Increased waste clearance in the brain is thought to occur most readily during deep sleep (stage N3). Sleep deprivation disrupts time spent in deeper sleep stages, fragmenting the clearance process. Here, we have utilized the publicly available Stockholm Sleepy Brain Study to investigate whether various sleep-related measures are associated with changes in perivascular space (PVS) volume fraction following a late-night short-sleep experiment. The study sample consisted of 60 participants divided into old (65–75 years) and young (20–30 years) age groups. We found that partial sleep deprivation was not significantly associated with major PVS changes. In our centrum semiovale models, we observed an interaction between percentage of total sleep time spent in N3 and sleep deprivation status on PVS volume fraction. In our basal ganglia models, we saw an interaction between N2 (both percentage of total sleep time and absolute time in minutes) and sleep deprivation status. However, the significance of these findings did not survive multiple comparisons corrections. This work highlights the need for future longitudinal studies of PVS and sleep, allowing for quantification of within-subject morphological changes occurring in PVS due to patterns of poor sleep. Our findings here provide insight on the impact that a single night of late-night short-sleep has on the perivascular waste clearance system.

Marsh et al. (Educational Psychology Review, 36(2), 53, 2024) recently reported associations between academic achievement and self-concept (i.e., self-perceived academic competence). Marsh et al. claimed that their analyses supported a reciprocal effects model, according to which academic achievement and self-concept reinforce one another. Marsh et al. (Educational Psychology Review, 36(2), 53, 2024) further recommended to test alternative models and juxtapose their results and interpretations. Here, we followed this recommendation and tested different models using data simulated to resemble the data they used. However, contrary to Marsh et al. (Educational Psychology Review, 36(2), 53, 2024), in the present analyses we found contradictory positive, negative, and null effects between within-individual math self-concept and subsequent change in within-individual math achievement and vice versa. This suggests that the findings by Marsh et al. (Educational Psychology Review, 36(2), 53, 2024) may have been spurious and that the reciprocal effects model can be challenged.

Objectives: To systematically evaluate timely reporting of clinical trial results at medical universities and university hospitals in the Nordic countries. Study Design and Setting: In this cross-sectional study, we included trials (regardless of intervention) registered in the European Union (EU) Clinical Trials Registry and/or ClinicalTrials.gov, completed 2016–2019 and led by a university with medical faculty or university hospital in Denmark, Finland, Iceland, Norway, or Sweden. We identified summary results posted at the trial registries and conducted systematic manual searches for results publications (eg, journal articles, preprints). We present proportions with 95% confidence intervals (CI) and medians with interquartile range (IQR). Protocol: https://osf.io/wua3r. Results: Among 2112 included clinical trials, 1650 (78.1%, 95% CI 76.3%–79.8%) reported any results during our follow-up; 1097 (51.9%, 95% CI 49.8%-54.1%) reported any results within 2 years of the global completion date; and 48 (2.3%, 95% CI 1.7%–3.0%) posted summary results in the registry within 1 year. The median time from global completion date to results reporting was 690 days (IQR 1103). 856/1681 (50.9%) of ClinicalTrials.gov registrations were prospective. Denmark contributed approximately half of all trials. Reporting performance varied widely between institutions. Conclusion: Missing and delayed results reporting of academically led clinical trials are a pervasive problem in the Nordic countries. We relied on trial registry information, which can be incomplete. Institutions, funders, and policymakers need to support trial teams, ensure regulation adherence, and secure trial reporting before results are permanently lost. Plain Language Summary: Reporting of results from clinical trials is necessary for evidence-based clinical decision-making. We followed up reporting of clinical trials in the Nordic countries sponsored by medical universities and university hospitals. Of 2112 studies completed 2016–2019 in two major trials registries, about half reported results in any form within 24 months, and more than one in five did not report results at all. These results show that there is a need for improvement in the reporting of Nordic clinical trials.

