Effects of Motion Sickness on Encoding and Retrieval Performance and on Psychophysiological Responses

Background: Motion sickness has previously been found to deteriorate performance. In complex working environments, sustained ability to perform despite motion sickness is crucial. This study focuses on effects of motion sickness on encoding and retrieval of words. In addition, the temporal development of psychophysiological responses and their relationship with perceived motion sickness were investigated. Methods: Forty healthy participants (20 male and 20 female, age 19-51) performed an encoding and retrieval task during exposure to an optokinetic drum and were compared with 20 controls (8 male and 12 female, age 21-47) not exposed to motion sickness. Measurements of heart rate, heart rate variability, skin conductance, blood volume pulse, respiration rate, and skin temperature were made throughout optokinetic drum exposure. Results: Moderate levels of motion sickness did not affect the ability to encode or retrieve words. Perceived motion sickness was positively related to heart rate, blood volume pulse and skin temperature and negatively related to respiration rate. Conclusions: The psychophysiological measurements did not show consistent patterns of sympathetic activation and parasympathetic withdrawal, as could be expected. Subjective reports of progressing symptoms are still likely to be the most reliable way of assessing motion sickness