Regional skin wetness perception and its modulation by warm and cold whole body skin temperatures in people with multiple sclerosis.

Skin wetness sensing is important for thermal stress resilience. Individuals with multiple sclerosis (MS) present greater vulnerability to thermal stress; yet, it is unclear whether they present wetness-sensing abnormalities. We investigated the effects of MS on wetness sensing and their modulation with changes in mean skin temperature (Tsk). Twelve participants with MS [5 males (M)/7 females (F); 48.3 ± 10.8 yr; Expanded Disability Status Scale (EDSS) range: 1-7] and 11 healthy controls (4 M/7 F; 47.5 ± 11.3 yr) undertook three trials, during which they performed a quantitative sensory test with either a thermoneutral (30.9°C), warm (34.8°C), or cold (26.5°C) mean Tsk. Participants reported on visual analog scales local wetness perceptions arising from the static and dynamic application of a cold-, neutral-, and warm-wet probe (1.32 cm2; water content: 0.8 mL), to the index finger pad, forearm, and forehead. Data were analyzed for the group-level effect of MS, as well as for its individual variability. Our results indicated that MS did not alter skin wetness sensitivity at a group level, across the skin sites and temperature tested, neither under normothermia nor under conditions of shifted thermal state. However, when taking an individualized approach to profiling wetness-sensing abnormalities in MS, we found that 3 of the 12 participants with MS (i.e., 25% of the sample) presented a reduced wetness sensitivity on multiple skin sites and to different wet stimuli (i.e., cold, neutral, and warm wet). We conclude that some individuals with MS may possess reduced wetness sensitivity; however, this sensory symptom may vary greatly at an individual level. Larger-scale studies are warranted to characterize the mechanisms underlying such individual variability.

Automation transparency: implications of uncertainty communication for human-automation interaction and interfaces.

Operators of highly automated driving systems may exhibit behaviour characteristic for overtrust issues due to an insufficient awareness of automation fallibility. Consequently, situation awareness in critical situations is reduced and safe driving performance following emergency takeovers is impeded. A driving simulator study was used to assess the impact of dynamically communicating system uncertainties on monitoring, trust, workload, takeovers, and physiological responses. The uncertainty information was conveyed visually using a stylised heart beat combined with a numerical display and users were engaged in a visual search task. Multilevel analysis results suggest that uncertainty communication helps operators calibrate their trust and gain situation awareness prior to critical situations, resulting in safer takeovers. In addition, eye tracking data indicate that operators can adjust their gaze behaviour in correspondence with the level of uncertainty. However, conveying uncertainties using a visual display significantly increases operator workload and impedes users in the execution of non-driving related tasks. Practitioner Summary: This article illustrates how the communication of system uncertainty information helps operators calibrate their trust in automation and, consequently, gain situation awareness. Multilevel analysis results of a driving simulator study affirm the benefits for trust calibration and highlight that operators adjust their behaviour according to multiple uncertainty levels.

Sleep-related eye symptoms and their potential for identifying driver sleepiness.

The majority of individuals appear to have insight into their own sleepiness, but there is some evidence that this does not hold true for all, for example treated patients with obstructive sleep apnoea. Identification of sleep-related symptoms may help drivers determine their sleepiness, eye symptoms in particular show promise. Sixteen participants completed four motorway drives on two separate occasions. Drives were completed during daytime and night-time in both a driving simulator and on the real road. Ten eye symptoms were rated at the end of each drive, and compared with driving performance and subjective and objective sleep metrics recorded during driving. 'Eye strain', 'difficulty focusing', 'heavy eyelids' and 'difficulty keeping the eyes open' were identified as the four key sleep-related eye symptoms. Drives resulting in these eye symptoms were more likely to have high subjective sleepiness and more line crossings than drives where similar eye discomfort was not reported. Furthermore, drivers having unintentional line crossings were likely to have 'heavy eyelids' and 'difficulty keeping the eyes open'. Results suggest that drivers struggling to identify sleepiness could be assisted with the advice 'stop driving if you feel sleepy and/or have heavy eyelids or difficulty keeping your eyes open'.

Causal factors of hot air ballooning incidents: identification, frequency, and potential impact.

