In four experiments, rats were tested for short-term retention of a target spatial location either with or without prior exposures to alternate spatial locations in a T-maze. In all cases, exposure to alternate locations prior to exposure to the target location impaired retention of the target. This impairment increased as the number of exposures to the alternate location was increased, and the impairment decreased as the interval between alternate and target exposures was increased. In no case was the magnitude of the impairment found to increase as the retention interval was lengthened.