[an error occurred while processing this directive] Experiment 9 Navy frogmen

Experiment 9.
NAVY FROGMEN NORTH SEA BED
(drs j.p.krol (diver / exp.neuropsychologist))

APPARATUS USED IS DESCRIBED UNDER :
13. APPARATUS AND REGISTRATION

Purpose of the experiment was to investigate if the BCG with LDSR-unit could be used to measure the effect of mental load without information handling, on information handling capacity.

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The mental load consisted of a dangerous condition, created at 60 ft depth on the North sea bed.

The experiment also served to demonstrate how an isolated situation was made accessible for psychometric measurement with the BCG with LDSR-unit.

 

Materials and methods.

A navy ship with thirteen frogman was taken out to sea for the experiment.

In this experiment, strictly speaking, mental load of the tension type is only assumed to be truly present in the dangerous condition.(E2).

This "dangerous condition" consisted of taking out the mouthpiece of the breathe apparatus at 60 ft, for a period of 30 seconds, subjects being relaxed at the bottom.

The danger element is mainly that if a subject has difficulty in putting back the mouthpiece,(e.g. swallows water, starts coughing), he still has 60 ft of water above him, and he is already out of breath.

Under the prevailing experimental conditions visibility was approximately 1 ft, resulting in total darkness at the bottom.

Control for the dangerous condition-was a one minute sample, taken a short time before subject removed the mouthpiece ( El ) .

Conditions El - E2 replicated at ships deck as controls for the effects of submersion.

Thus Cl was a sample in a relaxed position shortly before the dive and C2 under same conditions but with the mouthpiece removed and breath holding.

In order of supposedly increasing load the conditions are ranked Cl - C2 - El - E2.

Subjects were reasonably experienced frogman, average age 23 years.

Each subject descended alone to the bottom were the LDSR-unit was placed.

All other apparatus was situated at the ships deck.

 

Results.

TO SEE COMPLETE GRAPH:
SLIDE TO THE RIGHT WITH BOTTOM SLIDEBAR.

Figure 1 shows the effect of experimental treatments on information handling capacity.
scien24.gif (2628 bytes)

 

It is clear that information handling capacity decreases in the predicted direction.

Figures 2. E2 and C2 show an example of computer processing of data (response interval times).
figure 2

 

Figures 2. E2 and C2 show an example of computer processing of data. Left plot is 30 seconds with mouthpiece removed at bottom (E2), next plot is 30 seconds breath holding at ships deck (C2). Each interval time between responses is expressed as per minute equivalent.

It is shown that this particular subject worked irregularly in the dangerous condition (control comparison on the right).

 

DISCUSSION.

The experiment shows that the BCG can be used for psychometric measurement in the submarine environment.

It also shows an effect on information handling capacity in this environment, and more so in the critical condition.

It should be pointed out however that, although protective gloves were worn under all conditions, water temperature ( + 5° Celsius) may still have influenced manual dexterity.

This could have influenced performance as measured, but not necessarily information handling capacity as intended.

APPARATUS USED IS DESCRIBED UNDER :
13. APPARATUS AND REGISTRATION

Validation of constructs II   "Main Page"

Copyright drs j. p. krol (diver/exp.neuropsychologist) ©