In a variety of settings (e.g., transportation, power-plant management), inadequate sleep is a major contributing factor to mental fatigue, decrements in performance, and safety lapses. Inadequate sleep can arise from a variety of uncontrollable factors, such as illness or stress, but can also result from individual failures to properly manage sleep schedules. For example, in a recent survey, 70% of adults reported that their work or school schedules actually allow for adequate sleep each night. A substantial portion of these individuals, however, go to work or school at-risk for drowsiness and mental fatigue issues. Two possible sources of difficulties for these individuals are failures of self-control or failures of self-regulation. This project investigates the efficacy of self-control and self-regulation training programs that are targeted towards building skills for individuals to better manage their sleep schedules. Development of these skills, in turn, is expected to reduce the frequency of situations of inadequate sleep at work and school.
This research project involves a translation of clinical self-control and self-regulation interventions to non-clinical use through a combined self-control and self-regulation training approach. The purpose is to determine whether a fully integrated intervention has beneficial effects on sleep-duration management. A unique feature of this project is the objective assessment of sleep duration and sleep interruptions obtained through wrist actigraphs, which provide reliable and valid indicators of sleep/non-sleep states. The research includes a comoparison of these objective measures with daily self-report questionnaires of sleep duration and fatigue. Together, these assessments allows for a determination of whether the intervention effects pertain mainly to subjective estimates of sleep duration, objective measures of sleep duration, or some combination of the two. The new knowledge from these studies may have significant implications for reduction of sleep deprivation in work and school settings.
Self-regulation and self-control are motivational constructs involved in the process of goal pursuit (Karoly, 1993). Although investigators within and across various fields of psychology have used the terms interchangeably, theoretical work stemming from the clinical field suggests that self-control refers to a distinct construct that operates in the context of self-regulation (e.g., F. Kanfer & Karoly, 1972). We evaluated the efficacy of a training intervention that included both self-regulation and self-control and compared that to a training that only included self-regulation and to no training. Sleep duration was chosen as the target of training because ‘lack of sleep’ has been associated with negative mental, physical, and work-related outcomes (Oginska & Pokorski, 2006; Perfect, Elkins, Lyle-Lahroud, & Posey, 2010; Spiegel, Leproult, & Cauter, 1999). Participants included 49 college students and 41 full-time employed adults with no sleep-related disorders. Data on sleep duration and fatigue, affect, and productivity impairment were obtained by Fitbit actigraphs and bi-daily self-reports over a three-week period. Participants were randomly assigned to one of three groups: (1) control, (2) self-regulation (SR), and (3) combined self-regulation and self-control (SC) group. Prior to Week 2, intervention groups attended a 60-minute training session focused on getting more sleep during the week. After each training session, participants completed a knowledge test to evaluate whether they understood the material presented. All training group participants scored over 73% and the average was over 90%. Participants also completed an evaluation of the session. On a scale from 1 (Strongly disagree) to 6 (Strongly agree), with higher scores indicating a positive evaluation, the average score was 5.24 (SD = .40). Participants in the training groups demonstrated better adherence to sleep duration goals during the intervention period compared to the control group. Figure 1 shows the overall group differences in goal adherence during Week 2 (F (2, 87) = 4.54, p < .05). Both training groups had better goal adherence than the control group (d = .49 and .75 for the SR and SC groups, respectively) and the SC group demonstrated better goal adherence than the SR group (d = .27). While there were overall group differences in goal adherence during the follow-up period of Week 3 (F (2, 87) = 8.12, p < .05), there were no significant differences between training groups (see Figure 2). Additionally, participants in the SC group reported more positive post-intervention changes compared to the SR group and the control group. Specifically, training group participants reported feeling less fatigued, greater energy, better concentration, better mood, greater engagement in endeavors, and more overall changes in mood and sleepiness from the beginning to the end of the study, compared to the control group. Furthermore, the SC group demonstrated greater differences in many of these variables than the SR group. In the current project, we demonstrated the efficacy of two self-management interventions in helping individuals without diagnosed sleep disorders to get more sleep during the week. The intervention that included self-control led to greater goal adherence during Week 2 and more positive changes in mood and sleepiness after the study period. This training session could be particularly useful in settings where sleep debt can play an important role in work outcomes, such as the medical field or air traffic control.
