FUNCTIONAL ANALYSIS AND TREATMENT OF ESCAPE-MAINTAINED AGGRESSION CORRELATED WITH SLEEP DEPRIVATION

Functional analysis identified the consequences that maintained aggressive behavior and the relationship between those consequences and sleep deprivation for an individual with severe mental retardation. Results showed that aggression was maintained by negative reinforcement contingencies (escape from demand) and that aggression was more severe when sleep deprivation was present. A multicomponent intervention resulted in reductions of aggression for up to 7 months.     

Cocaine's effects on food-reinforced pecking in pigeons depend on food-deprivation level.

Four pigeons deprived to 80% of their laboratory free-feeding weights pecked keys under a multiple fixed-ratio 30 fixed-interval 5-min schedule of food presentation. Components alternated strictly with 15-s timeouts separating them; each was presented six times. When rates of pecking were stable, 2 pigeons' weights were reduced to 70%, and the other 2 pigeons' weights were increased to 82.5% to 85% of free-feeding levels. Cocaine (1.0, 3.0, 5.6, and 10.0 mg/kg and saline) was administered 5 min prior to sessions. When each dose had been tested twice, pigeons' weights were adjusted to the level that they had not yet experienced, and cocaine was tested again. Cocaine reduced response rates in a dose-dependent manner under the fixed-ratio schedule and under the fixed-interval schedule at high doses, and increased rates under the fixed-interval schedule at low low doses. Reductions in pecking rates occurred at lower doses under both schedules in 3 of 4 pigeons when they were less food deprived compared to when they were more food deprived. Low doses of cocaine increased low baseline rates of pecking in the initial portions of the fixed-interval schedules by a greater magnitude when pigeons were more food deprived. Thus, food-deprivation levels altered both the rate-decreasing and rate-increasing effects of cocaine. The implications of these results for the mechanisms by which food deprivation increases cocaine self-administration and for the dependence of cocaine's effects on the baseline strength of operant behavior are discussed.     

Sleep deprivation and hallucinations. A qualitative study of military personnel

Much anecdotal evidence suggests that sleep deprivation not only impairs performance, but also brings about other extraordinary effects like hallucinations. However, knowledge about how sleep deprivation may trigger hallucinations is limited. To qualitatively describe hallucinatory experiences during sleep deprivation 12 male military officers from the Norwegian Armed Forces who all had experienced at least one sleep loss-induced hallucinatory experience were recruited. Data were collected and analyzed by semi-structured interviews and thematic analysis. This resulted in the identification of three distinct main themes: (1) Modalities, (2) circumstances/triggers and (3) reactions to hallucinations. Hallucinations were experienced in several modalities (visual, auditory and multi-modality), although visual hallucinations seemed to dominate. Typical reported circumstances/triggers were sleep loss, physical exhaustion, time-of-day, low calorie intake, mental exhaustion and lack of external stimuli (low sensory and social input, boring situations, and monotonous activity). Negative emotions were dominant during the hallucinatory episodes. Often some reasoning and checking on behalf of the officers were necessary to differentiate between real percepts and hallucinations. In some cases the hallucinations caused erroneous actions. Retrospectively, most officers viewed their hallucinatory experiences in light of positive emotions and several emphasized having learned something from them. The results are discussed in relation to the existing literature and suggestions for future studies are outlined.     

No Evidence That Sleep Deprivation Effects and the Vigilance Decrement Are Functionally Equivalent: Comment on Veksler and Gunzelmann (2017)

Veksler and Gunzelmann (2017) make an extraordinary claim, which is that sleep deprivation effects and the vigilance decrement are functionally equivalent. Extraordinary claims require extraordinary evidence, which is missing from Veksler and Gunzelmann's study. Their behavioral data offer only weak theoretical constraint, and to the extent their modeling exercise supports any position, it is that these two performance impairments involve functionally distinct underlying mechanisms.     

Caffeine reduces the impact of drowsiness on driving errors

AimThe study examined the moderating effect of repeat-dose, chewing gum-administered caffeine on the well-established relationship between drowsiness and driving performance, under the conditions of accumulating sleep loss.Method50-h sleep deprivation protocol with a double-blind, placebo-controlled design. Eleven volunteers (6 male), aged 18–28 years were screened for pre-existing medical conditions (including sleep disturbances), tobacco and recreational drug use, recent time-zone travel and shift-work. They were randomly allocated to placebo or caffeine group and administered 4 oral doses of either caffeinated gum pellets (200 mg/dose) or non-caffeinated placebo gum every two hours (01:00, 03:00, 05:00, 07:00) on the first and second nights of the protocol. Participants were constantly monitored and remained awake for 50 h, while performing 15 identical, evenly-spaced 40-min monotonous driving tasks in a medium-fidelity moving-base driving simulator. Their drowsiness was monitored with a spectacle frame-mounted infra-red sensor registering ocular parameters and converting them into a Johns Drowsiness Scale (JDS) score every 60 s. Lane keeping and speed variability measures were used to assess driving performance.ResultsDriving performance declined and drowsiness increased from the first simulated drive to the last. When driving performance was examined in one-minute epochs synchronised with JDS scores, both lateral lane positioning and speed variability were found to be associated with drowsiness. The strength of this association was significantly weaker in the caffeine group, compared to placebo. Placebo group replicated the linear relationship between drowsiness and driving errors across the full range of JDS scores. This pattern was significantly weaker under the caffeine condition, and was even reversed at the upper range of JDS, with higher JDS scores not resulting in further degradation of driving performance. This dissociation between drowsiness and driving errors persisted across the 24-h cycle under the caffeine condition, despite caffeine being administered only during early morning hours.ConclusionStrategically timed, repeat 200 mg doses of caffeine administered via chewing gum can mitigate fatigue-induced impairments in driving performance by not only reducing drowsiness but also by significantly weakening its impact on driving errors. This dual effect of sustained drowsiness reduction and the dissociation between drowsiness levels and driving errors seems worth further investigation as it might offer an effective emergency countermeasure against driver drowsiness and its subsequent conversion into potentially fatal driving errors.     

