COVID-19 has been suspected to have long-lasting effects on cognitive function. The SARS-CoV-2 virus may enter the central nervous system (Frontera et al., 2020; Miners, Kehoe, & Love, 2020), explaining the observed detrimental effects of COVID-19 on verbal planning and reasoning (Hampshire et al., 2021; Wild et al., 2021), executive function (Hadad et al., 2022), and long-term memory (Guo et al., 2022). In particular, Guo et al. (2022) used verbal item recognition and non-verbal associative memory tasks. Weinerova et al. (2024), in the current study, propose to conduct a replication of Guo et al. (2022), but specifically, to disentangle the effect of COVID-19 infection status on both memory type (item vs. associative) and stimulus modality (verbal vs. non-verbal). Furthermore, Weinerova et al. (2024) propose to analyze cognitive function based on vaccination status before infection to provide a critical test of the potential protective effects of vaccination on cognitive function.

Data collection has been completed with 325 participants after exclusion criteria were applied (COVID group N = 232, No COVID group N = 93). Simulations assuming an effect size observed in Guo et al. (2022), a Bayesian t-test comparing the groups, and a Bayes Factor of 6 indicated that N = 320 is sufficient to detect an effect on 79% of simulations. The main analyses will be conducted using a Bayesian ANCOVA that allows for the inclusion of control variables such as age, sex, country, and education level. Both accuracy and reaction times from the item and associative recognition tasks will be analyzed as the dependent variables. In one analysis, vaccination status will be included as a between-subjects factor, to understand whether vaccination status at the time of infection influences subsequent cognitive function. 

It is important to note that participants were recruited through long-COVID Facebook groups and clinics. Therefore, the results must be interpreted carefully to avoid generalizing to all COVID-19 infections. The data are part of a larger longitudinal study, and the current pre-registration applies only to the baseline timepoint for a cross-sectional analysis. The remaining longitudinal data collection is ongoing and is not part of the current pre-registration.  

The study plan was refined after one round of review, with input from three external reviewers who all agreed that the proposed study was well-designed and scientifically valid. The recommender then reviewed the revised manuscript and judged that the study met the Stage 1 criteria for in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/tjs5u (under temporary private embargo)
 
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. Frontera, J., Mainali, S., Fink, E.L. et al. Global Consortium Study of Neurological Dysfunction in COVID-19 (GCS-NeuroCOVID): Study Design and Rationale. Neurocrit Care 33, 25–34 (2020). https://doi.org/10.1007/s12028-020-00995-3

2. Guo, P., Benito Ballesteros, A., Yeung, S. P., Liu, R., Saha, A., Curtis, L., Kaser, M., Haggard, M. P. & Cheke, L. G. (2022). COVCOG 2: Cognitive and Memory Deficits in Long COVID: A Second Publication From the COVID and Cognition Study. Frontiers in Aging Neuroscience. https://doi.org/10.3389/fnagi.2022.804937  

3. Hadad, R., Khoury, J., Stanger, C., Fisher, T., Schneer, S., Ben-Hayun, R., Possin, K., Valcour, V., Aharon-Peretz, J. & Adir, Y. (2022). Cognitive dysfunction following COVID-19 infection. Journal of NeuroVirology, 28(3), 430–437. https://doi.org/10.1007/s13365-022-01079-y  

4. Hampshire, A., Trender, W., Chamberlain, S. R., Jolly, A. E., Grant, J. E., Patrick, F., Mazibuko, N., Williams, S. C., Barnby, J. M., Hellyer, P. & Mehta, M. A. (2021). Cognitive deficits in people who have recovered from COVID-19. EClinicalMedicine, 39, 101044. https://doi.org/10.1016/j.eclinm.2021.101044

5. Miners, S., Kehoe, P. G., & Love, S. (2020). Cognitive impact of COVID-19: looking beyond the short term. Alzheimer's research & therapy, 12, 1-16. https://doi.org/10.1186/s13195-020-00744-w 

 

6. Weinerova, J., Yeung, S., Guo, P., Yau, A., Horne, C., Ghinn, M., Curtis, L., Adlard, F., Bhagat, V., Zhang, S., Kaser, M., Bozic, M., Schluppeck, D., Reid, A., Tibon, R. & Cheke, L. G. (2024). Changes in memory function in adults following SARS-CoV-2 infection: findings from the Covid and Cognition online study. In principle acceptance of Version 2 by Peer Community in Registered Reports. https://osf.io/tjs5u

7. Wild, C. J., Norton, L., Menon, D. K., Ripsman, D. A., Swartz, R. H. & Owen, A. M. (2022). Disentangling the cognitive, physical, and mental health sequelae of COVID-19. Cell Reports Medicine, 3, 100750. https://doi.org/10.1016/j.xcrm.2022.100750