Deficits in reach target selection during inactivation of the midbrain superior colliculus

摘要

Visual scenes are often crowded with many different objects. As a result, goal-directed actions (e.g., reaching for a pencil on a cluttered desk) typically require the selection of a single target (the pencil) from a field of many possible targets (e.g., paper clips, a coffee cup, a computer mouse). The majority of research into the neural mechanisms of target selection for visually guided actions has focused on selection-related signals observed within brain areas involved in planning and executing movements of specific parts of the body, such as the eyes or the hand. A key question, and one that we attempt to address, is whether such activity represents a competition between alternative movement plans for a given part of the body or whether it constitutes a more abstract signal for target selection that is not bound to one particular type of movement.