The relationship between visual memory and rider expertise in a show-jumping context

Individuals develop visual skills while participating in sport. The aim of this study was to assess the effect of reported riding expertise on the recall of visual information relating to show-jumps. We identified a relevant (F1) and irrelevant (F2) point of focus in 22 photographs of show-jumps. Participants were students (n = 40) with varying levels of horse riding ability. The task, having viewed each photograph for four seconds, was to identify F1s or F2s from four alternatives viewed for ten seconds. F1s were recalled significantly more than F2s (P<0.001). Riding expertise did not affect overall recall but only intermediate/advanced riders recalled F1s significantly better than F2s (P<0.05 and P<0.001 respectively). Recall of F1s but not of F2s was significantly correlated with riding expertise (P<0.05). Training riders in visual attention techniques might improve ridden performance and could reduce the number of accidents associated with lack of experience and/or rider error

Analysis of the origin of Aufeis feed-water on the arctic slope of Alaska

The origin of water feeding large aufeis fields (overflow river ice) on the Arctic Slope of Alaska is analyzed. Field measurements of two large aufeis fields on the eastern Arctic Slope were taken during July of 1978 and 1979. Measurements of aufeis extent and distribution were made using LANDSAT Multispectral Scanner Subsystem (MSS) satellite data from 1973 through 1979. In addition, ice cores were analyzed in the laboratory. Results of the field and laboratory studies indicate that the water derived from aufeis melt water has a chemical composition different from the adjacent upstream river water. Large aufeis fields are found in association with springs and faults thus indicating a subterranean origin of the feed water. In addition, the maximum extent of large aufeis fields was not found to follow meteorological patterns which would only be expected if the origin of the feed water were local. It is concluded that extent of large aufeis in a given river channel on the Arctic Slope is controlled by discharge from reservoirs of groundwater. It seems probable that precipitation passes into limestone aquifers in the Brooks Range, through an interconnecting system of subterranean fractures in calcareous rocks and ultimately discharges into alluvial sediments on the coastal plain to form aufeis. It is speculated that only small aufeis patches are affected by local meteorological parameters in the months just prior to aufeis formation

Film study for a star correlator Final report

Photographic recording film evaluation for star field image processing in spacecraft environment and use in star correlato

Keeping your eye on the rail: gaze behaviour of horse riders approaching a jump

The gaze behaviour of riders during their approach to a jump was investigated using a mobile eye tracking device (ASL Mobile Eye). The timing, frequency and duration of fixations on the jump and the percentage of time when their point of gaze (POG) was located elsewhere were assessed. Fixations were identified when the POG remained on the jump for 100 ms or longer. The jumping skill of experienced but non-elite riders (n=10) was assessed by means of a questionnaire. Their gaze behaviour was recorded as they completed a course of three identical jumps five times. The speed and timing of the approach was calculated. Gaze behaviour throughout the overall approach and during the last five strides before take-off was assessed following frame-by-frame analyses. Differences in relation to both round and jump number were found. Significantly longer was spent fixated on the jump during round 2, both during the overall approach and during the last five strides (p , 0.05). Jump 1 was fixated on significantly earlier and more frequently than jump 2 or 3 (p , 0.05). Significantly more errors were made with jump 3 than with jump 1 (p=0.01) but there was no difference in errors made between rounds

Study of behavioral modifications resulting from exposure to high let radiation

Animal irradiations, behavioral studies, neurological studies, and nuclear medicine studies are discussed