Fighter pilots' heart rate, heart rate variation and performance during instrument approaches.

Fighter pilots' heart rate (HR), heart rate variation (HRV) and performance during instrument approaches were examined. The subjects were required to fly instrument approaches in a high-fidelity simulator under various levels of task demand. The task demand was manipulated by increasing the load on the subjects by reducing the range at which they commenced the approach. HR and the time domain components of HRV were used as measures of pilot mental workload (PMWL). The findings of this study indicate that HR and HRV are sensitive to varying task demands. HR and HRV were able to distinguish the level of PMWL after which the subjects were no longer able to cope with the increasing task demands and their instrument landing system performance fell to a sub-standard level. The major finding was the HR/HRV's ability to differentiate the sub-standard performance approaches from the high-performance approaches. Practitioner Summary: This paper examined if HR and HRV were sensitive to varying task demands in a fighter aviation environment and if these measures were related to variations in pilot's performance.

Sleep in children with disruptive behavioral disorders.

This study compared sleep in patients with Conduct Disorder/Oppositional Defiant Disorder (CD/ODD) and normative children and evaluated the associations between sleep and behavioral symptoms in patients. Participants were 30 patients, aged 7 to 12 years, with diagnoses of CD/ODD and their age and gender matched controls. Patients with CD/ODD and their parents reported significantly more sleep problems than did the control children and their parents (p values < 0.01). By actigraphy, CD/ODD children with comorbid ADHD slept significantly less than did the patients with CD/ODD alone and the controls. In patients, low sleep amount and efficiency associated with increased amount of parent-reported externalizing symptoms (r = -0.72, 0.66, p values < 0.001). Results highlight the need of evaluating sleep in children with CD/ODD. Improving their sleep may ease their symptoms.

Working memory, attention, inhibition, and their relation to adaptive functioning and behavioral/emotional symptoms in school-aged children.

The present study investigated the development of executive functions (EFs) and their associations with performance and behavior at school in 8-12-year-old children. The EFs were measured by computer-based n-back, Continuous Performance and Go/Nogo tasks. School performance was evaluated by Teacher Report Form (TRF) and behavior by TRF and Child Behavior Checklist. The studied dimensions of EF were cognitive efficiency/speed, working memory/attention and inhibitory control. Strong age effects were found for these cognitive abilities (p values <0.01). Inhibitory control was associated with better adaptive functioning (learning, working hard and behaving well), academic performance and less psychiatric symptoms (p values <0.05), specially in 8-9-year-old children. In this youngest age group low inhibitory control was also associated with teacher-reported inattention (p = 0.042). Low inhibitory control was associated with teacher- and parent-reported internalizing symptoms (p < 0.01). These results suggest that maturational factors may underlie low adaptive functioning and psychiatric symptoms during early school years. Further studies are needed to evaluate the association between inhibition and emotional symptoms.

Snoring was related to self-reported daytime sleepiness and tiredness in young adults performing compulsory conscript service.

STUDY OBJECTIVES: In young adults performing compulsory military service, fatigue and somnolence are common and presumably associated with objective or self-reported sleep deprivation. We aimed to find out whether objective sleep parameters from ambulatory polysomnography could explain their self-reported tiredness and sleepiness and whether habits were associated with sleep parameters or tiredness. METHODS: Seventy (67 male, age 18-24 years) participants had their sleep assessed with polysomnography. Their self-reported symptoms and demographic data were obtained from online survey including Epworth Sleepiness Scale, Beck's Depression Inventory, items from Basic Nordic Sleep Questionnaire, Internet Addiction Scale, and lifestyle questions. RESULTS: Snoring (audio recording, percentage of total sleep time) was associated with self-reported sleepiness (P = .010) and tiredness (P = .030) and snoring seemed to, partially, explain sleepiness (P = .029). Twenty-six percent of the conscripts had self-reported sleep deprivation (mismatch between reported need for sleep and reported sleep). Self-reported sleep deprivation was significantly associated with somnolence (P = .016) and fatigue (P = .026). Smartphone usage, both average time (P = .022) and frequency of usage (P = .0093) before bedtime, was associated with shorter total sleep time. On average, objective sleep time was rather short (7 hours, 6 minutes), sleep efficiency high (94.9%), proportion of N3 sleep high (27.7%), and sleep latency brief (9 minutes)-suggesting that many of the conscripts might have chronic partial sleep deprivation. CONCLUSIONS: Snoring might predispose to tiredness in presumably healthy young adults. Conscripts may have partial sleep deprivation. CITATION: Orjatsalo M, Toppila J, Heimola M, et al. Snoring was related to self-reported daytime sleepiness and tiredness in young adults performing compulsory conscript service. J Clin Sleep Med. 2023;19(2):243-251.

