Physiological and psychological effects of escape from a sunken submarine on shore and at sea.
BACKGROUND
The stress effects induced by diverse military scenarios are usually studied under tightly controlled conditions, while only limited research has addressed realistic scenarios. This study was designed to compare the effects of two levels of realism in stressful training for escape from a sunken submarine.


METHODS
Thirteen qualified submariners served as subjects. All had previously participated in underwater escape training using a simulated submarine in a land-based tank submerged at a depth of 6 m; for this study, they repeated the simulator escape, following which six of them executed escape from an actual submarine lying at a depth of 30 m on the sea floor. The men were studied before the exercises, immediately after surfacing, and 2 h later. Measured variables included sympathovagal balance, salivary cortisol, perceived mood, and sleep, as well as short-term and declarative memory.


RESULTS
Compared to the simulator exercise in the tank, the escape at sea showed the following significant differences: 1) higher salivary cortisol values (6.33 +/- 3.9 nmol x L(-1) on shore and 13.38 +/- 7.5 nmol x L(-1) at sea); 2) greater adverse changes in mood, including vigor, tension, and ability to fall asleep; and 3) impairment in declarative memory. Responses were found to differ further for the five submariners who had prior experience of accident or injury while at sea.


CONCLUSIONS
The psychophysiological and cognitive effects of military exercises may be influenced by the realism of conditions and by prior exposure to life-threatening situations.
Trousselard
Marion
M
Centre de Recherches du Service de Santé des Armées, Département des Facteurs Humains, La Tronche Cedex, France.
Cian
Corinne
C
Barraud
Pierre-Alain
PA
Ferhani
Ouamar
O
Roux
Alain
A
Claverie
Damien
D
Canini
Frederic
F
Baert
Patrice
P
D000328:Adult; D000339:Affect; D004924:Escape Reaction / Q000502:physiology*; D005602:France; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008889:Military Personnel / Q000523:psychology*; D013315:Stress, Psychological / Q000097:blood / Q000503:physiopathology*; D013366:Submarine Medicine
D006854:Hydrocortisone