW, 2502, Australia; Black Dog Institute, University of New South Wales, Sydney, NSW, 2031, Australia.
| | - Jacqueline A Rushby
- School of Psychology, University of New South Wales, Sydney, NSW, 2502, Australia
| | - Frances M De Blasio
- School of Psychology, University of New South Wales, Sydney, NSW, 2502, Australia
| | - Travis Wearne
- School of Psychology, University of New South Wales, Sydney, NSW, 2502, Australia
| | | | - Heather Francis
- School of Psychology, University of New South Wales, Sydney, NSW, 2502, Australia
| | - Mei Xu
- Discipline of Psychiatry and Mental Health, University of New South Wales, Sydney, NSW, 2502, Australia; Black Dog Institute, University of New South Wales, Sydney, NSW, 2031, Australia
| | - Colleen Loo
- Discipline of Psychiatry and Mental Health, University of New South Wales, Sydney, NSW, 2502, Australia; Black Dog Institute, University of New South Wales, Sydney, NSW, 2031, Australia
| | - Skye McDonald
- School of Psychology, University of New South Wales, Sydney, NSW, 2502, Australia
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14
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The effect of tDCS electrode montage on attention and working memory. Neuropsychologia 2023. [DOI: 10.1016/j.neuropsychologia.2022.10846t2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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15
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Krzyzanowski D, Kusi M, Goghari VM. Malleability of expectations of computerized cognitive training. PERSONALITY AND INDIVIDUAL DIFFERENCES 2022. [DOI: 10.1016/j.paid.2022.111737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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16
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Sansevere KS, Wooten T, McWilliams T, Peach S, Hussey EK, Brunyé TT, Ward N. Self-reported Outcome Expectations of Non-invasive Brain Stimulation Are Malleable: a Registered Report that Replicates and Extends Rabipour et al. (2017). JOURNAL OF COGNITIVE ENHANCEMENT 2022. [DOI: 10.1007/s41465-022-00250-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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17
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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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18
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Cheng J, Li P, Tang Y, Zhang C, Lin L, Gao J, Wang Z. Transcranial direct current stimulation improve symptoms and modulates cortical inhibition in obsessive-compulsive disorder: A TMS-EEG study. J Affect Disord 2022; 298:558-564. [PMID: 34801604 DOI: 10.1016/j.jad.2021.11.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 10/12/2021] [Accepted: 11/14/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND Obsessive-compulsive disorder (OCD) is a disabling condition for which approximately 40% of patients do not respond to first-line treatment. Transcranial direct current stimulation (tDCS) is a safe and accessible technique that modulates cortical excitability and inhibition, but evidence of its efficacy for OCD is insufficient. OBJECTIVE To investigate the efficacy of tDCS for OCD and alterations of cortical excitability and inhibition after treatment measured by concurrent transcranial magnetic stimulation-electroencephalography (TMS-EEG). METHODS Twenty-four OCD patients underwent 10 20-min sessions of 1.5 mA high-definition tDCS with a cathode placed over the right orbitofrontal cortex (OFC) and anode electrodes set around the cathodal electrode. TMS-EEG was performed before and after tDCS treatment. OCD symptom severitys was assessed using Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), and the Beck Depression Inventory-Ⅱ (BDI-Ⅱ), and Beck Anxiety Inventory (BAI) were used to assess the severity of depression and anxiety symptoms. Twenty-seven healthy controls were recruited with TMS-EEG recorded. RESULTS Following tDCS, the Y-BOCS, BDI-Ⅱ, and BAI scores decreased significantly (all p = 0.000). TMS-evoked N100 amplitude, thought to be related to GABAB receptor function, was significantly reduced after tDCS (Z = -2.143, p = 0.032) which was higher in OCD patients than in healthy controls at baseline (Z = -2.151, p = 0.031). LIMITATIONS Pharmacotherapy during tDCS treatment may influence the effect of tDCS and EEG. CONCLUSIONS Cathodal high-definition tDCS applied over the OFC could improve OCD, depression, and anxiety symptoms along with alleviation of GABAB receptor function.
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Affiliation(s)
- Jiayue Cheng
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wan Ping Nan Road, Shanghai 200030, China
| | - Puyu Li
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wan Ping Nan Road, Shanghai 200030, China
| | - Yingying Tang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wan Ping Nan Road, Shanghai 200030, China
| | - Chen Zhang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wan Ping Nan Road, Shanghai 200030, China; Schizophrenia Program, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Liangjun Lin
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wan Ping Nan Road, Shanghai 200030, China
| | - Jian Gao
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wan Ping Nan Road, Shanghai 200030, China
| | - Zhen Wang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wan Ping Nan Road, Shanghai 200030, China; Institute of Psychological and Behavioral Science, Shanghai Jiao Tong University, Shanghai, PR China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China.
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19
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Knehans R, Schuhmann T, Roef D, Nelen H, à Campo J, Lobbestael J. Modulating Behavioural and Self-Reported Aggression with Non-Invasive Brain Stimulation: A Literature Review. Brain Sci 2022; 12:brainsci12020200. [PMID: 35203963 PMCID: PMC8870113 DOI: 10.3390/brainsci12020200] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/24/2022] [Accepted: 01/27/2022] [Indexed: 12/04/2022] Open
Abstract
Aggressive behaviour is at the basis of many harms in society, such as violent crime. The efforts to explain, study, and possibly reduce aggression span various disciplines, including neuroscience. The specific brain networks which are involved in the modulation of aggressive behaviour include cortical asymmetry and brain areas such as the dorsolateral prefrontal cortex (DLPFC), the ventrolateral prefrontal cortex (VLPFC), and the ventromedial prefrontal cortex (VMPFC). Recent non-invasive brain stimulation (NIBS) research suggests that both transcranial direct current stimulation (tDCS) and continuous theta burst stimulation (cTBS) can play a role in the modulation of aggressive behaviour by directly changing brain activity. In this review, we systematically explore and discuss 11 experimental studies that aimed to modulate aggressive behaviour or self-reported aggression using NIBS. Out of these 11 studies, nine significantly up- or downregulated aggression by using tDCS or cTBS targeting the DLPFC, VLPFC or VMPFC. The potential applications of these findings span both the clinical and the forensic psychological domains. However, the results are limited by the methodological heterogeneity in the aggression measures used across the studies, and by their generally small sample sizes. Future research should consider improving the localization and specificity of NIBS by employing neuro-navigational instruments and standardized scoring methods.
