There are a number of broad assumptions about memory which have penetrated societal understanding and mostly reflect supporting academic evidence e.g., that acute stress can compromise memory performance (Shields et al., 2017) and that practicing recalling critical information can help retain that knowledge (Moriera et al., 2019). The evidence base is less consistent when evaluating whether retrieval practice can protect against the negative effects of acute stress on memory, despite it being highly important for educators as to whether this specific strategy for supporting memorisation can be evidenced as especially effective under stressful conditions. A rigorous review of this mixed evidence base could provide the basis for developments in memory theory and research practice, with potential for direct educational applications.

 

Meta-analyses can play a critical role in furthering our understanding of complex cognitive mechanisms where the evidence base includes a wide range of methods, factors and effect size estimates. Furthermore, there is a lack of rigorous meta-analyses that prioritise open and reproducible processes (Topor et al., 2022) which help role-model good practice. In the current Registered Report, Mihaylova et al. (2024) have proposed a rigorous meta-analysis to systematically review and synthesise the evidence on the effects of retrieval practice for memory performance under acute stress. The work looks to be especially valuable for a) informing future research directions through a structured risk of bias evaluation, and b) generating theoretical developments through a range of confirmatory moderators (including stressor types, memory strategies, time of delay and task type). The findings of the planned analyses are expected to be of immediate interest to educational and occupational domains where memory recall is a priority.

 

The Stage 1 manuscript was evaluated over two rounds of in-depth review. Based on detailed responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 1 criteria and therefore awarded in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/pkrzb
 
Level of bias control achieved: Level 3. At least some data/evidence that will be used to the answer the research question has been previously accessed by the authors (e.g. downloaded or otherwise received), but the authors certify that they have not yet observed ANY part of the data/evidence.
 
List of eligible PCI RR-friendly journals:

 

 

 

1. Mihaylova, M., Kliegel, M, & Rothen, N. (2024). Does retrieval practice protect memory against stress? A meta-analysis. In principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/pkrzb

 

2. Moreira, B. F. T., Pinto, T. S. S., Starling, D. S. V., & Jaeger, A. (2019). Retrieval practice in classroom settings: A review of applied research. In Frontiers in Education (Vol. 4, p. 5). Frontiers Media SA. https://doi.org/10.3389/feduc.2019.00005 

 

3. Shields, G. S., Sazma, M. A., McCullough, A. M., & Yonelinas, A. P. (2017). The effects of acute stress on episodic memory: A meta-analysis and integrative review. Psychological Bulletin, 143, 636–675. https://doi.org/10.1037/bul0000100 

 

4. Topor, M. K., Pickering, J. S., Mendes, A. B., Bishop, D., Büttner, F., Elsherif, M. M., ... & Westwood, S. (2022). An integrative framework for planning and conducting Non-Intervention, Reproducible, and Open Systematic Reviews (NIRO-SR). Meta-Psychology. https://osf.io/preprints/metaarxiv/8gu5z

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

In neurostimulation research, the parameters of a stimulation protocol crucially impact on the effects of the stimulation. Transcranial direct current stimulation (tDCS) is a neurostimulation technique that typically uses current intensities about 1-2 mA in human research to modulate motor and cognitive behavior. The current sham-controlled study by Hsu et al. (2024) applies current intensities not only of 2 mA but also of 4 mA and 6 mA and thus extends our understanding of stimulation parameters while ethical standards are preserved.

 

The influence of tDCS over the primary motor cortex will be evaluated for neural plasticity during motor learning. Stimulation effects will be tested not only behaviorally but also physiologically by motor evoked potentials elicited by transcranial magnetic stimulation (TMS). The presented pilot data are promising and underline the feasibility of the proposed research design. The study will contribute to tDCS research by uncovering reasons for controversial findings and thus increase reproducibility.

 

The Stage 1 manuscript was evaluated over two rounds of in-depth review. Based on detailed responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 1 criteria and therefore awarded in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/jyuev
 
Level of bias control achieved: Level 2. At least some data/evidence that will be used to answer the research question has been accessed and partially observed by the authors, but the authors certify that they have not yet observed the key variables within the data that will be used to answer the research question.
 
List of eligible PCI RR-friendly journals:

 

• Brain and Neuroscience Advances
• Imaging Neuroscience
• NeuroImage: Reports
• Peer Community Journal
• PeerJ
• Royal Society Open Science
• Studia Psychologica

 

 

Hsu, G., Edwards, D. J., Cohen, L. G., & Parra, L. C. (2024). Dose-response of tDCS effects on motor learning and cortical excitability: a preregistered study. In principle acceptance of Version 1.3 by Peer Community in Registered Reports. https://osf.io/jyuev

How well animals may be able to cope with changes of habitat, specifically with rapid changes and thus novelty they encounter in an environment densely populated by humans, may be influenced by how they respond to novelty in general (Batisteli et al., 2022; Biondi et al., 2024; Castano et al., 2024; Heales et al., 2024). In considering this, it may be important to account for any difference in behavioural responses that animals exhibit when encountering a novel situation alone versus when they are doing so as part of a group.

