Visually based path-planning by Japanese monkeys

To construct an animal model of strategy formation, we designed a maze path -finding task. First, we asked monkeys to capture a goal in the maze by mov ing a cursor on the screen. Cursor movement was linked to movements of each wrist. When the animals learned the association between cursor movement an d wrist movement, we established a start and a goal in the maze, and asked them to find a path between them. We found that the animals took the shorte st pathway, rather than approaching the goal randomly. We further found tha t the animals adopted a strategy of selecting a fixed intermediate point in the visually presented maze to select one of the shortest pathways, sugges ting a visually based path planning. To examine their capacity to use that strategy flexibly, we transformed the rash; by blocking pathways in the maz e, providing a problem to solve. The animals then developed a strategy of s olving the problem by planning a novel shortest path from the start to the goal and rerouting the path to bypass the obstacle. (C) 2001 Elsevier Scien ce B.V. All rights reserved.