RETRACTED: l-Tyrosine administration modulates the effect of transcranial direct current stimulation on working memory in healthy humans

Abstract

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).

This retraction comes after a thorough and time-consuming analysis of the published article and the data it reports, following an investigation from the University of Leiden.

On date 17th November 2021 Cortex received advice from University of Leiden, containing allegations of misconduct concerning the data reported in this article. Due to the nature of the concerns raised about this paper, the Editor-in-Chief, in consultation with the Co-Editor, examined all documents provided, all aspects of the peer review and editorial process and requested the view of each of the authors. The Editor-in-Chief wishes to acknowledge the co-operation of all parties. The Editor-in-Chief found no evidence of fraud. However, there is a legitimate cause for concern regarding the number of participants tested for the study and the number reported in the paper. The reason for this discrepancy was not mentioned in the methods of the paper and cannot be justified. The Editor-in-Chief commends the authors for their willingness in participating in this dialogue. However, given the concerns raised, the suggestion of the University of Leiden, and the view expressed by some of the authors, Retraction of this paper is inevitable. The Editor-in-Chief, the Co-Editor and the entire editorial board will use this case as a reminder to be as diligent as possible in the peer review process and to support transparency and openness in data sharing.