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Affiliation(s)
- Ruben Knehans
- Department of Criminal Law and Criminology, Faculty of Law, Maastricht University, 6211 LH Maastricht, The Netherlands; (D.R.); (H.N.); (J.à.C.)
- Correspondence:
| | - Teresa Schuhmann
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands;
| | - David Roef
- Department of Criminal Law and Criminology, Faculty of Law, Maastricht University, 6211 LH Maastricht, The Netherlands; (D.R.); (H.N.); (J.à.C.)
| | - Hans Nelen
- Department of Criminal Law and Criminology, Faculty of Law, Maastricht University, 6211 LH Maastricht, The Netherlands; (D.R.); (H.N.); (J.à.C.)
| | - Joost à Campo
- Department of Criminal Law and Criminology, Faculty of Law, Maastricht University, 6211 LH Maastricht, The Netherlands; (D.R.); (H.N.); (J.à.C.)
| | - Jill Lobbestael
- Department of Clinical Psychological Science, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands;
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20
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Ward N, Hussey E, Wooten T, Marfeo E, Brunyé TT. Modulating Cognitive–Motor Multitasking with Commercial-off-the-Shelf Non-Invasive Brain Stimulation. Brain Sci 2022; 12:brainsci12020180. [PMID: 35203943 PMCID: PMC8870640 DOI: 10.3390/brainsci12020180] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 02/04/2023] Open
Abstract
One growing area of multitasking research involves a focus on performing cognitive and motor tasks in tandem. In these situations, increasing either cognitive or motor demands has implications for performance in both tasks, an effect which is thought to be due to competing neural resources. Separate research suggests that non-invasive brain stimulation may offer a means to mitigate performance decrements experienced during multitasking. In the present study, we investigated the degree to which a commercially available non-invasive brain stimulation device (Halo Sport) alters balance performance in the presence of different types of cognitive demands. Specifically, we tested if performing a secondary cognitive task impacts postural sway in healthy young adults and if we could mitigate this impact using transcranial direct current stimulation (tDCS) applied over the primary motor cortex. Furthermore, we included conditions of unstable and stable surfaces and found that lower surface stability increased postural sway. In addition, we found that cognitive load impacted postural sway but in the opposite pattern we had anticipated, with higher sway found in the single-task control condition compared to executive function conditions. Finally, we found a small but significant effect of tDCS on balance with decreased sway for active (compared to sham) tDCS.
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Affiliation(s)
- Nathan Ward
- Department of Psychology, Tufts University, Medford, MA 02155, USA;
- Correspondence:
| | - Erika Hussey
- Defense Innovation Unit, Mountain View, CA 94043, USA;
| | - Thomas Wooten
- Department of Psychology, Tufts University, Medford, MA 02155, USA;
| | - Elizabeth Marfeo
- Department of Occupational Therapy, Tufts University, Medford, MA 02155, USA;
| | - Tad T. Brunyé
- U.S. Army DEVCOM Soldier Center, Natick, MA 01760, USA;
- Center for Applied Brain & Cognitive Sciences, Tufts University, Medford, MA 02155, USA
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21
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Stanković M, Živanović M, Bjekić J, Filipović SR. Blinding in tDCS Studies: Correct End-of-Study Guess Does Not Moderate the Effects on Associative and Working Memory. Brain Sci 2021; 12:brainsci12010058. [PMID: 35053802 PMCID: PMC8773753 DOI: 10.3390/brainsci12010058] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/27/2021] [Accepted: 12/27/2021] [Indexed: 11/16/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) has become a valuable tool in cognitive neuroscience research as it enables causal inferences about neural underpinnings of cognition. However, studies using tDCS to modulate cognitive functions often yield inconsistent findings. Hence, there is an increasing interest in factors that may moderate the effects, one of which is the participants’ beliefs of the tDCS condition (i.e., real or sham) they received. Namely, whether participants’ correct guessing of sham condition may lead to false-positive tDCS effects. In this study, we aimed to explore if participants’ beliefs about received stimulation type (i.e., the success of blinding) impacted their task performance in tDCS experiments on associative (AM) and working memory (WM). We analyzed data from four within-subject, sham-controlled tDCS memory experiments (N = 83) to check if the correct end-of-study guess of sham condition moderated tDCS effects. We found no evidence that sham guessing moderated post-tDCS memory performance in experiments in which tDCS effects were observed as well as in experiments that showed null effects of tDCS. The results suggest that the correct sham guessing (i.e., placebo-like effect) is unlikely to influence the results in tDCS memory experiments. We discuss the results in light of the growing debate about the relevance and effectiveness of blinding in brain stimulation research.
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Affiliation(s)
- Marija Stanković
- Human Neuroscience Group, Institute for Medical Research, University of Belgrade, 11000 Belgrade, Serbia; (M.S.); (S.R.F.)
| | - Marko Živanović
- Institute of Psychology and Laboratory for Research of Individual Differences, Department of Psychology, Faculty of Philosophy, University of Belgrade, 11000 Belgrade, Serbia;
| | - Jovana Bjekić
- Human Neuroscience Group, Institute for Medical Research, University of Belgrade, 11000 Belgrade, Serbia; (M.S.); (S.R.F.)
- Correspondence:
| | - Saša R. Filipović
- Human Neuroscience Group, Institute for Medical Research, University of Belgrade, 11000 Belgrade, Serbia; (M.S.); (S.R.F.)
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22
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The Role of Expectation and Beliefs on the Effects of Non-Invasive Brain Stimulation. Brain Sci 2021; 11:brainsci11111526. [PMID: 34827526 PMCID: PMC8615662 DOI: 10.3390/brainsci11111526] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/14/2021] [Accepted: 11/16/2021] [Indexed: 11/25/2022] Open
Abstract
Non-invasive brain stimulation (NIBS) techniques are used in clinical and cognitive neuroscience to induce a mild magnetic or electric field in the brain to modulate behavior and cortical activation. Despite the great body of literature demonstrating promising results, unexpected or even paradoxical outcomes are sometimes observed. This might be due either to technical and methodological issues (e.g., stimulation parameters, stimulated brain area), or to participants’ expectations and beliefs before and during the stimulation sessions. In this narrative review, we present some studies showing that placebo and nocebo effects, associated with positive and negative expectations, respectively, could be present in NIBS trials, both in experimental and in clinical settings. The lack of systematic evaluation of subjective expectations and beliefs before and after stimulation could represent a caveat that overshadows the potential contribution of placebo and nocebo effects in the outcome of NIBS trials.
