Mediation of timing accuracy by operant behavior

We attempted to demonstrate that timing performance on a temporal discrimination would be enhanced if rats were required to fill a duration with behavior than when they were not required to respond. Six rats were trained to discriminate between a 3- and 9-s stimulus in a symbolic-matching-to-sample task. In two conditions, a tone was used to signal the sample, and in the other two conditions, a light was used to signal the sample. In two conditions, the rats were required to respond on a lever mounted on the rear wall of the experimental chamber before making their discriminative response to one of the two levers mounted on the front wall of the experimental chamber. In the other two conditions, the rear lever was not presented during sample presentation, and no response was required. Consistent with our predictions, timing performance was significantly better when a lever-response was required during sample presentation than when no response was required.