Using topic modeling to develop multi-level descriptions of naturalistic driving data from drivers with and without sleep apnea

One challenge in using naturalistic driving data is producing a holistic analysis of these highly variable datasets. Typical analyses focus on isolated events, such as large g-force accelerations indicating a possible near-crash. Examining isolated events is ill-suited for identifying patterns in continuous activities such as maintaining vehicle control. We present an alternative approach that converts driving data into a text representation and uses topic modeling to identify patterns across the dataset. This approach enables the discovery of non-linear patterns, reduces the dimensionality of the data, and captures subtle variations in driver behavior. In this study topic models were used to concisely described patterns in trips from drivers with and without untreated obstructive sleep apnea (OSA). The analysis included 5000 trips (50 trips from 100 drivers; 66 drivers with OSA; 34 comparison drivers). Trips were treated as documents, and speed and acceleration data from the trips were converted to “driving words.” The identified patterns, called topics, were determined based on regularities in the co-occurrence of the driving words within the trips. This representation was used in random forest models to predict the driver condition (i.e., OSA or comparison) for each trip. Models with 10, 15 and 20 topics had better accuracy in predicting the driver condition, with a maximum AUC of 0.73 for a model with 20 topics. Trips from drivers with OSA were more likely to be defined by topics for smaller lateral accelerations at low speeds. The results demonstrate topic modeling as a useful tool for extracting meaningful information from naturalistic driving datasets.     

Screen use before bedtime: Consequences for nighttime sleep in young children

There is increasing interest in the relation between screen use and sleep problems in early childhood. In a sample of 30-month-old children, this study used observational measures of screen use during the hour or so leading up to bedtime, parent reports of screen use during the child’s bedtime routine, and actigraphic measures of toddler sleep to complement parent-reported sleep problems. Whether screen use was observed during the pre-bedtime period or was reported by the parents as part of the nightly bedtime routine, greater screen use in either context was associated with more parent-reported sleep problems. Additionally, more frequent parent-reported screen use during the bedtime routine was also associated with actigraphic measures of later sleep, shorter sleep, and more night-to-night variability in duration and timing of sleep. These associations suggest the negative consequences of screen use for children’s sleep extend both to aspects of sleep reported by parents (e.g., bedtime resistance, signaled awakenings) and to aspects measured by actigraphy (e.g., shorter and more variable sleep).     

父亲参与教养与农村寄宿制学生学校适应：自我控制的中介作用和相对剥夺感的调节作用

为探讨父亲参与教养与学校适应的关系及其作用机制,采用问卷法对548名农村寄宿制学生进行调查。结果发现：（1）父亲参与教养与自我控制、学校适应呈显著正相关;（2）父亲参与教养既能直接正向预测农村寄宿制学生的学校适应,也能通过自我控制的中介预测学校适应;（3）相对剥夺感在自我控制的中介作用中起到调节,当农村寄宿制学生的相对剥夺感较高时,父亲参与教养对自我控制的作用减弱。研究结果揭示了父亲参与教养对农村寄宿制学生学校适应的影响及作用机制,能为提高农村寄宿制学生的学校适应水平提供有效启示。     

The effect of the two feet-in-the-door technique on tobacco deprivation

The ‘Foot-in-the-door’ (FITD) is a well-known compliance technique that increases compliance with a request. Many investigations on this paradigm have generally used prosocial requests to test the effect of the technique. A new evaluation of the effect of the FITD technique was carried out on tobacco deprivation. A two feet-in-the-door technique in which the target request was preceded by two small target requests was used to encourage students to stop smoking for 24 h. The results were compared with two single foot-in-the- door procedures in which the final request was only preceded by one small request, as well as with a control condition using only a 24 h stop-smoking request. Results showed that the single FITD and the two feet-in-the-door procedures were effective to increase verbal compliance (accepting to stop smoking) but only the two feet-in-the-door technique significantly increased behavioural compliance (not smoking for 24 h) with the request.