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Cited by 368Transcranial Magnetic Stimulation StudiesTraumatic Brain Injury ResearchElectroconvulsive Therapy Studies

Efficacy of non-invasive brain stimulation on cognitive functioning in brain disorders: a meta-analysis

Open access
Begemann, Marieke J., Brand, Bodyl A., Ćurčić-Blake, Branislava, Aleman, André, Sommer, Iris E.·2020·Psychological Medicine
DOI 10.1017/s0033291720003670PMC PMC7737055
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Abstract

Background: Cognition is commonly affected in brain disorders. Non-invasive brain stimulation (NIBS) may have procognitive effects, with high tolerability. This meta-analysis evaluates the efficacy of transcranial magnetic stimulation (TMS) and transcranial Direct Current Stimulation (tDCS) in improving cognition, in schizophrenia, depression, dementia, Parkinson's disease, stroke, traumatic brain injury, and multiple sclerosis. Methods: A PRISMA systematic search was conducted for randomized controlled trials. Hedges' g was used to quantify effect sizes (ES) for changes in cognition after TMS/tDCS v. sham. As different cognitive functions may have unequal susceptibility to TMS/tDCS, we separately evaluated the effects on: attention/vigilance, working memory, executive functioning, processing speed, verbal fluency, verbal learning, and social cognition. Results: We included 82 studies ( n = 2784). For working memory, both TMS (ES = 0.17, p = 0.015) and tDCS (ES = 0.17, p = 0.021) showed small but significant effects. Age positively moderated the effect of TMS. TDCS was superior to sham for attention/vigilance (ES = 0.20, p = 0.020). These significant effects did not differ across the type of brain disorder. Results were not significant for the other five cognitive domains. Conclusions: Our results revealed that both TMS and tDCS elicit a small trans-diagnostic effect on working memory, tDCS also improved attention/vigilance across diagnoses. Effects on the other domains were not significant. Observed ES were small, yet even slight cognitive improvements may facilitate daily functioning. While NIBS can be a well-tolerated treatment, its effects appear domain specific and should be applied only for realistic indications (i.e. to induce a small improvement in working memory or attention).

AI snapshot

Written from the paper’s full text.

TL;DR

This meta-analysis of 82 sham-controlled RCTs (93 samples, n = 2784) found small transdiagnostic procognitive effects of TMS and tDCS on working memory, and of tDCS on attention/vigilance. Effects on five other cognitive domains were not significant.

Key findings

  • Both TMS and tDCS showed small significant effects on working memory: TMS ES = 0.17, p = 0.015; tDCS ES = 0.17, p = 0.021.
  • tDCS was superior to sham for attention/vigilance (ES = 0.27, p = 0.006; after excluding one outlier, ES = 0.20, p = 0.020), but this effect was no longer significant when single-dose/challenge studies were excluded (ES = 0.12, p = 0.140).
  • TMS did not significantly affect attention/vigilance (ES = 0.10, p = 0.210), and neither TMS nor tDCS significantly affected executive functioning, processing speed, verbal fluency, or verbal learning; tDCS showed only a trend for social cognition (ES = 0.27, p = 0.070).
  • Age positively moderated the TMS effect on working memory (slope coefficient = 0.020, p = 0.005); significant effects did not differ across brain disorders.

Methods

  • PRISMA systematic search of PubMed (Medline), EMBASE, Web of Science, and Cochrane Database of Systematic Reviews, with search cutoff 1 May 2019, for randomized controlled trials of TMS or tDCS versus sham in schizophrenia, depression, dementia, Parkinson’s disease, stroke, traumatic brain injury, and multiple sclerosis.
  • Included 82 studies reporting 93 study samples and 2784 patients; cognitive outcomes were categorized into seven domains: attention/vigilance, working memory, executive functioning, processing speed, verbal fluency, verbal learning, and social cognition.
  • Hedges’ g quantified effect sizes separately for TMS and tDCS; analyses included subgroup comparisons by brain disorder when k ≥ 3, heterogeneity assessment (Q, I²), outlier evaluation, publication-bias checks (funnel plot, Egger’s test, Rosenthal’s fail-safe N), and sensitivity analyses for shared control groups, single-dose studies, and moderators including age, gender, and number of sessions.

Limitations

  • The paper states that many included studies did not primarily study cognition, so cognitive tests were often secondary outcomes and may lack sensitivity to detect improvement; few studies were available for some analyses (e.g., tDCS for stroke and PD; tDCS and TMS for TBI), affecting power.
  • The paper states that heterogeneity is inevitably present due to technical factors (coil type, sham technique, coil positioning, stimulation protocol), broad cognitive tests, practice effects, ceiling/floor effects, and small samples; post-treatment testing occurred right after stimulation, leaving long-term effects understudied, and test-based improvements may not transfer to daily life.
  • Evident in the text: the abstract/results report 82 included studies, while the Discussion says “83 randomized” studies; the tDCS attention/vigilance effect was not robust to excluding single-dose studies, and the social cognition finding was only trend-significant with potential publication bias and few studies.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1017/s0033291720003670

Cites

153 of 153 references verified0 citation errors · 0 not checkable

Statistics

17 tests recomputed · 0 with the reported and recomputed p on opposite sides of .05

Claims the paper makes

16 of 58 cited sources checked · 5 supported · 1 flagged · accuracy not yet measured

  • Premisecitation

    Non-invasive brain stimulation can be a well-tolerated treatment.

