Spatial orientation in construction divers--are there associations with diving experience?

Abstract

Objective: The purpose of this work was to investigate whether or not navigation abilities are impaired in construction divers and if putative deficits can be related to MRT-verified brain lesions and/or to diving experience.

Methods: Nineteen construction divers and 19 controls matched for age, intelligence, and socioeconomic background were studied by use of a "locomotor search through" task which resembled working conditions at ground. The task incorporated a spatial working memory and a spatial reference memory component. Moreover, navigation parameters (i.e., rotational turns, distances traveled, speed of navigation) were derived from the participant's locomotor behavior, which was recorded automatically. Groups were compared by navigation performance, standard neuropsychological tests, and the number of brain lesions obtained by MRT-scans.

Results: Divers were widely comparable with respect to neuropsychological test scores, exploration behavior and speed of navigation during testing. Performance deficits in divers were seen in the three test trials with respect to the number of reference memory errors and navigation behavior. Only in controls were age and the number of MRI-verified lesions related to neuropsychological test performance and to maze variables, but in divers the number of lesions seemed to be related to hyperbaric exposure.

Conclusion: Despite possible positive selection effects in long-term construction divers, these results may have implications for health care of middle-aged divers who are exposed to critical depths of more than 60 meter sea water (msw).