The Impact of Long-term Isolation in Antarctica on Social Touch and Its Underlying Biological Mechanisms in Winter-over Crew Members, Assessed During Their Stay Using Standardized Touch Stimulation, Computer-based Touch Sensitivity Tests, Questionnaires and Biological Markers.

TACTICE investigates how long-term isolation and reduced social touch during an Antarctic winter-over affect the way people perceive and respond to touch. The study will follow winter-over crew members at Concordia Station in Antarctica during the 2027 and 2028 seasons. The study focuses on so-called C-tactile (CT) sensitivity. CT afferents are specialized nerve fibers in the skin that are known to be involved in the pleasant and regulatory effects of social touch. They may also play a role in how prolonged social isolation affects people during a long-term mission in an isolated, confined, and extreme (ICE) environment. Participants will be assessed repeatedly before, during and after their stay. CT sensitivity will be measured using standardized touch stimulation and computer-based tasks involving touch-related stimuli. Participants will also complete questionnaires on social touch, loneliness, stress, relationships and coping. Saliva and blood samples will be collected to measure biological markers related to stress regulation and social processes, including cortisol and oxytocin. The main hypothesis is that prolonged isolation and reduced opportunities for social touch change CT sensitivity and reduce an important source of stress regulation. These changes are expected to become more pronounced with time spent at the station and to be related to changes in stress responses, behaviour, attitudes and interpersonal functioning. The study aims to improve understanding of how people adapt to prolonged isolation and confinement and may help inform the planning of future long-duration missions in remote and extreme environments, including space missions.