Influences of APOE ε4 and expertise on performance of older pilots

Little is known about how APOE ε4-related differences in cognitive performance translate to real-life performance, where training and experience may help to sustain performance. We investigated the influences of APOE ε4 status, expertise (FAA pilot proficiency ratings), and their interaction on longitudinal flight simulator performance. Over a 2-year period, 139 pilots aged 42-69 years were tested annually. APOE ε4 carriers had lower memory performance than noncarriers (p = .019). APOE interacted with Expertise (p = .036), such that the beneficial influence of expertise (p = .013) on longitudinal flight simulator performance was more pronounced for ε4 carriers. Results suggest that relevant training and activity may help sustain middle-aged and older adults' real-world performance, especially among APOE ε4 carriers.     

Differential Sensitivity of Using Simulators Versus Actual Aircraft to Evaluate the Effects of a Stimulant Medication on Aviator Performance

The comparability of simulator versus aircraft results was examined with a quasi-experimental approach. Flight data from 10 UH-60 pilots, who flew a helicopter simulator, and 10 pilots who flew an aircraft were pooled to assess the influence of the flight platform on Dexedrine® versus placebo effects in two 40-hr periods of sustained wakefulness. Overall, performance under Dexedrine® was better than performance under placebo, but consistent stimulant and fatigue effects were observed across both flight platforms less than one third of the time. Sensitivity was lower in the aircraft, likely because of differences due to environmental influences (weather, temperature, and turbulence) and other factors (radio traffic and, possibly, anxieties about safety). Thus, simulator studies, although desirable in terms of cost and safety, may overestimate the impact of stressors (e.g., fatigue) as well as the potential benefits from fatigue countermeasures (e.g., Dexedrine®). Conversely, in-flight studies may underestimate these types of performance effects. As a result, caution is advised when attempting to generalize findings from one flight platform to the other.     

Effects of Unilateral Entorhinal Cortex Lesion on Retention of Water Maze Performance

In a previous study, adult male Sprague-Dawley rats with unilateral, electrolytic entorhinal cortex lesions showed significant deficits in acquisition of a water maze task that measured working memory. The 10 days of testing used two trials per day with an intertrial interval of 1 h, and the rats with entorhinal damage were impaired in total distance to the platform in both trials. In the present retention study, rats who learned the same task prior to injury and were then retested for 5 days after lesion showed only a first day deficit in total distance to platform in the second trial. Analysis of swim patterns indicated that rats with unilateral entorhinal lesions used an altered strategy in retention testing to find the platform in the second trial of each day and incorporated the use of headings appropriate for Trial 1 only. This altered or compensatory strategy was not the optimum choice for problem solution. Although the rats then were able to switch headings and find the platform without significant impairment in total distance to platform on days 2–5 of testing, the use of an initial incorrect strategy indicated subtle residual deficits in cue integration and use of working memory.     

Investigating systematic individual differences in sleep-deprived performance on a high-fidelity flight simulator

Laboratory research has revealed considerable systematic variability in the degree to which individuals' alertness and performance are affected by sleep deprivation. However, little is known about whether or not different populations exhibit similar levels of individual variability. In the present study, we examined individual variability in performance impairment due to sleep loss in a highly select population of militaryjet pilots. Ten active-duty F-117 pilots were deprived of sleep for 38 h and studied repeatedly in a high-fidelity flight simulator. Data were analyzed with a mixed-model ANOVA to quantify individual variability. Statistically significant, systematic individual differences in the effects of sleep deprivation were observed, even when baseline differences were accounted for. The findings suggest that highly select populations may exhibit individual differences in vulnerability to performance impairment from sleep loss just as the general population does. Thus, the scientific and operational communities' reliance on group data as opposed to individual data may entail substantial misestimation of the impact of job-related stressors on safety and performance.     