The effect of higher education on intelligence has been examined using longitudinal data. Typically, these studies reveal a positive effect, approximately 1 IQ point per year of higher education, particularly when pre-education intelligence is considered as a covariate in the analyses. However, such covariate adjustment is known to yield positively biased results if the covariate has measurement errors and is correlated with the predictor. Simultaneously, a negative bias may emerge if the intelligence measure after higher education has non-classical measurement errors as in data from the 1970 British Cohort Study that were used in a previous study of the effect of higher education. In response, we have devised an estimation method that used iterated simulations to account for both classical measurement errors in the covariate and non-classical errors in the dependent variable. Upon applying this method in a reanalysis of the data from the 1970 British Cohort Study, we find that the estimated effect of higher education diminishes to 0.4 IQ points per year. Additionally, our findings suggest that the impact of higher education is somewhat more pronounced in the initial 2 years of higher education, aligning with the notion of diminishing marginal cognitive benefits.

Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions’ effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior—several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people’s initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors.

Introduction: Loss of empathy is a core symptom of behavioral variant frontotemporal dementia (bvFTD). In particular, the affective aspect of empathy appears to be independent of decrease in the other socioemotional abilities and general cognition in bvFTD. We used an established functional magnetic resonance imaging (MRI) paradigm to assess bvFTD-related alterations in brain responses during empathy for pain (EFP) in a case-control study.

Recent studies found positive effects of breastfeeding on the child’s cognitive ability and educational outcomes even when adjusting for maternal cognitive ability in addition to a large number of other potential confounders. The authors claimed an important role of breastfeeding for the child’s cognitive scores. However, it is well known that error in the measurement of confounders can leave room for residual confounding. In the present reanalyses, we found incongruent effects indicating simultaneous increasing and decreasing effects of breastfeeding on the child’s cognitive ability and educational outcomes. We conclude that findings in the reanalyses may have been due to residual confounding due to error in the measurement of maternal cognitive ability. Consequently, it appears premature to assume a genuine increasing effect of breastfeeding on the child’s cognitive ability and educational outcomes and claims in this regard may be challenged.

The ongoing reproducibility crisis in psychology and cognitive neuroscience has sparked increasing calls to re-evaluate and reshape scientific culture and practices. Heeding those calls, we have recently launched the EEGManyPipelines project as a means to assess the robustness of EEG research in naturalistic conditions and experiment with an alternative model of conducting scientific research. One hundred sixty-eight analyst teams, encompassing 396 individual researchers from 37 countries, independently analyzed the same unpublished, representative EEG data set to test the same set of predefined hypotheses and then provided their analysis pipelines and reported outcomes. Here, we lay out how large-scale scientific projects can be set up in a grassroots, community-driven manner without a central organizing laboratory. We explain our recruitment strategy, our guidance for analysts, the eventual outputs of this project, and how it might have a lasting impact on the field.

Exhaustion disorder (ED) was introduced to the Swedish version of the International Classification of Diseases, 10th edition (ICD-10) 2005. Primarily characterized by general fatigue and cognitive deficits, ED has become one of the most common mental health diagnoses in Sweden. Little is still known regarding the discriminative validity of the ED diagnosis and how it relates to other diagnostic constructs. The study aimed to investigate the discriminative validity of ED compared with two similar diagnoses, major depressive disorder (MDD) and adjustment disorder (AD). Using data from a sample of patients with a principal diagnosis of either ED (n = 352), MDD (n = 99), or AD (n = 302), we compared demographic and clinical variables and scores on self-report symptom scales. Results showed that ED patients were of a higher age and had a higher frequency of sickness absence than MDD and AD patients. There was a substantial overlap of symptoms between ED and MDD, only differing on two of nine self-report symptom scales, with ED patients rating lower work ability d = −0.37 and alcohol consumption d = −0.57. Compared with AD patients, ED patients reported more severe symptoms in every symptom domain. Given the prevalent use of ED diagnosis, its diagnostic validity and clinical usefulness merit further attention.

A recent meta-analysis claimed to provide evidence that academic self-concept and achievement have reciprocal prospective effects on each other (reciprocal effects model). However, prospective effects were estimated while adjusting for a prior measurement of the outcome, and this method is susceptible to spurious findings due to correlations with residuals and regression to the mean. Here we re-analyze the meta-analytic effects and show that different plausible models can support opposing claims: either that self-concept had an increasing or a decreasing effect on achievement, and vice versa. Consequently, claims beyond a positive cross-sectional correlation between academic self-concept and achievement, including the reciprocal effects model, can be questioned. The findings were validated by analyses of simulated data, which indicated that true prospective effects were not necessary for the observed meta-analytic associations. We further propose the extended skill development model (ESDM) as a more parsimonious alternative to the reciprocal effects model.