    “While NIBS can be a well-tolerated treatment, its effects appear domain specific and should be applied only for realistic indications (i.e. to induce a small improvement in working memory or attention).”
    Quote in the paperNot a substantial claim2 of 3 sources checked
    • cites Aleman, Sommer, & Kahn, 2007, 2018

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Chervyakov, Chernyavsky, Sinitsyn, & Piradov, 2015 source

      The Introduction (page unavailable) describes repetitive transcranial magnetic stimulation as an effective treatment for several conditions, supporting the treatment aspect of the claim. It does not discuss whether patients tolerate it well, and its discussion concerns TMS rather than non-invasive brain stimulation generally. (LLM, conf=0.78)

      Experimental — accuracy not yet measured
    • cites Lage, Wiles, Shergill, & Tracy, 2016 source
  • Findingown data

    One outlier study (Orlov et al., 2017) was identified in the tDCS attention/vigilance analysis.

    “One outlier study was identified (Z-score>1.96; Orlov et al., 2017).”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Orlov et al., 2017 source
  • Findingown data

    The significant effects for working memory and attention/vigilance did not differ across the type of brain disorder.

    “These significant effects did not differ across the type of brain disorder.”
    Quote in the paperNot a substantial claim
  • Findingown data

    tDCS was superior to sham in improving performance on attention/vigilance tasks (ES = 0.27, p = 0.006).

    “tDCS (k = 29; n = 980) was superior to sham in improving performance on attention/vigilance tasks (ES = 0.27, p = 0.006; Table 4; Fig. 2a).”
    • Also stated in: § Conclusions · plain
      “tDCS also showed a superior effect on attention/vigilance.”
    Quote in the paperSubstantial claim
  • Findingown data

    Age positively moderated the effect of transcranial magnetic stimulation.

    “Age positively moderated the effect of TMS.”
    Quote in the paperNot a substantial claim
  • May combine two claims. 49
  • Classified as probably not a substantial claim. 36

  • May combine two claims.

    Findingown data

    Moreno et al. (2015) and Biundo et al. (2015) used the RBANS written coding task.

    “Diverging from other included studies, both Moreno et al. (2015) (Z-score >1.96) and Biundo et al. (2015) (Z-score >1.96) used the RBANS written coding task.”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites Moreno et al. (2015) source

      Section 2.3 (Procedures; page unavailable) identifies the tasks used by Moreno et al. as the 2-back and Internal Shift Task, not the RBANS written coding task. Section 2.5 (Statistical analysis; page unavailable) likewise describes analyses of those two tasks; it does not report the claimed Z-score threshold. This verdict concerns Moreno et al. only, not Biundo et al. (LLM, conf=0.87)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
    • cites Biundo et al. (2015) source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    High tolerability with few side-effects is considered an important advantage over medication and, in the case of transcranial direct current stimulation, has a potential to be applied at home.

    “High tolerability with few side-effects is considered an important advantage over medication and, in the case of tDCS, has a potential to be applied at home (Aleman, Sommer, & Kahn, 2007, 2018; Chervyakov, Chernyavsky, Sinitsyn, & Piradov, 2015; Lage, Wiles, Shergill, & Tracy, 2016; Rossi et al., 2009; Slotema, Aleman, Daskalakis, & Sommer, 2012).”
    Quote in the paperNot a substantial claim2 of 3 sources checked
    • cites Aleman, Sommer, & Kahn, 2007, 2018

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Chervyakov, Chernyavsky, Sinitsyn, & Piradov, 2015 source

      The Introduction discusses the clinical use and efficacy of rTMS, and the Conclusion describes its stimulation as painless. Neither section addresses high tolerability with few side effects as an advantage over medication or the potential for at-home tDCS use. Searches for tolerability, side effects, medication, and at-home use found no passage supporting those points. (LLM, conf=0.77)

      Experimental — accuracy not yet measured
    • cites Lage, Wiles, Shergill, & Tracy, 2016 source

      The Discussion (page unavailable) says the review supports the general safety of rTMS and a lack of harm to cognitive functioning; the Introduction describes stimulation as relatively painless. The paper does not establish high tolerability or few side effects compared with medication, and its discussion of tDCS does not address use at home. (LLM, conf=0.84)

      Experimental — accuracy not yet measured

  • Classified as probably not a substantial claim.

    Premisecitation

    Cognition is commonly affected in brain disorders.

    “Cognitive functioning is affected in many brain disorders (Robbins, 2011).”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Robbins, 2011 source

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    A PRISMA systematic search was conducted for randomized controlled trials.

    “A PRISMA systematic search was conducted for randomized controlled trials.”
    • Also stated in: § Search strategy · plain
      “Following the Preferred Reporting for Systematic Reviews and Meta-analysis (PRISMA) Statement (Moher, Liberati, Tetzlaff, & Altman, 2009), a systematic search was performed in PubMed (Medline), EMBASE, Web of Science, and Cochrane Database of Systematic Reviews”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Moher, Liberati, Tetzlaff, & Altman, 2009 source

  • Classified as probably not a substantial claim.

    Premisecitation

    The efficacy of non-invasive brain stimulation is unclear.

    “Until now, the efficacy of NIBS is unclear and some have questioned whether these techniques have any effect on the brain at all (Vöröslakos et al., 2018).”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Vöröslakos et al., 2018 source

      The Introduction (page unavailable) says the effectiveness of currently used transcranial electrical stimulation (TES) protocols on local neuronal networks is extensively debated. That supports uncertainty about TES, but the citing sentence broadens this to all non-invasive brain stimulation and to whether the techniques have any effect on the brain at all. The Introduction also describes indirect effects on brain activity, so the paper's stated uncertainty is narrower. (LLM, conf=0.86)

      Experimental — accuracy not yet measured

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Skepticism is increased by lack of clear theories and evidence on working mechanisms of both interventions, which hampers smart applications.

