The influence of visual target information on the online control of movements

- We review how visual signals of target properties influence online arm motor control.
- Techniques such as removal of visual information and visual illusions are discussed.
- Emphasis is given to the double-step paradigm in which target location is perturbed.
- The special role of the parietal cortex in online response control is highlighted.
- A challenge is to grasp the integration of these visual signals with other signals.

The continuously changing properties of our environment require constant monitoring of our actions and updating of our motor commands based on the task goals. Such updating relies upon our predictions about the sensory consequences of our movement commands, as well as sensory feedback received during movement execution. Here we focus on how visual information about target location is used to update and guide ongoing actions so that the task goal is successfully achieved. We review several studies that have manipulated vision of the target in a variety of ways, ranging from complete removal of visual target information to changes in visual target properties after movement onset to examine how such changes are accounted for during motor execution. We also examined the specific role of a critical neural structure, the parietal cortex, and argue that a fundamental challenge for the future is to understand how visual information about target location is integrated with other streams of information, during movement execution, to estimate the state of the body and the environment in order to ensure optimal motor performance.