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Offline tDCS modulates prefrontal-cortical-subcortical-cerebellar fear pathways in delayed fear extinction. Exp Brain Res 2021; 240:221-235. [PMID: 34694466 DOI: 10.1007/s00221-021-06248-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 10/15/2021] [Indexed: 11/27/2022]
Abstract
Transcranial direct current stimulation (tDCS) has been studied to enhance extinction-based treatments for anxiety disorders. However, the field shows conflicting results about its anxiolytic effect and only a few studies have observed the extinction of consolidated memories. We looked to study the effect of offline 1 mA tDCS over the right dorsolateral pre-frontal cortex across the fear pathways, in consolidated fear response during delayed extinction. Participants (N = 34 women) underwent in a two-day fear conditioning procedure. On day 1, participants were assigned to the control group (N = 18) or the tDCS group (N = 16) and went through a fear acquisition procedure. On day 2, the tDCS group received 20 min tDCS before extinction and while inside the MRI scanner. The control group completed the extinction procedure only. The tDCS session (for the tDCS group) and the fMRI scan (for both groups) were completed just on the second day. Univariate fMRI analysis showed stimulation-dependent activity during late extinction with the tDCS group showing decreased neural activity during the processing of threat cues (CS +) and increased activity during the processing of safety cues (CS -), in prefrontal, postcentral and paracentral regions, during late extinction. ROI to whole-brain psychophysiological interaction (PPI) analysis showed the tDCS effect on the connectivity between the left dorsolateral prefrontal cortex three cortical-amygdalo-hippocampal-cerebellar pathway clusters during the processing of the CS + in late extinction (TFCE corrected; p < 0.05). Increased neuronal activity during the processing of safety cues and stronger coupling during the processing of threat cues might be the mechanisms by which tDCS contributes to stimuli discrimination.
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Wischnewski M, Mantell KE, Opitz A. Identifying regions in prefrontal cortex related to working memory improvement: A novel meta-analytic method using electric field modeling. Neurosci Biobehav Rev 2021; 130:147-161. [PMID: 34418436 DOI: 10.1016/j.neubiorev.2021.08.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 07/09/2021] [Accepted: 08/15/2021] [Indexed: 12/17/2022]
Abstract
Altering cortical activity using transcranial direct current stimulation (tDCS) has been shown to improve working memory (WM) performance. Due to large inter-experimental variability in the tDCS montage configuration and strength of induced electric fields, results have been mixed. Here, we present a novel meta-analytic method relating behavioral effect sizes to electric field strength to identify brain regions underlying largest tDCS-induced WM improvement. Simulations on 69 studies targeting left prefrontal cortex showed that tDCS electric field strength in lower dorsolateral prefrontal cortex (Brodmann area 45/47) relates most strongly to improved WM performance. This region explained 7.8 % of variance, equaling a medium effect. A similar region was identified when correlating WM performance and electric field strength of right prefrontal tDCS studies (n = 18). Maximum electric field strength of five previously used tDCS configurations were outside of this location. We thus propose a new tDCS montage which maximizes the tDCS electric field strength in that brain region. Our findings can benefit future tDCS studies that aim to affect WM function.
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Affiliation(s)
- Miles Wischnewski
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States.
| | - Kathleen E Mantell
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Alexander Opitz
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
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25
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Acute effect of high-definition and conventional tDCS on exercise performance and psychophysiological responses in endurance athletes: a randomized controlled trial. Sci Rep 2021; 11:13911. [PMID: 34230503 PMCID: PMC8260713 DOI: 10.1038/s41598-021-92670-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 06/03/2021] [Indexed: 02/06/2023] Open
Abstract
Transcranial direct current stimulation (tDCS) has been used aiming to boost exercise performance and inconsistent findings have been reported. One possible explanation is related to the limitations of the so-called "conventional" tDCS, which uses large rectangular electrodes, resulting in a diffuse electric field. A new tDCS technique called high-definition tDCS (HD-tDCS) has been recently developed. HD-tDCS uses small ring electrodes and produces improved focality and greater magnitude of its aftereffects. This study tested whether HD-tDCS would improve exercise performance to a greater extent than conventional tDCS. Twelve endurance athletes (29.4 ± 7.3 years; 60.15 ± 5.09 ml kg-1 min-1) were enrolled in this single-center, randomized, crossover, and sham-controlled trial. To test reliability, participants performed two time to exhaustion (TTE) tests (control conditions) on a cycle simulator with 80% of peak power until volitional exhaustion. Next, they randomly received HD-tDCS (2.4 mA), conventional (2.0 mA), or active sham tDCS (2.0 mA) over the motor cortex for 20-min before performing the TTE test. TTE, heart rate (HR), associative thoughts, peripheral (lower limbs), and whole-body ratings of perceived exertion (RPE) were recorded every minute. Outcome measures were reliable. There was no difference in TTE between HD-tDCS (853.1 ± 288.6 s), simulated conventional (827.8 ± 278.7 s), sham (794.3 ± 271.2 s), or control conditions (TTE1 = 751.1 ± 261.6 s or TTE2 = 770.8 ± 250.6 s) [F(1.95; 21.4) = 1.537; P = 0.24; η2p = 0.123]. There was no effect on peripheral or whole-body RPE and associative thoughts (P > 0.05). No serious adverse effect was reported. A single session of neither HD-tDCS nor conventional tDCS changed exercise performance and psychophysiological responses in athletes, suggesting that a ceiling effect may exist.