The Effects of Individual Characteristics of the Naval Personnel on Sleepiness and Stress during Two Different Watchkeeping Schedules.

BACKGROUND: Naval service can have a significant impact on the wellbeing of seafarers, and the operation of warships is highly dependent on the personnel on board. Nevertheless, there is a lack of knowledge concerning the impact of seafarers' individual characteristics on their wellbeing in a naval environment. Therefore, the aim of this study was to investigate individual characteristics of the naval personnel that may be associated with the amount of sleepiness, fatigue and stress responses experienced during shift work and irregular working hours in a naval environment. METHODS: The study took place on a Finnish Defence Forces' Navy missile patrol boat on which 18 crewmembers served as study participants. The measurement periods lasted two separate weeks (seven days and six nights) during shift work with two different watchkeeping systems (4:4, 4:4/6:6). The onboard measurements consisted of the Karolinska Sleepiness Scale, salivary stress hormones, cognitive tests (Sustained Attention to Response Task and N-back Task) and heart rate variability. RESULTS: Participants of older ages or with a longer history in naval service were associated with a greater amount of sleepiness, fatigue and stress responses on board. On the contrary, increased physical activity and a higher level of physical fitness, especially standing long jump, were associated with a lower amount of sleepiness, fatigue and fewer stress responses. In addition, an athletic body composition together with a healthy lifestyle may be beneficial, considering the stress responses on board. CONCLUSION: The present results are well in line with the previous literature regarding shift work and irregular working hours. The results highlight the importance of regular physical activity and good physical fitness during service in the naval environment.

Chronotype as self-regulation: morning preference is associated with better working memory strategy independent of sleep.

Study Objectives: We set out to examine how chronotype (diurnal preference) is connected to ability to function in natural conditions where individuals cannot choose their sleep schedule. We conducted a cross-sectional study in military conscript service to test the hypothesis that sleep deprivation mediates the adverse effects of chronotype on cognitive functioning. We also examined the effects of time of day. Methods: One hundred forty participants (ages 18-24 years) completed an online survey, including the Morningness-Eveningness Questionnaire and a Cambridge Neuropsychological Test Automated Battery. Most (n = 106) underwent an actigraphy recording. After bivariate analyses, we created a mediation model (self-reported sleepiness and sleep deprivation mediating effect of chronotype on cognition) and a moderation model (synchrony between most alert time and testing time). Results: Reaction times in inhibition task correlated negatively with sleep efficiency and positively with sleep latency in actigraphy. There was no relation to ability to inhibit responses. More significantly, spatial working memory performance (especially strategicness of performance) correlated positively with morning preference and negatively with sleep deprivation before service. Synchrony with most alert time of the day did not moderate these connections. No other cognitive task correlated with morningness or sleep variables. Conclusions: In line with previous research, inhibitory control is maintained after insufficient sleep but with a tradeoff of slower performance. The connection between morning preference and working memory strategy is a novel finding. We suggest that diurnal preference could be seen as an adaptive strategy, as morningness has consistently been associated with better academic and health outcomes.

Parent and self-report of sleep-problems and daytime tiredness among adolescents with inflammatory bowel disease and their population-based controls.

