Sleep and reward each have an important role in human memory. According to the active system consolidation hypothesis, memory consolidation during sleep originates from the repeated reactivation of memory representations that were encoded during wake (Rasch & Born, 2013). Research has also consistently shown that memory performance is enhanced for items or stimuli associated with higher vs. lower rewards. While these lines of evidence are relatively clear, the role of sleep in shaping the interaction between reward and memory is more opaque, likely due to a combination of methodological variation between studies but also due to the field’s reliance on small-N designs and biased reporting practices. Clarifying this three-way relationship, and setting field benchmarks for effect sizes, is crucial not only for building richer neurocognitive models of memory, but for clinical applications such as targeted sleep interventions to treat addiction and other forms of mental illness. 

 

Using a large, stratified online German sample (N=1750), Morgan et al. (2022) will study the three-way relationship between sleep, reward and memory by asking whether, and if so how, reward influences the magnitude of sleep-dependent memory consolidation. Using an AM:PM-PM:AM design in combination with a motivated learning task, the authors will address three main questions: first, whether sleep yields greater memory performance compared to an equivalent period of wake; second whether information associated with higher reward leads to greater memory performance compared to lower reward; and third, the crucial interaction of whether sleep causes greater recognition memory performance for higher vs. lower reward items. The design also includes a series of rigorous positive controls to confirm testability of the hypotheses, while measuring a host of additional moderating variables for exploratory analyses (including age, education status, mental health, and more).

 

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/q5pk8
 
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. Rasch, B. & Born, J. (2013). About Sleep's Role in Memory. Physiological Revews, 93, 681–766. https://doi.org/10.1152%2Fphysrev.00032.2012

 

2. Morgan, D. P., Nagel, J., Cagatay Gürsoy, N., Kern, S. & Feld, G. B. (2022). Estimating the effect of reward on sleep-dependent memory consolidation – A Registered Report, in principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/q5pk8

Infant-directed speech (IDS) – colloquially known as “baby talk” – is a form of speech produced by parents that may be important for emotional bonding with children while also helping infants with early language development. In contrast to adult-directed speech (ADS), IDS is characterised by a higher and broader pitch range, slower speech rate, and shorter/simpler syntax. A significant body of research has studied the dynamics of IDS and shown that infants prefer IDS over ADS, however the great majority of this work has focused on maternal speech, leaving much to be discovered about the differences and similarities between paternal and maternal IDS, the relative preference infants exhibit for paternal IDS compared with ADS, and the role of paternal interaction in shaping these dynamics.

 

Using a Norwegian sample of 70 fathers and children, the proposed study by Robberstad et al. (2022) takes an important step into this less-explored domain, asking whether (and if so, how) fathers employ IDS when interacting with infants, whether any such modulation of speech is related to the amount of time they spend as a caregiver, whether infants show the same preferences for IDS over ADS in fathers as observed previously in mothers, and whether that preference is related to the amount of exposure the infant has to parental speech. The authors will analyse speech modulation using acoustic analysis, while preference for IDS will be tested using eye-tracking to measure infants’ overt gaze orientation while listening to IDS vs ADS.

 

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/c43xu
 
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. Robberstad, S., Kartushina, N. & Mayor, J. (2022). Fathers learning on the job: Role of paternity leave duration on paternal infant-directed speech and preference for male infant-directed speech in infants, in principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/sjupt

Recent studies have revealed potential benefits of unconditional cash transfers (UCTs) on a variety of health and social outcomes, including self-reported happiness and life satisfaction (Haushofer & Shapiro, 2016), economic and financial well-being (Blattman et al., 2013; Baird et al., 2018) and educational attainment (Baird et al., 2016). Although the effects of UCTs do not always out-perform rigorous control conditions (Whillans & West, 2022), these findings prompt the question of whether the alleviation of poverty via UCTs can also influence cognitive processing and performance.

 

In the current study, Szaszi et al. analysed the results of a previous randomised trial of UCTs by Blattman et al. (2017) to test whether a $200 lump sum – equivalent to three months of income – administered to a sample of young men in Liberia carries both short- and long-term benefits for a range of executive functions, including attention, response inhibition, and working memory capacity. Overall, the results suggest minimal if any consequences of the intervention – the observed effects of UCTs on cognition were several times smaller than suggested by previous research, and the evidence for a positive effect was inconclusive. Extensive multiverse analyses showed that these findings were robust to a range of alternative analytical specifications, and the authors estimate that a sample size of nearly 5000 would be required to provide strong evidence.

 

In their Discussion, the authors explore a range of reasons for the negative findings compared with previous research, including the more rigorous and severe causal test enabled by the randomised trial design, the demographic homogeneity of the sample demographic, the use of pen-and-paper tests (cf. computerised tests in previous studies), and the delivery of a lump-sum cash transfer compared with a regular monthly installment. In addition, although the results were negative or inconclusive, there were hints that a positive effect of UCTs may be more evident in some cognitive domains than in others – in this case, potentially benefiting working memory more than inhibitory control. Further research would be required to confirm this hypothesis.

 

The Stage 2 manuscript was evaluated over one round of in-depth review. Based on the responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 2 criteria and awarded a positive recommendation.

 

URL to the preregistered Stage 1 protocol: https://osf.io/k56yv

 

Level of bias control achieved: Level 2. At least some data/evidence that was used to answer the research question had been accessed and partially observed by the authors prior to Stage 1 acceptance, but the authors certified that they had not yet observed the key variables within the data that would be used to answer the research question AND they took additional steps to maximise bias control and rigour.

 

 

 

 

1. Haushofer, J. & Shapiro, J.  (2016). The short-term impact of unconditional cash transfers to the poor: Experimental evidence from Kenya. Quarterly Journal of Economics, 13, 1973–2042. https://doi.org/10.1093/qje/qjw025

 

2. Blattman, C., Fiala, N. & Martinez, S. (2013) Generating skilled self-employment in developing countries: Experimental evidence from Uganda. Quarterly Journal of Economics, 129, 697–752. https://doi.org/10.1093/qje/qjt057

 

3. Baird, S., McKenzie, D., & Özler, B. (2018). The effects of cash transfers on adult labor market outcomes. IZA Journal of Development and Migration, 8, 1-20. https://doi.org/10.1186/s40176-018-0131-9

 

4. Baird, S., Chirwa, E., De Hoop, J., & Özler, B. (2016). Girl power: cash transfers and adolescent welfare: evidence from a cluster-randomized experiment in Malawi. In African Successes, Volume II: Human Capital (pp. 139-164). University of Chicago Press. https://www.nber.org/system/files/chapters/c13380/c13380.pdf

 

5. Whillans, A., & West, C. (2022). Alleviating time poverty among the working poor: A pre-registered longitudinal field experiment. Scientific Reports, 12(1), 1-17. https://doi.org/10.1038/s41598-021-04352-y

 

6. Blattman, C., Jamison, J. C. & Sheridan, M. (2017). Reducing crime and violence: Experimental evidence from cognitive behavioral therapy in Liberia. American Economic Review, 107, 1165–1206. http://doi.org/10.1257/aer.20150503

 

7. Szaszi, B., Palfi, B., Neszveda, G., Taka, A., Szecsi, P., Blattman, C., Jamison, J. C., & Sheridan, M. (2022). Does alleviating poverty increase cognitive performance? Short- and long-term evidence from a randomized controlled trial. Stage 2 Registered Report, acceptance of Version 2 by Peer Community in Registered Reports. https://psyarxiv.com/4gyzh

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