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Andressa de Souza J, Ferrari Corrêa JC, Marduy A, Dall'Agnol L, Gomes de Sousa MH, Nunes da Silva V, Alves AB, Silva SM, Fregni F, Corrêa FI. To Combine or Not to Combine Physical Therapy With tDCS for Stroke With Shoulder Pain? Analysis From a Combination Randomized Clinical Trial for Rehabilitation of Painful Shoulder in Stroke. FRONTIERS IN PAIN RESEARCH 2021; 2:696547. [PMID: 35295490 PMCID: PMC8915613 DOI: 10.3389/fpain.2021.696547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 05/31/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: Transcranial Direct Current Stimulation (tDCS) is an intervention that seems to be an ideal tool to enhance the effects of rehabilitation therapies given it facilitates generation of plasticity in the stimulated brain area. In stroke this strategy has been highly utilized; however, the results have been mixed. In this trial we have evaluated the analgesic and functional effects of Transcranial Direct Current Stimulation (tDCS) combined with physiotherapy in stroke survivors with shoulder pain. Methods: Twenty-six stroke surviving adults with shoulder pain received 10 sessions of passive mobilization and performed upper limb exercises using a cycle ergometer, combined with active or sham tDCS. The intensity of pain in the hemiplegic shoulder was measured using the Visual Analog Scale (VAS); secondary outcomes were the level of motor impairment, handgrip strength, range of motion, motor function of the upper limbs, and quality of life (QOL) assessed before and after 10 sessions and 1 month after the end of the treatment. Results: A clinically important pain reduction (3 points) was found in both groups and was maintained at follow-up; there was no significant difference between groups (p = 0.3). Similarly, the shoulder range of motion improved, motor function and quality of life improved showed no significant differences between groups. One result that needs to be underscored is that both groups had a significant effect size toward improvement in all of these outcomes. Conclusions: We discuss in this study that tDCS is not a useful combination strategy when the physical therapy has a large effect by itself and we also review other negative trials of combined therapy under this framework of ceiling effect of the main physical therapy. Trial registry: Trial registration: Brazilian Registry of Clinical Trials, RBR-8F5MNY (http://www.ensaiosclinicos.gov.br/rg/RBR-8f5mny/). Registered on June 2, 2017. Beginning of the recruitment of the volunteers: august, 2017.
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Affiliation(s)
- Janaina Andressa de Souza
- Doctorate and Masters Program in Rehabilitation Science of University Nove de Julho, UNINOVE, São Paulo, Brazil
| | - João Carlos Ferrari Corrêa
- Doctorate and Masters Program in Rehabilitation Science of University Nove de Julho, UNINOVE, São Paulo, Brazil
| | - Anna Marduy
- Department of Physical Medicine and Rehabilitation, Neuromodulation Center, Harvard Medical School, Spaulding Rehabilitation Hospital, Boston, MA, United States
| | - Letizzia Dall'Agnol
- Doctorate and Masters Program in Rehabilitation Science of University Nove de Julho, UNINOVE, São Paulo, Brazil
| | - Maria Helena Gomes de Sousa
- Doctorate and Masters Program in Rehabilitation Science of University Nove de Julho, UNINOVE, São Paulo, Brazil
| | - Victor Nunes da Silva
- Doctorate and Masters Program in Rehabilitation Science of University Nove de Julho, UNINOVE, São Paulo, Brazil
| | - André Barreto Alves
- Doctorate and Masters Program in Rehabilitation Science of University Nove de Julho, UNINOVE, São Paulo, Brazil
| | - Soraia Micaela Silva
- Doctorate and Masters Program in Rehabilitation Science of University Nove de Julho, UNINOVE, São Paulo, Brazil
| | - Felipe Fregni
- Department of Physical Medicine and Rehabilitation, Neuromodulation Center, Harvard Medical School, Spaulding Rehabilitation Hospital, Boston, MA, United States
| | - Fernanda Ishida Corrêa
- Doctorate and Masters Program in Rehabilitation Science of University Nove de Julho, UNINOVE, São Paulo, Brazil
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Stevens CE, Lausen MA, Wagstaff LE, McRae TR, Pittman BR, Amthor FR, Boggiano MM. Effect of transcranial direct current stimulation (tDCS) on food craving and eating when using a control method that minimizes guessing of the real vs. control condition. Eat Weight Disord 2021; 26:1669-1674. [PMID: 32748372 DOI: 10.1007/s40519-020-00970-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/24/2020] [Indexed: 02/04/2023] Open
Abstract
PURPOSE Validation of transcranial direct current stimulation (tDCS) to treat obesity is hampered by evidence that participants can distinguish real from the traditional-control condition. Correctly guessing the real condition precludes knowing if it is neuromodulation or expectation that suppresses food craving and eating. Therefore, this study tested the putative efficacy of tDCS to the dorsolateral prefrontal cortex (DLPFC) to reduce food craving and eating when an alternative control condition was used that would be difficult to distinguish from the real condition. METHODS N = 28 adults with a 26-50 BMI range received a typical 20-min 2 mA current session of tDCS targeting the DLPFC as the real condition and a same duration/current tDCS session targeting the sensorimotor cortex (SMC), a region not expected to affect appetite, as the control. Food image craving ratings, in-lab food consumption, and momentary ratings of physical sensations were measured. RESULTS DLPFC failed to reduce food craving and consumption compared to SMC stimulation. When interviewed, 71% of participants were unable to guess real from control conditions. Those who guessed DLPFC tDCS as real attributed their guess to increased number and frequency of sensations. However, their sensation ratings during tDCS did not differ between conditions. CONCLUSIONS The results question if tDCS suppresses craving and eating at all, or if the DLPFC is the best target to do so. The results also indicate that alternate-site constant stimulation as the control method may strengthen the scientific evaluation of tDCS to treat obesity. LEVEL OF EVIDENCE Level I, experimental study.
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Affiliation(s)
- Carl E Stevens
- Department of Psychology, The University of Alabama at Birmingham, 415 Campbell Hall, 1300 University Blvd., Birmingham, AL, 35294-1170, USA
| | - Marissa A Lausen
- Department of Psychology, The University of Alabama at Birmingham, 415 Campbell Hall, 1300 University Blvd., Birmingham, AL, 35294-1170, USA
| | - Laura E Wagstaff
- Department of Psychology, The University of Alabama at Birmingham, 415 Campbell Hall, 1300 University Blvd., Birmingham, AL, 35294-1170, USA
| | - Tommy R McRae
- Department of Psychology, The University of Alabama at Birmingham, 415 Campbell Hall, 1300 University Blvd., Birmingham, AL, 35294-1170, USA
| | - Bethany R Pittman
- Department of Psychology, The University of Alabama at Birmingham, 415 Campbell Hall, 1300 University Blvd., Birmingham, AL, 35294-1170, USA
| | - Franklin R Amthor
- Department of Psychology, The University of Alabama at Birmingham, 415 Campbell Hall, 1300 University Blvd., Birmingham, AL, 35294-1170, USA
| | - Mary M Boggiano
- Department of Psychology, The University of Alabama at Birmingham, 415 Campbell Hall, 1300 University Blvd., Birmingham, AL, 35294-1170, USA.
