The Effects of Age and Experience on Sonar Performance.

Abstract : Age and experience related differences in visual detection of sonar targets and in visual perceptual functions were examined in 60 men. Thirty Navy expert sonar operators, 15 young (<25 yrs) and 15 older (<35 yrs), were matched in age and education to groups of 15 young and 15 older controls, all of whom had no sonar experience. Subjects were individually administered the WAIS-R IQ test, a battery of visual perceptual measures, and a visual detection task on a simulated sonar display. The task involved the detection and location of targets embedded in a random noise background. Three separate conditions, 50 trials per condition, varied in signal-to-noise (SN) level, making the task vary in difficulty. A signal detection analysis revealed that all groups performed below threshold (d' < 1) for the most difficult condition, and so this condition was dropped from further analyses. In the remaining two conditions all four groups of subjects performed comparably in detection sensitivity. Planned comparisons suggested that older sonar experts performed as well as younger experts and better than older controls when the task was moderately difficult. This maintenance of visual detection skills was accompanied by an age-related decrement in a speeded visual discrimination task, suggesting that age-related losses in general cognitive or perceptual-motor functions have little or no net effect on the highly practiced performance of an expert, such as an experienced sonar operator. (SDW)