    “Skepticism is increased by lack of clear theories and evidence on working mechanisms of both interventions, which hampers smart applications (Chase, Boudewyn, Carter, & Phillips, 2020; Singh, Erwin-Grabner, Goya-Maldonado, & Antal, 2019)”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites Chase, Boudewyn, Carter, & Phillips, 2020 source

      The “Mechanism(s) of action” section says that limited understanding of how tDCS affects brain circuitry constrains experimental design, and that better mechanistic understanding would help calibrate protocols. This supports the claim for tDCS, but the passage does not address both interventions or say that this uncertainty increases skepticism. Page numbers were not supplied with the passages. (LLM, conf=0.83)

      Experimental — accuracy not yet measured
    • cites Singh, Erwin-Grabner, Goya-Maldonado, & Antal, 2019 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Impairments may affect multiple cognitive domains, including information processing, working memory, executive functioning and attention.

    “Impairments may affect multiple cognitive domains, including information processing, working memory, executive functioning and attention (Caviness et al., 2007; Higuchi et al., 2017; Maloni, 2018).”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites Caviness et al., 2007 source
    • cites Higuchi et al., 2017 source
    • cites Maloni, 2018 source

  • May combine two claims.

    Premisecitation

    Because the dorsolateral prefrontal cortex is laterally located and often close to the area of stimulation, working memory may be a cognitive function expected to benefit from non-invasive brain stimulation.

    “As the dorsolateral prefrontal cortex (DLPFC) is laterally located and often close to the area of stimulation, working memory may be a cognitive function expected to benefit from NIBS (Brunoni & Vanderhasselt, 2014; Miniussi & Rossini, 2011; Pope & Chris Miall, 2014; Tracy et al., 2015).”
    Quote in the paperSubstantial claim3 of 3 sources checked
    • cites Brunoni & Vanderhasselt, 2014 source

      The Introduction links DLPFC activity to working memory, and the Discussion reports that non-invasive prefrontal stimulation, particularly rTMS, is associated with working-memory improvement. The paper does not give the cited explanation that this benefit is expected because the DLPFC is laterally located and close to the area of stimulation. The indexed passages have section labels but no page numbers. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites Miniussi & Rossini, 2011 source

      The TMS AND COGNITIVE NEUROREHABILITATION section (page not provided) says TMS may enhance cognitive performance and may strengthen networks supporting specific functions. It does not give the claimed rationale that the DLPFC’s lateral location makes working memory especially likely to benefit; the working-memory study listed in the References concerns stimulation of the precuneus. (LLM, conf=0.82)

      Experimental — accuracy not yet measured
    • cites Pope & Chris Miall, 2014 source

      The Introduction section “tDCS after-effects and the cerebellum” says prefrontal stimulation can enhance performance on working-memory tasks, supporting the proposed benefit. It does not say that the DLPFC is often close to the stimulation area or give proximity as the reason for that benefit. Page numbers are unavailable in our copy. (LLM, conf=0.86)

      Experimental — accuracy not yet measured

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    To avoid arbitrary definitions of cognitive domains, the authors based their seven domains on the guidelines of the two most commonly used cognitive test batteries.

    “To avoid that the definition of cognitive domains would be arbitrary, we based our seven domains on the guidelines of the two most commonly used cognitive test batteries (Green et al., 2004; Litvan et al., 2012).”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites Green et al., 2004 source
    • cites Litvan et al., 2012 source

      The Neuropsychological Evaluation section says that assigning tests to domains is somewhat arbitrary and that the task force followed established conventions. The Level I and II criteria give guidelines for testing across five cognitive domains, so the paper is relevant to the citing authors’ domain definitions. It does not describe itself as one of the two most commonly used cognitive test batteries or prescribe seven domains. Page numbers were not supplied in our copy. (LLM, conf=0.84)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingcitation

    Post-treatment cognitive testing took place right after brain stimulation, so the potential long-term effect of NIBS on cognition remains understudied.

    “Also, post-treatment cognitive testing took place right after brain stimulation and therefore the potential long-term effect of NIBS on cognition remains understudied (Cirillo et al., 2017; Gersner, Kravetz, Feil, Pell, & Zangen, 2011).”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites Cirillo et al., 2017 source
    • cites Gersner, Kravetz, Feil, Pell, & Zangen, 2011 source

      The Introduction says most neurobiological studies assessed immediate effects of rTMS and that its long-lasting neurochemical and physiological effects were poorly understood. It does not say cognitive testing occurred immediately after stimulation or establish that long-term effects on cognition were understudied. The Methods describe measuring neuroplasticity markers in rats three days after stimulation, not cognitive testing. (LLM, conf=0.84)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingown data

    The number of null studies needed to render the tDCS attention/vigilance effect non-significant was 93, with no evidence for publication bias.

    “The number of null-studies needed to render this effect non-significant (NR) was 93, with no evidence for publication bias (online Supplementary Fig. S11).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    Table 3 depicts the mean demographical group characteristics for the 43 transcranial magnetic stimulation studies and 39 transcranial direct current stimulation studies.

    “Table 3 depicts the mean demographical group characteristics for the 43 TMS studies and 39 tDCS studies.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The meta-analysis included 82 studies, reporting on 93 study samples, evaluating a grand total of 2784 patients.