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Effect of anodal high-definition transcranial direct current stimulation on the pain sensitivity in a healthy population: a double-blind, sham-controlled study. Pain 2021; 162:1659-1668. [PMID: 33449508 DOI: 10.1097/j.pain.0000000000002187] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 12/30/2020] [Indexed: 02/07/2023]
Abstract
ABSTRACT High-definition transcranial direct current stimulation (HD-tDCS) of brain areas related to pain processing may provide analgesic effects evident in the sensory detection and pain thresholds. The somatosensory sensitivity was assessed after HD-tDCS targeting the primary motor cortex (M1) and/or the dorsolateral prefrontal cortex (DLPFC). Eighty-one (40 females) subjects were randomly assigned to 1 of 4 anodal HD-tDCS protocols (20 minutes) applied on 3 consecutive days: Sham-tDCS, DLPFC-tDCS, M1-tDCS, and DLPFC&M1-tDCS (simultaneous transcranial direct current stimulation [tDCS] of DLPFC and M1). Subjects and experimenter were blinded to the tDCS protocols. The somatosensory sensitivity were assessed each day, before and after each tDCS by detection and pain thresholds to thermal and mechanical skin stimulation, vibration detection thresholds, and pressure pain thresholds. Subjects were effectively blinded to the protocol, with no significant difference in rates of whether they received real or placebo tDCS between the 4 groups. Compared with the Sham-tDCS, none of the active HD-tDCS protocols caused significant changes in detection or pain thresholds. Independent of tDCS protocols, pain and detection thresholds except vibration detection were increased immediately after the first tDCS protocol compared with baseline (P < 0.05). Overall, the active stimulation protocols were not able to induce significant modulation of the somatosensory thresholds in this healthy population compared with sham-tDCS. Unrelated to the HD-tDCS protocol, a decreased sensitivity was found after the first intervention, indicating a placebo effect or possible habituation to the quantitative sensory testing assessments. These findings add to the increasing literature of null findings in the modulatory effects of HD-tDCS on the healthy somatosensory system.
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29
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Poppe A, Bais L, van Duin D, Ćurčić-Blake B, Pijnenborg GHM, van der Meer L. Improving cognition in severe mental illness by combining cognitive remediation and transcranial direct current stimulation: study protocol for a pragmatic randomized controlled pilot trial (HEADDSET). Trials 2021; 22:275. [PMID: 33849658 PMCID: PMC8042354 DOI: 10.1186/s13063-021-05230-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 03/27/2021] [Indexed: 02/08/2023] Open
Abstract
Background A fundamental challenge for many people with severe mental illness (SMI) is how to deal with cognitive impairments. Cognitive impairments are common in this population and limit daily functioning. Moreover, neural plasticity in people with SMI appears to be reduced, a factor that might hinder newly learned cognitive skills to sustain. The objective of this pilot trial is to investigate the effects of cognitive remediation (CR) on cognitive and daily functioning in people dependent on residential settings. In addition, transcranial direct current stimulation (tDCS) is used to promote neural plasticity. It is expected that the addition of tDCS can enhance learning and will result in longer-lasting improvements in cognitive and daily functioning. Methods This is a pragmatic, triple-blinded, randomized, sham-controlled, pilot trial following a non-concurrent multiple baseline design with the participants serving as their own control. We will compare (1) CR to treatment as usual, (2) active/sham tDCS+CR to treatment as usual, and (3) active tDCS+CR to sham tDCS+CR. Clinical relevance, feasibility, and acceptability of the use of CR and tDCS will be evaluated. We will recruit 26 service users aged 18 years or older, with a SMI and dependent on residential facilities. After a 16-week waiting period (treatment as usual), which will serve as a within-subject control condition, participants will be randomized to 16 weeks of twice weekly CR combined with active (N = 13) or sham tDCS (N = 13). Cognitive, functional, and clinical outcome assessments will be performed at baseline, after the control (waiting) period, directly after treatment, and 6-months post-treatment. Discussion The addition of cognitive interventions to treatment as usual may lead to long-lasting improvements in the cognitive and daily functioning of service users dependent on residential facilities. This pilot trial will evaluate whether CR on its own or in combination with tDCS can be a clinically relevant addition to further enhance recovery. In case the results indicate that cognitive performance can be improved with CR, and whether or not tDCS will lead to additional improvement, this pilot trial will be extended to a large randomized multicenter study. Trial registration Dutch Trial Registry NL7954. Prospectively registered on August 12, 2019.
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Affiliation(s)
- Anika Poppe
- Department of Rehabilitation, Lentis Psychiatric Institute, Lagerhout E35, 9741 KE, Zuidlaren, The Netherlands.,Department of Clinical and Developmental Neuropsychology, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands
| | - Leonie Bais
- Department of Rehabilitation, Lentis Psychiatric Institute, Lagerhout E35, 9741 KE, Zuidlaren, The Netherlands
| | - Daniëlle van Duin
- Trimbos Institute, Utrecht, The Netherlands.,Phrenos Center of Expertise, Utrecht, The Netherlands
| | - Branislava Ćurčić-Blake
- Department of Biomedical Sciences of Cells and Systems, Cognitive Neuroscience Center, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Gerdina Hendrika Maria Pijnenborg
- Department of Clinical and Developmental Neuropsychology, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands.,Department of Psychotic Disorders, GGZ Drenthe, Assen, The Netherlands
| | - Lisette van der Meer
- Department of Rehabilitation, Lentis Psychiatric Institute, Lagerhout E35, 9741 KE, Zuidlaren, The Netherlands. .,Department of Clinical and Developmental Neuropsychology, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands.