BACKGROUND: Hot air ballooning incidents are relatively rare; however, when they do occur they are likely to result in a fatality or serious injury. Human error is commonly attributed as the cause of hot air ballooning incidents; however, error in itself is not an explanation for safety failures. This research aims to identify and establish the relative importance of factors contributing toward hot air ballooning incidents. METHODS: Twenty-two Australian Ballooning Federation (ABF) incident reports were thematically coded using a bottom-up approach to identify causal factors. Subsequently, 69 balloonists (mean 19.51 yr experience) participated in a survey to identify additional causal factors and rate (out of 7) the perceived frequency and potential impact to ballooning operations of each of the previously identified causal factors. Perceived associated risk was calculated by multiplying mean perceived frequency and impact ratings. RESULTS: Incident report coding identified 54 causal factors within 9 higher level areas: Attributes, Crew Resource Management, Equipment, Errors, Instructors, Organizational, Physical Environment, Regulatory Body, and Violations. Overall, 'weather', 'inexperience,' and 'poor/inappropriate decisions' were rated as having greatest perceived associated risk. DISCUSSION: Although errors were nominated as a prominent cause of hot air ballooning incidents, physical environment and personal attributes are also particularly important for safe hot air ballooning operations. In identifying a range of causal factors, the areas of weakness surrounding ballooning operations have been defined; it is hoped that targeted safety and training strategies can now be put into place to remove these contributing factors and reduce the chance of pilot error.

Exploring schema-driven differences in situation awareness between road users: an on-road study of driver, cyclist and motorcyclist situation awareness.

Collisions between different road users make a substantial contribution to road trauma. Although evidence suggests that different road users interpret the same road situations differently, it is not clear how road users' situation awareness differs, nor is it clear which differences might lead to conflicts. This article presents the findings from an on-road study conducted to examine driver, motorcyclist and cyclist situation awareness in different road environments. The findings suggest that, in addition to minor differences in the structure of different road users' situation awareness (i.e. amount of information and how it is integrated), the actual content of situation awareness in terms of road user schemata, the resulting interaction with the world and the information underpinning situation awareness is markedly different. Further examination indicates that the differences are likely to be compatible along arterial roads, shopping strips and at roundabouts, but that they may create conflicts between different road users at intersections. Interventions designed to support compatible situation awareness and behaviour between different road users are discussed.

Using the event analysis of systemic teamwork (EAST) to explore conflicts between different road user groups when making right hand turns at urban intersections.

Collisions between different types of road users at intersections form a substantial component of the road toll. This paper presents an analysis of driver, cyclist, motorcyclist and pedestrian behaviour at intersections that involved the application of an integrated suite of ergonomics methods, the Event Analysis of Systemic Teamwork (EAST) framework, to on-road study data. EAST was used to analyse behaviour at three intersections using data derived from an on-road study of driver, cyclist, motorcyclist and pedestrian behaviour. The analysis shows the differences in behaviour and cognition across the different road user groups and pinpoints instances where this may be creating conflicts between different road users. The role of intersection design in creating these differences in behaviour and resulting conflicts is discussed. It is concluded that currently intersections are not designed in a way that supports behaviour across the four forms of road user studied. Interventions designed to improve intersection safety are discussed. Practitioner Summary: Intersection safety currently represents a key road safety issue worldwide. This paper presents a novel application of a framework of ergonomics methods for studying differences in road user behaviour at intersections. The findings support development of interventions that consider all road users as opposed to one group in isolation.

Proposing a framework for evidence-based road safety policy-making: Connecting crash causation, countermeasures and policy.

Effective evidence-based policy making within road safety is a several step cyclic process that involves gathering data about the causes of crashes, analysing these data, developing countermeasures and implementing and evaluating them. There are many examples of crash causation focused data collection activities available to policy makers but knowledge on how these finding may have led to countermeasure implementation and new policy is much less well established. This paper proposes a framework for best practice evidence-based policy making. To address existing gaps, the framework consists of three pillars: these are (1) Crash causation establishment; (2) Countermeasure development and implementation; and (3) road safety management. A key element in this framework is the recommendation for the establishment of an organisation responsible for road safety that has a strategic and coordination role. This framework, as a whole, aims to provide a practical high-level map by connecting evidence to policy at every point in the policy making cycle and ensuring that evidence-based road safety policy is a national priority. It is anticipated that using this framework to inform road safety policy development will enhance the success of any developed policy.

Exploring sleepiness and stress among London bus drivers: An on-road observational study.

