The success of policy involves not only good design but a good understanding of how the public wi... more The success of policy involves not only good design but a good understanding of how the public will respond behaviorally to the benefits or detriments of that policy. Behavioral science has greatly contributed to how we understand the impact of monetary costs on behavior and has therefore contributed to policy design. Consumption taxes are a direct result of this; for example, cigarette taxes that aim to reduce cigarette consumption. In addition to monetary costs, time may also be conceptualized as a constraint on consumption. Time costs may therefore have policy implications, for example, long waiting times could deter people from accessing certain benefits. Recent data show that behavioral economic demand curve methods used to understand monetary cost may also be used to understand time costs. In this article we discuss how the impact of time cost can be conceptualized as a constraint on demand for public benefits utilization and public health when there are delays to receiving the benefits. Policy examples in which time costs may be relevant and demand curve methods may be useful are discussed in the areas of government benefits, public health, and transportation design.
Journal of the Experimental Analysis of Behavior, Sep 1, 2006
Given a commodity available at different prices, a unit-price account of choice predicts preferen... more Given a commodity available at different prices, a unit-price account of choice predicts preference for the cheaper alternative. This experiment determined if rhesus monkeys preferred remifentanil (an ultra-short-acting m-opioid agonist) delivered at a lower unit price over a higher-priced remifentanil alternative (Phases 1 and 3). Choice between equal-priced alternatives also was assessed (Phase 2). A discrete-trials procedure was arranged in which three monkeys chose between two remifentanil alternatives by responding on one of two levers. Different prices were arranged by manipulating drug dose (0.3 and 0.1 mg/kg/injection) and/or the ratio requirement. Monkeys usually chose the largerdose alternative even when it was more expensive. Only when unit prices were relatively high (e.g., large response requirements) did monkeys choose the cheaper (or equally priced) smaller-dose alternative. Employing larger doses (0.9 and 0.3 mg/kg/injection) attenuated the larger-dose preference. The results demonstrate that choice was not determined simply by unit price. An alternative model that employs demand-function analysis to generate choice predictions is proposed.
Sensors that track physiological biomarkers of health must be successfully incorporated into a fi... more Sensors that track physiological biomarkers of health must be successfully incorporated into a fieldable, wearable device if they are to revolutionize the management of remote patient care and preventative medicine. This perspective article discusses logistical considerations that may impede the process of adapting a body-worn laboratory sensor into a commercial-integrated health monitoring system with a focus on examples from sleep tracking technology.
Impaired neurobehavioral performance induced by fatigue may compromise safety in 24-hr operationa... more Impaired neurobehavioral performance induced by fatigue may compromise safety in 24-hr operational environments such as aviation. As such, non-invasive, reliable, and valid methods of objectively detecting compromised performance capacity in operational settings could be valuable as a means of identifying, preventing, and mitigating fatigue-induced safety risks. One approach that has attracted attention in recent years is quantitative speech analysis, but the extent of its operational feasibility, validity of the metrics, and sensitivity to operationally-relevant factors in aviation remains unknown. To this end, the present report offers an initial proof-of-concept evaluation of a speech analysis method based on Cepstrum Coefficient modeling, using voice files from a broad sample of 195 cabin crew personnel collected during the 2009-2010 U.S. Civil Aerospace Medical Institute-sponsored Flight Attendant Field Study . Using a personal digital assistant device, participants recited five standardized phrases in random order before and after each workday and sleep episode throughout their respective 3-4 week study periods. Operational acceptability of the procedure was high, as indicated by high protocol compliance and, despite the inherent variability of the timing and environments in which the test sessions occurred, the 13,975 files from 2,795 valid sessions were of sufficient quality for formal analysis. Individualized "baseline" speech models were built from the files collected during test sessions coinciding with optimal neurobehavioral performance, as determined by 5-min Psychomotor Vigilance Test (PVT) reaction times (RT), then speech deviation scores relative to individual baseline models were calculated for the test sessions that preceded and concluded each "trip" of multiple consecutive work days. Regarding validity, speech scores correlated significantly with PVT RTs and Lapses (RTs > 500 msec), with a stronger relationship to Lapses, but high variability at the low range of both performance variables suggests the influence of other factors. Regarding sensitivity to operational factors, average Pre-Trip vs. Post-Trip speech scores differed significantly, although scores unexpectedly decreased from Pre to Post, an artifact attributable to the composition of the baseline session pool. Nonetheless, the pattern of speech data echoed performance data from our previous report in which scores were most affected in crew of Regional carriers, with Junior seniority, and in Domestic operations. These initial results reveal promising validity and sensitivity of Cepstrum Coefficient modeling for speech signal analysis of fatigue in dynamic operational environments. Remaining questions underscore the need to further explore the dataset to determine the precise relationship between speech production and neurobehavioral performance capacity, the parameters for constructing individualized models, and standardized quantitative speech-based definitions of fatigue.
Journal of the Experimental Analysis of Behavior, Mar 1, 1990
In Experiment 1, 4 rats earned their daily food ration by choosing between two levers. One lever ... more In Experiment 1, 4 rats earned their daily food ration by choosing between two levers. One lever delivered two regular and one quinine-adulterated food pellets, and the other delivered two regular and four quinine pellets. A 20-s intertrial interval separated successive choices. Sessions began with 10 forced trials during which only one lever, selected with p = .5 and cued by a light above it, could deliver its reinforcer. Forced trials were followed by 30 or 150 trials, depending on the condition, during which choices to either lever could be reinforced. Over this range, absolute choice of the four- quinine, two-regular-pellet lever was inversely related to the number of free-choice trials, establishing this reinforcer as an inferior good. In Condition 1 of Experiment 2, the prior design was altered in two ways: (a) one lever delivered four quinine pellets, and the other lever delivered one standard pellet; and (b) sessions ended after 140 free-choice trials. When the number of free-choice trials was reduced to 100 (Condition 2), all 3 rats increased their preference for quinine pellets, confirming their status as an inferior good. In the next several conditions, the number of quinine pellets provided for selecting its associated lever was varied between three and four. Preference for the quinine-pellet alternative was inversely related to the number of pellets it provided, a result defining it as a Giffen good. These findings are not accommodated readily by extant choice models and complicate the search for a unitary model of choice.
