Much of how we use our perception involves judgements on how similar things are: You might vaguely recognise an actor's face in a movie but not immediately recognise where you have seen it before. Some people claim to be "bad with faces". Is that in fact based on objectively poorer ability to recognise faces? Psychophysical lab studies of perception typically use forced-choice discrimination tasks in which participants must make explicit, and usually binary, decisions. Such designs can yield parametric information about underlying perceptual processes, but it is very different from how we use perception in daily life.

 

Here, Moharramipour and colleagues (2024) seek to better understand the link between such subjective similarity jugdements and objective discrimination ability. They argue that subjective similarity can be considered a metacognitive process, reflecting the person's awareness of their perceptual capacity. Participants will be asked to discriminate face pairs across a spectrum of morphing steps in a classical forced-choice paradigm to estimate perceptual threshold performance, as well as provide subjective ratings of similarity of the face pairs. The researchers hypothesise a correlation between objective perceptual ability and subjective similarity judgements. They will evaluate this at the group level, and also use a resampling approach to determine the specificity of this relationship in individual participants. Confirming this hypothesis would advance our knowledge of how perceptual ability links with our metacognitive introspection of it. Are you really "bad with faces" or do you only think you are?

 

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 awarded in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/pzugy
 
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: 

 

 

Moharramipour, A., Zhou, W., Rahnev, D., & Lau, H. (2024). Is subjective perceptual similarity metacognitive? In principle acceptance of Version 4 by Peer Community in Registered Reports. https://osf.io/pzugy

Adverse environments involving threat, uncertainty, deprivation, and stress have been shown to have significant impacts on cognition and development. In this Stage 2 manuscript, Vermeent et al. (2024) adhere to their Stage 1 protocol, investigating the effects of adversity on working memory (WM) using a comprehensive, psychometric modeling approach. The authors aimed to clarify seemingly contradictory findings from previous research: The evidence for working memory capacity impairments in adverse environments versus the possibility that adversity might enhance specific aspects of WM, such as updating ability. Moreover, they examined the effects of distinct types of adversity—neighborhood threat, material deprivation, and unpredictability—on WM performance.

 

The results of the study were, overall, inconclusive: the authors did not find consistent associations between adversity and either WM capacity or WM updating ability. Despite using a large sample and employing latent variable modeling, the study did not reveal significant effects that were either clearly positive or negative for any type of adversity examined. In addition, no evidence for equivalence to zero associations was found. The lack of clear associations suggests that the relationship between adversity and WM is likely more complex than previously thought.

 

As with the Stage 1 evaluation, this manuscript has undergone a rigorous peer review process at Stage 2. The reviewers included specialists in child and youth cognitive development. The constructive feedback from the reviewers ensured that the pre-registered protocol was followed accurately, deviations were reported appropriately, and all concerns raised were addressed satisfactorily. These processes helped to refine Vermeent et al.'s methods and confirm that the planned analysis was followed. Despite the inconclusive results, this study makes a significant contribution to our understanding of the subtle effects of adversity on working memory by providing transparent and rigorous findings that add valuable data to the field. Therefore, I am fully confident that this manuscript is suitable for Stage 2 recommendation.

 

URL to the preregistered Stage 1 protocol: https://osf.io/dp7wc
 
Level of bias control achieved: Level 3. At least some data/evidence that was used to the answer the research question had been previously accessed by the authors (e.g. downloaded or otherwise received), but the authors certify that they had not yet observed ANY part of the data/evidence until after Stage 1 in-principle acceptance.
 
List of eligible PCI RR-friendly journals:
 

 

 

1. Vermeent, S., Schubert, A.-L., DeJoseph, M. L., Denissen, J. J. A, van Gelder, J.-L. & Frankenhuis, W. E. (2024). Inconclusive evidence for associations between adverse experiences in adulthood and working memory performance [Stage 2]. Acceptance of Version 3 by Peer Community in Registered Reports. https://github.com/StefanVermeent/liss_wm_profiles_2023/blob/master/manuscript/stage2_tracked.pdf

A growing body of research suggests that feelings of curiosity are associated with better memory for new information. However, while curiosity has been broadly defined as an instrinsic drive to obtain information, much of this existing work has focused on learning of trivia facts or factual information, settings where people have relatively little freedom to actively explore aspects of the environment that generate those feelings of curiosity. In this Stage 1 manuscript, O'Donoghue, Cen, and Gruber (2025) propose to conduct an experiment to examine whether feelings of curiosity promote the formation of cognitive maps when exploring novel spatial environments. Participants will encounter a series of virtual rooms for which they report their level of curiosity before exploring each room. The experiment will compare groups of participants who can actively explore for themselves vs. passive observers of the same exploration patterns. The proposed analyses will examine whether anticipatory curiosity leads to better memory for the spatial environments for both active or passive participants, or if benefits to memory are mediated by active participants' ability to act of their feelings of curiosity through their exploration of the environment. The findings of the study will provide new insight into the mechanisms through which anticipatory curiosity enhances memory.

 

The Stage 1 submission was evaluated by three expert reviewers. After three rounds of revision, the recommender determined that the manuscript met the Stage 1 criteria and awarded in-principle acceptance (IPA).

 

 

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.

