A Verification Report of Three Meta-Analyses in Transcranial Direct-Current Stimulation-Motor Learning Research.

Area of Science:

• Neuroscience
• Cognitive Science
• Rehabilitation Science

Background:

• Transcranial direct-current stimulation (tDCS) is increasingly used in motor learning research and commercial applications.
• Evaluating the quality of evidence, particularly from meta-analyses, is crucial for research and clinical practice.
• Meta-analyses significantly influence scientific and clinical decision-making regarding tDCS effectiveness.

Purpose of the Study:

• To assess the methodological quality of meta-analyses examining tDCS effects on motor learning.
• To focus on reproducibility, reporting quality, and publication bias control in these meta-analyses.

Main Methods:

• Verification of the methodology of three selected meta-analyses.
• Assessment of adherence to PRISMA reporting guidelines.
• Evaluation of reproducibility of pooled effect size estimates.
• Analysis of methods used for publication bias detection.

Main Results:

• The meta-analyses generally followed PRISMA guidelines and allowed for reproduction of effect sizes.
• Significant underreporting in methods and results sections was identified, hindering judgment of procedural soundness.
• Publication bias detection methods were insufficient for making informed decisions about bias presence or extent.

Conclusions:

• While meta-analyses on tDCS for motor learning show some adherence to guidelines, methodological transparency is insufficient.
• Underreporting compromises the ability to assess the reliability and reproducibility of findings.
• Enhanced transparency in reporting and rigorous quality evaluation of meta-analyses are essential.