Bus driver sleepiness is commonplace but often goes unreported within the industry. Whilst past research has begun to shed a light on the prevalence, potential causes, and consequences of bus driver sleepiness, this is often done using self-report methods. This is the first study to investigate sleepiness amongst city bus drivers on-road using a live bus route with drivers' regular schedules. A total of 16 participants completed two drives of their regular bus route once during an early morning shift and once during a daytime shift whilst physiological and self-report measures of sleep and stress were taken. Prior to these drives, drivers recorded their sleep in a diary and wore an actigraph to obtain objective sleep measures. Results showed that most drivers did not obtain sufficient sleep prior to early morning shifts, and often did not obtain as much sleep as they would need in order to feel rested before work. Sleepiness and stress were observed in both shifts. During early morning shifts sleepiness was likely a result of working during circadian lows and not obtaining enough sleep prior to the shift. In contrast, sleepiness during the daytime shift was likely a result of completing a highly demanding task in complex traffic which not only contributed to fatigue, but also led to increased levels of stress. As well as demonstrating the prevalence of sleepiness amongst bus drivers, these findings show that the causes of sleepiness can be multifaceted and often come about due to a combination of work and personal factors. In addition, the experience of sleepiness is not the same for all drivers, with individual differences in the experience of sleepiness playing a large role. These differences highlight the need for individualised interventions which should be considered by policymakers alongside the combination of causal factors within a larger systems approach.

A framework for countermeasures design to support professional drivers' fitness-to-drive.

This paper presents a new conceptual framework, and stepwise approach to populate it, for informing countermeasure development to support fitness-to-drive for professional drivers. Professional drivers are vital to the transport network; however, the job is demanding and drivers are vulnerable to impairments which may impact safe driving. Countermeasures are any action or activity that mitigates the impact or frequency of occurrence of driver impairment. The framework proposes countermeasures to be delivered across three time points: Operational (during shift), Tactical (immediately after shift) and Strategic (outside of on-shift) and at multiple system levels, e.g., driver, manager, enforcement etc. The framework was successfully pilot tested with three different professional driver use cases: autonomous shuttles, taxi, and garbage truck drivers. This structured approach to countermeasure design offers potential to improve driver health and enhance road safety. The work was conducted within PANACEA, an EU project, grant agreement number 953426.

One night's CPAP withdrawal in otherwise compliant OSA patients: marked driving impairment but good awareness of increased sleepiness.

PURPOSE: Obstructive sleep apnoea (OSA) patients effectively treated by and compliant with continuous positive air pressure (CPAP) occasionally miss a night's treatment. The purpose of this study was to use a real car interactive driving simulator to assess the effects of such an occurrence on the next day's driving, including the extent to which these drivers are aware of increased sleepiness. METHODS: Eleven long-term compliant CPAP-treated 50-75-year-old male OSA participants completed a 2-h afternoon, simulated, realistic monotonous drive in an instrumented car, twice, following one night: (1) normal sleep with CPAP and (2) nil CPAP. Drifting out of road lane ('incidents'), subjective sleepiness every 200 s and continuous electroencephalogram (EEG) activities indicative of sleepiness and compensatory effort were monitored. RESULTS: Withdrawal of CPAP markedly increased sleep disturbance and led to significantly more incidents, a shorter 'safe' driving duration, increased alpha and theta EEG power and greater subjective sleepiness. However, increased EEG beta activity indicated that more compensatory effort was being applied. Importantly, under both conditions, there was a highly significant correlation between subjective and EEG measures of sleepiness, to the extent that participants were well aware of the effects of nil CPAP. CONCLUSIONS: Patients should be aware that compliance with treatment every night is crucial for safe driving.

Keeping the service running: Examining working relationships and workload of London bus network iBus controllers.

Bus controllers are an essential part of the London bus network. Although the bus driver is the individual directly in control of the vehicle, inputs from both the controller and driver influence operations. Currently, little research has focused on the dynamic between these parties, and how it works in the day-to-day operation of a bus. In the current study, data was collected across focus groups with controllers to understand the controller-driver relationship from the controller perspective. The objectives of the research were to: investigate interactions and working relationships between bus controllers and drivers in London and to explore the effect of controller/driver relationships on workload, stress and fatigue. It is clear that the working relationship between controllers and drivers is a challenging one, with both parties often misunderstanding the role of the other. This is made worse by the nature of communication via radio including poor quality audio leading to difficult interactions. All of the participating controllers expressed being overloaded with work, leading to feelings of stress and fatigue, with shift work and irregular hours being discussed as a cause of controller fatigue. Any steps taken to improve the difficult working relationship between drivers and controllers can be seen as beneficial because they could improve efficiency, worker wellbeing, and possibly safety.