 

 

 

 

1. O'Donoghue, E. M., Cen, D., & Gruber, M. (2025). Disentangling the Influences of Curiosity and Active Exploration on Cognitive Map Formation. In principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/86r3x

A poor diet has severe detrimental health effects, and attempts to reduce caloric intake often prove unsuccessful. Unhealthy foods, high in fat, sugar, and salt tend to be highly appetitive, and can undermine individuals’ ability to refrain themselves from consuming them. Computerized cognitive retraining techniques have shown promise in curbing the intake of unhealthy foods and promoting weight loss. However, in real-world scenarios, adherence to such retraining programs can be suboptimal, potentially diminishing their effectiveness.

 

In the present study, Maclellan et al. (2024) aimed to investigate whether the incorporation of gamified elements, transforming the cognitive retraining task into a game-like experience, can enhance adherence and overall intervention effectiveness by boosting engagement and motivation.

 

Upon testing the main hypotheses, the authors found mostly non-significant effects of adding gamified elements to adherence, motivation, or effectiveness of food response inhibition training programs. These results hold high relevance, as indeed there has been a push in introducing gamified elements to cognitive retraining programs. These findings should guide future developments in the field of cognitive retraining.

 

The Stage 2 manuscript was evaluated over one round of review and revision. Based on detailed evaluations by two expert reviewers, 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.
 
List of eligible PCI RR-friendly journals:
 

• Addiction Research & Theory
• Advances in Cognitive Psychology
• Collabra: Psychology
• Journal of Cognition
• Peer Community Journal
• PeerJ
• Royal Society Open Science
• Studia Psychologica
• Swiss Psychology Open
   

 

MacLellan, A., Pennington, C. R., Lawrence, N., Westwood, S. J., Jones, A., Slegrova, A., Sung, B., Parker, L., Relph, L., Miranda, J. O., Shakeel, M., Mouka, E., Lovejoy, C., Chung, C., Lash, S., Suhail, Y., Nag M., and Button​, K. S. (2024). The effects of isolated game elements on adherence rates in food response inhibition training​ [Stage 2]. Acceptance of Version 3 by Peer Community in Registered Reports.

Higher-level cognitive processes like attention, memory, or mental imagery can produce pupil responses, without any actual difference in luminance of the visual stimulus. Interestingly, the inverse scenario remained untested to date: when a physical luminance difference is perceptually eliminated from awareness, does pupil size still track attention to the stimulus? In this Registered Report, Vilotijević and Mathôt (2024) sought to test this experimentally using a perceptual fading phenomenon where two Gaussian patches with different luminances fade from consciousness and are thus perceived as mid-level uniform grey (or at least the subjective difference is much reduced). This fading manipulation, as well as a control condition without perceptual fading, were presented in separate blocks. Participants were instructed to covertly attend one of the patches.

The authors hypothesised that if pupil size reflects attentional selection, these pupil responses in the fading condition​ should be eliminated or at least reduced, and this should evolve with time as the stimuli are perceptually fading. Their results show that pupil responses during covert attention are indeed reduced during perceptual fading - but they are not eliminated. Interestingly, this reduction did not depend on time or self-reports of the strength of perceptual fading. The findings therefore suggest that pupil dilation tracks subjective brightness differences.

 

One inherent issue with experiments like these is that the experimental and control conditions necessarily involve a physical difference in the stimulus. Here, the fading condition had the same spatial configuration of light and dark stimuli throughout a block while in the control (non-fading) condition the light and dark stimuli alternated sides between trials. It is therefore impossible to completely rule out that the physical difference affects the results. However, the only alternative to this would be an experimental design in which the stimuli never change, but only the subjective perceptual state varies. Such a design is completely at the mercy of the participant's subjective state and therefore loses experimental control and statistical sensitivity. The present results confirmed the authors' prediction that there are indeed differences in overall pupil responses during the fading and control conditions, irrespective of covert attention.

 

Critically, the fact that the attention effect did not vary with time or subjective self-reports of the illusion supports the authors' interpretation that this reflects higher-level cognition: the mere act of attending to the dark side - even if the actual appearance has faded - could cause a sustained pupil dilation. This would be consistent with the type of pupil effects for memory and mental imagery that motivated the present study. However, a simpler alternative is that the experience of perceptual fading was incomplete (as possibly suggested by Figures 2D and 2F) but that self-reports fail to capture this subjective experience accurately. Perhaps a future study could compare the magnitude of the attentional pupil effects when the initial stimulus is completely removed. If similar differences in pupil response persist this would suggest that the present results are due to high-level modulation or the residual low-level luminance difference.

 

The Stage 2 manuscript was evaluated by two reviewers and the recommender over two rounds of review. One reviewer again advised additional robustness checks to rule out eye movement confounds, an issue they had already raised during Stage 1 review. The researchers provide clear evidence that this is unlikely to have confounded their findings. This has been added to the supplementary data repository. Following this review and revision, the recommender judged that the Stage 2 criteria were met and awarded a positive recommendation.

 

URL to the preregistered Stage 1 protocol: https://osf.io/bmtp6
 
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.
 
List of eligible PCI RR-friendly journals:

 

 

 

1. Vilotijević, A. & Mathôt, S. (2024). The effect of covert visual attention on pupil size during perceptual fading [Stage 2]. Acceptance of Version 2 by Peer Community in Registered Reports. https://osf.io/ku8qc?view_only=f331df53b50f431386fabba9e386b387