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Denkinger S, Spano L, Bingel U, Witt CM, Bavelier D, Green CS. Assessing the Impact of Expectations in Cognitive Training and Beyond. JOURNAL OF COGNITIVE ENHANCEMENT 2021. [DOI: 10.1007/s41465-021-00206-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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31
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Gregoret L, Zamorano AM, Graven‐Nielsen T. Effects of multifocal transcranial direct current stimulation targeting the motor network during prolonged experimental pain. Eur J Pain 2021; 25:1241-1253. [DOI: 10.1002/ejp.1743] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Luisina Gregoret
- Center for Neuroplasticity and Pain (CNAP) Department of Health Science and Technology Faculty of Medicine Aalborg University Aalborg Denmark
| | - Anna M. Zamorano
- Center for Neuroplasticity and Pain (CNAP) Department of Health Science and Technology Faculty of Medicine Aalborg University Aalborg Denmark
| | - Thomas Graven‐Nielsen
- Center for Neuroplasticity and Pain (CNAP) Department of Health Science and Technology Faculty of Medicine Aalborg University Aalborg Denmark
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32
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Villa-Sánchez B, Emadi Andani M, Cesari P, Fiorio M. The effect of motor and cognitive placebos on the serial reaction time task. Eur J Neurosci 2021; 53:2655-2668. [PMID: 33587782 DOI: 10.1111/ejn.15148] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 11/26/2022]
Abstract
Motor learning is a key component of human motor functions. Repeated practice is essential to gain proficiency over time but may induce fatigue. The aim of this study was to determine whether motor performance and motor learning (as assessed with the serial reaction time task, SRTT) and perceived fatigability (as assessed with subjective scales) are improved after two types of placebo interventions (motor and cognitive). A total of 90 healthy volunteers performed the SRTT with the right hand in three sessions (baseline, training and final). Before the training and the final session, one group underwent a motor-related placebo intervention in which inert electrical stimulation (TENS) was applied over the hand and accompanied by verbal suggestion that it improves movement execution (placebo-TENS). The other group underwent a cognitive-related placebo intervention in which sham transcranial direct current stimulation (tDCS) was delivered to the supraorbital area and accompanied by verbal suggestion that it increases attention (placebo-tDCS). A control group performed the same task without receiving treatment. Overall better performance on the SRTT (not ascribed to sequence-specific learning) was noted for the placebo-TENS group, which also reported less perceived fatigability at the physical level. The same was observed in a subgroup tested 24 hr later. The placebo-tDCS group reported less perceived fatigability, both at the mental and physical level. These findings indicate that motor- and cognitive-related placebo effects differently shape motor performance and perceived fatigability on a repeated motor task.
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Affiliation(s)
- Bernardo Villa-Sánchez
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Mehran Emadi Andani
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Paola Cesari
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Mirta Fiorio
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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33
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Smits FM, de Kort GJ, Geuze E. Acceptability of tDCS in treating stress-related mental health disorders: a mixed methods study among military patients and caregivers. BMC Psychiatry 2021; 21:97. [PMID: 33588798 PMCID: PMC7883955 DOI: 10.1186/s12888-021-03086-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 02/01/2021] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Noninvasive brain stimulation techniques like transcranial direct current stimulation (tDCS) offer potential new approaches to treat stress-related mental health disorders. While the acceptability of tDCS as a treatment tool plays a crucial role in its development and implementation, little is known about tDCS acceptability for users in mental healthcare, especially in the context of stress-related disorders. METHODS Using a mixed-methods approach, we investigated tDCS acceptability among 102 active duty and post-active military patients with stress-related symptoms (posttraumatic stress disorder, anxiety and impulsive aggression) who participated in a 5-session tDCS intervention. Quantitative dropout and adverse effects data was collected for all patients involved in the sham-controlled tDCS intervention. We additionally explored perspectives on the acceptability of tDCS treatment via a theory-based semi-structured interview. A subgroup of patients as well as their caregivers were interviewed to include the views of both patients and mental healthcare professionals. RESULTS Quantitative outcomes showed minimal tDCS-related adverse effects (mild itching or burning sensations on the scalp) and high tDCS treatment adherence (dropout rate: 4% for active tDCS, 0% for sham). The qualitative outcomes showed predominantly positive attitudes towards tDCS interventions for stress-related disorders, but only as complementary to psychotherapy. Remarkably, despite the perception that sufficient explanation was provided, patients and caregivers stressed that tDCS treatment comprehension was limited and should improve. Also, the travel associated with frequent on-site tDCS sessions may produce a significant barrier to care for patients with stress-related disorders and active-duty military personnel. CONCLUSIONS Acceptability numbers and perspectives from military patients and caregivers suggest that tDCS is an acceptable complementary tool in the treatment of stress-related disorders. Critically, however, if tDCS is to be used beyond scientific studies, adequately educating users on tDCS working mechanisms is vital to further improve its acceptability. Also, the perceived potential barrier to care due to frequent travel may favor home-based tDCS solutions. TRIAL REGISTRATION The tDCS intervention was part of a sham-controlled trial registered on 05-18-2016 at the Netherlands Trial Register with ID NL5709 .
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Affiliation(s)
- Fenne M. Smits
- grid.462591.dBrain Research & Innovation Centre, Ministry of Defence, Lundlaan 1, 3584 EZ Utrecht, The Netherlands ,grid.7692.a0000000090126352Department of Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Guido J. de Kort
- grid.462591.dBrain Research & Innovation Centre, Ministry of Defence, Lundlaan 1, 3584 EZ Utrecht, The Netherlands
| | - Elbert Geuze
- grid.462591.dBrain Research & Innovation Centre, Ministry of Defence, Lundlaan 1, 3584 EZ Utrecht, The Netherlands ,grid.7692.a0000000090126352Department of Psychiatry, UMC Utrecht Brain Center, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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Turner C, Jackson C, Learmonth G. Is the "end-of-study guess" a valid measure of sham blinding during transcranial direct current stimulation? Eur J Neurosci 2020; 53:1592-1604. [PMID: 33098709 PMCID: PMC8048983 DOI: 10.1111/ejn.15018] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 09/30/2020] [Accepted: 10/16/2020] [Indexed: 11/28/2022]
Abstract
Studies using transcranial direct current stimulation (tDCS) typically incorporate a fade‐in, short‐stimulation, fade‐out sham (placebo) protocol, which is assumed to be indistinct from a 10–30 min active protocol on the scalp. However, many studies report that participants can dissociate active stimulation from sham, even during low‐intensity 1 mA currents. We recently identified differences in the perception of an active (10 min of 1 mA) and a sham (20 s of 1 mA) protocol that lasted for 5 min after the cessation of sham. In the present study we assessed whether delivery of a higher‐intensity 2 mA current would exacerbate these differences. Two protocols were delivered to 32 adults in a double‐blinded, within‐subjects design (active: 10 min of 2 mA, and sham: 20 s of 2 mA), with the anode over the left primary motor cortex and the cathode on the right forehead. Participants were asked “Is the stimulation on?” and “How sure are you?” at 30 s intervals during and after stimulation. The differences between active and sham were more consistent and sustained during 2 mA than during 1 mA. We then quantified how well participants were able to track the presence and absence of stimulation (i.e. their sensitivity) during the experiment using cross‐correlations. Current strength was a good classifier of sensitivity during active tDCS, but exhibited only moderate specificity during sham. The accuracy of the end‐of‐study guess was no better than chance at predicting sensitivity. Our results indicate that the traditional end‐of‐study guess poorly reflects the sensitivity of participants to stimulation, and may not be a valid method of assessing sham blinding.