A patient-centred evaluation of phantom skin wetness as a sensory symptom in people with multiple sclerosis.

BACKGROUND: A noticeable but unknown proportion of people with multiple sclerosis (pwMS) report the sudden experience of wetness on a dry skin site, i.e., phantom wetness. Yet, we lack patient-centred investigations on the prevalence and subjective experience of this uncomfortable symptom. OBJECTIVES: To assess the prevalence of phantom wetness in pwMS, its association with individual factors, and subjective experience. METHODS: 757 pwMS completed an online survey assessing the frequency and subjective experience of phantom wetness. We calculated descriptive statistics and odd ratios and performed a thematic analysis to extract a patient-centred description of phantom wetness. RESULTS: 220 participants reported experiencing phantom wetness (29%). Females and those affected by Relapsing Remitting (RR) MS were 2.17 [1.39, 3.34] (p<0.001) and 1.73 [1.23, 2.40] (p = 0.001) times as likely to experience phantom wetness as males and those not affected by RR MS, respectively. The thematic analysis indicated phantom wetness is more often experienced as water trickling on the skin of the lower limb. CONCLUSION: Phantom wetness is a paraesthesia occurring in almost a third of the sample surveyed. Clinicians are encouraged to discuss with pwMS to validate their experience as a genuine symptom. Using the patient-generated language we report may help facilitate such conversations.

Heat and cold sensitivity in multiple sclerosis: A patient-centred perspective on triggers, symptoms, and thermal resilience practices.

BACKGROUND: The negative effects of heat and cold on Multiple Sclerosis (MS) have been known for ∼100 years. Yet, we lack patient-centred investigations on temperature sensitivity in persons with MS (pwMS). OBJECTIVES: To evaluate triggers, symptoms, and thermal resilience practices of temperature sensitivity pwMS via a dedicated survey. METHODS: 757 pwMS completed an online survey assessing the subjective experience of temperature sensitivity. We performed descriptive statistics and regression analyses to evaluate association between individual factors and susceptibility/resilience to thermal stress. RESULTS: Temperature sensitivity varied significantly in pwMS, with 58% of participants being heat sensitive only; 29% heat and cold sensitive; and 13% cold sensitive only (p<0.001). Yet, all pwMS: i) experienced hot and cold days as primary triggers; ii) reported fatigue as the most common worsening symptom, impacting walking and concentration; iii) used air conditioning and changes in clothing insulation as primary thermal resilience practices. Furthermore, certain individual factors (i.e. age, level of motor disability, experience of fatigue) were predictive of greater susceptibility to certain triggers (e.g. hot days) and symptoms (e.g. fatigue). CONCLUSION: Patient-centred evidence on the impact of and response to temperature sensitivity could play an important role in the development of individualised healthcare plans for temperature-sensitive pwMS.

Predicting the intention of distracted pedestrians at road crossings.

Despite improvements to road safety, accidents involving pedestrians are still numerous, for example in the UK there were over 20,000 pedestrian casualties on public roads in 2019. One of the potential causal factors is pedestrian distraction. Therefore, this study aimed to predict pedestrian intention to cross the road under conditions of distraction (using phone maps, talking to another pedestrian, listening to music through headphones), by applying the Theory of Planned Behaviour (TPB) using an online survey. This also involved investigation of the impact of selected traffic characteristics (traffic density, vehicle speed) and crossing type (pelican, zebra, unmarked). The survey consisted of 72 questions and took approximately 15 min to complete. The results (N = 81) revealed that the TPB construct of perceived behavioural control (PBC) was a significant predictor of intention to cross the road while distracted across all scenarios. Furthermore, crossing type was a significant predictor of PBC across all scenarios, with marked crossings facilitating feelings of PBC. Findings suggest that high feelings of PBC, as measured through ease and confidence, are linked with stronger intention to cross the road while distracted. This understanding of pedestrian motivation can be used to help design interventions (such as auditory and visual pedestrian warnings) that prevent conflict between distracted pedestrians and vehicles. These interventions should target marked crossing types, whereby pedestrians are more likely to cross while distracted.

