Age differences in simulated driving performance: compensatory processes.

In the context of driving, the reported experiment examines compensatory processes for age-related declines in cognitive ability. Younger (26-40 years) and older (60+ years) participants (n=22 each group) performed a car following task in a driving simulator. Several performance measures were recorded, including assessments of anticipation of unfolding traffic events. Participants also completed a range of measures of cognitive ability - including both fluid and crystallised abilities. Three examples of age-related compensation are reported: (i) older drivers adopted longer headways than younger drivers. Data were consistent with this being compensation for an age-related deficit in complex reaction time; (ii) older drivers with relatively higher cognitive ability anticipated traffic events more frequently, whereas the reverse pattern was found for younger drivers; and, (iii) older drivers with greater crystallised ability were less reliant on spatial ability to maintain lane position. Consistent with theories of 'cognitive reserve', interactions between crystallised ability and age for self-report workload suggested that compensation for age-related cognitive ability deficits required investment of additional effort. Results are considered in the context of the prospects of further assessment of older drivers.

Nursing, maternal postures, and fetal position.

The objectives of this study were to (a) determine if a safe, simple, and economic nursing procedure--maternal posturing--would result in the rotation of a fetus in the posterior or transverse position to the optimal anterior position and (b) evaluate the relative effectiveness of a series of maternal postures for facilitating anterior fetal rotation. One hundred healthy women at term pregnancy were randomly assigned to four treatment and one control posture for a 10-minute period. At two nurse-midwifery clinics, one certified nurse-midwife postured the subjects and one midwife measured the dependent variable (fetal position) with Leopold's maneuvers. Hypotheses I-IV, which predicted that the four rotation postures would have a greater proportion of anterior fetal rotations than the control posture, were supported (p less than .000). Essentially all four postures were effective and there was little difference between the treatment postures. A second posturing was performed to determine if an additional 10 minutes in a treatment posture would result in an anterior fetal position. There was a greater proportion of anterior fetal rotations with the four rotation postures than the control posture. The Sims posture was used as a maintenance posture for anterior positions, and was successful when done on the opposite side of the fetal back. The theoretical explication of how maternal postures effect fetal rotation remains sound.