Predicting individual differences in response to sleep loss: application of current techniques.

BACKGROUND: Fatigue's negative impact on safety represents one of the top threats to military transportation. Biomathematical models have been developed to predict the response to fatigue; however, current models do not take into account stable individual differences in fatigue susceptibility. Readiness Screening Tools (RSTs) can capture individual differences in fatigue response, but cannot predict performance long-term. The objective of this study was to combine an existing biomathematical model of fatigue with existing RST-derived measures to determine current ability to predict individual differences in fatigue response. We hypothesized that the predictive ability of the biomathematical model could be significantly improved by incorporating cognitive and oculometric measures shown to be sensitive to individual differences in fatigue response. METHODS: Data on multiple cognitive and oculometric measures were collected at rested baseline and then every 3 h across 25 h of continual wakefulness. Results characterized actual fatigued performance at the group and individual levels. Actual performance was compared to predicted performance decrements over the same time period. The unique variance explained by each approach was then combined to determine if RST-derived individual difference measures added significant predictive power to the model. RESULTS: Addition of individual-difference sensitive RST measures to an existing fatigue model significantly increased the amount of variance in performance explained by the model from 13.8 to 35.7%. DISCUSSION: Simply leveraging RSTs' ability to capture individual differences in fatigue susceptibility can substantially improve biomathematical prediction of fatigued performance.

Forehead-mounted reflectance oximetry for in-cockpit hypoxia early detection and warning.

INTRODUCTION: Effective hypoxia-related mishap prevention relies upon aircrew rapid recognition of hypoxia symptoms. The objectives of this experiment were twofold: to compare the effectiveness of a forehead-mounted reflectance oximeter and finger-mounted pulse oximeter for application in a hypoxia early warning detection system, and to determine whether the forehead-mounted sensor could be placed within an aviation helmet. METHODS: Subjects donned an aviation flight mask and were instrumented with a forehead reflectance oximeter, a finger pulse oximeter, a blood pressure cuff, and a skin temperature sensor. Following instrumentation, subjects breathed ambient air for 10 min through the Reduced Oxygen Breathing Device (ROBD) to allow for acclimation. The baseline period was followed by one of two counterbalanced ascent profiles used to model rapid exposures to altitude. Data were collected at 1 Hz from both sensors for the duration of the protocol. RESULTS: Analyses indicated an exceptionally strong agreement between the forehead and finger sensors at all ranges of desaturation. The sensitivity data revealed that the forehead sensor was significantly faster when responding to rapid changes in SpO2 than the finger. The sensor was successfully integrated inside the helmet; however, once donned by the subject, there was considerable artifact due to pressure fluctuations. DISCUSSION: While these data may seem to suggest that the forehead sensor is accurate and sensitive to altitude induced changes in SpO2, major drawbacks exist for the technology utilized in the current study. Significant improvements aimed at diminishing noise, curbing motion artifact, and improving reliability are required to reduce errant measurements.

Blame attribution as a moderator of perceptions of sexual orientation-based hate crimes.

Blame attribution is a valuable mechanism explaining decision making. However, present literature mainly employs blame attribution as a dependent variable. The shortcoming of this fact is that blame attribution offers a potentially valuable explanatory mechanism for decision making. The authors designed two studies to investigate blame attribution as a moderator of sentencing decisions in sexual orientation-based hate crimes. Study 1 showed that mock jurors punished perpetrators of hate crimes more severely than a control condition. Also, degree of victim blame influenced punitive decision making. In Study 2, mock jurors extended findings that perpetrators of hate crimes are more harshly punished than those of other types of crimes. Victim and perpetrator blame failed to moderate decision making in this more complex scenario. Results are discussed in relation to hate crimes definitions and attribution theory.

Self-reported pain in persons with dementia predicts subsequent decreased psychosocial functioning.

OBJECTIVES: Pain self-report is the assessment gold standard in cognitively intact populations but has been discouraged in persons with dementia because of significant evidence that pain intensity is often underreported by persons with dementia. However, most community-dwelling persons with dementia are cared for in primary care settings where a more in depth pain assessment is unlikely. Therefore, it is vital to know the clinical predictive value of self-report pain assessment in this population. Psychosocial functioning is a meaningful focus for clinical prediction, because psychosocial constructs are integrally related to quality of life, physical functioning, and one's ability to function in the presence of pain. The purpose of this study was to investigate the degree to which answers to simple self-report pain questions can predict changes in psychosocial functioning 4 months later in community-dwelling older adults with dementia. DESIGN: Longitudinal. Patients and caregivers were assessed every 4 months for 24 months. SETTING: Veterans Affairs Medical Center, Houston, TX. PARTICIPANTS: One hundred seventy-one patients over age 60 years diagnosed with dementia in the previous year and with no previous aggression were recruited from Veterans Administration clinics. MEASUREMENTS: Pain, agitation, depression, involvement in pleasant events, caregiver burden, psychosis, and patient/caregiver relationship quality (mutuality). RESULTS: Pain scores at each time period were predictive of increased agitation and depression and decreased pleasant event frequency 4 months later. CONCLUSIONS: Our results suggest that persons with dementia who affirmatively respond to pain questions are at higher risk for developing negative psychosocial states.