Recent studies indicate that the timing of food intake can significantly affect metabolism and weight management. Workers operating at atypical times of the 24-h day are at risk of disturbed feeding patterns. Given the increased risk of weight gain, obesity and metabolic syndrome in shift working populations, further research is required to understand whether their eating behavior could contribute to these increased metabolic risks. The objective of this study was to characterize the dietary patterns of police officers across different types of shifts in their natural environments. Thirty-one police officers (six women; aged 32.1 ± 5.4 years, mean ± SD) from the province of Quebec, Canada, participated in a 28- to 35-day study, comprising 9- to 12-h morning, evening, and night shifts alternating with rest days. Sleep and work patterns were recorded with actigraphy and diaries. For at least 24 h during each type of work day and rest day, participants logged nutrient intake by timestamped photographs on smartphones. Macronutrient composition and caloric content were estimated by registered dieticians using the Nutrition Data System for Research database. Data were analyzed with linear mixed effects models and circular ANOVA. More calories were consumed relative to individual metabolic requirements on rest days than both evening- and night-shift days (p = 0.001), largely sourced from increased fat (p = 0.004) and carbohydrate (trend, p = 0.064) intake. Regardless, the proportions of calories from carbohydrates, fat, and protein did not differ significantly between days. More calories were consumed during the night, between 2300 h and 0600 h, on night-shift days than any other days (p < 0.001). Caloric intake occurred significantly later for night-shift days (2308 h ± 0114 h, circular mean ± SD) than for rest days (1525 h ± 0029 h; p < 0.01) and was dispersed across a longer eating window (13.9 h ± 3.1 h vs. 11.3 h ± 1.8 h, mean ± SD). As macronutrient proportions were similar and caloric intake was lower, the finding of later meals times on night-shift days versus rest days is consistent with emerging hypotheses that implicate the biological timing of food intake—rather than its quantity or composition—as the differentiating dietary factor in shift worker health.

Shift work, an essential part of our 24/7 society, inevitably leads to displacement of the habitual sleep period and thereby to misalignment of the internal circadian timing system with the rest–activity cycle and the environment. How interindividual differences in circadian organization affect sleep duration and timing during rotating shift work is not fully understood. The objective of this study was to assess the effect of chronotype, shift type, and their interaction on actigraphy-based sleep behavior in 74 police officers (20 women and 54 men; age [mean ± SD]: 32.1 ± 5.4 years) involved in rotating shift work throughout a 28- to 35-day work cycle consisting of morning, evening, and night shifts. Using linear mixed modeling, we found that chronotype was associated with sleep duration depending on the shift type: increasing morningness was correlated with longer sleep duration during series of consecutive morning shifts, while increasing eveningness was correlated with longer sleep duration during series of evening shifts. During series of night shifts, increasing eveningness was associated with a longer duration of the main sleep episode, but this relationship was attenuated and no longer significant when naps were taken into account due to increased napping in morning chronotypes during series of night shifts. Providing a detailed within-subject characterization of sleep behavior across a complete work cycle consisting of morning, evening, and night shifts, this study advances the understanding of the relationship between chronotype and sleep in rotating shift workers and supports the implementation of work schedules that take into account chronobiological principles.

Study Objectives: This exploratory study assessed the impact of sex and hormonal contraceptives (HC) use on the homeostatic and diurnal variation of alertness, fatigue, sleepiness, psychomotor performance, and sleep behavior in police officers working rotating shifts.Methods: A total of 56 men and 20 women (6 using, 11 not using, and 3 with unknown use of HC) participated in an observational study throughout a month-long work cycle. Participants wore an actigraph, filled out a sleep and work log, answered questionnaires (Samn-Perelli, KSS, Visual Analogue Scales), and completed 5-min Psychomotor Vigilance Tasks (PVT) according to an ecological momentary assessment approach. Linear mixed-effects models were used to analyze the effects of group (men, women, and HC use), time awake, and time of day on the dependent variables.Results: Self-reported parameters and performance significantly varied with time awake and time of day. Women were more fatigued and sleepier than men, when considering both time awake and time of day. Compared to men, women using HC were more fatigued, less alert, and sleepier. Women had less attention lapses than men after 7 and 17 h awake, although no main effect of HC was detected.Conclusions: Women tended to rate themselves as more fatigued than men, especially when using HC. Surprisingly, psychomotor performances of women were sometimes better than those of men. This exploratory study indicates that sex and HC are important factors to consider in occupational medicine.