Journal of the Experimental Analysis of Behavior, Jul 1, 1974
Pigeons' choice responses on either of two keys occasionally produced entry into a terminal link ... more Pigeons' choice responses on either of two keys occasionally produced entry into a terminal link associated with that key. During the terminal links, responses produced access to grain according to mixedor multiple-interval schedules. The multiple schedules provided stimuli correlated with the interval of time preceding reinforcement whereas the mixed schedules did not. The two subjects reliably preferred the multiple schedules to the mixed schedules throughout a series of replications. Preference for the lmlultiple schedule was much smaller than suggested by earlier work comparing multiple and mixed schedules that had much higher rates of entry into the terminal links. Preference for the multiple schedule was greatly increased in this study when the rate of entry into the terminal schedules was increased. As in previous studies, these high preferences may have been the result of a sharp increase in the number of reinforcements on the multiple (as opposed to the mixed) schedule. The reliable but smaller preferences for the multiple schedule found with lower rates of entry into the terminal links were unconfounded by differences in the number of reinforcements obtained in the two terminal links. 'In conducting the research described in this report, the investigators adhered to the "Guide for Laboratory Animal Facilities and Care", as promulgated by the Committee on Revision of the Guide for Laboratory Animal Facilities and Care of the Institute of Labora-
A. Basic and Translational Sleep and Circadian Science X. Behavior and Performance stressor react... more A. Basic and Translational Sleep and Circadian Science X. Behavior and Performance stressor reactivity to insufficient sleep differed between day and night shift nurses working at a cancer hospital. Methods: Participants were 39 day-shift and 19 night-shift nurses at a cancer hospital (M age =35.36±12.00). Using ecological momentary assessments for 14 days, we asked participants about their previous night's sleep characteristics and their daily stressor frequency and severity before lunch, during afternoon, and before bedtime. Using multi-level modeling, we tested whether previous night's sleep duration, quality, or sufficiency predicted next day's total stressor frequency or severity. For analyses with significant within-person effects, we extracted a reactivity slope for each participant. We used t-tests to examine whether day and night shift nurses differed in reactivity. Results: There were significant within-person associations of sleep duration with (a) stressor frequency (b=-.07, p<.001) and (b) stressor severity (b=-.76, p<.001), but no associations of sleep quality or sufficiency with stressor frequency or severity. Day and night shift nurses did not differ in either of these operationalizations of stressor reactivity to insufficient sleep, or on any stressor or sleep variables except for average sleep duration (M night =6.87±2.57 vs. M day =8.02±1.84, p<.001). Conclusion: These findings suggest that the phenomenon of perceiving more stressors in response to insufficient sleep exists regardless of work shifts. Given the previously found association between stressor reactivity to insufficient sleep and body mass index in middle-aged workers, further analyses will test how this reactivity is associated with health outcomes in oncology nurses.
Fatigue-induced impairments in neurobehavioral performance capacity may compromise safety in 24-h... more Fatigue-induced impairments in neurobehavioral performance capacity may compromise safety in 24-hr operational environments, and developing reliable and valid methods of identifying work/rest patterns that produce fatigue and undermine performance is important. One approach is the use of biomathematical modeling as a means of predicting, preventing, and mitigating fatigue-induced safety risks. The Sleep, Activity, Fatigue, and Task Effectiveness model (SAFTE; is among the more mature fatigue models currently used in military, shift-work, and various transportation operations. The SAFTE model was constructed empirically, integrating classical physiological and circadian processes with task effectiveness predictions based on the scientific literature of standardized laboratory tests. SAFTE has been validated against accident risk in railroad operations; however, as with virtually all fatigue models, the extent to which variations in model predictions correspond to variations in actual performance capacity in the aviation environment is largely unknown. The present report offers a field validation of the SAFTE model using data from a broad sample of 178 aviation cabin crew from the 2009-2010 FAA Civil Aerospace Medical Institute (CAMI)-sponsored Flight Attendant Field Study . Data were collected daily throughout each individual's continuous 3 to 4-week study period. Objective sleep/wake patterns were determined via actigraphy. In addition, a personal digital assistant device was used to maintain an activity log documenting work schedules and locations, and neurobehavioral performance capacity was assessed via standardized 5-min Psychomotor Vigilance Tests (PVT) taken before and after each work day and sleep episode. Individual sleep, wake, and work patterns were entered into the Fatigue Avoidance Scheduling Tool (FAST) software for continuous records of Predicted Effectiveness (PVT Speed [1/Reaction Time] expressed as a % of individual optimum baseline). SAFTE-FAST performance predictions were then temporally aligned with the 10,659 valid PVT test sessions from the field study, and performance data from each session were expressed as Actual Effectiveness (same as Predicted Effectiveness), Reaction Time (RT), Speed (1/RT), Lapses (RTs>500 msec), and False Starts (FS; premature responses). Linear regression of mean PVT performances across 5% SAFTE prediction bins revealed significant correlations between SAFTE Predicted Effectiveness and PVT Actual Effectiveness (R 2 =0.884, p<.001), RT (R 2 =0.745, p<.01), and Lapses (R 2 =0.486, p<.05). Identical analyses of the 7,533 valid PVT sessions completed while away on a multi-day work "trip" (i.e., excluding sessions while off-duty at home) revealed significant correlations between SAFTE Predicted Effectiveness and mean PVT Actual Effectiveness (R 2 =0.889, p<.001), RT (R 2 =0.819, p<.001), Speed (R 2 =0.808, p<.001), and Lapses (R 2 =0.484, p<.05). Finally, separate regression analyses of all valid Pre-Work (n=1,712) and Post-Work (n=1,934) PVT sessions revealed a significant Pre-Work correlation between SAFTE Predicted Effectiveness and mean PVT Actual Effectiveness (R 2 =0.530, p<.05), and significant Post-Work correlations between SAFTE Predicted Effectiveness and mean PVT Actual Effectiveness (R 2 =0.600, p<.05), RT (R 2 =0.887, p<.001), Speed (R 2 =0.539, p<.05), and Lapses (R 2 =0.901, p<.001). Despite inherent technical limitations and issues of inter-individual variability, these results clearly support the validity of the SAFTE model for population-level prediction of fatigue-induced impairments in objective neurobehavioral performance capacity in extremely dynamic 24-hr field operations such as commercial aviation.
Impaired performance induced by fatigue may compromise safety in commercial aviation. Given the d... more Impaired performance induced by fatigue may compromise safety in commercial aviation. Given the direct role flight attendants play in passenger safety, the U.S. Congress ordered a comprehensive examination of fatigue in cabin crew, including a field study of actual flight operations. This report provides an overview of the field study results, focusing on objective measures of sleep patterns and neurocognitive performance (Psychomotor Vigilance Test, PVT) over a 3-4 week period in 202 U.S.-based flight attendants of all seniority levels working for network, low-cost, and regional carriers embarking on domestic and international flight operations. On average, flight attendants slept 6.3 hr on days off and 5.7 hr on work days, fell asleep 29 min after going to bed, awoke four times per sleep episode, and spent 77% of each episode actually sleeping. After controlling for reserve status, gender, and age, junior-level flight attendants had the shortest sleep latencies on their days off. Those working international operations slept significantly less (4.9 hr vs. 5.9 hr) and less efficiently (75% vs. 79%), compared with their colleagues in domestic operations. All flight attendants exhibited significant impairments during prework PVT tests when compared to their own optimum baseline performance. Across the workday, regional flight attendants committed fewer premature PVT responses, junior-level participants produced significantly higher post-work reaction times, and those working international flights produced better pre-work reaction times but had a greater increase in lapses. These objective data are consistent with other shift work research and echo subjective survey findings across the U.S. flight attendant community. Additional planned analyses of this dataset may identify the precise operational variables that contribute to fatigue in cabin crew.
beezdemand: Behavioral Economic Easy Demand, a novel package for performing behavioral economic a... more beezdemand: Behavioral Economic Easy Demand, a novel package for performing behavioral economic analyses, is introduced and evaluated. beezdemand extends the statistical program to facilitate many of the analyses performed in studies of behavioral economic demand. The package supports commonly used options for modeling operant demand and performs data screening, fits models of demand, and calculates numerous measures relevant to applied behavioral economists. The free and open source beezdemand package is compared to commercially available software (i.e., GraphPad Prism™) using peerreviewed and simulated data. The results of this study indicated that beezdemand provides results consistent with commonly used commercial software but provides a wider range of methods and functionality desirable to behavioral economic researchers. A brief overview of the package is presented, its functionality is demonstrated, and considerations for its use are discussed.
