Blinding in tDCS Studies: Correct End-of-Study Guess Does Not Moderate the Effects on Associative and Working Memory
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 incr...
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MDPI AG
2021-12-01
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| Series: | Brain Sciences |
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| Online Access: | https://www.mdpi.com/2076-3425/12/1/58 |
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| author | Marija Stanković Marko Živanović Jovana Bjekić Saša R. Filipović |
| author_facet | Marija Stanković Marko Živanović Jovana Bjekić Saša R. Filipović |
| author_sort | Marija Stanković |
| collection | DOAJ |
| description | 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 (<i>N</i> = 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. |
| first_indexed | 2024-03-10T01:49:21Z |
| format | Article |
| id | doaj.art-aacf9ee6605a470dbf75c1876c6bcb3b |
| institution | Directory Open Access Journal |
| issn | 2076-3425 |
| language | English |
| last_indexed | 2024-03-10T01:49:21Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Brain Sciences |
| spelling | doaj.art-aacf9ee6605a470dbf75c1876c6bcb3b2023-11-23T13:09:28ZengMDPI AGBrain Sciences2076-34252021-12-011215810.3390/brainsci12010058Blinding in tDCS Studies: Correct End-of-Study Guess Does Not Moderate the Effects on Associative and Working MemoryMarija Stanković0Marko Živanović1Jovana Bjekić2Saša R. Filipović3Human Neuroscience Group, Institute for Medical Research, University of Belgrade, 11000 Belgrade, SerbiaInstitute of Psychology and Laboratory for Research of Individual Differences, Department of Psychology, Faculty of Philosophy, University of Belgrade, 11000 Belgrade, SerbiaHuman Neuroscience Group, Institute for Medical Research, University of Belgrade, 11000 Belgrade, SerbiaHuman Neuroscience Group, Institute for Medical Research, University of Belgrade, 11000 Belgrade, SerbiaTranscranial 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 (<i>N</i> = 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.https://www.mdpi.com/2076-3425/12/1/58transcranial direct current stimulation (tDCS)blindingplaceboshamassociative memoryworking memory |
| spellingShingle | Marija Stanković Marko Živanović Jovana Bjekić Saša R. Filipović Blinding in tDCS Studies: Correct End-of-Study Guess Does Not Moderate the Effects on Associative and Working Memory Brain Sciences transcranial direct current stimulation (tDCS) blinding placebo sham associative memory working memory |
| title | Blinding in tDCS Studies: Correct End-of-Study Guess Does Not Moderate the Effects on Associative and Working Memory |
| title_full | Blinding in tDCS Studies: Correct End-of-Study Guess Does Not Moderate the Effects on Associative and Working Memory |
| title_fullStr | Blinding in tDCS Studies: Correct End-of-Study Guess Does Not Moderate the Effects on Associative and Working Memory |
| title_full_unstemmed | Blinding in tDCS Studies: Correct End-of-Study Guess Does Not Moderate the Effects on Associative and Working Memory |
| title_short | Blinding in tDCS Studies: Correct End-of-Study Guess Does Not Moderate the Effects on Associative and Working Memory |
| title_sort | blinding in tdcs studies correct end of study guess does not moderate the effects on associative and working memory |
| topic | transcranial direct current stimulation (tDCS) blinding placebo sham associative memory working memory |
| url | https://www.mdpi.com/2076-3425/12/1/58 |
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