    “The total number of included studies was 82, reporting on 93 study samples (k), evaluating a grand total of 2784 patients.”
    • Also stated in: § Results · plain
      “We included 82 studies (n = 2784).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    TMS showed a small yet significant effect on working memory (ES = 0.17, p = 0.015), with low heterogeneity.

    “TMS (k = 25; n = 873) showed a small yet significant effect, with low heterogeneity (ES = 0.17, p = 0.015; Table 4; Fig. 2b).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    This is the first meta-analysis reporting improvements in attention/vigilance in tDCS as compared to placebo stimulation (ES = 0.19), while the ES of 0.10 for TMS was not significant.

    “In addition, this is the first meta-analysis reporting improvements in attention/vigilance in tDCS as compared to placebo stimulation (ES = 0.19), while the ES of 0.10 for TMS was not significant.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The DLPFC is one of the key anatomical regions most frequently targeted to improve cognition in the retrieved studies.

    “For example, as reflected in our retrieved studies (Tables 1 and 2) the DLPFC is one of the key anatomical regions that is most frequently targeted to improve cognition.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    After excluding one outlier study (Sun et al., 2015), heterogeneity decreased and the overall TMS verbal learning ES remained non-significant.

    “After excluding one outlier study (Z-score >1.96) (Sun, Lu, Zhang, Wen, & Sun, 2015), heterogeneity decreased and overall ES remained non-significant (Table 4).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Sun, Lu, Zhang, Wen, & Sun, 2015

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Findingown data

    The funnel plot and Egger's regression test indicated potential publication bias for the tDCS social cognition effect (p = 0.09), but the power of this test is limited due to the small number of studies included.

    “The funnel plot and Egger's regression test indicated potential publication bias (p = 0.09; online Supplementary Fig. S13), yet the power of this test is limited due to the small number of studies included (Egger et al., 1997).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Egger et al., 1997 source

  • May combine two claims.

    Findingown data

    No superior effect was found for TMS on verbal fluency (ES = −0.05, p = 0.538), with low heterogeneity.

    “No superior effect was found for TMS (k = 21; n = 747) on verbal fluency, with low heterogeneity (ES = −0.05, p = 0.538; Table 4)”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    The two studies on depression were positive for tDCS social cognition but could not be combined in meta-analysis.

    “although the two studies on depression were positive they could not be combined in meta-analysis.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Heterogeneity for the tDCS processing speed effect was moderate to high, and three outlier studies were identified.

    “Heterogeneity was moderate to high (Table 4), three outlier studies were identified.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Only one study investigating the effect of TMS on social cognition was retrieved, so no meta-analysis could be conducted.

    “As we retrieved only one study investigating the effect of TMS on social cognition (Wölwer et al., 2014), no meta-analysis could be conducted.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Wölwer et al., 2014 source

  • May combine two claims.

    Findingown data

    The TMS working memory effect did not change after correcting control group sample sizes of five studies with multiple interventions (ES = 0.16, p = 0.032) or after excluding one single-dose study (ES = 0.15, p = 0.049).

    “This effect of TMS on working memory did not change after correcting control group sample sizes of the five studies that compared multiple interventions (ES = 0.16, p = 0.032) or after excluding one single-dose study (ES = 0.15, p = 0.049).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    After excluding the outlier, the tDCS effect on attention/vigilance remained significant and heterogeneity decreased (ES = 0.20, p = 0.020).

    “After exclusion, ES remained significant and heterogeneity decreased (ES = 0.20, p = 0.020; Table 4; Fig. 2b).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Using a domain-specific approach, the meta-analysis found a positive effect of both TMS (ES = 0.17) and tDCS (ES = 0.17) compared to sham on working memory.

    “Using a domain-specific approach, we found a positive effect of both TMS (ES = 0.17) and tDCS (ES = 0.17) as compared to sham on working memory.”
    • Also stated in: § Conclusions · plain
      “Overall, we found a small yet significant effect of both TMS and tDCS on working memory in patients with brain disorders as compared to sham treatment”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Mattioli et al. (2016) and the DLPFC-condition of Chalah et al. (2017) were identified as outliers in the tDCS executive functioning analysis.

    “Mattioli, Bellomi, Stampatori, Capra, and Miniussi (2016) and the DLPFC-condition of Chalah, Créange, Lefaucheur, and Ayache (2017) were both identified as outliers.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Mattioli, Bellomi, Stampatori, Capra, and Miniussi (2016) source
    • cites Chalah, Créange, Lefaucheur, and Ayache (2017) source

  • May combine two claims.

    Findingown data

    TMS was not superior to sham in improving executive functioning (ES = 0.07, p = 0.243), with low heterogeneity.

    “Overall, TMS (k = 40; n = 1145) was not superior to sham in improving executive functioning, with low heterogeneity (ES = 0.07, p = 0.243; Table 4)”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    After excluding outliers, heterogeneity decreased and the tDCS executive functioning effect remained non-significant (ES = 0.00, p = 0.992).

    “After exclusion, heterogeneity decreased and ES remained non-significant (ES = 0.00, p = 0.992; Table 4).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    tDCS showed a small significant effect on working memory (ES = 0.17, p = 0.021), with homogeneous studies.

    “A small significant effect on working memory was detected for tDCS, studies were homogeneous (k = 28; n = 939; ES = 0.17, p = 0.021; Table 4; Fig. 2c)”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    A broad range of cognitive tests were administered throughout the included studies.

    “Notably, a broad range of the cognitive tests were administered throughout the included studies.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Mattioli et al. (2016) was a positive outlier and the only study using total errors of the Wisconsin Card Sorting Test as an outcome measure.