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Affiliation(s)
| | | | - Gemma Learmonth
- School of Psychology, University of Glasgow, Glasgow, UK.,Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK
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35
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de Melo GA, de Oliveira EA, Dos Santos Andrade SMM, Fernández-Calvo B, Torro N. Comparison of two tDCS protocols on pain and EEG alpha-2 oscillations in women with fibromyalgia. Sci Rep 2020; 10:18955. [PMID: 33144646 PMCID: PMC7609530 DOI: 10.1038/s41598-020-75861-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 10/21/2020] [Indexed: 11/09/2022] Open
Abstract
Transcranial Direct Current Stimulation (tDCS) has been used as an alternative treatment for pain reduction in fibromyalgia. In this study, in addition to behavioral measures, we analyzed oscillations in alpha 2 frequency band in the frontal, occipital, and parietal regions, in response to the application of two neuromodulation protocols in fibromyalgia. The study was a randomized, double-blind, placebo-controlled clinical trial with 31 women diagnosed with fibromyalgia. The participants were allocated to three groups with the anodic stimulation applied on the left motor cortex: Group 1, for five consecutive days; Group 2, for 10 consecutive days; and Group 3, sham stimulation for five consecutive days. Statistical analysis showed a reduction in pain intensity after treatment for groups in general [F (1.28) = 8.02; p = 0.008; η2 = 0.223], in addition to a reduction in alpha 2 in the frontal (p = 0.039; d = 0.384) and parietal (p = 0.021; d = 0.520) regions after the treatment on five consecutive days. We conclude that neuromodulation protocols produced similar effects on pain reduction, but differed with respect to the changes in the alpha 2 frequency band in the frontal and parietal regions.
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Affiliation(s)
- Géssika Araújo de Melo
- Department of Psychology, Federal University of Paraiba, João Pessoa, 58051-900, Brazil.
| | | | | | - Bernardino Fernández-Calvo
- Department of Psychology, Federal University of Paraiba, João Pessoa, 58051-900, Brazil
- Department of Psychology, University of Córdoba, 14071, Córdoba, Spain
- Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Reina Sofia University Hospital, University of Cordoba, Córdoba, Spain
| | - Nelson Torro
- Department of Psychology, Federal University of Paraiba, João Pessoa, 58051-900, Brazil
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Gaynor AM, Pergolizzi D, Alici Y, Ryan E, McNeal K, Ahles TA, Root JC. Impact of transcranial direct current stimulation on sustained attention in breast cancer survivors: Evidence for feasibility, tolerability, and initial efficacy. Brain Stimul 2020; 13:1108-1116. [PMID: 32353419 DOI: 10.1016/j.brs.2020.04.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 02/26/2020] [Accepted: 04/19/2020] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND A significant subset of breast cancer survivors experience cognitive difficulties in attention and memory, which persist for years following treatment. Transcranial direct current stimulation (tDCS) has been shown to be effective in improving working memory, attention, processing speed, and other cognitive functions in both healthy and clinical populations. To date, no studies have examined tDCS for rehabilitation of cancer-related cognitive dysfunction. OBJECTIVE/HYPOTHESIS We aimed to provide preliminary evidence for feasibility, tolerability, acceptability, and efficacy of tDCS in improving performance on a measure of sustained attention. METHODS In a within-subjects design, 16 breast cancer survivors underwent 2 consecutive days of active tDCS over the prefrontal cortex, and 2 days of sham tDCS, counterbalanced for order of stimulation condition, while performing a continuous performance test. RESULTS Stimulation was feasible and tolerable, with 89% of participants completing all sessions, and none reporting more than mild to moderate discomfort. Analyses of efficacy showed that during active stimulation, participants had significantly lower standard errors of reaction times overall, indicating better sustained attention ability, as compared to sham stimulation (p < 0.05). Furthermore, the effect of stimulation on standard errors of reaction times differed by inter-stimulus interval (ISI): for 1 and 2 s ISIs, there was no significant difference in performance between sham and active tDCS conditions, but for 4 s ISIs, stimulation improved variability in response times relative to sham (p < 0.05). CONCLUSIONS Results suggest that tDCS is feasible, tolerable, and may be an effective intervention to improve sustained attention difficulties in survivors with cancer-related cognitive dysfunction.
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Affiliation(s)
- Alexandra M Gaynor
- Memorial Sloan Kettering Cancer Center, Department of Psychiatry and Behavioral Sciences, New York, NY, USA.
