ABSTRACT
The effects of a delayed school start time by one hour were examined at a boarding school in Hong Kong. Two cohorts of high school students (Nâ¯=â¯228; 61.8% female) were recruited respectively before and after a school start time changed from 7:30am to 8:30am. Both cross-cohort and within-cohort longitudinal comparisons yielded significant increase in total sleep time. Cross-cohort comparison yielded improvement in sleep quality, insomnia, life satisfaction, and psychological distress. Longitudinal data suggested that the longer the additional sleep time, the better was sleep quality, day-time functioning, and subjective wellbeing.
Subject(s)
Personal Satisfaction , Sleep Deprivation/prevention & control , Sleep/physiology , Students/psychology , Adolescent , Anxiety/epidemiology , Depression/epidemiology , Female , Hong Kong , Humans , Longitudinal Studies , Male , Schools , Self Report , Sleep Initiation and Maintenance Disorders/epidemiology , Sleepiness , Stress, Psychological/epidemiology , Time FactorsABSTRACT
This study examined the longer-term individual- and school-level changes in students seven months after a one-hour delay in school start time (SST). Two cohorts of Grade 11 students (N = 227; 60.8% female, age = 17.0 [0.85]) at a residential high school in Hong Kong completed a questionnaire assessing sleep duration, insomnia symptoms, depression, anxiety, stress, and subjective well-being in 2017 and 2018, respectively. One of the cohorts was reassessed seven months after the implementation of a delay in SST, from 7:30am to 8:30am (n = 83, 65.1% female). School-level data on breakfast consumption, attendance, tardiness, and health clinic visits were collected. Between-group and within-group prospective comparisons suggest that the delay in SST was associated with improved sleep duration, mental health, and life satisfaction. School-level data revealed increased breakfast consumption and decreased unexcused absences, tardiness, and clinic visits.
ABSTRACT
This study aimed to evaluate P300 as an electrophysiological marker of cognitive function in patients with systemic lupus erythematosus (SLE) who had previous neuropsychiatric (NPSLE) involvement and were diagnosed to have cognitive impairment by standard neuropsychological tests. Event-related potentials (ERPs) were assessed by the auditory and visual oddball paradigms. Amplitude and latency of P300 at the frontal (Fz), central (Cz), and parietal (Pz) regions were determined and compared with controls. P300 detection was performed in NPSLE patients with pre-diagnosed cognitive impairment (n = 9), matched SLE patients without previous NPSLE (non-NPSLE) (n = 9), and healthy controls (n = 15). Auditory oddball task did not show any P300 abnormality between groups. Visual oddball task revealed reduced amplitude of P300 over Fz ( P = .002) and Cz ( P = .009) electrodes in NPSLE patients compared with healthy controls and among those who had predominant memory deficit ( P = .01 at Fz). Abnormal P300 was also observed in non-NPSLE patients at Fz and Cz. Using visual oddball paradigm, abnormal P300 was found in NPSLE patients over frontal and parietal regions compared with normal controls but was not discriminative from possible subclinical disease in non-NPSLE patients. In conclusion, visual oddball paradigm was a more sensitive electrophysiological marker than auditory oddball paradigm for cognitive impairment in NPSLE patients.
Subject(s)
Cognition Disorders/diagnosis , Cognition Disorders/physiopathology , Cognition , Electroencephalography/methods , Event-Related Potentials, P300 , Lupus Vasculitis, Central Nervous System/physiopathology , Nervous System Diseases/physiopathology , Adult , Auditory Perception , Cognition Disorders/complications , Female , Humans , Lupus Vasculitis, Central Nervous System/complications , Lupus Vasculitis, Central Nervous System/diagnosis , Male , Nervous System Diseases/complications , Nervous System Diseases/diagnosis , Observer Variation , Reproducibility of Results , Sensitivity and Specificity , Visual PerceptionABSTRACT
The case of a 67-year-old right-handed Chinese man with Central Pontine Myelinolysis [CPM] is described to illustrate the resulting cognitive and emotional disturbances. A comparison of the data in this report with that in published studies suggests that ethnicity does not seem to have much effect on the symptoms of CPM. Possible underlying neural-pathological mechanisms are discussed. This case further substantiates the speculation that the brainstem plays a role in higher cognitive processes and emotional regulation.
Subject(s)
Affective Symptoms/etiology , Cognition Disorders/etiology , Myelinolysis, Central Pontine/complications , Affective Symptoms/diagnosis , Aged , Brain/pathology , Cognition Disorders/diagnosis , Humans , Magnetic Resonance Imaging , Male , Myelinolysis, Central Pontine/diagnosis , Neuropsychological Tests , Severity of Illness IndexABSTRACT
Risky decision-making is subserved by the frontostriatal system, which includes a network of interconnected brain regions known to be dysfunctional in patients with schizophrenia. This study aimed to investigate whether and to what extent patients with schizophrenia display a different pattern of risk-taking behavior relative to matched healthy controls. The Balloon Analogue Risk Task (BART) and the Risky-Gains Task were used as naturalistic measures of risk-taking behavior in 25 patients with schizophrenia and 25 controls. Results of the BART revealed that patients behaved more conservatively, and this in turn led to suboptimal risky decision-making. Consistently, patients behaved more conservatively in the Risky-Gains Task. Interestingly, however, they adjusted the pattern of risk-taking following a punished trial similar to controls. These findings indicate that patients have impaired reward but preserved punishment processing. This study complements previous studies on decision-making in schizophrenia and suggests specific rather than widespread abnormalities along the frontostriatal system in schizophrenia.
Subject(s)
Learning Disabilities/etiology , Punishment , Reward , Risk-Taking , Schizophrenia/complications , Schizophrenic Psychology , Adult , Analysis of Variance , Asian People/psychology , Female , Humans , Intelligence Tests , Male , Middle Aged , Neuropsychological Tests , Psychiatric Status Rating ScalesABSTRACT
Neurophysiological studies in monkeys show that activity of neurons in primary cortex (M1), pre-motor cortex (PMC), and cerebellum varies systematically with the direction of reaching movements. These neurons exhibit preferred direction tuning, where the level of neural activity is highest when movements are made in the preferred direction (PD), and gets progressively lower as movements are made at increasing degrees of offset from the PD. Using a functional magnetic resonance imaging adaptation (fMRI-A) paradigm, we show that PD coding does exist in regions of the human motor system that are homologous to those observed in non-human primates. Consistent with predictions of the PD model, we show adaptation (i.e., a lower level) of the blood oxygen level dependent (BOLD) time-course signal in M1, PMC, SMA, and cerebellum when consecutive wrist movements were made in the same direction (0° offset) relative to movements offset by 90° or 180°. The BOLD signal in dorsolateral prefrontal cortex adapted equally in all movement offset conditions, mitigating against the possibility that the present results are the consequence of differential task complexity or attention to action in each movement offset condition.