High frequency transcranial random noise stimulation (hf-tRNS) is a relatively novel form of non-invasive brain stimulation, thought to enhance neural excitability and facilitate processing in targeted brain areas. The evidence for the efficacy of hf-tRNS is mixed, so a high-powered test of the proposed facilitatory effects would be of value to the field. This Registered Report will target the human middle temporal complex (hMT+), an area with a well-established critical role in global motion processing. The protocol is adapted from a study by Ghin and colleagues (2018) but focusing on a sub-set of the original experimental conditions and using a fully within-subjects design (n=42). Global motion processing will be operationalised in terms of the coherence threshold for identification of the dominant direction of random-dot motion. The experiment will test the predicted facilitation of contralateral motion processing (reduced coherence threshold) during hf-tRNS to the left hMT+. The specificity of this effect will be tested by comparison to a sham stimulation control condition and an active stimulation control condition (left forehead). By targeting a brain area with a well-established critical role in behaviour, this study will provide important information about the replicability and specificity of the facilitatory effects of hf-tRNS.

 

Following two rounds of in-depth review, the recommender judged that the manuscript met the Stage 1 criteria and awarded in-principle acceptance (IPA).  
 
URL to the preregistered Stage 1 protocol: https://osf.io/bce7u
 
Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA. 
 
List of eligible PCI RR-friendly journals:
 

 

1. Ghin, F., Pavan, A., Contillo, A., & Mather, G. (2018). The effects of high-frequency transcranial random noise stimulation (hf-tRNS) on global motion processing: an equivalent noise approach. Brain Stimulation, 11, 1263–75.

 

2. Caroll, M. B., Edwards, G. & Baker, C. I. (2022). Replicating the facilitatory effects of transcranial random noise stimulation on motion processing: A registered report, in principle acceptance of Version 7 by Peer Community in Registered Reports. https://osf.io/bce7u