[A review on behavior and brain imaging research of human visually-guided action]

Bipedalism (using only two legs for walking) and having the capability to use tools have long been considered characteristic features that differentiate human beings from animals. Being able to walk upright freed up human hands, allowing us to reach, grasp, carry food, make and use tools, which greatly increased the survivability of our ancestors. Hand actions not only involve muscles and joints to execute actions but also require computations in the brain to analyze the visual environment and select the appropriate action, as well as formulate the action before execution and correct it in real-time during execution. Here, we review the behavioral and brain imaging research of human hand actions from a perspective of cognitive neuroscience. The review includes the research contents and methods of visually-guided action, existing theories, current debates, new evidence of existing theories, and the applications of action research in robotics and artificial intelligence.