Injury crashes and the relationship with disease causing excessive daytime sleepiness.

OBJECTIVE: The objective of this study was to understand the relationship between some of the most common diseases that are known to contribute to excessive daytime sleepiness (EDS) and traffic injury crashes. Specific focus was on the relationship between disease and crash type (single-vehicle or multiple-vehicle crash) and between disease and injury severity. METHODS: This registry-based study considered all passenger car drivers involved in a crash in Sweden between 2011 and 2016 who were 40 years or older at the time of the crash (n = 54,090). For each crash-involved driver, selected medical diagnoses registered from 1997 until the day before the crash were extracted from the National Patient Register. The drivers were assigned to 1 of 4 groups, depending on prior diseases: sleep apnea (SA; group 1, n = 2,165), sleep disorders (group 2, n = 724), Parkinson's or epilepsy (group 3, n = 645) and a reference group (group 4, n = 50,556). Logistic regression analysis compared single-vehicle crashes with multiple-vehicle crashes and moderately/severely injured drivers with slightly/uninjured drivers. RESULTS: Drivers with EDS-related diseases (groups 1-3) had higher probability of a single-vehicle crash than a multiple-vehicle crash compared to the reference group. The most sizeable effect was found for Parkinson's/epilepsy with an odds ratio (OR) of 2.5 (confidence interval [CI], 2.1-3.0). For multiple-vehicle crashes, the probability of a moderate/severe injury was higher for drivers with other sleep disorders (OR = 1.5; CI, 1.0-2.2) and Parkinson's/epilepsy (OR = 1.6; CI, 1.1-2.3) compared to the reference group. CONCLUSIONS: This study has made first steps toward understanding the relationship between some of the most common diseases that are known to contribute to EDS and crashes. Having Parkinson's/epilepsy, in particular, elevated the probability of a single-vehicle crash compared to a multiple-vehicle crash. A single-vehicle crash was seen as indicative of causing a crash; thus, having Parkinson's/epilepsy could be interpreted as a risk factor for crash involvement. Having Parkinson's/epilepsy, as well as other sleep disorders, was also related to more severe outcomes in multiple-vehicle crashes, given that a crash occurred. This was not identified in single-vehicle crashes.

Going underground: Fatigue and sleepiness in tunnelling operations.

This research represents one of the first qualitative studies to investigate fatigue in the tunnelling sector of the construction industry. It explores the opinions of tunnellers and their managers about how fatigue influences or is influenced by tunnelling, and how this is managed. Fatigue and sleepiness were discussed in six focus groups with frontline workers (n = 42) and 10 manager interviews. Fatigue was seen to be a problem, with all participants having experienced, or recognised in others, the feeling of sleepiness whilst at work. Fatigue and sleepiness are not commonly discussed between tunnelling workers and they do not feel comfortable reporting instances of fatigue. The research shows that workers in the tunnelling construction sector are exposed to a wide range of occupational factors that potentially increase their vulnerability to fatigue, including the physical environment, repetitive and monotonous tasks, variable shift patterns and manual work. Additionally, personal factors such as social and family demands, long commute times and living away from home, can increase the risk of fatigue. The construction industry in general has gone some way to address fatigue and there is opportunity to further improve fatigue management. However, a major shift is needed before workers will feel able to openly discuss fatigue with their employer.

Bus driver fatigue: A qualitative study of drivers in London.

The research represents one of the first major qualitative studies to subjectively investigate fatigue amongst city bus drivers. Funded by TfL (grant no. 94050), the study considers the perspectives of both the bus drivers themselves and their managers. It explores opinion specifically in relation to how fatigue influences or is influenced by bus driving, and how this is managed. Data was collected from focus groups with bus drivers (n = 65 drivers) and one-to-one interviews with bus driver managers (n = 11). Fatigue was seen to be a problem, with all drivers having experienced for themselves the feeling of sleepiness whilst driving the bus, or knowing about it in others. The managers agreed that fatigue amongst drivers is evident, seeing it particularly as a contributor to serious incidents. Fatigue and sleepiness are not discussed between drivers as a general rule and they do not feel comfortable reporting instances of fatigue for fear of being disciplined. Managers would encourage drivers to report these issues and therefore hoped to create a more open culture. Factors identified as contributors to fatigue included: working overtime, having insufficient sleep, spending time with family, other non-work commitments, shift schedules, and work pressure.

