Dichotic listening and sleep deprivation: vigilance effects

Twelve sleep-deprived and 13 non-deprived Navy cadets were tested with the dichotic listening procedure for effects of sleep deprivation on hemispheric asymmetry and sustained attention. Consonant-vowel syllables were presented to the subjects in three different conditions, a divided (non-forced) attention condition, a forced right ear and a forced left ear attention condition. In the two forced attention conditions the subjects were instructed to focus attention only on the right or left ear stimulus. The results showed an expected right ear advantage for both groups during the non-forced and forced right attention conditions, indicating superior left hemisphere processing. During the forced left attention condition, the sleep-deprived subjects showed no ear advantage at all, while the non-deprived subjects showed an expected left ear advantage. The results are discussed within a theoretical framework of a dual process model, where sleep deprivation disrupts the ability to sustain attention, caused by a temporary failure of the right hemisphere's top-down (instruction-driven) processing to override the left hemisphere's bottom-up (stimulus-driven) processing.     

Prospective Longitudinal Associations Between Persistent Sleep Problems in Childhood and Anxiety and Depression Disorders in Adulthood

The objective of this study was to examine the associations between persistent childhood sleep problems and adulthood anxiety and depression. Parents of 943 children (52% male) participating in the Dunedin Multidisciplinary Health and Development Study provided information on their childrens sleep and internalizing problems at ages 5, 7, and 9 years. When the participants were 21 and 26 years, adult anxiety and depression were diagnosed using a standardized diagnostic interview. After controlling for childhood internalizing problems, sex, and socioeconomic status, persistent sleep problems in childhood predicted adulthood anxiety disorders (OR (95% CI) = 1.60 (1.05–2.45), p = .030) but not depressive disorders (OR (95% CI) = .99 (.63–1.56), p = .959). Persistent sleep problems in childhood may be an early risk indicator of anxiety in adulthood.     

Variable-interval reinforcement schedule value influences responding following REM sleep deprivation

The effects of rapid-eye movement sleep deprivation (REMSD) in rats were studied in relation to variable-interval (VI) reinforcement schedule value. Initially, lever pressing was maintained on a VI 30-s schedule of food pellet delivery. After a baseline was established, rats were repeatedly exposed to 96 hr of REMSD and control conditions of an equivalent duration. Responding decreased following REMSD but not after exposure to control conditions. Lever pressing was then maintained on a VI 15-s schedule of food pellet delivery and exposure to the REMSD and control conditions was repeated. Under this condition following repeated REMSD exposures, rates of lever pressing became similar to baseline responding. A VI 30-s schedule of food pellet delivery was then reinstated and REMSD and control conditions were repeated. Lever pressing following exposure to the REMSD condition decreased for 3 of 4 rats. Results suggest that VI schedule value influences the effects of REMSD on responding.     

Possible contribution of better maternal psychological well-being to the acquisition of sleeping through the night in infants during the early postpartum period

The objective of this study was to elucidate whether better maternal psychological well-being contributes to the acquisition of “sleeping through the night” (STN) in infants during the early postpartum period. Fifty-two primiparous mothers completed the General Health Questionnaire-28 (GHQ-28) in the third trimester (prenatal) and when the conceptional ages of their babies reached 8–9 weeks (hereafter, 2 months), 12–13 weeks (3 months), and 16–17 weeks (4 months). They also recorded babies’ nocturnal sleep patterns in a timetable for 5 consecutive days each month postpartum. “Regular STN” was defined when the mean of longest nocturnal sleep duration for 5 consecutive days was > 8 h or between 6 and 8 h with < 1.0 nocturnal awakenings. According to these criteria, a total of 14 infants (27 %) acquired regular STN at 4 months (referred to as “STN infants”), with STN infants showing a marked increase in longest nocturnal sleep duration and a decrease in nocturnal awakenings from 2 to 3 months of age. The mothers of STN infants demonstrated steady reductions in postnatal GHQ-28 scores and had significantly lower prenatal GHQ-28 scores compared with the mothers of non-STN infants (3.7 ± 3.0 vs. 6.4 ± 4.1, p = 0.027). In random forest models for binomial classification, both prenatal and postnatal (at 4 months) GHQ-28 scores were identified as significant covariates for distinguishing STN infants, and other important covariates, including weeks of delivery, stepfamily, birth weight of the infant, and maternal co-sleeping at bedtime, were selected. Among these covariates, maternal co-sleeping at bedtime had relatively stronger correlations with both STN infants (r = − 0.440) and prenatal maternal GHQ-28 scores (r = 0.377). In conclusion, because prenatal maternal psychological well-being was thought to predict the acquisition of STN in infants, infants born from mothers with better psychological well-being appear to have some advantages in acquiring STN. These cross-lagged correlations suggest that the pathway from mothers to infants may be mediated by certain parenting behaviors, such as maternal co-sleeping at bedtime.     