Journal of Pharmacology and Experimental Therapeutics, Mar 29, 2006
Human polydrug abusers often take combinations of opioids and stimulants, but it is not clear why... more Human polydrug abusers often take combinations of opioids and stimulants, but it is not clear why. Behavioral economics with demand curve analysis is uniquely able to separate two of the possibilities: that the drug combination increases the reinforcing potency of the component drugs or that the drug combination is a more effective reinforcer than either drug alone. Rhesus monkeys self-administered a range of doses of cocaine, remifentanil, and combinations of the drugs through indwelling intravenous catheters; the number of responses required for each drug infusion increased across drug-availability
Journal of the Experimental Analysis of Behavior, Nov 1, 1995
The concepts of behavioral economics have proven to be useful for understanding the environmental... more The concepts of behavioral economics have proven to be useful for understanding the environmental control of overall levels of responding for a variety of commodities, including reinforcement by drug self-administration. These general concepts have implications for the assessment of abuse liability and drug abuse intervention and the formulation of public policy on drug abuse. An essential requirement is the ability to compare the demand for different drugs directly in order to assess relative abuse liability, and to compare demand for the same drug under different environmental and biological interventions to assess their ability to reduce demand. Until now, such comparisons were hampered by the confounding effect of varying drug doses and potencies that prevent quan- titative comparisons of demand elasticity-sensitivity of consumption and responding to the con- straint of price (effort). In this paper we describe a procedure to normalize demand-curve analysis that permits dose-and potency-independent comparisons of demand across drugs. The procedure is shown to be effective for comparing drug demand within and across the drug classes. The tech- nique permits a quantitative ordering of demand that is consistent with the peak levels of responding maintained by the drugs. The same technique is generalized for the comparison of other types of reinforcers under different biological conditions.
Journal of the Experimental Analysis of Behavior, Sep 1, 1991
The concepts of behavioral economics have proven useful for understanding the environmental contr... more The concepts of behavioral economics have proven useful for understanding the environmental control of overall levels of responding for a variety of commodities, including reinforcement by drug selfadministration. These general concepts are summarized for application to the analysis of drug-rein- forced behavior and proposed as the basis for future applications. This behavioral agenda includes the assessment of abuse liability, the assay of drug-reinforcer interactions, the design of drug abuse interventions, and the formulation of drug abuse public policy. These separate domains of investigation are described as part of an overall strategy for designing model projects to control drug use and testing public policy initiatives.
Journal of the Experimental Analysis of Behavior, Mar 1, 1998
In Experiments 1 and 2, 25 and 48 college students made binary choices between hypothetical money... more In Experiments 1 and 2, 25 and 48 college students made binary choices between hypothetical money amounts. In Part A, choices were between small amounts available with certainty and larger amounts ($10 to $10,000) available with risk. Choices in Part B were between immediate small amounts and delayed larger amounts. As money amount grew, risk aversion and delay aversion both changed but in opposite ways: Risk aversion grew but delay aversion shrank. Part C of Experiment 1 pitted risky amounts against delayed amounts, and its results were consistent with those of Parts A and B. Equivalences of particular risks and delays depended on the particular monetary amounts to which they attached. In Experiment 3, 20 college students made binary choices between money amounts, knowing that they would actually receive some of the selections they made. In Part A, choices were between certain small amounts and risky larger amounts ($1 and $10). Choice problems in Part B were between immediate small amounts and delayed receipt of $1 or $10. The results were like those of Experiment 1, though weaker. These results argue against models of choice that posit an equivalence of risk and delay that is independent of monetary amount.
Journal of the Experimental Analysis of Behavior, Nov 1, 2007
This experiment was conducted to test the predictions of two behavioral-economic approaches to qu... more This experiment was conducted to test the predictions of two behavioral-economic approaches to quantifying relative reinforcer efficacy. The normalized demand analysis suggests that characteristics of averaged normalized demand curves may be used to predict progressive-ratio breakpoints and peak responding. By contrast, the demand analysis holds that traditional measures of relative reinforcer efficacy (breakpoint, peak response rate, and choice) correspond to specific characteristics of nonnormalized demand curves. The accuracy of these predictions was evaluated in rats' responding for food or water: two reinforcers known to function as complements. Consistent with the first approach, predicted peak normalized response output values obtained under single-schedule conditions ordinally predicted progressive-ratio breakpoints and peak response rates obtained in a separate condition. Combining the minimum-needs hypothesis with the normalized demand analysis helped to interpret prior findings, but was less useful in predicting choice between food and water-two strongly complementary reinforcers. Predictions of the demand analysis had mixed success. Peak response outputs predicted from the non-normalized water demand curves were significantly correlated with obtained peak responding for water in a separate condition, but none of the remaining three predicted correlations was statistically significant. The demand analysis fared better in predicting choice-relative consumption of food and water under single schedules of reinforcement predicted preference under concurrent schedules significantly better than chance.
Background. Previous research conducted by DRDC Toronto to evaluate watch schedule variants used ... more Background. Previous research conducted by DRDC Toronto to evaluate watch schedule variants used on RCN submarines indicated very significant and deleterious effects of the watch system on modeled cognitive effectiveness of RCN submariners. Subsequently, DRDC Toronto hosted an International Submarine Watch Schedule Symposium which led to a new RCN submarine watch schedule which improved modeled performance by about 30%. The RCN surface fleet is aware of this work and supported a request to conduct an evaluation of the surface fleet watch schedule. We evaluated the watch schedules used aboard HMCS St John's at the end of Op Nanook 2011, over the 8 days that STJ transitioned from the high Arctic to Halifax. Methods. The ages of the forty-five sailors who participated in this at-sea trial ranged from 21 to 48 years, with a mean age and standard deviation of 32.9 ± 7.7 years. Ten of these sailors were non-watch-standers, 14 sailors were from the 1-in-2 Port (Front) watch, 14 sailors were from the 1-in-2 Starboard (Back) watch, three sailors were from the 1-in-3 Engineering watch, and four sailors were from the 1-in-4 Engineering watch. All subjects wore wrist activity monitors (actigraphs) to measure their daily sleep patterns quantitatively. The actigraphically-measured sleep and daily work hours were the two data sets that were inputted to the FAST TM (Fatigue Avoidance Scheduling Tool) software to generate modeled cognitive effectiveness for each subject. All subjects maintained a daily activity, sleep and mood log. Results. Modeled cognitive effectiveness showed worrisome levels of performance equivalent to intoxicated levels of blood alcohol (BAC 0.05% and 0.08%) and well beyond those levels for all watch system variants. The main effect of 'groups' for 'difficulty falling asleep' was significant with post hoc tests showing that the 1-in-2 Port (Front) watch had less difficulty getting to sleep relative to the non-watch standers. With respect to the Visual Analogue Scale data, the non-watch-standers