Nitrogen narcosis and tactile shape memory in low visibility

Area of Science:

• Occupational Health
• Human Physiology
• Sensory Perception

Background:

• Commercial diving operations frequently occur in environments with limited visibility.
• Divers rely heavily on their tactile senses for tasks and environmental awareness.
• Nitrogen narcosis is a known risk factor affecting cognitive function in divers.

Purpose of the Study:

• To investigate the impact of nitrogen narcosis on tactile shape memory in commercial divers.
• To explore how psychological and biographical factors modulate the relationship between narcosis and tactile memory.

Main Methods:

• A crossover study involving 139 commercial divers in a hyperbaric chamber at 1 and 6 atmospheres absolute.
• Divers used tactile senses to memorize shapes while blindfolded.
• Delayed shape recall was assessed after simulated dives, alongside psychological and biographical data collection.

Main Results:

• Hyperbaric pressure significantly impaired tactile memory, with recall deteriorating by 8% when learning occurred at depth versus the surface.
• The sequence of testing also affected performance.
• Lower trait anxiety correlated with better recall, while lower educational attainment correlated with poorer recall.

Conclusions:

• Findings highlight the detrimental effect of hyperbaric conditions on tactile memory crucial for underwater tasks.
• The study underscores the need for alternative recording methods during deep diving in low visibility.
• Implementing aids for memory encoding and recall is vital for diver safety and operational efficiency.