    “Mattioli et al. (2016) was a positive outlier (Z-score >1.96) and the only study using total errors of the Wisconsin's Card Sorting Test as an outcome measure.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Mattioli et al. (2016) source

  • May combine two claims.

    Findingown data

    The tDCS working memory effect remained significant when adjusting control group sample sizes for three studies with multiple intervention groups (ES = 0.15, p = 0.038) and when excluding five single-dose studies (ES = 0.17, p = 0.038).

    “ES remained significant when adjusting control group sample sizes for the three studies with multiple intervention groups (ES = 0.15, p = 0.038) and when excluding five single-dose studies (ES = 0.17, p = 0.038).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    tDCS did not differ from sham on verbal learning (ES = 0.05, p = 0.609), with homogeneous studies.

    “tDCS did not differ from sham (k = 18; n = 550), included studies were homogeneous (ES = 0.05, p = 0.609; Table 4)”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    No superior effect was found for TMS on processing speed (ES = −0.01, p = 0.900), with low heterogeneity.

    “No superior effect was found for TMS (k = 30; n = 941) v. sham, with low heterogeneity (ES = −0.01, p = 0.900; Table 4)”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    tDCS did not differ from sham in executive functioning (ES = 0.04, p = 0.726), with moderate heterogeneity.

    “tDCS (k = 19, n = 662) did not differ from sham, with moderate heterogeneity (ES = 0.04, p = 0.726; Table 4).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Subgroup analyses showed that tDCS was not superior to sham for processing speed in depression, schizophrenia, or stroke.

    “subgroup analyses showed that tDCS was not superior for depression (k = 8; n = 389; ES = −0.00, 95% CI −0.20 to 0.20, p = 0.997), schizophrenia (k = 7; n = 194; ES = −0.02, 95% CI −0.29 to 0.26, p = 0.894), and stroke (k = 3; n = 71; ES = 0.10, 95% CI −0.35 to 0.55, p = 0.654).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    TMS showed no positive effect on verbal learning versus sham (ES = 0.08, p = 0.635), with high heterogeneity.

    “Overall, TMS (k = 21; n = 690) showed no positive effect v. sham but heterogeneity was high (ES = 0.08, p = 0.635; Table 4).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    tDCS showed a trend-significant effect on social cognition (ES = 0.27, p = 0.070), with low heterogeneity.

    “tDCS (k = 7; n = 171) showed a trend-significant effect on social cognition, with low heterogeneity (ES = 0.27, p = 0.070; Table 4).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    No significant difference was found between tDCS and sham on verbal fluency (ES = 0.14, p = 0.193), with low heterogeneity.

    “No significant difference was found between tDCS (k = 9; n = 399) v. sham, heterogeneity was low (ES = 0.14, p = 0.193; Table 4)”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Number of treatment sessions and gender did not moderate the TMS working memory effect.

    “The number of treatment sessions and gender did not moderate ES (online Supplementary Table S2).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    After excluding outliers, heterogeneity decreased and the tDCS processing speed effect remained non-significant (ES = −0.02, p = 0.784).

    “After exclusion, heterogeneity decreased and ES remained non-significant (ES = −0.02, p = 0.784; Table 4).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Although TMS showed a positive effect on verbal learning for stroke only and tDCS on processing speed for MS and PD only, no definite conclusions could be drawn regarding the nature of these differences due to the limited number of studies.

    “Although TMS showed a positive effect on verbal learning for stroke only (k = 3) and tDCS on processing speed for MS (k = 1) and PD (k = 2) only, no definite conclusions could be drawn regarding the nature of these differences due to the limited number of studies that could be included for the relevant brain disorders.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S1 (asserted), S3 (load-bearing), S4 (based).

    Findingown data

    The effect of tDCS on verbal learning did not differ across disorders.

    “ES did not differ across disorders (online Supplementary Table S1).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    No year or language limits were applied in the systematic search.

    “No year or language limits were applied.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Current treatment options include rehabilitation, cognitive remediation, physical exercise, cognitive enhancing medication, and various brain stimulation techniques.

    “Current treatment options include rehabilitation, cognitive remediation, physical exercise, cognitive enhancing medication, and various brain stimulation techniques (Cicerone et al., 2005; Leroi, McDonald, Pantula, & Harbishettar, 2012; Wallace, Ballard, Pouzet, Riedel, & Wettstein, 2011), yet treatment effects vary and effect sizes (ES) are generally low.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Cicerone et al., 2005 source
    • cites Leroi, McDonald, Pantula, & Harbishettar, 2012 source
    • cites Wallace, Ballard, Pouzet, Riedel, & Wettstein, 2011 source

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationreasoning

    Even slight cognitive improvements may facilitate daily functioning.

    “Observed ES were small, yet even slight cognitive improvements may facilitate daily functioning.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Review articles and meta-analyses were examined for cross-references.

    “Review articles and meta-analyses were examined for cross-references.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Cognitive impairment can be relatively mild in depression.

    “The observed impairment can be profound, as in Alzheimer's disease or Parkinson's disease (PD), or relatively mild, as in depression (Brown & Marsden, 1990; Caviness et al., 2007; Douglas et al., 2018; Petersen et al., 2001).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Brown & Marsden, 1990 source
    • cites Caviness et al., 2007 source
    • cites Douglas et al., 2018 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Cognitive impairment can be profound in Alzheimer's disease or Parkinson's disease.