STUDY OBJECTIVES: to evaluate the frequency of sleep problems and daytime tiredness among adolescents with inflammatory bowel disease (IBD) in comparison with their healthy peers. DESIGN: Parent and self-reports of sleep problems and daytime tiredness. SETTING: questionnaire-based postal survey. INTERVENTION: N/A. PARTICIPANTS: one hundred sixty Finnish adolescents with IBD; 236 adolescents matched for age, sex, and place of residence; and the parents of both groups. MEASUREMENTS AND RESULTS: Sleep Self-Report and sleep questions of the Child Behavior Check-List, and Youth Self-Report. The parents of adolescents with IBD reported in their index child more trouble sleeping (P < 0.01), more nightmares (P < 0.01), sleeping more than most children during the day/night (P < 0.001), and overtiredness (P < 0.001) than did the parents of control subjects. In contrast, adolescents with IBD themselves did not report more problems than their peers. However, in the group of patients with self-reported severe IBD symptoms, both the parents and the adolescents reported trouble sleeping and overtiredness more often (P values < 0.01) than in the group with mild symptoms or control subjects. Adolescents with severe IBD reported more often that their symptoms affected the quality of their sleep (P < 0.001) than did adolescents with mild disease. CONCLUSIONS: adolescents with severe IBD symptoms have disturbed sleep and are overtired more often than are adolescents with mild IBD symptoms or control subjects. Thus, in adolescents with severe IBD symptoms, evaluating sleep is important in characterizing the disease burden. Both parent and adolescent reports are needed for comprehensive assessment of sleep in the young.

Sentences with core knowledge violations increase the size of N400 among paranormal believers.

A major problem in research on paranormal beliefs is that the concept of "paranormality" remains to be adequately defined. The aim of this study was to empirically justify the following definition: paranormal beliefs are beliefs in physical, biological, or psychological phenomena that contain core ontological attributes of one of the other two categories [e.g., a stone (physical) having thoughts (psychological)]. We hypothesized that individuals who believe in paranormal phenomena are slower in understanding whether sentences with core knowledge violations are literally true than skeptics, and that this difference would be reflected by a more negative N400. Ten believers and 10 skeptics (six men, age range 23-49) participated in the study. Event-related potentials (N400) were recorded as the participants read 210 three-word Finnish sentences, of which 70 were normal ("The house has a history"), 70 were anomalies ("The house writes its history") and 70 included violations of core knowledge ("The house knows its history"). The participants were presented with a question that contextualized the sentences: "Is this sentence literally true?" While the N400 effects were similar for normal and anomalous sentences among the believers and the skeptics, a more negative N400 effect was found among the believers than among the skeptics for sentences with core knowledge violations. The results support the new definition of "paranormality", because participants who believed in paranormal phenomena appeared to find it more difficult to construct a reasonable interpretation of the sentences with core knowledge violations than the skeptics did as indicated by the N400.

Fighter pilots' heart rate, heart rate variation and performance during an instrument flight rules proficiency test.

Increased task demand will increase the pilot mental workload (PMWL). When PMWL is increased, mental overload may occur resulting in degraded performance. During pilots' instrument flight rules (IFR) proficiency test, PMWL is typically not measured. Therefore, little is known about workload during the proficiency test and pilots' potential to cope with higher task demands than those experienced during the test. In this study, fighter pilots' performance and PMWL was measured during a real IFR proficiency test in an F/A-18 simulator. PMWL was measured using heart rate (HR) and heart rate variation (HRV). Performance was rated using Finnish Air Force's official rating scales. Results indicated that HR and HRV differentiate varying task demands in situations where variations in performance are insignificant. It was concluded that during a proficiency test, PMWL should be measured together with the task performance measurement.

Motor activity in depressed children.

