Bioastronautics Laboratory, Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado Boulder, Boulder, CO, United States.
COHRINT Laboratory, Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado Boulder, Boulder, CO, United States.
Front Neural Circuits. 2021 Oct 15;15:757817. doi: 10.3389/fncir.2021.757817. eCollection 2021.
Reliable perception of self-motion and orientation requires the central nervous system (CNS) to adapt to changing environments, stimuli, and sensory organ function. The proposed computations required of neural systems for this adaptation process remain conceptual, limiting our understanding and ability to quantitatively predict adaptation and mitigate any resulting impairment prior to completing adaptation. Here, we have implemented a computational model of the internal calculations involved in the orientation perception system's adaptation to changes in the magnitude of gravity. In summary, we propose that the CNS considers parallel, alternative hypotheses of the parameter of interest (in this case, the CNS's internal estimate of the magnitude of gravity) and uses the associated sensory conflict signals (i.e., difference between sensory measurements and the expectation of them) to sequentially update the posterior probability of each hypothesis using Bayes rule. Over time, an updated central estimate of the internal magnitude of gravity emerges from the posterior probability distribution, which is then used to process sensory information and produce perceptions of self-motion and orientation. We have implemented these hypotheses in a computational model and performed various simulations to demonstrate quantitative model predictions of adaptation of the orientation perception system to changes in the magnitude of gravity, similar to those experienced by astronauts during space exploration missions. These model predictions serve as quantitative hypotheses to inspire future experimental assessments.
可靠的自我运动和方向感知需要中枢神经系统（CNS）适应不断变化的环境、刺激和感觉器官功能。为适应过程所需的神经计算系统仍然是概念性的，这限制了我们的理解能力，也无法在完成适应之前定量预测适应和减轻任何由此产生的损伤。在这里，我们实现了一个计算模型，用于模拟与重力大小变化相关的方向感知系统适应过程中的内部计算。总之，我们提出中枢神经系统会考虑感兴趣参数的平行、替代假设（在这种情况下，是中枢神经系统对重力大小的内部估计），并使用相关的感觉冲突信号（即感觉测量值与预期值之间的差异），根据贝叶斯规则，顺序更新每个假设的后验概率。随着时间的推移，来自后验概率分布的内部重力的中枢估计会不断更新，然后用于处理感觉信息并产生自我运动和方向感知。我们在计算模型中实现了这些假设，并进行了各种模拟，以展示方向感知系统对重力大小变化的适应的定量模型预测，这些预测类似于宇航员在太空探索任务中所经历的情况。这些模型预测为激发未来的实验评估提供了定量假设。