    “The observed impairment can be profound, as in Alzheimer's disease or Parkinson's disease (PD), or relatively mild, as in depression (Brown & Marsden, 1990; Caviness et al., 2007; Douglas et al., 2018; Petersen et al., 2001).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Brown & Marsden, 1990 source
    • cites Caviness et al., 2007 source
    • cites Douglas et al., 2018 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Multiple sclerosis, schizophrenia, or traumatic brain injury can co-occur with varying levels of cognitive performance, with either mild or severe cognitive dysfunction.

    “Other brain disorders, such as multiple sclerosis (MS), schizophrenia or traumatic brain injury (TBI) can co-occur with more varying levels of cognitive performance, with either mild or severe cognitive dysfunction (Chiaravalloti & DeLuca, 2008; Heinrichs & Zakzanis, 1998; Sun, Tan, & Yu, 2014; Walker & Tesco, 2013).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Chiaravalloti & DeLuca, 2008 source
    • cites Heinrichs & Zakzanis, 1998 source
    • cites Sun, Tan, & Yu, 2014 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    Single-dose challenge studies were included, and sensitivity analyses were run with and without these challenge studies.

    “Single-dose (i.e. challenge) studies were included, sensitivity analyses were run with and without these challenge studies.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Cathodal transcranial direct current stimulation has a suppressive effect.

    “It is generally considered that anodal tDCS (AtDCS) increases the function of the underlying areas of the cortex, whereas cathodal tDCS has a suppressive effect (Nitsche & Paulus, 2011).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Nitsche & Paulus, 2011 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Non-invasive brain stimulation entails modulation of brain excitability and activity and consists of different methods, such as transcranial magnetic stimulation and transcranial direct current stimulation.

    “Non-invasive brain stimulation (NIBS) entails the modulation of brain excitability and activity (Ziemann et al., 2008) and consists of different methods, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Ziemann et al., 2008 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    For (trend-)significant results, potential publication bias was investigated by visual inspection of the funnel plot and Egger's test.

    “For (trend-)significant results, potential publication bias was investigated by means of a visual inspection of the funnel plot and Egger's test (p < 0.1, two-tailed) (Egger, Smith, Schneider, & Minder, 1997).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Egger, Smith, Schneider, & Minder, 1997 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Cognitive disturbances can profoundly impact daily functioning and quality of life.

    “These disturbances can profoundly impact daily functioning and quality of life (Papakostas et al., 2004; Schrag, Jahanshahi, & Quinn, 2000).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Papakostas et al., 2004 source
    • cites Schrag, Jahanshahi, & Quinn, 2000

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationown data

    Both transcranial magnetic stimulation and transcranial direct current stimulation elicit a small trans-diagnostic effect on working memory.

    “Our results revealed that both TMS and tDCS elicit a small trans-diagnostic effect on working memory”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    Rosenthal's fail-safe number was calculated, estimating the number of unpublished studies with non-significant results needed to bring an observed result to non-significance.

    “Rosenthal's fail-safe number (NR) was calculated, estimating the number of unpublished studies with non-significant results needed to bring an observed result to non-significance (NR ⩾ 5k + 10 to rule out a file drawer problem) (Rosenthal, 1979).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Rosenthal, 1979 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    Sensitivity analyses were performed for (trend-)significant results, correcting for inflated control groups, single-dose studies, and moderator effects of the number of treatment sessions, mean age, and gender.

    “Sensitivity analyses were performed for (trend-)significant results, correcting for inflated control groups, single-dose studies, and moderator effects of the number of treatment sessions, mean age, and gender (online Supplementary Methods).”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Anodal transcranial direct current stimulation increases the function of the underlying areas of the cortex.

    “It is generally considered that anodal tDCS (AtDCS) increases the function of the underlying areas of the cortex, whereas cathodal tDCS has a suppressive effect (Nitsche & Paulus, 2011).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Nitsche & Paulus, 2011 source

  • May combine two claims.

    Premisecitation

    Treatment effects of current options vary and effect sizes are generally low.

    “Current treatment options include rehabilitation, cognitive remediation, physical exercise, cognitive enhancing medication, and various brain stimulation techniques (Cicerone et al., 2005; Leroi, McDonald, Pantula, & Harbishettar, 2012; Wallace, Ballard, Pouzet, Riedel, & Wettstein, 2011), yet treatment effects vary and effect sizes (ES) are generally low.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Cicerone et al., 2005 source
    • cites Leroi, McDonald, Pantula, & Harbishettar, 2012 source
    • cites Wallace, Ballard, Pouzet, Riedel, & Wettstein, 2011 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Cognition determines, to a considerable extent, one's social and professional success and the ability to live independently.

    “Cognition determines, to a considerable extent, one's social and professional success and the ability to live independently (Audet, Hebert, Dubois, Rochette, & Mercier, 2007; Benedict & Zivadinov, 2006; Green, Kern, Braff, & Mintz, 2000).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Audet, Hebert, Dubois, Rochette, & Mercier, 2007

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Benedict & Zivadinov, 2006 source
    • cites Green, Kern, Braff, & Mintz, 2000 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductreasoning

    Although the authors aimed to avoid major differences in methodology by careful inspection of included studies, heterogeneity is inevitably present.

    “Although we aimed to avoid major differences in methodology as far as possible by careful inspection of the included studies, heterogeneity is inevitably present.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    Practice effects, ceiling and/or floor effects, and test battery sensitivity may still have contributed to heterogeneity within cognitive domains.