 

Here, Allaert et al. (2025) tested how neophobia – the fear of unfamiliar objects – is affected by the social context in gulls, birds that are increasingly forced to live in urban environments due to the loss of natural coastlines. In this study, in which they reared herring gulls from egg and tested them taking into account that nestmates are not tested within the same groups, the authors found that the birds were faster to eat and spent more time in the zone of interest when they were tested in a group than when they were tested individually, specifically when a novel object was placed next to the food compared to when that object was a familiar one. The birds were also faster to enter the testing area when tested in a group, but this was not specific to the novel object condition. In addition to these changes in the average responses, the authors also report reduced variance when tested in a group in two of their three measures, namely in the latency to enter the testing area and time spent in the zone of interest.

 

The authors interpret their findings as being mostly in line with the ‘risk-dilution’ hypothesis, which is often considered in terms of predation risk (Krause & Buxton, 2002). They discuss possible reasons why other studies, with different species and different methodological setups, found support for alternative explanations.

 

The Stage 2 report was evaluated by the same two reviewers who had also reviewed the Stage 1 manuscript. In the revision, the authors focused on adding sex as a factor in their statistical models, which was the planned procedure for the statistical analyses in the Stage 1 report, and adding information regarding the problems encountered during testing and how these were handled. This specifically refers to the planned sample size (which the authors planned in the Stage 1 report taking into account both mortality and the fact that some birds would be not herring gulls but lesser black-backed gulls, which can only be established after hatching). However, there was higher than expected mortality, leading to a larger-than-planned overall reduction in sample size. During the study, the authors had contacted the recommender and discussed this issue, and the recommender advised on continuing the study and approved of the planned changes in the Stage 2 report. During the revision process, the authors added more information and also conducted an exploratory analysis, which included all birds, i.e. herring gulls and lesser black-backed gulls. This was suggested by a reviewer and the authors present this exploratory analysis in full in the supplemental material, while the main inferences are presented in the main text. In addition, during the Stage 2 review it became apparent that some minor details regarding the procedure would be useful to be included in the Stage 2 report, which the authors included in the Stage 2 revision. This did not alter the procedure as described in the Stage 1 report, but merely added more clarity to the text.

 

Based on detailed engagement with these points and the reviewers' comments, the recommender judged that the manuscript met the Stage 2 criteria and awarded a positive recommendation.

 

 
Level of bias control achieved: Level 6. No part of the data or evidence that was used to answer the research question was generated until after IPA.

 

 

• Peer Community Journal
• PeerJ
• Personality Science
• Royal Society Open Science

 

 

1. Allaert, R., Knoch, S., Braem, S., Debeer, D., Martel, A., Müller, W., Stienen, E., Lens, L., & Verbruggen, F. (2025). Neophobia across social contexts in juvenile Herring gulls [Stage 2]. Acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/b58ha

 

2. Batisteli, A. F., Pizo, M. A., & Sarmento, H. (2022). Female neophobia predicts the use of buildings as nesting sites in a Neotropical songbird. Animal Behaviour, 183, 151-157. https://doi.org/10.1016/j.anbehav.2021.11.008

 

3. Biondi, L. M., Medina, A., Bonetti, E. A., Paterlini, C. A., & Bó, M. S. (2024). Cognitive flexibility in a generalist raptor: a comparative analysis along an urbanization gradient. Behavioral Ecology, 35, arae025. https://doi.org/10.1093/beheco/arae025

 

4. Castano, M. V., Zumpano, F., Biondi, L. M., & García, G. O. (2024). Does urbanization affect behavioral responses to novel objects in marine birds? The Olrog’s Gull as a case of study. Urban Ecosystems, 27, 427-437. https://doi.org/10.1007/s11252-023-01465-2

 

5. Heales, H. E., Flood, N. J., Oud, M. D., Otter, K. A., & Reudink, M. W. (2024). Exploring differences in neophobia and anti-predator behaviour between urban and rural mountain chickadees. Journal of Urban Ecology, 10, juae01. https://doi.org/10.1093/jue/juae014

 

6. Krause, J. & Ruxton, G. (2002). Living in Groups. Oxford University Press, USA.

​​​Making causal judgements are part of everyday life, whether seeking to understand the action of complex humans or the relations between inanimate objects in our environments. Albert Michotte’s (1963) classic book, The perception of causality, contained an extensive report of experiments demonstrating not only that observers perceive causality of inanimate shapes, but do so in manifold ways, creating different “causal impressions.” This work has been highly influential across psychology and neuroscience.

 

In the current study, White (2023) proposes a series of experiments to replicate and extend Michotte’s work. Despite the fact that this research is foundational to current work on perception and understanding of causal relations, it has never been subjected to rigorous replication. Moreover, like many research studies from that era, Michotte was sparse on details about methodology and did not rely on statistical analysis. White has proposed an ambitious set of 14 experiments that directly replicate and, in some cases, extend Michotte’s experiments. 

 

The Stage 1 manuscript was evaluated over three rounds of in-depth review, the first two rounds consisting of detailed comments from two reviewers and the third round consisting of a close read by the recommender. Based on detailed responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 1 criteria and was therefore awarded in-principle acceptance (IPA). 

 

URL to the preregistered Stage 1 protocol: https://osf.io/5jx8f
 
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. Michotte, A. (1963). The perception of causality (T. R. Miles & E. Miles, trans.). London: Methuen. (English translation of Michotte, 1954).

 

2. White, P. A. (2023). Michotte's research on perceptual impressions of causality: A registered replication study. In principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/5jx8f