BACKGROUND: Motor retardation is a cardinal feature in adult depression. Limited information exists about motor activity in depressed children. The present study evaluated motor activity in depressed children compared to controls and investigated whether motor activity can be linked with the severity of symptoms in depressed children. METHOD: Motor activity during both day- and night time was recorded by actigraphy in twenty-two depressed children and their controls. A K-SADS-PL interview of the child and his/her mother was used to diagnose depression. The depressed children filled in the Child Depression Inventory (CDI) as a self-report of the severity of depression. Parents and teachers of both depressed children and controls filled in the Child Behavior Checklist (CBCL) and the Teacher Report Form (TRF). RESULTS: Motor activity was reduced during the daytime in depressed children compared to controls (p<0.001). Depressed children spent more time in total immobility during the night time than their peers (p<0.05). In depressed children motor activity was linked with the severity of self- (r=-0.45, p<0.05) and teacher-reported (r=-0.52, p<0.05) symptoms. Depressed children with suicidal ideation (n=10) differed significantly in motor activity compared to depressed children without suicidal ideation (n=12) and controls (n=22). LIMITATIONS: Sample size was only moderate. CONCLUSIONS: Reduced motor activity is an important feature of childhood depression. Objectively measured motor activity can distinguish depressed children from their peers. Motor retardation can be linked with the severity of depression, especially suicidal ideation and possibly subtype depressed children into groups with different etiology, treatment needs and course of illness.

Psychosocial symptoms and competence among adolescents with inflammatory bowel disease and their peers.

BACKGROUND: The aim was to evaluate psychosocial symptoms and competence as reported by the parents and the adolescents themselves among patients with inflammatory bowel disease (IBD) in relation to population-based controls. METHODS: Standardized Achenbach questionnaires-Child Behavior Checklist (CBCL) for the parents and Youth Self-Report (YSR) for the adolescents-were sent to Finnish families of adolescents with IBD (age 10-18 years), and their controls matched for age, gender, and place of residence. The final study group comprised 160 adolescents with IBD and 236 controls with their parents, respectively. RESULTS: According to parent reports, adolescents with IBD had more symptoms of anxious/depressed mood (P < 0.001), withdrawn/depressed mood (P < 0.05), social problems (P < 0.05), thought problems (P < 0.001), somatic complaints (P < 0.001), and lower competence (P < 0.05) than population-based controls. Unexpectedly, there was no group difference in the amount of self-reported psychosocial symptoms, somatic complaints, or competence between adolescents with IBD and their peers. However, adolescents with severe IBD reported significantly more emotional problems (P < 0.001) than those with mild symptoms or controls. CONCLUSIONS: According to parents, adolescents with IBD have more emotional problems, social problems, thought problems, and lower competence than their population-based peers. Self-perceived severity of the IBD symptoms is associated with a larger amount of parent and self-reported emotional symptoms. Complementary methods should be used while assessing the psychosocial well-being of adolescents with IBD as questionnaires alone may be insufficient.

Mood is associated with snoring in preschool-aged children.

OBJECTIVE: To study emotional and behavioral problems and sleep and cognitive performance in snoring and nonsnoring 3- to 6-year-old children. METHODS: As part of an epidemiological study of sleep disordered breathing (SDB) in preschool-aged children, 43 snorers and 46 nonsnorers participated in a clinical study. Their parents completed the Child Behavior Checklist (CBCL). The children were assessed with Wechsler Preschool and Primary Scale of Intelligence, Revised and subtests of the Developmental Neuropsychological Assessment (NEPSY-A) representing aspects of attention, language skills, sensorimotor functions, memory, and learning. RESULTS: On the CBCL snoring children had significantly more parent reported internalizing symptoms (p < .05) than the nonsnoring children, especially symptoms of anxious/depressed mood (p < .01) and emotional reactivity (p < .05). More children from the snoring group than from the nonsnoring group (22 vs 11%) scored in the subclinical or clinical range on the internalizing scale. Interestingly, no significant difference between the groups was found in the amount of externalizing symptoms. The amount of sleep problems other than snoring was higher in the snoring than in the nonsnoring group (p < .01). On tests measuring auditory attention (p < .01) and language skills (verbal IQ, p < .05), the snoring group performed worse than the nonsnoring group. CONCLUSIONS: Our results support the view that SDB should be considered a possible risk factor for mood disorder symptoms and impaired cognitive performance in children.