This experiment studied the learning phenomena by three behavioral indicators. The configural association theory insists that the hippocampus is required to solve configural discrimination learning tasks in rats. The theory identifies the negative patterning discrimination task as a typical example. We used this task to examine three behavioral indicators, i.e., the number of responses during the inter-trial interval, reaction time, and response rate. The results showed the serial changes of these indicators depend on learning progress. At first, number of responses during inter-trial inter...