Spatial and temporal response patterns on the eight-arm radial maze.

Six maze-experienced hooded rats were timed during five trials on which they collected water from all arms of an eight-arm radial maze, then made five more choices. All subjects frequently exhibited a "task-completion pause:" The subjects rarely spent more than 1 sec in the center of the maze between choices until they had entered all eight arms, then stopped in the center of the maze. In contrast, the time spent in each arm gradually increased until all of the water had been obtained, then decreased slightly. Four subjects began every trial by choosing eight consecutive adjacent arms. The task-completion pause indicates that these subjects recognized when all of the arms had been entered, without having to repeat one. Therefore, even extreme degrees of response stereotypy do not imply a fundamental dependence on response strategies.