Attenuation of 8-OH-DPAT-induced decreases in 5-Ht synthesis in brain regions of rats adapted to a repeated stress schedule

Previously it has been shown that single episode of 2 h restraint produced behavioral deficits in rats which were not observed following daily restraint period of 2h/day for 5 days. It was suggested that adaptation to a stress schedule develops when the similar stress is administered repeatedly. In view of a role of 5-hydroxytryptamine (5-HT) in adaptation to stress the present study concerns effects of a 5-HT-1A agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) on the synthesis of 5-HT in brain regions of rats adapted to a repeated restraint stress schedule of 2h/day for 5 days. The drug injected systemically at a dose of 1 mg/kg decreased 5-HT synthesis in the hypothalamus, cortex, hippocampus, striatum and raphe regions of previously unrestrained rats. These decreases were either smaller (raphe) or not observed (hypothalamus, cortex and hippocampus) in most brain regions of rats adapted to the repeated restraint stress schedule of 2h/day for 5 days. These results suggest that a subsensitive negative feedback effect on the synthesis of 5-HT leading to an increase in synaptic 5-HT concentration might help coping with stress demand to produce adaptation to stress.     

Impact of automation on aircrew communication and decision-making performance

Increasing levels of automation are being introduced into the cockpit. Yet, it is difficult to predict the impact of these automatic systems on other elements of flight, such as crew communication and the ability to arrive at an effective decision. This study attempted to clarify the relation among these variables. Forty-eight pilots were assigned to two-person crews and asked to fly a simulated mission in either automated or manual conditions using a low-fidelity simulator. The scenario was designed to require crewmembers to arrive at a collective decision based on information obtained about an evolving simulated disaster. The results indicated that the introduction of automation was not associated with better performance. However, several significant differences were observed in the communications of crews flying in the automated versus manual conditions. The results are discussed in terms of their implications for communications training for advanced technology aircraft.     

Cognitive ability, expertise, and age differences in following air-traffic control instructions

Differences in cognitive ability and domain-specific expertise may help explain age differences in pilot performance. Pilots heard air-traffic controller messages and then executed them while "flying" in a simulator. Messages varied in length and speech rate. Age was associated with lower accuracy, but the expected Age x Message Difficulty interactions were not obtained. Expertise, as indexed by pilot ratings, was associated with higher accuracy; yet expertise did not reduce age differences in accuracy. The effect of age on communication task accuracy was largely explainable as an age-associated decrease in working memory span, which in turn was explainable as decreases in both speed and interference control. Results are discussed within frameworks of deliberate practice and cognitive mediation of age differences.     

The effect of sleep-need and time-on-task on driver fatigue

Both sleep- and task-related factors are thought to contribute to driver fatigue, with each factor individually associated with deteriorated driving performance. However, the relative and combined effects of these factors in the context of monotonous driving have not been well studied. This study (N = 60) investigated lateral and longitudinal vehicle control, subjective fatigue and physiological response (EEG) during three 10-minute periods of time-on-task spread across a monotonous, 2-hour simulator drive. Level of physiological sleep-need was manipulated between participants by varying the instructed time spent in bed on the night before testing (≤5h or ≥ 8 h). In addition, half of the participants in each sleep group read the applicable speed limit from periodic roadside signs whereas the others performed an arithmetic calculation, displayed on the signs, to determine the speed limit. This task manipulation has been demonstrated to reduce performance decrements over time. Results demonstrated effects of time-on-task and sleep need on self-report ratings, an effect of time-on-task on EEG indices, and an interaction of sleep-need and time-on-task on an EEG index of mental workload and on the lateral control measure of driving performance. There were no significant effects on the measure of speed variability. These results confirm that both sleep-need and time-on-task negatively affect driver state, and that time-on-task decrements in driver performance can occur in the absence of heightened sleep-need. Results also suggest that drivers with heightened sleep-need could protect their performance for a short time, perhaps by exerting effort to compensate for reduced capacity. The secondary task did not counteract declining performance.     

Expanded vs. equal interval spaced retrieval practice: exploring different schedules of spacing and retention interval in younger and older adults

The present study was designed to help answer several questions regarding the impact of spacing and expanded retrieval on memory performance in younger and older adults. Three expanded/equal interval schedule pairings, matched in average spacing (1-2-3/2-2-2; 1-3-5/3-3-3; and 1-3-8/4-4-4), were compared, and the effect of retention interval on spaced retrieval benefits was examined by comparing performance on a same day test to a test delayed by 24 h. Both age groups showed a learning phase retrieval success advantage for expanded items compared to equal interval items. Only older adults in the same day test condition showed a significant expansion effect in final recall. After a 24-h delay, the final recall advantage for items in the expanded condition was lost in both groups, and in fact these items were at a significant recall disadvantage for younger adults. Results indicate that younger and older adults benefit from a rehearsal technique that incorporated any type of spaced retrieval whether it is distributed as an expanding schedule or not. Although we did not find robust advantages for expanded retrieval compared to equal interval practice, there could be certain advantages (such as reinforcement due to high success rates) to using expanded retrieval depending on the ultimate goals of an individual memory training program.     

