Proceedings of the Annual Meeting of the Cognitive Science Society

Does heightened proprioceptive precision promote the more aggressive updating predicted by reliability weighting, or the more conservative updating predicted by source estimation? To address this question, we introduced an unperturbed tuning phase prior to prism adaptation, varying visual availability during reaching across three contexts: eyes closed (EC), eyes open with ambient vision masked (EO-), and eyes open with ambient vision (EO+). Proprioceptive uncertainty estimates revealed context-dependent tuning effects, with the strongest sharpening in EC, weaker and less consistent changes in EO-, and a trend toward increased uncertainty in EO+. To examine how these pre-tuned proprioceptive states shaped subsequent updating, we modeled prism adaptation behavior using a hierarchical Bayesian state-space framework. This analysis demonstrated that sharpened proprioception was primarily coupled with more conservative state updating, consistent with a source-estimation account. In addition, the model captured a complementary modulation of performance stability, where improved proprioceptive precision suppressed trial-to-trial fluctuations in movement. Both effects followed an EC > EO+ > EO- ordering, revealing a non-monotonic mapping between proprioceptive tuning magnitude and functional impact. This divergence suggests that the influence of proprioceptive sharpening depends not only on uncertainty reduction, but also on how visual availability organizes the sensory context during action. Collectively, these findings suggest that error interpretation is a state-dependent process shaped by prior sensory context, with sharpened proprioception biasing error evaluation toward more conservative updating.