Polychromatic percepts during hypergravity.

Future helmet mounted systems and cockpit displays will rely on color graphics and information that high performance aircraft pilots will need to discern and understand. Color in displays may help reduce pilot workload. The effect of high G and reduced eye level blood pressure on field-of-view has been study extensively.

The effect of brief headward acceleration on human G tolerance.

Objective: To generate, on a multi-axial centrifuge, a negative to positive acceleration profile that reproduces the physiological reaction and subjective symptoms experienced by agile aircraft pilots. Previous research will be summarized and current status of research described.

Methods: Experiments have been accomplished with the Dynamic Environment Simulator (DES) using different profile generating techniques.

Female exposure to high G: chronic adaptations of cardiovascular functions.

Introduction: Exposure to microgravity is associated with increased leg venous compliance and reductions in cardiac output, baroreflex functions, and tolerance to orthostatism. However, the effects of chronic exposure to high-G environments are unknown. In addition, there is evidence that females have lower orthostatic tolerance than males, although the underlying mechanisms are unclear.

Female exposure to high G: effects of simulated combat sorties on cerebral and arterial O2 saturation.

Background: One of the key factors in maintaining optimal cognitive performance in the high-G environment is the adequate delivery of oxygen to the cerebral tissue. As eye-level blood pressure is compromised at 22 mmHg x G(-1), perfusion to the peripheral cerebral tissues (cerebral cortex) may not be adequate to support the mental demands of flight. This study measured the effect of closed-loop flight simulations (3 min) on cerebral oxygen saturation changes (rSO2), arterial oxygen saturation (SAO2), and heart rate (HR), in both rested (8 h of rest) and sleepless (24 h without sleep) conditions.

Female exposure to high G: performance of simulated flight after 24 hours of sleep deprivation.

Background: Ground-based research has investigated the loss of cognitive function in the extreme conditions of G-induced loss of consciousness, however, little is known about pilots' abilities to maintain cognitive performance throughout prolonged conscious exposure in the high-G environment. The effects of fatigue and G layoff on performance during exposure to high G are mostly unknown for the female population.

Methods: This research was conducted on the centrifuge Dynamic Environment Simulator.

Effect of G suit type on cognitive performance.

Background: Sustained acceleration protection ensembles are being developed to help pilots of high performance aircraft endure high G exposures for longer periods of time. It has been assumed that better G endurance confers better pilot task performance. This premise was studied on the Armstrong Laboratory Dynamic Environment Simulator centrifuge.

The acceleration-velocity relationship: identification of normal and spastic upper extremity movement.

This study defines and evaluates a non-invasive technique that will identify a spasm as an uncommanded movement (U) from a normally commanded movement (C). Upper arm function during a tracking task is recognized as non-linear and characterized by a phase plane with acceleration (second derivative of stick position) plotted on the ordinate and velocity (first derivative of stick position) plotted on the abscissa. An acceleration time constant (tau A) is defined as (VA/AM) where AM is the maximal acceleration and VA is the velocity at AM.

Investigating gender differences under conditions of fatigue in a simulated high G aerial combat environment.

Advances in technology have equipped high-performance combat aircraft with the capability of delivering higher and higher sustained acceleration or G-forces on the pilots flying them. While the physiological effects of increased g-forces on the human body continue to be investigated, studies examining the effects of acceleration on the cognitive abilities of high-performance aircraft pilots remain sparse. Additionally, as higher technology is making its way into the cockpit, so are female pilots.

Performance study involving a force-reflecting joystick for spastic individuals performing two types of tracking tasks.

10 upper-extremity spastic subjects and 10 normal subjects were studied with a force-reflecting joystick in the performance of a continuous time-tracking task as well as an acquisition task termed, "Fitts' Law." Certain force-reflection paradigms, in a spatial sense, allowed the spastic subjects to obtain performance proficiency near levels of the normal subjects as measured by a capacity metric.

The effect of head tilt on perception of self-orientation while in a greater than one G environment.

The effect of head tilt on the perception of self-orientation while in a greater than one G environment was studied in nine subjects using the Armstrong Laboratory Dynamic Environment Simulator. After a 12-s stabilization period at a constant head tilt and G level, subjects reported their perception of the horizon by placing their right hand in a position they believed to be horizontal. Head tilt conditions ranged from -30 degrees to +45 degrees pitch over each of three head yaw positions.