INTRODUCTION: Facial expression perception is the process by which someone can interpret the emotion of another individual using their facial cues. Below-average scores on tests designed to measure facial expression recognition (FER) accuracies are associated with inappropriate behavioral responses and are often linked to mental or neurological disorders. Head-down bed rest microgravity analog studies show changes in facial emotion processing that may indicate a behavioral health risk during spaceflight.

METHODS: During short-duration space analog missions at two separate facilities, 15 subjects took daily FER tests before, during, and after the mission. Each test was accompanied by questionnaires measuring either potential causal or impacted variables: stress, depression, loneliness, irritability, risk-taking, empathy, and intrinsic motivation.

RESULTS: Analysis of variance and post hoc t-tests showed that during the mission, the subjects were less likely to identify angry, sad, or fearful faces as disgusted compared to the baseline. Also, interest/enjoyment and perceived competence increased throughout the mission lifecycle. Multiple regression analyses were able to account for greater than 20% of the variance for depression and health/safety risk-taking using the FER data.

DISCUSSION: Changes in FER during space mission simulations show that perception changes are not limited to microgravity analogs. A perceptual change was observed during the short-duration missions, but there is not sufficient evidence to show behavioral health impacts. However, associations between FER and the questionnaires show a potential to develop predictive models, countermeasures, or psychological monitoring tools using FER. Additional research is required to determine the efficacy of such tools during long-duration spaceflight.

Van Hoy S. Facial expression perception and psychological changes during space analogs. Aerosp Med Hum Perform. 2024; 95(12):913–918.