Experiment 11
FREE ESCAPE FROM HABITAT
Author / experimenter : drs J. P. Krol (diver / experimental 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 with minimum information handling on information handling capacity.

THIS PAGE HAS DIFFERENT LANGUAGES TO CHOOSE FROM:  flagFRAN.gif (157 bytes)   flagGERM.gif (153 bytes)   flagspain.gif (593 bytes)   flagportbraz.gif (279 bytes)   flag-italy.GIF (165 bytes)

The mental load consisted of a dangerous condition: " Free escape " from an underwater habitat standing at a depth of 40 ft.

The experiment also served to demonstrate how a condition that was totally in-accessible for psychological observation, let alone psychometric measurement, was made accessible for psychometric measurement with the BCG with LDSR-unit.

 

Material and methods.

The underwater habitat was positioned at about 150 ft from shore.

Shore facilities consisted of large army tents were the subject-divers were looked after (catering etc.).

Medical facilities included standard emergency equipment, a decompression tank and two physicians for medical supervision.

The electronic apparatus (BCG with cardiomod for electronic storage of performance) was placed in a boat moored at a buoy above the underwater habitat.

A speed boat was available for transport between this boat and the landing side.

Telecommunication was provided between the habitat, the boat with the apparatus, and the shore via a radio-van.

The author conducted the experiment from inside the habitat and, as a senior diver, was responsible for the divers safety inside the habitat until the moment they actually left the habitat shaft for free escape.

During "free escape" subjects were accompanied by a "buddy" who had been waiting outside the habitat.

Procedure.

Two subjects would leave the shore (150 ft. from habitat) after a call from the habitat.

They would swim to the buoy, collect the LDSR-unit from the boat and then descend to the habitat below.

One subject entered the habitat, took off his scuba-equipment and was instructed.

After this a one minute practice with the LDSR -unit was given, followed by one minute registration (CB).

After this, subject would descend in the habitat shaft, with the LDSR-unit in the left hand.

When settled, he would commence free escape after clearance from the experimenter.

He was instructed to operate the LDSR-unit during the actual period of free escape (F/E).

The condition of "free escape" is characterized by a change in pressure (100% in this case ) and of course the absence of external air.

Subjects are constantly exhaling to compensate for the reducing pressure.

Under the conditions of the experiment, visibility was approximately 5ft, meaning that the subjects were ascending "in the green" for the greater part of the trajectory.

 

Results.

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

Figure shows effect of free escape on information handling capacity, with registration in the habitat (CB) as a reference.

F/E shows the performance during free escape.

Value in the graph are the averages of all subjects.
scien27a.gif (3007 bytes)

THE RESULTS BELOW SHOW INDIVIDUAL PERFORMANCE TRACES OF THE 16 SUBJECTS.

THESE TRACES ARE OBTAINED BY PRINTING OUT THE RESULTS FROM THE ELECTRO MAGNETIC STORAGE APPARATUS.

THE LEFT PART OF THE TRACE SHOWS PERFORMANCE  BEFORE   FREE ESCAPE (IN HABITAT: CB).

THE RIGHT PART OF THE TRACE SHOWS PERFORMANCE DURING   FREE ESCAPE.

IT IS OBVIOUS THAT THE REGISTRATIONS DURING FREE ESCAPE ARE CHARACTERIZED BY PERFORMANCE INTERRUPTIONS AND ERRORS (= PEAKS).
scien27b.gif (53001 bytes)

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

Figure shows individual performance traces of 16 subjects.

This type of registration shows the occurrence of performance "blocks" (large response interval times).

Comparison of choice making capacity in the habitat with free escape shows a reduction of 78 % during free escape.

Inter- individual differences were extreme, ranging from 8% to 100% reduction.

It appeared that these differences were more or less related to the degree of experience of the various subjects.

 

Discussion.

The experiment has demonstrated that the BCG with LDSR-unit can be used to measure ( spare) information handling capacity during such complex conditions as free escape.

The data provide a comparison between conditions and also between individuals.

To our knowledge this is the first time a method had been used to quantify an important aspect of cerebral functioning during this exercise.

Free escape has a distinct place in naval training programs of many countries, notably in relation with sub-marine personnel.

The considerable inter-individual differences in performance found in this experiment indicate that the instrument could be used as a selection device or as a tool with which the degree of proficiency in this exercise could be established.

APPARATUS USED IS DESCRIBED UNDER :
13. APPARATUS AND REGISTRATION

SOME FOLLOW-UP RESEARCH OF THIS EXPERIMENT :
12. DEPTH 90 METERS

 

Validation of constructs II  "Main Page"

Copyright J. P. Krol ©