Competitive speedcubing - the timed solving of Rubik's Cube puzzles under standardised World Cube Association (WCA) rules - uniquely couples rapid visuospatial processing and working memory with high-speed bimanual fine motor execution, making it a tractable paradigm for investigating time-of-day associations in real-world expert cognitive-motor performance. We analysed 6,600 record-setting performances across four puzzle categories (3 × 3 × 3, 4 × 4 × 4, 5 × 5 × 5, 6 × 6 × 6) from WCA competitions held between 2003 and 2025 using an exposure-adjusted framework in which record probability is expressed as records per attempt within 15-minute local-time bins, evaluated against a within-competition permutation null that preserves schedule structure. Raw record counts exhibit a bimodal distribution with morning and evening peaks; however, exposure adjustment demonstrates that this pattern is substantially attributable to the non-uniform scheduling of competition rounds across the day. After schedule correction, the 4 × 4 × 4 event shows a statistically significant suppression of record probability during the 12:30-15:00 window (outside-to-inside ratio: 1.14×; one-tailed permutation p = 0.020), consistent in timing with the post-prandial alertness dip. This effect is not statistically significant for the 3 × 3 × 3, 5 × 5 × 5, or 6 × 6 × 6 events. Sensitivity analyses confirm that the 4 × 4 × 4 finding is broadly distributed across regions and competitive eras and persists within early rounds alone. The late-evening elevation in raw counts is explained by final-round competitor selection. These results demonstrate the methodological importance of exposure adjustment in ecological performance analyses and identify a residual midday suppression in 4 × 4 × 4 record probability that warrants further investigation.
Introduction:Sleep plays a vital role in maintaining overall health, supporting processes like restoration, memory consolidation, emotional regulation, and metabolism. However, many people remain unaware of their sleep needs, leading to poor sleep quality and patterns that can negatively impact health, workplace performance, and daily life. Sleep behaviors are shaped by various factors, including cultural practices, urbanization, and lifestyle changes. This study focuses on adults in Karachi, Pakistan, where religious routines and modern living create unique sleep challenges. By exploring these patterns, we aim to identify ways to enhance sleep quality and promote better well-being in this population. Methodology:This cross-sectional study was conducted in Karachi, Pakistan, over one year, with 400 adults aged 18-64 were recruited. Exclusion criteria included conditions affecting sleep, chronic illnesses, and use of sleep aids. Data collection employed a Google Forms-based structured questionnaire covering demographics, religious practices, and sleep habits. Sleep quality and daytime sleepiness were assessed using the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS), respectively. Data analysis, performed in SPSS, included descriptive statistics and hypothesis testing using Chi-squared, Mann-Whitney, and Kruskal-Wallis tests. Sleep patterns were categorized as monophasic, biphasic, or polyphasic using conditional formulas in Excel. Results:The mean age of participants (n = 384) was 29 ± 0.1 years, with 66.4% women. The most common sleep pattern was monophasic (40.4%), followed by biphasic-siesta (21.6%), biphasic-dawn (20.8%), and polyphasic (17.2%). Women favored segmented sleep patterns (p = 0.019). Biphasic-dawn sleepers reported the least daytime sleepiness (ESS = 7.18 ± 3.85, p = 0.024), while biphasic-siesta sleepers had the poorest sleep quality (PSQI = 6.94 ± 3.01, p = 0.013). Men had better sleep quality (PSQI = 5.22 ± 2.70) and lower daytime sleepiness (ESS = 6.89 ± 3.65) than women (p < 0.001). Weekend sleep disruptions were significant (p < 0.001). Conclusions:Monophasic sleep dominates, though gender differences suggest women prefer segmented patterns. Biphasic-dawn sleep aligns with better quality and less daytime sleepiness, while biphasic-siesta sleepers experience the poorest outcomes. Men and employed individuals generally report better sleep metrics. Morning prayers improve sleep quality slightly. Students exhibit higher daytime sleepiness and worse sleep quality compared to others.
The hypothalamic suprachiasmatic nucleus (SCN), the circadian pacemaker of the mammalian brain, integrates both environmental and endogenous information to modulate various physiological and behavioral processes. Both light and physical activity entrain SCN circadian rhythmicity, but the underlying molecular mechanisms for physical activity remain elusive. Repetitive neuronal stimulation results in accumulation of the stable transcription factor ΔFOSB, that has been implicated in long-term brain plasticity, altered neuronal excitability, and changes in behavior. In rodents, voluntary wheel running (VWR) mimics aspects of exercise training and increases ΔFOSB in several brain regions. Whether VWR also alters ΔFOSB in the SCN is unexplored. Here, young-adult male and female Wistar rats were housed sedentary or allowed to run for four weeks followed by quantification of ΔFOSB in the SCN. VWR lowered SCN ΔFOSB-positive cell numbers in males and females compared to sedentary housing. Total running distance did not correlate with ΔFOSB suppression. Analysis taking estrous cycle into account revealed that ΔFOSB-positive cell numbers were cyclic in sedentary females, being lowest during proestrus and highest during diestrus. Remarkably, this cyclicity was absent in runners, where ΔFOSB-positive cell numbers remained comparable to those observed during proestrus in sedentary controls. Finally, estradiol replacement following ovariectomy in sedentary females lowered SCN ΔFOSB-positive cell numbers. Thus, VWR and estrous cycle, via, at least in part, estradiol, modulate SCN ΔFOSB. Given its role in long-term plasticity and behavioral adaptations, ΔFOSB may provide a molecular link between VWR and/or estrous cycle and the output of the SCN and its related behavioral adaptations.
Introduction:Circadian processes may be causal in the development and maintenance of binge eating. We used a rodent model of binge-like eating and a circadian disruption protocol to test whether circadian disruption causes increased consumption during 24h access to a high energy diet (HED). Method:Eight male mice underwent a two-week baseline with ad-lib standard chow and maintained a 12h light-dark schedule. Mice then completed two binge cycles. After, mice received a circadian disruption manipulation or remained on typical light schedule (i.e., were non-circadian disrupted). All mice received two binge cycles after manipulation. Chow and HED were measured every 12h and 24h. Independent samples t-tests compared consumption between the disrupted and non-disrupted groups. Results:Binge-like eating occurred in both experimental groups across all phases of the study. Circadian disrupted mice consumed more during HED access than non-disrupted mice, indicating that circadian disruptions may exacerbate binge-like eating. Circadian disruption also altered consumption timing; disrupted mice consumed more during typical rest hours (7:00-19:00) than non-disrupted mice but did not alter consumption during typical active hours (19:00-7:00). Conclusions:These results provide justification for research examining circadian processes implicated in binge eating. Future research may inform on the utility of circadian regulating adjunctive treatment (e.g., bright light therapy or exercise).
Morningness is associated with several positive health outcomes and personality traits such as conscientiousness. In the current report, meta-analysis demonstrated a significant association between morningness and conscientiousness, data that are consistent with previous meta-analyses. Further, survey report and resting-state functional Magnetic Resonance Imaging (rs-fMRI, N = 43) indicated that the relationship between morningness and conscientiousness was moderated by functional connectivity with the Default Mode Network (DMN). DMN connectivity has been implicated in a number of cognitive functions and higher connectivity in this network is associated with higher conscientiousness.