reported being in a 'happier' mood than either of the 1-in-2 Port (Front) and Starboard (Back) watch. Collapsed over the non-watch-standers, 1-in-2 Port (Front) watch, and 1-in-2 Starboard (Back) watch syndicates, 6 SOAP parameters (difficulty concentrating, level of depression, level of irritability, level of fatigue, work frustration and physical discomfort) deteriorated during the trial relative to the pre-trial baseline. Conclusions. The current surface fleet watch schedule is sub-optimal in that it results in worrisome levels of cognitive effectiveness in many of our sailors. Recommendations. An alternative watch schedule which is more sparing of submariner cognitive effectiveness should be developed and implemented. Please see the details of an alternative watch system in the body of this report under 'recommendations'. ii DRDC Toronto TR 2012-078 Résumé …..... Des recherches antérieures réalisées par RDDC Toronto pour évaluer les variantes d'horaire de garde utilisées à bord des sous-marins de la MRC montrent des incidences importantes et néfastes du système de quart sur l'efficacité cognitive des sous-mariniers. Subséquemment, RDDC Toronto a organisé un symposium international sur les horaires de garde à bord des sous-marins qui a permis de réaliser un nouvel horaire de garde à bord des sous-marins de la MRC, améliorant d'environ 30 p. cent le rendement modélisé. Les membres de la flotte de surface de la MRC connaissent ces travaux et ont demandé qu'une évaluation de l'horaire de garde de la flotte de surface soit réalisée. Nous avons évalué les horaires de garde utilisés à bord du NCSM St John's à la fin de l'opération Nanook 2011, pendant les huit jours de la traversée du St John's de l'Extrême-Arctique à Halifax. Méthodologie. Les quarante-cinq marins qui ont participé à cette expérience en mer étaient âgées de 21 à 48 ans, avec une moyenne d'âge de 32,9 ans et un écart type de ± 7,7 ans. Dix de ces marins étaient affectés à des postes autres que des poste de garde, quatorze étaient affectés comme vigies de quart avant, à raison d'un tour de garde sur deux, quatorze comme vigies de quart arrière, à raison d'un tour de garde sur deux, trois comme mécaniciens chefs de quart, à raison d'un tour de garde sur trois et quatre comme mécaniciens chefs de quart, à raison d'un tour de garde sur quatre. Chacun des participants portait un bracelet moniteur (actigraphe) de ses activités, afin de mesurer quantitativement sa structure de sommeil. Les heures de travail quotidien et de sommeil mesurées par actigraphe sont les deux ensembles de données enregistrés dans le logiciel FAST TM (Fatigue Avoidance Scheduling Tool) pour établir l'efficacité cognitive de chaque participant. Tous les participants ont tenu, quotidiennement, un registre sur leurs activités, leur sommeil et leur humeur. Résultats. L'efficacité cognitive a montré des niveaux de rendement inquiétants, équivalents à un rendement en état d'ébriété (à un taux d'alcoolémie se situant entre 0,05 % et 0,08 %) et bien au-delà des niveaux de toutes les variantes d'un système de garde. Le principal effet des « groupes » à l'égard de la « difficulté à s'endormir » s'est avéré important dans les essais ultérieurs montrant que les vigies de quart avant, à raison d'un tour sur deux, avaient moins de difficulté à s'endormir que les marins affectés à des postes autres que des poste de garde. En ce qui concerne les données de l'échelle visuelle analogue, les marins affectés à des postes autres que des poste de garde se sont avérés être de meilleure humeur que les vigies de quart avant et les vigies de quart arrière, à raison d'un tour de garde sur deux. Tant chez les marins affectés à des postes autres que des poste de garde, que chez les vigies de quart avant et les vigies de quart arrière, à raison d'un tour de garde sur deux, six paramètres du profil d'évaluation des opérations spéciales (difficulté de concentration, niveau de dépression, niveau d'irritabilité, niveau de fatigue, frustration au travail et inconfort physique) se sont détériorés au cours de l'essai. Conclusions. L'horaire de garde actuel de la flotte de surface est sous-optimal du fait qu'il entraîne une réduction inquiétante du niveau d'efficacité cognitive de certains de nos marins. Recommandations. Un nouvel horaire de garde, moins éprouvant pour l'efficacité cognitive des sous-mariniers, devrait être élaboré et mis en oeuvre. Veuillez voir les détails d'un nouvel horaire de garde dans le corps du présent rapport sous « Recommandations ».
This study was conducted to evaluate the impact of public perceptions of vaccine safety and effic... more This study was conducted to evaluate the impact of public perceptions of vaccine safety and efficacy on intent to seek COVID-19 vaccination using hypothetical vaccine acceptance scenarios. The behavioral economic methodology could be used to inform future public health vaccination campaigns designed to influence public perceptions and improve public acceptance of the vaccine. In June 2020, 534 respondents completed online validated behavioral economic procedures adapted to evaluate COVID-19 vaccine demand in relation to a hypothetical development process and efficacy. An exponential demand function was used to describe the proportion of participants accepting the vaccine at each efficacy. Linear mixed effect models evaluated development process and individual characteristic effects on minimum required vaccine efficacy required for vaccine acceptance. The rapid development process scenario increased the rate of decline in acceptance with reductions in efficacy. At 50% efficacy, 68.8% of respondents would seek the standard vaccine, and 58.8% would seek the rapid developed vaccine. Rapid vaccine development increased the minimum required efficacy for vaccine acceptance by over 9 percentage points, γ = 9.36, p < 0.001. Past-3-year flu vaccination, γ = -23.00, p < 0.001, and male respondents, γ = -4.98, p = 0.037, accepted lower efficacy. Respondents reporting greater conspiracy beliefs, γ = 0.39, p < 0.001, and political conservatism, γ = 0.32, p < 0.001, required higher efficacy. Male, γ = -4.43, p = 0.013, and more conservative, γ = -0.09, p = 0.039, respondents showed smaller changes in minimum required efficacy by development process. Information on the vaccine development process, vaccine efficacy, and individual differences impact the proportion of respondents reporting COVID-19 vaccination intentions. Behavioral economics provides an empirical method to estimate vaccine demand to target subpopulations resistant to vaccination.
Impaired performance induced by fatigue may compromise safety in commercial aviation. Given the d... more Impaired performance induced by fatigue may compromise safety in commercial aviation. Given the direct role flight attendants play in passenger safety, the U.S. Congress ordered a comprehensive examination of fatigue in cabin crew, including a field study of actual flight operations. This report provides an overview of the field study results, focusing on objective measures of sleep patterns and neurocognitive performance (Psychomotor Vigilance Test, PVT) over a 3-4 week period in 202 U.S.-based flight attendants of all seniority levels working for network, low-cost, and regional carriers embarking on domestic and international flight operations. On average, flight attendants slept 6.3 hr on days off and 5.7 hr on work days, fell asleep 29 min after going to bed, awoke four times per sleep episode, and spent 77% of each episode actually sleeping. After controlling for reserve status, gender, and age, junior-level flight attendants had the shortest sleep latencies on their days off. Those working international operations slept significantly less (4.9 hr vs. 5.9 hr) and less efficiently (75% vs. 79%), compared with their colleagues in domestic operations. All flight attendants exhibited significant impairments during prework PVT tests when compared to their own optimum baseline performance. Across the workday, regional flight attendants committed fewer premature PVT responses, junior-level participants produced significantly higher post-work reaction times, and those working international flights produced better pre-work reaction times but had a greater increase in lapses. These objective data are consistent with other shift work research and echo subjective survey findings across the U.S. flight attendant community. Additional planned analyses of this dataset may identify the precise operational variables that contribute to fatigue in cabin crew.
