Effects of Repetitive, Small-Spot, Incoherent Light Flashes on Pursuit Tracking Performance

摘要

The effects of repetitive, small-spot incoherent light flashes on pursuit tracking was studied in the BLASER tracking simulator under bright and dim ambient light conditions. Ten experimentally naive men served as volunteers. The target was a scale-model tank moving at a constant angular velocity of 5 mrad/sec at a simulated distance of 1 km. A series of 5 flashes, presented at a rate of 20 Hz, were presented during randomly selected tracking trials. Flashes were produced with a miniature xenon flash lamp housed within the tracking device and spatially filtered to produce a 100 micro retinal diameter spot at approximately 50% of the maximum permissible exposure level. Colored filters in front of the lamp were used to produce flashes in the red and green portions of the spectrum. Unfiltered light from the lamp produced white-light flashes. The flashes produced statistically significant increases in the horizontal standard deviation error scores. These were manifested mainly by lead or lag errors (crosshairs ahead or behind the target) in response to the flash, followed by a return to baseline error levels. The magnitude of this effect was greater in the dim viewing condition than in the bright, as measured by maximum aiming error and the temporal course of recovery. No significant effect was observed for flash color.