Effect of load carriage and natural terrain conditions on cognitive performance in desert environments

Background: Correct decision making is a critical component of cognitive performance of a soldier, which may be influenced by the load carriage and terrain conditions during their deployment in desert environment. Purpose: The present study was aimed to investigate the effects of loads and terrain conditions on the cognitive performance in a group of twelve healthy heat acclimatized infantry soldiers under natural desert environment. Methods: The soldiers participated in a 10 min walking trial during carrying no load and also carrying 10.7, 21.4 and 30 kg at two terrain conditions viz., sandy and hard. We studied attention, memory and executive function, which are having immense functional importance in military operations. Standardized cognitive test battery was applied to the participants after carrying each magnitude of load at each terrain. Baseline cognitive performance was recorded on a separate day and was compared with the performances recorded after the load carriage trials. An attempt was made to reveal the relationship between physiological workload (relative workload) and cognitive performance at the point of completion of load carriage trials. Results: Load, terrains and load x terrain interaction did not produce any significant effect (p > 0.05) on the cognitive performance. Attention and relative workload were found significantly correlated at hard terrain under no load, 21.4 kg and 30 kg. Significant correlation was found between executive function and relative workload at hard terrain under no load. Conclusion: Carrying upto 30 kg load for 10 min at 3.5-4 kmph walking speed resulted in improvement in attention at sandy terrain, decrement in memory at both sandy and hard terrains and improvement in executive function at sandy terrain.