| | - Denise Pergolizzi
- Universitat Internacional de Catalunya, School of Medicine and Health Sciences, Barcelona, Spain
| | - Yesne Alici
- Memorial Sloan Kettering Cancer Center, Department of Psychiatry and Behavioral Sciences, New York, NY, USA
| | - Elizabeth Ryan
- Memorial Sloan Kettering Cancer Center, Department of Psychiatry and Behavioral Sciences, New York, NY, USA
| | - Katrazyna McNeal
- Memorial Sloan Kettering Cancer Center, Department of Psychiatry and Behavioral Sciences, New York, NY, USA
| | - Tim A Ahles
- Memorial Sloan Kettering Cancer Center, Department of Psychiatry and Behavioral Sciences, New York, NY, USA
| | - James C Root
- Memorial Sloan Kettering Cancer Center, Department of Psychiatry and Behavioral Sciences, New York, NY, USA
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Greinacher R, Buhôt L, Möller L, Learmonth G. The time course of ineffective sham-blinding during low-intensity (1 mA) transcranial direct current stimulation. Eur J Neurosci 2019; 50:3380-3388. [PMID: 31228880 PMCID: PMC6899874 DOI: 10.1111/ejn.14497] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 06/10/2019] [Accepted: 06/17/2019] [Indexed: 11/27/2022]
Abstract
Studies using transcranial direct current stimulation (tDCS) typically compare an active protocol relative to a shorter sham (placebo) protocol. Both protocols are presumed to be perceptually identical on the scalp, and thus represent an effective method of delivering double-blinded experimental designs. However, participants often show above-chance accuracy when asked which condition involved active/sham retrospectively. We assessed the time course of sham-blinding during active and sham tDCS. We predicted that participants would be aware that the current is switched on for longer in the active versus sham protocol. Thirty-two adults were tested in a preregistered, double-blinded, within-subjects design. A forced-choice reaction time task was undertaken before, during and after active (10 min 1 mA) and sham (20 s 1 mA) tDCS. The anode was placed over the left primary motor cortex (C3) to target the right hand, and the cathode on the right forehead. Two probe questions were asked every 30 s: "Is the stimulation on?" and "How sure are you?". Distinct periods of non-overlapping confidence intervals were identified between conditions, totalling 5 min (57.1% of the total difference in stimulation time). These began immediately after sham ramp-down and lasted until the active protocol had ended. We therefore show a failure of placebo control during 1 mA tDCS. These results highlight the need to develop more effective methods of sham-blinding during transcranial electrical stimulation protocols, even when delivered at low-intensity current strengths.
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Affiliation(s)
- Robert Greinacher
- School of PsychologyUniversity of GlasgowGlasgowUK
- Quality and Usability LabTechnische Universität BerlinBerlinGermany
| | | | - Lisa Möller
- School of PsychologyUniversity of GlasgowGlasgowUK
- Department of NeurologyUniversity of LübeckLübeckGermany
| | - Gemma Learmonth
- School of PsychologyUniversity of GlasgowGlasgowUK
- Centre for Cognitive NeuroimagingInstitute of Neuroscience and PsychologyUniversity of GlasgowGlasgowUK
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An Expectancy Effect Causes Improved Visual Attention Performance After Video Game Playing. JOURNAL OF COGNITIVE ENHANCEMENT 2019. [DOI: 10.1007/s41465-019-00130-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Rabipour S, Vidjen PS, Remaud A, Davidson PSR, Tremblay F. Examining the Interactions Between Expectations and tDCS Effects on Motor and Cognitive Performance. Front Neurosci 2019; 12:999. [PMID: 30666182 PMCID: PMC6330301 DOI: 10.3389/fnins.2018.00999] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 12/11/2018] [Indexed: 11/13/2022] Open
Abstract
Background: Despite a growing literature and commercial market, the effectiveness of transcranial direct current stimulation (tDCS) remains questionable. Notably, studies rarely examine factors such as expectations of outcomes, which may influence tDCS response through placebo-like effects. Here we sought to determine whether expectations could influence the behavioral outcomes of a tDCS intervention. Methods: Through an initial study and self-replication, we recruited 121 naïve young adults 18-34 years of age (M = 21.14, SD = 3.58; 88 women). We evaluated expectations of tDCS and of motor and cognitive performance at three times: (i) at baseline; (ii) after being primed to have High or Low expectations of outcomes; and (iii) after a single session of sham-controlled anodal tDCS over the left or right motor cortex. Before and after stimulation, participants performed the Grooved Pegboard Test and a choice reaction time task as measures of motor dexterity, response time, and response inhibition. Results: Repeated measures ANOVA revealed that participants had varying, largely uncertain, expectations regarding tDCS effectiveness at baseline. Expectation ratings significantly increased or decreased in response to High or Low priming, respectively, and decreased following the intervention. Response times and accuracy on motor and cognitive measures were largely unaffected by expectation or stimulation conditions. Overall, our analysis revealed no effect attributable to baseline expectations, belief of group assignment, or experimental condition on behavioral outcomes. Subjective experience did not differ based on expectation or stimulation condition. Conclusions: Our results suggest no clear effects of tDCS or of expectations on our performance measures, highlighting the need for further investigations of such stimulation methods.
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Affiliation(s)
- Sheida Rabipour
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | | | - Anthony Remaud
- Bruyère Research Institute, Bruyère Continuing Care, Ottawa, ON, Canada
| | - Patrick S. R. Davidson
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
- Bruyère Research Institute, Bruyère Continuing Care, Ottawa, ON, Canada
| | - François Tremblay
- Bruyère Research Institute, Bruyère Continuing Care, Ottawa, ON, Canada
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The effect of expectation on transcranial direct current stimulation (tDCS) to suppress food craving and eating in individuals with overweight and obesity. Appetite 2019; 136:1-7. [PMID: 30611756 DOI: 10.1016/j.appet.2018.12.044] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/29/2018] [Accepted: 12/29/2018] [Indexed: 12/15/2022]
Abstract
Transcranial direct current stimulation (tDCS) is a neuromodulation technique with potential to treat eating disorders and obesity. As for any potential treatment, it is important to assess the degree to which expectation effects contribute to its reported efficacy. This study assessed the effect of tDCS on amount of food craving and eating while tightly controlling treatment expectation. N = 74 adults with overweight or obesity were informed of the known effects of tDCS to suppress craving and eating. Once electrodes were on the head, half of the participants were told they were receiving real, and the other half sham tDCS. Within these groups, approximately half actually received real and the other half sham tDCS. Stimulation parameters used were those previously found to reduce craving and eating, including in our lab: 2 mA, anode right/cathode left targeting the dorsolateral prefrontal cortex for 20 min (real), or only for the first and last minute (sham). Analyses controlled for demographics, hunger, trait impulsiveness, eating motives, dieting, binge eating, suggestibility, and baseline craving and eating. Participants told they were receiving real tDCS craved and ate less than participants told they were receiving sham tDCS (both p < 0.01), regardless of tDCS condition administered. There was no main effect of real vs. sham tDCS on craving or eating or an interaction between tDCS condition and expectation. The scientific validation of tDCS as a treatment for eating-related conditions hinges on controlling for the powerful effects of expectation. This can include the type of information provided on consent forms and participants' ability to guess real from sham conditions.
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