USB OF BRAIN WAVES FOR SELECTING SONAR OPERATIONS
The job of the submarine sonar operator is one of the most demanding of all activities on board a submarine. It requires an individual who is able to perform complex auditory and visual discriminations, maintain attention over prolonged periods of time, and effectively keep track of many different sonar signals simultaneously. Additionally the operator must be able to classify the signals received and determine which ones signify a threat to the submarine.
Some individuals are better able to perform these tasks than others. Unfortunately, paper and pencil tests for screening prospective sonar operators have not been able to predict on-the-job performance. Such tests still produce unacceptably high rates of attrition from “A” and “C” sonar training schools — rates that vary between 10 and 20 percent, with the highest rate associated with the “A” school. And, over 30J are lost during the total cycle of sonar training. Thus, a measurement system that could differentiate between good and poor sonar operators should greatly reduce training costs by predicting which individuals will become the good operators.
It is known that measures of brain wave activity are sensitive to such environmental stresses as fluctuations in air pressures, the dulling of the senses by overdoses of nitrogen, and the effects of oxygen poisoning. Brain waves are also affected by decreases in the alertness of an individual, and they can identify impairment in thought processes as well as disabilities in learning capability.
Navy research has examined the performance of sonar operators, radar intercept officers, and physical security personnel. These studies all report differences between high and low performers in the electrical amplitude of their brain waves in specific areas of the brain. These studies also show that there are differences in the electrical activity or the two sides or the brain during the performance of certain verbal and visual-spatial tasks.
If measurements of the electrical activity and nature of brain waves can discriminate between good and poor sonar operators, they might logically be used to differentiate between prospective candidates for sonar training who should become good operators and those who will not. If, however, brain wave differences are the result of learning rather than inherited differences, then brain wave measurements could be used to monitor the effectiveness of training techniques to determine a best way to teach prospective sonar operators.
Electrical measurement of brain waves have several advantages over the tests previously used. After a short period of preparation, a five minute test can provide enough data on many aspects of the information processing in a man’s brain to make judgements on his basic sensory capability as well as his level of attention on his job. These electro-physiological tests eliminate problems that many people have with paper and pencil tests, particularly since they do not require a written or verbal “answer” to the questions asked. It is thus much more difficult to malinger or fake such tests.
The Naval Submarine Medical Research Laboratory in Groton is currently giving a series of tests to a large number of experienced submarine sonar operators. The tests cover both visual and auditory sonar, target-detection tasks. After these tests, each sonar supervisor is asked to rate the sonar operator’s abilities; each operator is also requested to estimate his own performance as a sonar operator.
The goal of this work is an improved way to select candidates for sonar training. It should also suggest a system of hardware for this screening process. This year the Navy needs about 700 new sonar operators. With a present 30S being lost in training, the cost to the Navy of these failures amounts to several millions of dollars. If the failure rate can be reduced, the potential payoff is great.
(This work is being performed under a workunit, “Neurometric assessment systems for identification of specially skilled sonar personnel,” at the Naval Medical Research and Development Command.)