Autonomous Vehicles and Vulnerable Road-Users-Important Considerations and Requirements Based on Crash Data from Two Countries.

(1) Background: Passenger vehicles equipped with advanced driver-assistance system (ADAS) functionalities are becoming more prevalent within vehicle fleets. However, the full effects of offering such systems, which may allow for drivers to become less than 100% engaged with the task of driving, may have detrimental impacts on other road-users, particularly vulnerable road-users, for a variety of reasons. (2) Crash data were analysed in two countries (Great Britain and Australia) to examine some challenging traffic scenarios that are prevalent in both countries and represent scenarios in which future connected and autonomous vehicles may be challenged in terms of safe manoeuvring. (3) Road intersections are currently very common locations for vulnerable road-user accidents; traffic flows and road-user behaviours at intersections can be unpredictable, with many vehicles behaving inconsistently (e.g., red-light running and failure to stop or give way), and many vulnerable road-users taking unforeseen risks. (4) Conclusions: The challenges of unpredictable vulnerable road-user behaviour at intersections (including road-users violating traffic or safe-crossing signals, or taking other risks) combined with the lack of knowledge of CAV responses to intersection rules, could be problematic. This could be further compounded by changes to nonverbal communication that currently exist between road-users, which could become more challenging once CAVs become more widespread.

Post-trip safety interventions: State-of-the-art, challenges, and practical implications.

INTRODUCTION: Currently, risky driving behaviour is a major contributor to road crashes and as a result, wide array of tools have been developed in order to record and improve driving behaviour. Within that group of tools, interventions have been indicated to significantly enhance driving behaviour and road safety. This study critically reviews monitoring technologies that provide post-trip interventions, such as retrospective visual feedback, gamification, rewards or penalties, in order to inform an appropriate driver mentoring strategy delivered after each trip. METHOD: The work presented here is part of the European Commission H2020 i-DREAMS project. The reviewed platform characteristics were obtained through commercially available solutions as well as a comprehensive literature search in popular scientific databases, such as Scopus and Google Scholar. Focus was given on state-of-the-art-technologies for post-trip interventions utilized in four different transport modes (i.e. car, truck, bus and rail) associated with risk prevention and mitigation. RESULTS: The synthesized results revealed that smartphone applications and web-based platforms are the most accepted, frequently and easiest to use tools in cars, buses and trucks across all papers considered, while limited evidence of post-trip interventions in -rail was found. The majority of smartphone applications detected mobile phone use and harsh events and provided individual performance scores, while in-vehicle systems provided delayed visual reports through a web-based platform. CONCLUSIONS: Gamification and appropriate rewards appeared to be effective solutions, as it was found that they keep drivers motivated in improving their driving skills, but it was clear that these cannot be performed in isolation and a combination with other strategies (i.e. driver coaching and support) might be beneficial. Nevertheless, as there is no holistic and cross-modal post-trip intervention solution developed in real-world environments, challenges associated with post-trip feedback provision and suggestions on practical implementation are also provided.

The impact of sleep loss on sustained and transient attention: an EEG study.

Sleep is one of our most important physiological functions that maintains physical and mental health. Two studies examined whether discrete areas of attention are equally affected by sleep loss. This was achieved using a repeated-measures within-subjects design, with two contrasting conditions: normal sleep and partial sleep restriction of 5-h. Study 1 compared performance on a sustained attention task (Psychomotor Vigilance task; PVT) with performance on a transient attention task (Attentional Blink; AB). PVT performance, but not performance on the AB task, was impaired after sleep restriction. Study 2 sought to determine the neural underpinnings of the phenomenon, using electroencephalogram (EEG) frequency analysis, which measured activity during the brief eyes-closed resting state before the tasks. AB performance was unaffected by sleep restriction, despite clearly observable changes in brain activity. EEG results showed a significant reduction in resting state alpha oscillations that was most prominent centrally in the right hemisphere. Changes in individual alpha and delta power were also found to be related to changes in subjective sleepiness and PVT performance. Results likely reflect different levels of impairment in specific forms of attention following sleep loss.