    “Despite this, practice effects, ceiling and/or floor effects, and test battery sensitivity may still have contributed to heterogeneity within cognitive domains.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    tDCS may be superior to TMS in improving attention/vigilance, although firm conclusions require direct comparisons within one study randomizing participants across conditions.

    “This suggests that tDCS may be superior to TMS in improving attention/vigilance, although firm conclusions can only be drawn by making direct comparisons within one study randomizing participants across conditions.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    Positive effects as quantified by cognitive tests may not always transfer to cognitive functioning in daily life.

    “We do note that positive effects as quantified by cognitive tests may not always transfer to cognitive functioning in daily life.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    As a consequence of many included studies not primarily studying cognition, the included tests may lack sensitivity to detect cognitive improvement, and only a few studies could be included for certain analyses, affecting power.

    “As a consequence, the included tests may lack sensitivity to detect cognitive improvement, and only a few studies could be included for certain analyses which affected the power of those analyses (e.g. tDCS studies for stroke and PD; tDCS and TMS studies for TBI).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    While tDCS and TMS are different types of stimulation with different working mechanisms, the findings indicate that they might trigger comparable effects on cognition.

    “While tDCS and TMS are different types of stimulation with different working mechanisms, our findings indicate that they might trigger comparable effects on cognition.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationreasoning

    TMS and tDCS can only affect specific neural circuits if applied on frontal and temporal regions and hence can be applied to improve specific cognitive domains (i.e. working memory and attention/vigilance).

    “indicating that TMS and tDCS can only affect specific neural circuits if applied on frontal and temporal regions and hence can be applied to improve specific cognitive domains (i.e. working memory and attention/vigilance).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationown data

    The finding that both NIBS techniques elicit a similar effect in the same domain may suggest that the circuitry underlying working memory is readily accessible for activation using NIBS.

    “The finding that both NIBS techniques elicit a similar effect in the same domain may suggest that the circuitry underlying working memory is readily accessible for activation using NIBS.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationown data

    This meta-analysis provides an answer to the need for a comparison between the two most commonly used types of NIBS.

    “Also, this meta-analysis provides an answer to the need for a comparison between the two most commonly used types of NIBS.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Provided that the included studies had chosen an appropriate stimulation site based on the available literature, all stimulation sites were included in the meta-analysis.

    “Provided that the included studies had chosen an appropriate stimulation site based on the available literature, all stimulation sites were included in our meta-analysis.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: The included studies had chosen an appropriate stimulation site based on the available literature.

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductreasoning

    An important strength of this study is the inclusion of seven different cognitive domains that were analyzed separately, uncovering differences in effects across domains.

    “An important strength of this study is the inclusion of seven different cognitive domains that were analyzed separately, uncovering the differences in effects across different domains.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationnone given

    Meaningful changes in cognitive functioning may not always be fully quantifiable with the cognitive tasks used.

    “On the other hand, meaningful changes in cognitive functioning may not always be fully quantifiable with the cognitive tasks used.”
    Quote in the paperNot a substantial claim
73 of 73

  • The paper relies on this without support.

    Different cognitive functions are subserved by different cerebral and cerebellar circuits, which may be more or less susceptible to stimulation techniques.

    “Cognition is a broad concept and different cognitive functions are subserved by different cerebral and cerebellar circuits, which may be more or less susceptible to stimulation techniques.”

  • The paper relies on this without support.

    Both transcranial magnetic stimulation and transcranial direct current stimulation affect mainly the outer layers of the brain.

    “As both TMS and tDCS are thought to affect mainly the outer layers of the brain”

  • The paper relies on this without support.

    Cognitive circuits that rely on midbrain and other deep structures such as the cingulate gyrus and the hippocampus are insensitive to non-invasive brain stimulation.

    “cognitive circuits that rely on midbrain and other deep structures such as the cingulate gyrus and the hippocampus may be expected to be insensitive to NIBS.”

  • The paper relies on this without support.

    Cognitive functions that rely highly on subcortical or cerebellar circuits are not responsive to non-invasive brain stimulation.

    “cognitive functions that rely highly on subcortical or cerebellar circuits may not be expected to be responsive either.”

  • The paper relies on this without support.

    The results of studies on the effect of non-invasive brain stimulation on cognition remain inconsistent.

    “Although some studies showed promising findings, the results of studies on the effect of NIBS on cognition remain inconsistent and the field would benefit from an overarching systematic overview of findings so far.”

  • The authors state this as an assumption.

    The included studies had chosen an appropriate stimulation site based on the available literature.

    “Provided that the included studies had chosen an appropriate stimulation site based on the available literature, all stimulation sites were included in our meta-analysis.”

  • The authors state this as an assumption.

    Practice effects should not play a role in randomized controlled designs because they are present in both active and sham treatment groups.

    “In theory, practice effects should not play a role in randomized controlled designs, being present in both active and sham treatment groups, but with small sample sizes such effects may not cancel out.”
7 of 7

Statistics that don’t add up

Each reported p-value recomputed from its test statistic and degrees of freedom.

  • Inconsistent p-value: Q(6) = 1.72, p = .190

    Minor

    The paper reports p = .19 here; recomputing from the test statistic and its degrees of freedom gives p = .944. The check cannot tell whether the statistic or the p-value is the misprint.

    Reported p = .19 · recomputed p = .944

1 of 1

Statistics recomputed

Every reported test result, recomputed from its test statistic and degrees of freedom. A result shows as not adding up only once an independent check has confirmed it.

