摘要: | 研究期間:10108~10207;One of the cognitive abilities crucial to the survival of human beings is to represent and process magnitude information in different domains. Previous studies from my lab have provided evidence for an intimate correspondence between numerical and spatial representations (Hung, Hung, Tzeng, & Wu, 2008), especially with an action purpose in the task (Chiou, Chang, Tzeng, & Wu, 2009). These findings are consistent with the ATOM (a theory of magnitude) model (Walsh, 2003), in which a generalized magnitude code underlying the processing of quantity, space, and time is proposed. Following this theoretical framework, it is also hypothesized that the computation of numbers and time is supported by the common mechanism. To empirically verify this hypothesis, the currently proposed project aims to investigate whether task-irrelevant numerical magnitude modulates the subjectively perceived time duration of sub- and supra-second events in temporal discrimination and reproduction tasks. Specifically, eight behavioral and four electrophysiological experiments are proposed in a three-year period. Through Experiment 1 to 4, which are conducted in the first year, the methods and trial parameters of time discrimination and time reproduction are validated, and the variability of participants’ performance is evaluated to determine the optimal procedures for the following experiments. Moreover, the results from Experiment 2 and 4 will inform us whether verbal counting strategies are involved in the temporal tasks and whether articulatory suppression would remove the contamination from such confounds. In the first half of the second year, we plan to conduct Experiment 5 and 6 to replicate the electrophysiological findings from previous literature that the amplitude of an ERP component, namely, CNV, reflects subjective time perception in the time discrimination and reproduction tasks. Based on the results from Experiment 1 to 6, we propose to conduct Experiment 7 to 12 in the second half of the second year and the third year to directly address whether task-irrelevant numerical magnitude embedded in a digit modulates the subjectively perceived duration of the digit. Specifically, Experiment 7 and 9 examine such an effect on the perception of sub- and supra-second durations in the time discrimination and reproduction tasks, respectively. Experiment 8 and 10 will further verify whether such an effect interacts with verbal counting strategies and duration lengths, and whether such interaction will be removed with simultaneously articulatory suppression. Experiment 11 and 12 will apply ERP recordings to explore whether the effect from numerical magnitude can be reflected in neural signals associated with subjective temporal perception. We expect to observe that small and large numerical magnitude compresses and stretches the subjectively perceived time duration, respectively, and the amplitude of the CNV component is affected by the numerical magnitude accordingly. In summary, the findings from the proposed project will greatly improve our knowledge of behavioral characteristics and neural mechanisms of temporal processing and their interactions with numerical information. This project will also provide evidence for a common magnitude code underlying the representation of time, numbers, and space, which is consistent with the fundamental operation of a highly dynamic and interactive brain. |