Shinohara, K., Osaka University, Japan
The purpose of this study was to examine the contribution of the central executive of working memory system to the temporal information processing. Fourteen subjects performed the "logic gate" task and 2-sec interval production task simultaneously. In the logic gate task, a pair of digits (0 or 1) was presented. Subjects had to produce an alternative response (true or false) based on the Boolean logic (AND, OR, NAND, NOR or XOR) instructed before presenting a pair of digits. There were two logic conditions; in the fixed logic condition, only one logic gate was used through the experimental block. In this condition, subject had to keep one mental-set for the instructed logic gate. In the altered logic condition, different logic gates were instructed at each trial. In this condition subjects had to select and activate the mental-set of instructed logic gate at each trial. This selective activation process of mental-set was supposed to require the central executive function. Result showed that the produced interval was longer in the altered logic gate condition than in the fixed logic condition. In general, when the non-temporal processing during interval production is interfered with temporal processing, produced interval becomes longer. Therefore, this result suggests that the process of central executive on the selective activation of mental-set is closely related to the temporal information processing in the interval production.