  • Doesn’t add upQ(6) = 1.72reported p = .19 · recomputed p = .944

    “Q(6) = 1.72, p = .190”

  • Not confirmedQ(2) = 7.01reported p = .005 · recomputed p = .030

    “Q(2) = 7.01, p = .005”

  • ConsistentQ(20) = 19.15reported p = .512 · recomputed p = .512

    “Q(20) = 19.15, p = .512”

  • ConsistentQ(28) = 58.43reported p = .001 · recomputed p < .001

    “Q(28) = 58.43, p = .001”

  • ConsistentQ(24) = 22.47reported p = .551 · recomputed p = .551

    “Q(24) = 22.47, p = .551”

  • ConsistentQ(27) = 29.9reported p = .319 · recomputed p = .319

    “Q(27) = 29.90, p = .319”

  • ConsistentQ(39) = 38.36reported p = .499 · recomputed p = .499

    “Q(39) = 38.36, p = .499”

  • ConsistentQ(18) = 36.52reported p = .006 · recomputed p = .006

    “Q(18) = 36.52, p = .006”

  • ConsistentQ(16) = 11.51reported p = .777 · recomputed p = .777

    “Q(16) = 11.51, p = .777”

  • ConsistentQ(29) = 23.71reported p = .743 · recomputed p = .743

    “Q(29) = 23.71, p = .743”

  • ConsistentQ(23) = 76.87reported p < .05 · recomputed p < .001

    “Q(23) = 76.87, p < .05”

  • ConsistentQ(20) = 20.71reported p = .414 · recomputed p = .414

    “Q(20) = 20.71, p = .414”

  • ConsistentQ(20) = 14.12reported p = .825 · recomputed p = .824

    “Q(20) = 14.12, p = .825”

  • ConsistentQ(8) = 7.26reported p = .509 · recomputed p = .509

    “Q(8) = 7.26, p = .509”

  • ConsistentQ(20) = 32.21reported p = .041 · recomputed p = .041

    “Q(20) = 32.21, p = .041”

  • ConsistentQ(19) = 17.82reported p = .534 · recomputed p = .534

    “Q(19) = 17.82, p = .534”

  • ConsistentQ(17) = 16.44reported p = .493 · recomputed p = .493

    “Q(17) = 16.44, p = .493”

17 of 17

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Discussion gives a different number of included studies

    Minor

    The Results report 82 included studies, while the Discussion says 83.

  • tDCS processing-speed participant counts differ

    Minor

    The narrative reports 794 participants, whereas Table 4 reports 754 for the same 24 study samples.

  • tDCS verbal-learning participant counts differ

    Minor

    The narrative reports 550 participants, but Table 4 reports 551 for the same 18 study samples.

  • TMS attention/vigilance participant counts differ

    Minor

    The narrative reports 680 participants, but Table 4 reports 679 for the same 21 study samples.

  • I2 is described as sampling error rather than heterogeneity

    Minor

    The text attributes the reported I2 of 52.08% to random sampling error, but the table explicitly identifies I2 as heterogeneity. The same sentence also allocates 48.92% to true-effect differences, making its two stated shares total 101%.

  • Discussion changes the tDCS attention/vigilance effect size

    Minor

    The Discussion gives an effect size of 0.19, while Table 4 and the Results give 0.20 for the outlier-excluded result.

6 of 6

Cites

Flagged first, then by citations

Research works printed but not linked: 2

  1. Cohen, 1988, Statistical Power Analysis for the Behavioural Science
  2. Sun, 2015, Impact of repetitive transcranial magnetic stimulation on post-stroke dysmnesia and the role of BDNF Val66Met SNP, Medical Science Monitor, 21, 761, 10.12659/MSM.892337 · DOI

Cited by

Sorted by citations

Related

Authors
Begemann, M. J., Brand, B. A., Ćurčić-Blake, B., Aleman, A., & Sommer, I. E.
Affiliations
University Medical Center Groningen (NL)
Corresponding author
Brand, Bodyl A.
ORCID
Venue
Psychological Medicine
Publisher
Cambridge University Press (CUP)
Published
2020-10-19
Volume
50
Issue
15
Pages
2465-2486
ISSN
  • 0033-2917 (ISSN-L)
  • 1469-8978
DOI
10.1017/s0033291720003670
PMC
PMC7737055
OpenAlex
W3093320036
Cited by
368
References
153
Citations by year
2026: 59 · 2025: 79 · 2024: 102 · 2023: 67 · 2022: 43 · 2021: 18
FWCI
3.21
Type
journal article
Language
en
Open access
Licence
Locations
  • Psychological Medicine (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • University of Groningen research database (University of Groningen / Centre for Information Technology) (publishedVersion, cc-by)
  • University of Groningen research database (University of Groningen / Centre for Information Technology) (submittedVersion, cc-by)
Funders
Hersenstichting (PZ 2017.01.2)
Topics
  • Life Sciences › Neuroscience › Neurology › Transcranial Magnetic Stimulation Studies
  • Health Sciences › Medicine › Epidemiology › Traumatic Brain Injury Research
  • Health Sciences › Medicine › Psychiatry and Mental health › Electroconvulsive Therapy Studies
Keywords
non-invasive brain stimulation, transcranial magnetic stimulation, transcranial direct current stimulation, cognitive enhancement, working memory, attention, schizophrenia, depression, dementia, Parkinson's disease, stroke, traumatic brain injury, multiple sclerosis, verbal learning, social cognition
MeSH terms
Attention, Brain Diseases, Cognition, Humans, Memory, Short-Term, Randomized Controlled Trials as Topic, Transcranial Magnetic Stimulation, Transcranial Direct Current Stimulation

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-28.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-28.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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