P. 411, lines 36–43. Delete ‘Another way to make the task non-spatial. . . hippo-campal animals have no deficit’ and substitute: ‘Hippocampal lesions also produce severe deficits on spatial reversals but not object reversals. In the spatial reversal task, the animal is first rewarded for choosing the left one of two identical objects. After it learns to do this, the rewarded side is reversed and it must then learn to respond to the object on the right. This reversal is repeated several times. The object reversal is a non-spatial version of the same task. The procedure is the same except that two different objects are used and the animal is trained to respond first to one object, then to the other. On each trial, the side upon which the objects appears varies randomly. ‘Thus if the spatial aspect of these tasks is eliminated, hippocampal animals have no deficit . . .’ The Author and Editors regret the error.