The mental health of pilots: An overview

The impact and long-term psychological consequences of the 11th September 2001 terrorist attacks in the USA involving commercial aircraft are likely to be far-reaching. Pilots were directly affected by these events though it is too early to comprehend the specific psychological and occupational repercussions. While psychologists have written much on the selection of commercial and military aircrew, surprisingly little has been published on the mental health of pilots. They are a unique occupational group in terms of their selection, training, lifestyle, frequent competency and medical checks, as well as the nature and changing demands placed on them. Their 'office' is normally a cramped flight deck on board an aircraft at altitudes of thousands of feet. While some aspects of their job and lifestyle appear attractive to some, their working conditions are, at worst, inhospitable and unpleasant. This paper provides an overview of current research on the mental health of pilots, gathered from a number of different fields and specialities within commercial and military aviation. The review covers their lifestyle, psychological requirements for medical certification, psychological problems amongst air crew, personality factors, disruption to personal relationships, reactions to incidents and accidents, alcohol and drug misuse, suicide by aircraft and environmental challenges. Flight crew should have easy access to psychological support; however, many pilots are distrusting of mental health professionals. Further research is needed to improve an understanding of mental health issues among pilots, especially in order to better understand the psychological impact of the terrorist attacks upon them.     

Automation bias: decision making and performance in high-tech cockpits

Automated aids and decision support tools are rapidly becoming indispensable tools in high-technology cockpits and are assuming increasing control of"cognitive" flight tasks, such as calculating fuel-efficient routes, navigating, or detecting and diagnosing system malfunctions and abnormalities. This study was designed to investigate automation bias, a recently documented factor in the use of automated aids and decision support systems. The term refers to omission and commission errors resulting from the use of automated cues as a heuristic replacement for vigilant information seeking and processing. Glass-cockpit pilots flew flight scenarios involving automation events or opportunities for automation-related omission and commission errors. Although experimentally manipulated accountability demands did not significantly impact performance, post hoc analyses revealed that those pilots who reported an internalized perception of "accountability" for their performance and strategies of interaction with the automation were significantly more likely to double-check automated functioning against other cues and less likely to commit errors than those who did not share this perception. Pilots were also lilkely to erroneously "remember" the presence of expected cues when describing their decision-making processes.     

Sleepiness and days of recovery

In the literature recovery after work is taken for granted – one has 16 h off between work bouts and one has 36 h off each weekend. However, the situation for those working irregular work hours may be quite different because of night work, long shifts, or long sequences of working days. Strictly speaking we don't have any scientific support for theories on how recovery days should be patterned. This paper, therefore, brings together data from a series of our own studies that involve irregular work hours, with the specific purpose of looking at the recovery process. The results show that for the average normal office week worker two days of recovery are normally sufficient. For those who work long shifts in long sequences three days are needed for normalization, whereas 12 h shifts in 2–3 day sequences seem not to cause accumulated fatigue. Interestingly, fatigue/sleepiness is often at its peak during the first day of recovery – not the last day of the working week. Air crew and oil rig workers take a longer time to recover, probably because of too much adjustment of the biological clock. As a rule, long haul air crew is usually much more fatigued than short haul crew during their days off, despite the fact that long haul flying is voluntary and opted for by those who fly it. Also train drivers are affected during their days off by their irregular work hours – in particular backwards rotating schedules seem to cause accumulation of fatigue. The results suggest that one day of recovery never is sufficient, two days usually is, whereas 3–4 days are necessary after periods of severely disturbed circadian rhythmicity.     