The success of policy involves not only good design but a good understanding of how the public wi... more The success of policy involves not only good design but a good understanding of how the public will respond behaviorally to the benefits or detriments of that policy. Behavioral science has greatly contributed to how we understand the impact of monetary costs on behavior and has therefore contributed to policy design. Consumption taxes are a direct result of this; for example, cigarette taxes that aim to reduce cigarette consumption. In addition to monetary costs, time may also be conceptualized as a constraint on consumption. Time costs may therefore have policy implications, for example, long waiting times could deter people from accessing certain benefits. Recent data show that behavioral economic demand curve methods used to understand monetary cost may also be used to understand time costs. In this article we discuss how the impact of time cost can be conceptualized as a constraint on demand for public benefits utilization and public health when there are delays to receiving the benefits. Policy examples in which time costs may be relevant and demand curve methods may be useful are discussed in the areas of government benefits, public health, and transportation design.
Journal of the Experimental Analysis of Behavior, Sep 1, 2006
Given a commodity available at different prices, a unit-price account of choice predicts preferen... more Given a commodity available at different prices, a unit-price account of choice predicts preference for the cheaper alternative. This experiment determined if rhesus monkeys preferred remifentanil (an ultra-short-acting m-opioid agonist) delivered at a lower unit price over a higher-priced remifentanil alternative (Phases 1 and 3). Choice between equal-priced alternatives also was assessed (Phase 2). A discrete-trials procedure was arranged in which three monkeys chose between two remifentanil alternatives by responding on one of two levers. Different prices were arranged by manipulating drug dose (0.3 and 0.1 mg/kg/injection) and/or the ratio requirement. Monkeys usually chose the largerdose alternative even when it was more expensive. Only when unit prices were relatively high (e.g., large response requirements) did monkeys choose the cheaper (or equally priced) smaller-dose alternative. Employing larger doses (0.9 and 0.3 mg/kg/injection) attenuated the larger-dose preference. The results demonstrate that choice was not determined simply by unit price. An alternative model that employs demand-function analysis to generate choice predictions is proposed.
Sensors that track physiological biomarkers of health must be successfully incorporated into a fi... more Sensors that track physiological biomarkers of health must be successfully incorporated into a fieldable, wearable device if they are to revolutionize the management of remote patient care and preventative medicine. This perspective article discusses logistical considerations that may impede the process of adapting a body-worn laboratory sensor into a commercial-integrated health monitoring system with a focus on examples from sleep tracking technology.
Impaired neurobehavioral performance induced by fatigue may compromise safety in 24-hr operationa... more Impaired neurobehavioral performance induced by fatigue may compromise safety in 24-hr operational environments such as aviation. As such, non-invasive, reliable, and valid methods of objectively detecting compromised performance capacity in operational settings could be valuable as a means of identifying, preventing, and mitigating fatigue-induced safety risks. One approach that has attracted attention in recent years is quantitative speech analysis, but the extent of its operational feasibility, validity of the metrics, and sensitivity to operationally-relevant factors in aviation remains unknown. To this end, the present report offers an initial proof-of-concept evaluation of a speech analysis method based on Cepstrum Coefficient modeling, using voice files from a broad sample of 195 cabin crew personnel collected during the 2009-2010 U.S. Civil Aerospace Medical Institute-sponsored Flight Attendant Field Study . Using a personal digital assistant device, participants recited five standardized phrases in random order before and after each workday and sleep episode throughout their respective 3-4 week study periods. Operational acceptability of the procedure was high, as indicated by high protocol compliance and, despite the inherent variability of the timing and environments in which the test sessions occurred, the 13,975 files from 2,795 valid sessions were of sufficient quality for formal analysis. Individualized "baseline" speech models were built from the files collected during test sessions coinciding with optimal neurobehavioral performance, as determined by 5-min Psychomotor Vigilance Test (PVT) reaction times (RT), then speech deviation scores relative to individual baseline models were calculated for the test sessions that preceded and concluded each "trip" of multiple consecutive work days. Regarding validity, speech scores correlated significantly with PVT RTs and Lapses (RTs > 500 msec), with a stronger relationship to Lapses, but high variability at the low range of both performance variables suggests the influence of other factors. Regarding sensitivity to operational factors, average Pre-Trip vs. Post-Trip speech scores differed significantly, although scores unexpectedly decreased from Pre to Post, an artifact attributable to the composition of the baseline session pool. Nonetheless, the pattern of speech data echoed performance data from our previous report in which scores were most affected in crew of Regional carriers, with Junior seniority, and in Domestic operations. These initial results reveal promising validity and sensitivity of Cepstrum Coefficient modeling for speech signal analysis of fatigue in dynamic operational environments. Remaining questions underscore the need to further explore the dataset to determine the precise relationship between speech production and neurobehavioral performance capacity, the parameters for constructing individualized models, and standardized quantitative speech-based definitions of fatigue.
Journal of the Experimental Analysis of Behavior, Mar 1, 1990
In Experiment 1, 4 rats earned their daily food ration by choosing between two levers. One lever ... more In Experiment 1, 4 rats earned their daily food ration by choosing between two levers. One lever delivered two regular and one quinine-adulterated food pellets, and the other delivered two regular and four quinine pellets. A 20-s intertrial interval separated successive choices. Sessions began with 10 forced trials during which only one lever, selected with p = .5 and cued by a light above it, could deliver its reinforcer. Forced trials were followed by 30 or 150 trials, depending on the condition, during which choices to either lever could be reinforced. Over this range, absolute choice of the four- quinine, two-regular-pellet lever was inversely related to the number of free-choice trials, establishing this reinforcer as an inferior good. In Condition 1 of Experiment 2, the prior design was altered in two ways: (a) one lever delivered four quinine pellets, and the other lever delivered one standard pellet; and (b) sessions ended after 140 free-choice trials. When the number of free-choice trials was reduced to 100 (Condition 2), all 3 rats increased their preference for quinine pellets, confirming their status as an inferior good. In the next several conditions, the number of quinine pellets provided for selecting its associated lever was varied between three and four. Preference for the quinine-pellet alternative was inversely related to the number of pellets it provided, a result defining it as a Giffen good. These findings are not accommodated readily by extant choice models and complicate the search for a unitary model of choice.