The reliability of nocturnal vaginal blood flow

Fourteen subjects participated in a sleep study designed to document the reliability of measurements of REM-related vaginal blood-flow changes. Several standard sleep parameters were also examined for comparison with vaginal measures. The most reliable vaginal measure was the maximal change in disengorgement for a given REM period averaged across a night of REM periods. The reliability of this measure compared favorably with that of a highly reliable computerized measure of REM density. It is suggested that nocturnal vaginal blood-flow measures have sufficient reliability to be useful in the differential diagnosis of organic and psychogenic sexual dysfunction.This study was supported in part by a training grant to the Department of Clinical Psychology, University of Florida, Gainesville (USPHS532DE07133-02), and a grant from the NIH (USPHSCA26364R073241-29) to the second author.     

BEHAVIOR MANAGEMENT OF INFANT SLEEP DISTURBANCE

Using a nonconcurrent multiple baseline design, we evaluated the effects of extinction and stimulus control on nighttime sleep disturbances exhibited by 7 infants. Results showed that frequency and duration of night wakings decreased for all subjects, with corresponding improvements reflected through changes in responses to the sleep behavior scale. Observed improvements maintained at 3 and 24 months posttreatment.     

Treatment of sleep problems in a toddler: a replication of the faded bedtime with response cost protocol.

Multiple sleep problems of a 2-year-old girl improved following treatment with a faded bedtime with response cost procedure (Piazza & Fisher, 1991). These results extend the literature by implementing treatment in a home setting with a nondisabled child using the parents as therapists.     

Work and nonwork stressors,negative affective states,and pain complaints among firefighters and paramedics

Prior research has suggested that occupational stressors may contribute to the etiology, progression, and chronicity of pain problems in workers. This study used anonymous survey methods to assess the prevalence and frequency of self-reported pain symptoms and their relationships to demographic variables, sources of occupational stressors, nonwork stressors and affective distress in a large sample (N2000) of employed career public sector firefighters and paramedics. The findings were consistent with those of previous studies of high strain workers. More than 95% of the firefighter/paramedic sample reported at least one pain complaint (using a 1 week assessment time frame). A hierarchical multiple regression analysis entering demographic, occupational, and nonwork stressors, as well as measures of negative affective states targeting total pain scores, yielded significant relationships. Five occupational stressors were associated with respondent pain complaints. The results also suggest that negative affective states mediated the relationships between work and nonwork variables, and pain complaint outcomes. The implications of these findings for the development of preventive interventions for firefighters and paramedics as well as other emergency service workers are considered.     

Effects of sleep deprivation on free-operant avoidance

Two studies examined effects of sleep deprivation on free-operant avoidance by rats. In Experiment 1, a 5-s shock-shock (SS) interval and 20-s response-shock (RS) interval produced baseline performances, which were reestablished after each experimental manipulation. Once baselines were established, animals were exposed to 24, 48, or 96 hr of sleep deprivation and equivalent periods of home cage and food restriction as a control condition. Compared to baseline, sleep deprivation increased response rates by increasing the proportion of brief interresponse times (IRTs); response rates changed little in the control conditions. Percentage of shocks avoided did not systematically change across conditions. In Experiment 2, the RS interval was manipulated (10, 20, and 40 s), while the SS interval (5 s) and level of sleep deprivation (48 hr) were held constant. Across RS intervals, sleep deprivation increased response rates via a shift toward brief IRTs. In addition, sleep deprivation increased the percentage of shocks avoided as an inverse function of RS intervals.