Picking Your Brain
Posted By Paul Kotik on 10 July 2006
Ralph Potkin wants to explore three basic research issues, the first of which is whether, indeed, the phenomena associated with DCS can be observed in freedivers.
The measurement technologies are well-developed and have served the field of scuba diving, buthad never been applied to systematic data collection in freediving. The basic tool here is Doppler bubble detection. A small, rugged device non-invasively detects bubbles in the blood vessels as the nitrogen dissolved in tissues under hydrostatic pressure (at depth) expands under ambient surface air pressure.
Ancillary questions address the frequency with which significant nitrogen absorption occurs during freediving, the depth, time and other factors associated with incidence, and, as a practical matter, mitigation. When and how are freedivers at risk for DCS, and what can we do to prevent it?
Dr. Potkin recently disclosed that he’s found bubble formation in some freedivers examined shortly after diving. He’s understandably reluctant to be more specific at this early juncture, but it’s fair to say that his findings on Grand Cayman and elsewhere favor moving forward with the research.
A second broad area of research underway centers on the issue of long-term neurological effects of freediving. This is, of course, a hot-button item with the general public and more than a few freedivers themselves. Who hasn’t had a non-diving friend or relative declare that holding one’s breath deprives the brain of oxygen and leads to certain neurological damage? So? Is it true? Are we dumbing ourselves down?
It’s one of those things that ‘everybody knows’, but which turns out to be not exactly so.
The evidence for the protective effects of the mammalian dive reflex under apnea – diversion of blood to the most vital organs, bradycardia and so forth – is strong and is, as Dr.Potkin reminds us, surprising to the conventional medical wisdom. Having learned of a theretofore unknown homeostatic mechanism which seems to allow for some degree of apnea without harmful consequence, Dr. Potkin argues for asking the question at the margins. It may be that a seemingly innocuous activity, one ‘provided for’ by human physiological response, has consequences which become apparent only over time. Or, it may be that there are immediate limits to the adaptation afforded by the diver reflex: limitations of depth, time, frequency, other factors or combinations of factors.
- Bookmark with :
- what are these?