Schizophrenia is characterized by disturbances in both perception and expression that profoundly impair social functioning, yet these domains are typically studied in isolation. Predictive processing theories suggest that such symptoms may arise from abnormal updating of internal models, but the neural mechanisms linking perceptual and expressive dysfunction remain unclear. Using magnetoencephalography during multisensory perception and motor tasks, we tested whether beta-band activity (15-30 Hz), a neural signal implicated in predictive control, provides a shared substrate across domains. Compared to healthy individuals, patients with schizophrenia showed attenuated event-related modulation of beta activity, including weaker beta suppression during sensory processing and delayed or reduced post-movement beta rebound. These abnormalities were associated with a widened audiovisual temporal binding window, indicating atypical multisensory integration. Multivariate analyses further revealed that reduced beta modulation across sensory and motor systems covaried with impoverished semantic diversity, simplified syntactic structure in natural speech, and greater clinical symptom burden. Notably, beta abnormalities emerged as distributed latent patterns spanning sensory, motor, and frontotemporal regions. Together, these findings identify diminished event-related beta modulation as a common neural signature linking disrupted multisensory integration, action monitoring, and language organization in schizophrenia. We situate perceptual and expressive impairments within a unified framework of predictive dysfunction and advance a mechanistically grounded account that highlights beta dynamics as a promising target for future mechanistic and translational studies in psychosis. Significance Statement: Schizophrenia disrupts both how people perceive the world and how they express their thoughts, yet these symptoms are usually studied separately. Using magnetoencephalography during multisensory and motor tasks, we identify a shared neural mechanism linking these domains: reduced event-related modulation of beta-band (15–30 Hz) activity, a signal implicated in predictive control. Compared to healthy individuals, patients showed diminished beta changes during sensory processing and movement completion, suggesting reduced flexibility in updating internal models. Importantly, this neural pattern covaried with abnormal audiovisual binding, disorganized natural speech, and greater clinical severity. These findings reveal distributed beta modulation as a cross-domain neural marker of predictive dysfunction, offering a unified framework for understanding perceptual and expressive disturbances in schizophrenia.

Schizophrenia, major depressive disorder (MDD), and bipolar disorder (Severe Mental Illnesses: SMIs), share genetic risk and brain structure, but their neural mechanisms remain unclear. Magnetoencephalography (MEG), with millisecond precision, enables direct examination of shared and disorder-specific disturbances in neural timing. We reviewed resting-state MEG evidence on spectral power, connectivity, information-theoretic complexity, and brain dynamics across SMIs.A comprehensive search yielded 62 studies. Three reviewers screened, retrieved, and extracted data on MEG-related variables across regional activity (power), coordination of activity (connectivity, coherence, synchrony), regularity of activity (complexity, entropy), and overall dynamics.Three principal findings emerged. Beta oscillations emerge as the most consistently replicated transdiagnostic signal across separate disorder-specific studies, with increased power across all three disorders and correlating with hallucinations, sleep disturbances, and cognitive deficits, consistent with disrupted predictive processing. Preliminary evidence emerges that complexity–age dissociation may partition SMIs into neuroprogressive and state-dependent trajectories: neural complexity declines with age in schizophrenia and bipolar disorder (opposite to healthy aging), while depression preserves the normative trajectory. Slow-wave activity diverges sharply: schizophrenia shows a widespread increase characteristic of cortical ‘idling,’ while mood disorders show a decrease characteristic of ‘restlessness.’We propose a temporal disorganisation spectrum from excessive fragmentation (schizophrenia) to pathological rigidity (depression), with bipolar disorder occupying an intermediate position. This framework offers biomarker-type utility for stratifying illness severity, tracking neuroprogression, and identifying transdiagnostic therapeutic targets, particularly beta-modulatory neuromodulation interventions applicable across SMIs.