影响直升机飞行员飞入IMC的心理因素——一项基于三十年间NTSB事故报告的研究

气象因素对通航运行安全有重要影响,以此可以明确“直升机飞行员飞入仪表气象条件将会威胁飞行安全”这一基本事实。然而从近30年来美国国家运输安全委员会所记录的200起在仪表气象条件下的直升机事故来看,有近一半的飞行员有意地飞入仪表气象条件。这驱使研究者探究这一行为背后的心理因素。基于大量的文献,总结出飞行员的知识/经验、决策动机、情景评估、风险管理、认知偏差和社会压力能够合理地解释这一行为。     

Driving distraction at night: The impact of cell phone use on driving behaviors among young drivers

Currently, young drivers are more likely than other drivers to use cell phones while driving at night, which has become a major cause of road crashes. However, limited attention has been given to distracted nighttime driving. Therefore, the aim of this study was to explore the interaction effect of cell phone use and time of day (daytime and nighttime) on young drivers’ car-following performance. Forty-three young drivers engaged in a driving simulator experiment with a within-subject design that included three distractions (no distraction, talking and texting on a cell phone) and two times of day. This paper applied non-parametric tests to analyze the data and obtained the following results: (1) the standard deviation of lane position (SDLP) did not significantly differ at either time of day under no distraction, but it was significantly higher at night on straight roads and large-radius curves after introducing distractions. In addition, participants drove faster and gave less headway on small-radius curves under both distractions at night; (2) texting significantly increased the SDLP, while there was less lateral variation during the talking tasks than under no distraction on simple road sections; and (3) compared with the experienced drivers, the novice drivers drove faster during the talking tasks on small-radius curves, but there was no significant difference between groups during the texting tasks. These findings provide both theoretical and practical implications for related policy makers to enhance traffic safety.     

The effect of a delayed weekend sleep pattern on sleep and morning functioning

Abstract

It is a common practice for young adults to delay their weekend sleep schedule. The present study was designed to assess the effect of this sleep pattern on the sleep of Sunday night and the functioning of Monday morning. The sleep schedules of 30 young adults were manipulated for 2 consecutive weeks. In the Habitual-Sleep (HS) week, subjects followed their habitual sleep schedule throughout the week; in the Delayed-Sleep (DS) week, subjects' sleep schedule on Friday and Saturday nights were delayed by two hours. Compared to the HS week, subjects showed significantly lower subjective sleepiness near bedtime and trends of longer sleep onset latency on Sunday night in the DS week. In addition, there was both lowered cognitive performance and overall mood rating on Monday morning in the DS week. The delayed weekend sleep pattern contributes to Sunday night insomnia and the Monday morning “blues”.     

Forgetting as a function of sleep at different times of day

The experiment studied the separate effects of sleep and time period of retention interval on forgetting. A free recall task was given to independent groups of subjects either at night or in the morning, and a second recall demanded 5 h later, after an intervening period of sleeping or waking activity. Oral body temperatures (BT) were measured at each session. The data were analysed in terms of (a) immediate recall at test 1, and (b) amount forgotten from test 1 to test 2. Immediate recall was higher for morning groups, in agreement with previous findings, serial position analysis indicating that the effect is confined to enhancement of the primary memory component. Long-term retention was higher over the night interval, irrespective of sleeping conditions, though having slept at night produced better retention than having stayed awake. Sleep during the morning was not effective in reducing forgetting. BT showed a marked drop for both night groups and rise for day groups over the retention interval. Alternative explanations for the classical sleep/memory findings are suggested in terms of (a) differential effects of sleep stages on memory, and (b) the underlying diurnal variation in BT and other processes.     

Factors responsible for performance on the day–night task: response set or semantics?

In a recent study Diamond, Kirkham and Amso (2002) obtained evidence consistent with the claim that the day-night task requires inhibition because the picture and its corresponding conflicting response are semantically related. In their study children responded more accurately in a dog-pig condition (see /day picture/ say "dog"; see /night picture/ say "pig") than the standard day-night condition (see /day picture/ say "night"; see /night picture/ say "day"). However, there is another effect that may have made the day-night condition harder than the dog-pig condition: the response set effect. In the day-night condition the names of the two stimuli ("day" and "night") and the two corresponding conflicting responses ("night" and "day") are from the same response set: both "day" and "night". In the dog-pig condition the names of the stimuli ("day", "night") and the corresponding responses ("dog", "pig") are from a different response set. In two experiments (Experiment 1 with 4-year-olds (n = 25); Experiment 2 with , 4-, 5-, 7- and 11-year-olds (n = 81)) children were tested on four experimental conditions that enabled the effects of semantics and response set to be separated. Overall, our data suggest that response set is a major factor in creating the inhibitory demands of the day-night task in children of all ages. Results are discussed in relation to other inhibitory tasks.     

