Dexterous Manipulation During Rhythmic Arm Movements in Mars, Moon, and Micro-Gravity

Abstract

Predicting the consequences of one’s own movements can be challenging when confronted with completely novel environmental dynamics, such as microgravity in space. The absence of gravitational force disrupts internal models of the central nervous system (CNS) that have been tuned to the dynamics of a constant 1-g environment since birth. In the context of object manipulation, inadequate internal models produce prediction uncertainty evidenced by increases in the grip force (GF) safety margin that ensures a stable grip during unpredicted load perturbations. This margin decreases with practice in a novel environment. However, it is not clear how the CNS might react to a reduced, but non-zero, gravitational field, and if adaptation to reduced gravity might be beneficial for subsequent microgravity exposure. That is, we wondered if a transfer of learning can occur across various reduced-gravity environments. In this study, we investigated the kinematics and dynamics of vertical arm oscillations during parabolic flight maneuvers that simulate Mars gravity, Moon gravity, and microgravity, in that order. While the ratio of and the correlation between GF and load force (LF) evolved progressively with practice in Mars gravity, these parameters stabilized much quicker to subsequently presented Moon and microgravity conditions. These data suggest that prior short-term adaptation to one reduced-gravity field facilitates the CNS’s ability to update its internal model during exposure to other reduced gravity fields.

Static, Dynamic, and Cognitive Fit of Exosystems for the Human Operator

“…Predictions include expected sensory stimulation (Mussa-Ivaldi et al, 2011; Schaefer et al, 2012) and machine–systems behavior (Liu & Scheidt, 2008). Prediction errors lead to internal-model updates for better selection of subsequent movements (Cullen & Brooks, 2015; Opsomer et al, 2018; Schaefer et al, 2012), allowing unconscious adaptations (Mussa-Ivaldi et al, 2011). Theoretical perspectives vary in envisioning the relative richness or sparsity of logical detail in internal models.…”

Visual search under physical effort is faster but more vulnerable to distractor interference

“…For instance, adaptive increases in the grip force (GF) in microgravity Page 12 of 14 Park et al Cogn. Research (2021) 6:17 (Opsomer et al, 2018), additional physical efforts during extravehicular activity (EVA), reduced muscle strength over spaceflight missions (Winnard et al, 2019) could impair core cognitive processes, which could reciprocally reduce astronauts' sensorimotor functions (Bray et al, 2012). Together, these negative effects of physical effort pose a unique challenge and further necessitate development of strategies to account for suboptimal decisionmaking due to physical strain.…”

“…This can lead to a better understanding of the interactions between physical and cognitive activities in a broad range of domains, including education, ergonomic and work productivity, human–computer interfaces, defense and military, and sports. For instance, adaptive increases in the grip force (GF) in microgravity (Opsomer et al, 2018 ), additional physical efforts during extravehicular activity (EVA), reduced muscle strength over spaceflight missions (Winnard et al, 2019 ) could impair core cognitive processes, which could reciprocally reduce astronauts’ sensorimotor functions (Bray et al, 2012 ). Together, these negative effects of physical effort pose a unique challenge and further necessitate development of strategies to account for suboptimal decision-making due to physical strain.…”

The gravitational imprint on sensorimotor planning and control

“…Light, medium and dark traces correspond to early, middle, and late trials, respectively. [Adapted from Opsomer et al (2018). ] motor tasks (Schaal et al 2004).…”