Journal of the Experimental Analysis of Behavior, Jul 1, 1974
Pigeons' choice responses on either of two keys occasionally produced entry into a terminal link ... more Pigeons' choice responses on either of two keys occasionally produced entry into a terminal link associated with that key. During the terminal links, responses produced access to grain according to mixedor multiple-interval schedules. The multiple schedules provided stimuli correlated with the interval of time preceding reinforcement whereas the mixed schedules did not. The two subjects reliably preferred the multiple schedules to the mixed schedules throughout a series of replications. Preference for the lmlultiple schedule was much smaller than suggested by earlier work comparing multiple and mixed schedules that had much higher rates of entry into the terminal links. Preference for the multiple schedule was greatly increased in this study when the rate of entry into the terminal schedules was increased. As in previous studies, these high preferences may have been the result of a sharp increase in the number of reinforcements on the multiple (as opposed to the mixed) schedule. The reliable but smaller preferences for the multiple schedule found with lower rates of entry into the terminal links were unconfounded by differences in the number of reinforcements obtained in the two terminal links. 'In conducting the research described in this report, the investigators adhered to the "Guide for Laboratory Animal Facilities and Care", as promulgated by the Committee on Revision of the Guide for Laboratory Animal Facilities and Care of the Institute of Labora-
A. Basic and Translational Sleep and Circadian Science X. Behavior and Performance stressor react... more A. Basic and Translational Sleep and Circadian Science X. Behavior and Performance stressor reactivity to insufficient sleep differed between day and night shift nurses working at a cancer hospital. Methods: Participants were 39 day-shift and 19 night-shift nurses at a cancer hospital (M age =35.36±12.00). Using ecological momentary assessments for 14 days, we asked participants about their previous night's sleep characteristics and their daily stressor frequency and severity before lunch, during afternoon, and before bedtime. Using multi-level modeling, we tested whether previous night's sleep duration, quality, or sufficiency predicted next day's total stressor frequency or severity. For analyses with significant within-person effects, we extracted a reactivity slope for each participant. We used t-tests to examine whether day and night shift nurses differed in reactivity. Results: There were significant within-person associations of sleep duration with (a) stressor frequency (b=-.07, p<.001) and (b) stressor severity (b=-.76, p<.001), but no associations of sleep quality or sufficiency with stressor frequency or severity. Day and night shift nurses did not differ in either of these operationalizations of stressor reactivity to insufficient sleep, or on any stressor or sleep variables except for average sleep duration (M night =6.87±2.57 vs. M day =8.02±1.84, p<.001). Conclusion: These findings suggest that the phenomenon of perceiving more stressors in response to insufficient sleep exists regardless of work shifts. Given the previously found association between stressor reactivity to insufficient sleep and body mass index in middle-aged workers, further analyses will test how this reactivity is associated with health outcomes in oncology nurses.
Fatigue-induced impairments in neurobehavioral performance capacity may compromise safety in 24-h... more Fatigue-induced impairments in neurobehavioral performance capacity may compromise safety in 24-hr operational environments, and developing reliable and valid methods of identifying work/rest patterns that produce fatigue and undermine performance is important. One approach is the use of biomathematical modeling as a means of predicting, preventing, and mitigating fatigue-induced safety risks. The Sleep, Activity, Fatigue, and Task Effectiveness model (SAFTE; is among the more mature fatigue models currently used in military, shift-work, and various transportation operations. The SAFTE model was constructed empirically, integrating classical physiological and circadian processes with task effectiveness predictions based on the scientific literature of standardized laboratory tests. SAFTE has been validated against accident risk in railroad operations; however, as with virtually all fatigue models, the extent to which variations in model predictions correspond to variations in actual performance capacity in the aviation environment is largely unknown. The present report offers a field validation of the SAFTE model using data from a broad sample of 178 aviation cabin crew from the 2009-2010 FAA Civil Aerospace Medical Institute (CAMI)-sponsored Flight Attendant Field Study . Data were collected daily throughout each individual's continuous 3 to 4-week study period. Objective sleep/wake patterns were determined via actigraphy. In addition, a personal digital assistant device was used to maintain an activity log documenting work schedules and locations, and neurobehavioral performance capacity was assessed via standardized 5-min Psychomotor Vigilance Tests (PVT) taken before and after each work day and sleep episode. Individual sleep, wake, and work patterns were entered into the Fatigue Avoidance Scheduling Tool (FAST) software for continuous records of Predicted Effectiveness (PVT Speed [1/Reaction Time] expressed as a % of individual optimum baseline). SAFTE-FAST performance predictions were then temporally aligned with the 10,659 valid PVT test sessions from the field study, and performance data from each session were expressed as Actual Effectiveness (same as Predicted Effectiveness), Reaction Time (RT), Speed (1/RT), Lapses (RTs>500 msec), and False Starts (FS; premature responses). Linear regression of mean PVT performances across 5% SAFTE prediction bins revealed significant correlations between SAFTE Predicted Effectiveness and PVT Actual Effectiveness (R 2 =0.884, p<.001), RT (R 2 =0.745, p<.01), and Lapses (R 2 =0.486, p<.05). Identical analyses of the 7,533 valid PVT sessions completed while away on a multi-day work "trip" (i.e., excluding sessions while off-duty at home) revealed significant correlations between SAFTE Predicted Effectiveness and mean PVT Actual Effectiveness (R 2 =0.889, p<.001), RT (R 2 =0.819, p<.001), Speed (R 2 =0.808, p<.001), and Lapses (R 2 =0.484, p<.05). Finally, separate regression analyses of all valid Pre-Work (n=1,712) and Post-Work (n=1,934) PVT sessions revealed a significant Pre-Work correlation between SAFTE Predicted Effectiveness and mean PVT Actual Effectiveness (R 2 =0.530, p<.05), and significant Post-Work correlations between SAFTE Predicted Effectiveness and mean PVT Actual Effectiveness (R 2 =0.600, p<.05), RT (R 2 =0.887, p<.001), Speed (R 2 =0.539, p<.05), and Lapses (R 2 =0.901, p<.001). Despite inherent technical limitations and issues of inter-individual variability, these results clearly support the validity of the SAFTE model for population-level prediction of fatigue-induced impairments in objective neurobehavioral performance capacity in extremely dynamic 24-hr field operations such as commercial aviation.
Impaired performance induced by fatigue may compromise safety in commercial aviation. Given the d... more Impaired performance induced by fatigue may compromise safety in commercial aviation. Given the direct role flight attendants play in passenger safety, the U.S. Congress ordered a comprehensive examination of fatigue in cabin crew, including a field study of actual flight operations. This report provides an overview of the field study results, focusing on objective measures of sleep patterns and neurocognitive performance (Psychomotor Vigilance Test, PVT) over a 3-4 week period in 202 U.S.-based flight attendants of all seniority levels working for network, low-cost, and regional carriers embarking on domestic and international flight operations. On average, flight attendants slept 6.3 hr on days off and 5.7 hr on work days, fell asleep 29 min after going to bed, awoke four times per sleep episode, and spent 77% of each episode actually sleeping. After controlling for reserve status, gender, and age, junior-level flight attendants had the shortest sleep latencies on their days off. Those working international operations slept significantly less (4.9 hr vs. 5.9 hr) and less efficiently (75% vs. 79%), compared with their colleagues in domestic operations. All flight attendants exhibited significant impairments during prework PVT tests when compared to their own optimum baseline performance. Across the workday, regional flight attendants committed fewer premature PVT responses, junior-level participants produced significantly higher post-work reaction times, and those working international flights produced better pre-work reaction times but had a greater increase in lapses. These objective data are consistent with other shift work research and echo subjective survey findings across the U.S. flight attendant community. Additional planned analyses of this dataset may identify the precise operational variables that contribute to fatigue in cabin crew.
beezdemand: Behavioral Economic Easy Demand, a novel package for performing behavioral economic a... more beezdemand: Behavioral Economic Easy Demand, a novel package for performing behavioral economic analyses, is introduced and evaluated. beezdemand extends the statistical program to facilitate many of the analyses performed in studies of behavioral economic demand. The package supports commonly used options for modeling operant demand and performs data screening, fits models of demand, and calculates numerous measures relevant to applied behavioral economists. The free and open source beezdemand package is compared to commercially available software (i.e., GraphPad Prism™) using peerreviewed and simulated data. The results of this study indicated that beezdemand provides results consistent with commonly used commercial software but provides a wider range of methods and functionality desirable to behavioral economic researchers. A brief overview of the package is presented, its functionality is demonstrated, and considerations for its use are discussed.
