Jana Sumitash, Gopal Atul, Murthy Aditya
Department of Psychology, University of California San Diego, La Jolla, CA 92093, USA.
Laboratory of Sensorimotor Research, National Eye Institute, Bethesda, MD 20814, USA.
Brain Sci. 2021 May 10;11(5):607. doi: 10.3390/brainsci11050607.
Significant progress has been made in understanding the computational and neural mechanisms that mediate eye and hand movements made in isolation. However, less is known about the mechanisms that control these movements when they are coordinated. Here, we outline our computational approaches using accumulation-to-threshold and race-to-threshold models to elucidate the mechanisms that initiate and inhibit these movements. We suggest that, depending on the behavioral context, the initiation and inhibition of coordinated eye-hand movements can operate in two modes-coupled and decoupled. The coupled mode operates when the task context requires a tight coupling between the effectors; a common command initiates both effectors, and a unitary inhibitory process is responsible for stopping them. Conversely, the decoupled mode operates when the task context demands weaker coupling between the effectors; separate commands initiate the eye and hand, and separate inhibitory processes are responsible for stopping them. We hypothesize that the higher-order control processes assess the behavioral context and choose the most appropriate mode. This computational mechanism can explain the heterogeneous results observed across many studies that have investigated the control of coordinated eye-hand movements and may also serve as a general framework to understand the control of complex multi-effector movements.
在理解介导孤立的眼动和手动的计算和神经机制方面已经取得了重大进展。然而，对于这些运动协调时的控制机制了解较少。在这里，我们概述了我们使用积累到阈值和竞争到阈值模型的计算方法，以阐明启动和抑制这些运动的机制。我们认为，根据行为背景，协调的眼手运动的启动和抑制可以在两种模式下运行——耦合和解耦。当任务背景要求效应器之间紧密耦合时，耦合模式起作用；一个共同的指令启动两个效应器，并且一个统一的抑制过程负责停止它们。相反，当任务背景要求效应器之间的耦合较弱时，解耦模式起作用；单独的指令启动眼睛和手，并且单独的抑制过程负责停止它们。我们假设高阶控制过程评估行为背景并选择最合适的模式。这种计算机制可以解释在许多研究协调眼手运动控制的研究中观察到的异质结果，并且还可以作为理解复杂多效应器运动控制的一般框架。
