It is commonly established that simple action phrases are retained better when participants were instructed to perform the actions than they learned the phrases by reading. The superior memory performance after motor learning has been called the Subject Performed Tasks effect (SPT effect). Although a great many of researches have tried to account for the SPT effect and four theories had been proposed, none of them was sufficient to explain the enactment effect. However, the processing theories are contradictory with each other. The main contradiction is whether the SPT effect benefited from the automatic retrieval. So the current research applied the “recall-recognition” paradigm to clarify the mentioned divergence.

We recruited 80 college students to take part in two experiments and used between-subject design to explore the automatic retrieval mechanism by recall - recognition test. The participants were told to memorize the items for later recall by just reading them silently (VTs) or enacting them symbolically after reading (SPTs). An example of an item was given to the participants, which ensured that they were familiar with the task. After presenting the last item, a free recall test was administered which was audio recorded for later examination directly. Then the subjects were given the instructions for the recall-recognition test. Thirty-six words just learned were presented to the subjects on the computer screen. Subjects were instructed to judge whether the words had been recalled or not. The data were analyzed in terms of the serial position of items, by comparing the performance of free recall test and the recall-recognition test.

With regard to the free recall performance, it displayed that the participants recalled more phrases after finishing the SPTs than the VTs. However, the effects were only appeared in triplets 10, 11 and 12. A primacy and recency effect were observed after learning of a series of items in the VT condition. Whereas, for the SPT condition, no primacy effect but an extended recency effect could be found. In terms of recall-recognition test, the performance was significant worse under the SPTs condition than that under the VTs condition. However, such differences were observed only in blocks of 2~9, 10, 11 and 12. With regard to the category recall performance, there were similar serial position curves for VTs and SPTs, however the performance of recall-recognition was the same with the results of experiment 1.

The performance of free recall indicated that the SPT effect benefited from the extended recency effect which stems from an automatic pop-out mechanism. However, the recall-recognition test results demonstrated that the retrieval is automatically pop-out under the SPTs condition in blocks of 2~9, 10, 11 and 12. In conclusion, the SPT effects seem to be the result of a significant enhancement of middle and last blocks. The recall-recognition test results were different from the free recall results. It may be that "recall- recognition" paradigm is more sensitive to measure retrieval mechanism of SPT effect.