Michael Qin


Michael Qin

Sage 4101

April 27, 2011 12:00 PM - 1:30 PM


Dr. Michael Kaige Qin is a Principle Investigator at the Naval Submarine Medical Research Laboratory. He received his Electrical Engineering degree from Purdue University (BSEE) and his Ph.D. in Psychophysics from The Harvard-MIT Division of Health Sciences and Technology. Prior to his doctorate, he worked as an electrical engineer at General Motors and NASA.  Dr Qin's current research involves Human Factors Engineering and the bioeffects of underwater sound on humans. He currently has adjunct appointments at University of Connecticut and Worcester Polytechnic Institute.

Title:  Examining the deleterious effects of hyperbaric-nitrogen narcosis using the N-Back Technique Michael Qin, David Fothergill, Derek Schwaller, Matthew Babina, Kästley Marvin (Naval Submarine Medical Research Laboratory, Groton, CT 06349)


Previous research has reported that nitrogen narcosis is a problem breathing air as shallow as 100 fsw.  To the extent that these findings reflect the general performance of divers at depth, this would suggest that humans should have severe problems performing complex tasks while diving deep on compressed air.  However, the subjective impressions of experienced divers remain that they can overcome these narcotic effects. To examine the discrepancy, the N-Back technique was used to measure the cognitive and psychomotor performance of divers during compressed air dives up to 280 fsw.

 Materials and Methods:

Five U.S. Navy trained divers participated in two dry compressed air chamber dives to 190 fsw and one dive to 280 fsw. Cognitive and psychomotor performance was measured using an auditory N-back M-pitch procedure. Divers were asked to attend to a tone train and report whether the tone presented N tones prior has the same or different duration. As a distracter, the tones varied in pitch. Performance measurements were taken prior to diving, at depth, and again upon returning to surface.


Individual performance accuracy decreased by 7-22 percentage points during the first dive to 190 fsw and decreased by 2-14 percentage points during the second dive. At 280 fsw, performance accuracy decreased by 10-25 percentage points. Pre- and post-dive performances were not significantly different from each other.


While cognitive and psychomotor performance decreased at depth, the present findings suggest that some divers are still able to perform well-practiced complex tasks competently at air depths as deep as 280 fsw.

(Sponsored by ONR)

Examining the Deleterious Effects of Hyperbaric-Nitrogen Narcosis

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