Journal of Pharmacology and Experimental Therapeutics, Mar 29, 2006
Human polydrug abusers often take combinations of opioids and stimulants, but it is not clear why... more Human polydrug abusers often take combinations of opioids and stimulants, but it is not clear why. Behavioral economics with demand curve analysis is uniquely able to separate two of the possibilities: that the drug combination increases the reinforcing potency of the component drugs or that the drug combination is a more effective reinforcer than either drug alone. Rhesus monkeys self-administered a range of doses of cocaine, remifentanil, and combinations of the drugs through indwelling intravenous catheters; the number of responses required for each drug infusion increased across drug-availability
Journal of the Experimental Analysis of Behavior, Nov 1, 1995
The concepts of behavioral economics have proven to be useful for understanding the environmental... more The concepts of behavioral economics have proven to be useful for understanding the environmental control of overall levels of responding for a variety of commodities, including reinforcement by drug self-administration. These general concepts have implications for the assessment of abuse liability and drug abuse intervention and the formulation of public policy on drug abuse. An essential requirement is the ability to compare the demand for different drugs directly in order to assess relative abuse liability, and to compare demand for the same drug under different environmental and biological interventions to assess their ability to reduce demand. Until now, such comparisons were hampered by the confounding effect of varying drug doses and potencies that prevent quan- titative comparisons of demand elasticity-sensitivity of consumption and responding to the con- straint of price (effort). In this paper we describe a procedure to normalize demand-curve analysis that permits dose-and potency-independent comparisons of demand across drugs. The procedure is shown to be effective for comparing drug demand within and across the drug classes. The tech- nique permits a quantitative ordering of demand that is consistent with the peak levels of responding maintained by the drugs. The same technique is generalized for the comparison of other types of reinforcers under different biological conditions.
Journal of the Experimental Analysis of Behavior, Sep 1, 1991
The concepts of behavioral economics have proven useful for understanding the environmental contr... more The concepts of behavioral economics have proven useful for understanding the environmental control of overall levels of responding for a variety of commodities, including reinforcement by drug selfadministration. These general concepts are summarized for application to the analysis of drug-rein- forced behavior and proposed as the basis for future applications. This behavioral agenda includes the assessment of abuse liability, the assay of drug-reinforcer interactions, the design of drug abuse interventions, and the formulation of drug abuse public policy. These separate domains of investigation are described as part of an overall strategy for designing model projects to control drug use and testing public policy initiatives.
Journal of the Experimental Analysis of Behavior, Mar 1, 1998
In Experiments 1 and 2, 25 and 48 college students made binary choices between hypothetical money... more In Experiments 1 and 2, 25 and 48 college students made binary choices between hypothetical money amounts. In Part A, choices were between small amounts available with certainty and larger amounts ($10 to $10,000) available with risk. Choices in Part B were between immediate small amounts and delayed larger amounts. As money amount grew, risk aversion and delay aversion both changed but in opposite ways: Risk aversion grew but delay aversion shrank. Part C of Experiment 1 pitted risky amounts against delayed amounts, and its results were consistent with those of Parts A and B. Equivalences of particular risks and delays depended on the particular monetary amounts to which they attached. In Experiment 3, 20 college students made binary choices between money amounts, knowing that they would actually receive some of the selections they made. In Part A, choices were between certain small amounts and risky larger amounts ($1 and $10). Choice problems in Part B were between immediate small amounts and delayed receipt of $1 or $10. The results were like those of Experiment 1, though weaker. These results argue against models of choice that posit an equivalence of risk and delay that is independent of monetary amount.
Journal of the Experimental Analysis of Behavior, Nov 1, 2007
This experiment was conducted to test the predictions of two behavioral-economic approaches to qu... more This experiment was conducted to test the predictions of two behavioral-economic approaches to quantifying relative reinforcer efficacy. The normalized demand analysis suggests that characteristics of averaged normalized demand curves may be used to predict progressive-ratio breakpoints and peak responding. By contrast, the demand analysis holds that traditional measures of relative reinforcer efficacy (breakpoint, peak response rate, and choice) correspond to specific characteristics of nonnormalized demand curves. The accuracy of these predictions was evaluated in rats' responding for food or water: two reinforcers known to function as complements. Consistent with the first approach, predicted peak normalized response output values obtained under single-schedule conditions ordinally predicted progressive-ratio breakpoints and peak response rates obtained in a separate condition. Combining the minimum-needs hypothesis with the normalized demand analysis helped to interpret prior findings, but was less useful in predicting choice between food and water-two strongly complementary reinforcers. Predictions of the demand analysis had mixed success. Peak response outputs predicted from the non-normalized water demand curves were significantly correlated with obtained peak responding for water in a separate condition, but none of the remaining three predicted correlations was statistically significant. The demand analysis fared better in predicting choice-relative consumption of food and water under single schedules of reinforcement predicted preference under concurrent schedules significantly better than chance.
Background. Previous research conducted by DRDC Toronto to evaluate watch schedule variants used ... more Background. Previous research conducted by DRDC Toronto to evaluate watch schedule variants used on RCN submarines indicated very significant and deleterious effects of the watch system on modeled cognitive effectiveness of RCN submariners. Subsequently, DRDC Toronto hosted an International Submarine Watch Schedule Symposium which led to a new RCN submarine watch schedule which improved modeled performance by about 30%. The RCN surface fleet is aware of this work and supported a request to conduct an evaluation of the surface fleet watch schedule. We evaluated the watch schedules used aboard HMCS St John's at the end of Op Nanook 2011, over the 8 days that STJ transitioned from the high Arctic to Halifax. Methods. The ages of the forty-five sailors who participated in this at-sea trial ranged from 21 to 48 years, with a mean age and standard deviation of 32.9 ± 7.7 years. Ten of these sailors were non-watch-standers, 14 sailors were from the 1-in-2 Port (Front) watch, 14 sailors were from the 1-in-2 Starboard (Back) watch, three sailors were from the 1-in-3 Engineering watch, and four sailors were from the 1-in-4 Engineering watch. All subjects wore wrist activity monitors (actigraphs) to measure their daily sleep patterns quantitatively. The actigraphically-measured sleep and daily work hours were the two data sets that were inputted to the FAST TM (Fatigue Avoidance Scheduling Tool) software to generate modeled cognitive effectiveness for each subject. All subjects maintained a daily activity, sleep and mood log. Results. Modeled cognitive effectiveness showed worrisome levels of performance equivalent to intoxicated levels of blood alcohol (BAC 0.05% and 0.08%) and well beyond those levels for all watch system variants. The main effect of 'groups' for 'difficulty falling asleep' was significant with post hoc tests showing that the 1-in-2 Port (Front) watch had less difficulty getting to sleep relative to the non-watch standers. With respect to the Visual Analogue Scale data, the non-watch-standers reported being in