Effects of chlorpromazine on fixed-ratio responding: modification by fixed-interval discriminative stimuli.

Effects of chlorpromazine (1 to 100 mg/kg) were assessed on two pigeons' responding under various modifications of a multiple schedule of food delivery. During a fixed-interval component, the first response after 5 min produced food; during the subsequent, fixed-ratio component, the 30th response produced food. Modifications of the schedule entailed changes in stimulus conditions imposed during the fixed-ratio component that did not systematically alter characteristics of performance under non-drug conditions. In the first phase of the experiment, distinctive visual stimuli were correlated with each schedule component (conventional multiple schedule); chlorpromazine produced small decreases in fixed-ratio responding (20% at 30 mg/kg). When each response during the fixed-ratio component produced the stimulus correlated with the fixed-interval schedule (fixed-interval discriminative stimulus) for 1.2 s, effects of chlorpromazine were not different from those under the conventional multiple schedule. Chlorpromazine produced greater decreases in fixed-ratio responding (55% at 30 mg/kg) when either the first response of each fixed ratio changed the stimulus correlated with the fixed-ratio schedule to the fixed-interval discriminative stimulus for the remainder of the fixed-ratio component, or when the fixed-interval discriminative stimulus was presented independently of responding according to a matched temporal sequence. When the fixed-interval discriminative stimulus was present continuously during the fixed-ratio component (mixed schedule), chlorpromazine produced even more substantial decreases in fixed-ratio responding (greater than 80% at 30 mg/kg). Effects of chlorpromazine on fixed-interval responding were also modified by the schedules of fixed-interval discriminative stimulus presentation. The effects of chlorpromazine were a joint function of the stimuli prevailing during the multiple schedule and the degree to which responding influenced these stimuli.     

Finding everland: Flight fantasies and the desire to transcend mortality

Fantasies and dreams of flight are ubiquitous across cultures and throughout history and often linked to immortality. A perspective derived from terror management theory holds that flight fantasies are appealing because they suggest transcendence of the limitations of creatureliness and mortality. Five studies established the link between mortality concerns and flight fantasy. In Study 1, participants showed greater desire to fly after contemplating death compared to a control topic. In Study 2, participants showed greater desire to fly, but not to engage in other supernatural acts, after contemplating death compared to a control topic. In Studies 3 and 4, participants who engaged in flight fantasy did not subsequently demonstrate defensive reactions to a death reminder observed in nonflight conditions. Study 5 showed that flight fantasy, but not other pleasurable or empowering fantasies, decreased death thought accessibility after mortality salience, and this effect was uniquely mediated by a feeling of freedom from bodily limits.     

Inhibitory and working memory demands of the day–night task in children

Gerstadt, Hong, and Diamond (1994) investigated the development of inhibitory control in children aged 3½ – 7 years using the day–night task. In two studies we build on Gerstadt et al.'s findings with a measure of inhibitory control that can be used throughout childhood. In Study 1 (twenty‐four 3½‐year‐olds and sixteen 5‐year‐olds) we modified Gerstadt et al.'s day–night task. Using this modified task we obtained further evidence for the development of inhibitory control in children between 3½ and 5‐years‐old. We also obtained data suggestive of more moderate working memory development. In Study 2 we tested 84 children aged between 3½ and 11 years. The aim was to determine how much inhibition and working memory taxed children of different ages. We obtained evidence that inhibitory demands were high and that inhibitory development was non‐linear, with rapid improvements in children between 3½ and 5 years and only modest improvements thereafter. In contrast, working memory demands were low and working memory development was more linear. We interpret these findings as evidence that working memory has relatively little impact on performance in our modified version of the day–night task.