a 'happier' mood than either of the 1-in-2 Port (Front) and Starboard (Back) watch. Collapsed over the non-watch-standers, 1-in-2 Port (Front) watch, and 1-in-2 Starboard (Back) watch syndicates, 6 SOAP parameters (difficulty concentrating, level of depression, level of irritability, level of fatigue, work frustration and physical discomfort) deteriorated during the trial relative to the pre-trial baseline. Conclusions. The current surface fleet watch schedule is sub-optimal in that it results in worrisome levels of cognitive effectiveness in many of our sailors. Recommendations. An alternative watch schedule which is more sparing of submariner cognitive effectiveness should be developed and implemented. Please see the details of an alternative watch system in the body of this report under 'recommendations'. ii DRDC Toronto TR 2012-078 Résumé …..... Des recherches antérieures réalisées par RDDC Toronto pour évaluer les variantes d'horaire de garde utilisées à bord des sous-marins de la MRC montrent des incidences importantes et néfastes du système de quart sur l'efficacité cognitive des sous-mariniers. Subséquemment, RDDC Toronto a organisé un symposium international sur les horaires de garde à bord des sous-marins qui a permis de réaliser un nouvel horaire de garde à bord des sous-marins de la MRC, améliorant d'environ 30 p. cent le rendement modélisé. Les membres de la flotte de surface de la MRC connaissent ces travaux et ont demandé qu'une évaluation de l'horaire de garde de la flotte de surface soit réalisée. Nous avons évalué les horaires de garde utilisés à bord du NCSM St John's à la fin de l'opération Nanook 2011, pendant les huit jours de la traversée du St John's de l'Extrême-Arctique à Halifax. Méthodologie. Les quarante-cinq marins qui ont participé à cette expérience en mer étaient âgées de 21 à 48 ans, avec une moyenne d'âge de 32,9 ans et un écart type de ± 7,7 ans. Dix de ces marins étaient affectés à des postes autres que des poste de garde, quatorze étaient affectés comme vigies de quart avant, à raison d'un tour de garde sur deux, quatorze comme vigies de quart arrière, à raison d'un tour de garde sur deux, trois comme mécaniciens chefs de quart, à raison d'un tour de garde sur trois et quatre comme mécaniciens chefs de quart, à raison d'un tour de garde sur quatre. Chacun des participants portait un bracelet moniteur (actigraphe) de ses activités, afin de mesurer quantitativement sa structure de sommeil. Les heures de travail quotidien et de sommeil mesurées par actigraphe sont les deux ensembles de données enregistrés dans le logiciel FAST TM (Fatigue Avoidance Scheduling Tool) pour établir l'efficacité cognitive de chaque participant. Tous les participants ont tenu, quotidiennement, un registre sur leurs activités, leur sommeil et leur humeur. Résultats. L'efficacité cognitive a montré des niveaux de rendement inquiétants, équivalents à un rendement en état d'ébriété (à un taux d'alcoolémie se situant entre 0,05 % et 0,08 %) et bien au-delà des niveaux de toutes les variantes d'un système de garde. Le principal effet des « groupes » à l'égard de la « difficulté à s'endormir » s'est avéré important dans les essais ultérieurs montrant que les vigies de quart avant, à raison d'un tour sur deux, avaient moins de difficulté à s'endormir que les marins affectés à des postes autres que des poste de garde. En ce qui concerne les données de l'échelle visuelle analogue, les marins affectés à des postes autres que des poste de garde se sont avérés être de meilleure humeur que les vigies de quart avant et les vigies de quart arrière, à raison d'un tour de garde sur deux. Tant chez les marins affectés à des postes autres que des poste de garde, que chez les vigies de quart avant et les vigies de quart arrière, à raison d'un tour de garde sur deux, six paramètres du profil d'évaluation des opérations spéciales (difficulté de concentration, niveau de dépression, niveau d'irritabilité, niveau de fatigue, frustration au travail et inconfort physique) se sont détériorés au cours de l'essai. Conclusions. L'horaire de garde actuel de la flotte de surface est sous-optimal du fait qu'il entraîne une réduction inquiétante du niveau d'efficacité cognitive de certains de nos marins. Recommandations. Un nouvel horaire de garde, moins éprouvant pour l'efficacité cognitive des sous-mariniers, devrait être élaboré et mis en oeuvre. Veuillez voir les détails d'un nouvel horaire de garde dans le corps du présent rapport sous « Recommandations ».
This study was conducted to evaluate the impact of public perceptions of vaccine safety and effic... more This study was conducted to evaluate the impact of public perceptions of vaccine safety and efficacy on intent to seek COVID-19 vaccination using hypothetical vaccine acceptance scenarios. The behavioral economic methodology could be used to inform future public health vaccination campaigns designed to influence public perceptions and improve public acceptance of the vaccine. In June 2020, 534 respondents completed online validated behavioral economic procedures adapted to evaluate COVID-19 vaccine demand in relation to a hypothetical development process and efficacy. An exponential demand function was used to describe the proportion of participants accepting the vaccine at each efficacy. Linear mixed effect models evaluated development process and individual characteristic effects on minimum required vaccine efficacy required for vaccine acceptance. The rapid development process scenario increased the rate of decline in acceptance with reductions in efficacy. At 50% efficacy, 68.8% of respondents would seek the standard vaccine, and 58.8% would seek the rapid developed vaccine. Rapid vaccine development increased the minimum required efficacy for vaccine acceptance by over 9 percentage points, γ = 9.36, p < 0.001. Past-3-year flu vaccination, γ = -23.00, p < 0.001, and male respondents, γ = -4.98, p = 0.037, accepted lower efficacy. Respondents reporting greater conspiracy beliefs, γ = 0.39, p < 0.001, and political conservatism, γ = 0.32, p < 0.001, required higher efficacy. Male, γ = -4.43, p = 0.013, and more conservative, γ = -0.09, p = 0.039, respondents showed smaller changes in minimum required efficacy by development process. Information on the vaccine development process, vaccine efficacy, and individual differences impact the proportion of respondents reporting COVID-19 vaccination intentions. Behavioral economics provides an empirical method to estimate vaccine demand to target subpopulations resistant to vaccination.
Impaired performance induced by fatigue may compromise safety in commercial aviation. Given the d... more Impaired performance induced by fatigue may compromise safety in commercial aviation. Given the direct role flight attendants play in passenger safety, the U.S. Congress ordered a comprehensive examination of fatigue in cabin crew, including a field study of actual flight operations. This report provides an overview of the field study results, focusing on objective measures of sleep patterns and neurocognitive performance (Psychomotor Vigilance Test, PVT) over a 3-4 week period in 202 U.S.-based flight attendants of all seniority levels working for network, low-cost, and regional carriers embarking on domestic and international flight operations. On average, flight attendants slept 6.3 hr on days off and 5.7 hr on work days, fell asleep 29 min after going to bed, awoke four times per sleep episode, and spent 77% of each episode actually sleeping. After controlling for reserve status, gender, and age, junior-level flight attendants had the shortest sleep latencies on their days off. Those working international operations slept significantly less (4.9 hr vs. 5.9 hr) and less efficiently (75% vs. 79%), compared with their colleagues in domestic operations. All flight attendants exhibited significant impairments during prework PVT tests when compared to their own optimum baseline performance. Across the workday, regional flight attendants committed fewer premature PVT responses, junior-level participants produced significantly higher post-work reaction times, and those working international flights produced better pre-work reaction times but had a greater increase in lapses. These objective data are consistent with other shift work research and echo subjective survey findings across the U.S. flight attendant community. Additional planned analyses of this dataset may identify the precise operational variables that contribute to fatigue in cabin crew.
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