Abstract: Nontemporal information processing involving short-term memory requirements disturbs time estimation. Previous studies mostly used letters or digits, which are maintained in working memory by phonological loops. Since verbal and nonverbal information are processed by separate working-memory subsystems, how do nonverbal, object-based memory tasks affect time estimation? Our prior study adopted nonverbal objects as memory materials, and found that produced time increased with increasing memory-object size under both the active processing and passive retention conditions; mean produced time interval did not significantly differ between the two experimental conditions. This result suggests that estimated duration is also affected by memory item maintenance when retention of objects requires more mental resources. Since some researches suggest that two distinct timing mechanisms are involved in temporal information processing in the range of milliseconds and longer durations. What it is like the relationship between retaining working memory information and perceived duration in the milliseconds range. Several researches combined time perception and memory task in which participants were requested to either processing verbal information or maintaining working memory items during the duration discrimination task. They found that duration discrimination of brief intervals was not affected by a secondary task that demanded either maintenance or elaborative rehearsal, suggesting that perceived duration was not influenced by retention of verbal working memory. Based on these distinct effects of retention of verbal information and object information on timing in the range of seconds, we further investigated whether retention of object information into working memory could affect time judgment in the range of milliseconds. This study employed a dual task paradigm combing time bisection task and working memory to explore the effect of retention of WM content on time judgment. Abstract figures that were relatively difficult to verbalize, name, and distinguish from each other were selected from prior studies. In the time bisection task, the two standard durations and five new durations (intermediate durations) were presented across trials in random order. After the offset of each duration, the participants had to click a button to judge its duration approached either short or long anchor durations. Participants first memorized two or four objects, and then performed a duration judgment task by judging the current intermediate durations was similar to short or long standard durations. At the end of each trial, indicated whether a test items was the same to or different from the memorized items. The point of subjective simultaneity and RTs were served as measurement index. We manipulated memory load and SOA (SOA: the time interval from offset of memory items to onset of time judgment task). The results showed that perceived duration was not affected by memory load, yet the RTs under low memory load condition was shorter than the RTs under high memory load when the SOA was shorter. In Experiment 2, we further investigated whether the effect of memory load on timing depended on perceptual priming, in which subjects were only required to complete time perception task. The results demonstrated that the impact of perceptual load on perceived duration is distinguished from the effect of memory load. These results suggest that time judgment in the range of milliseconds is affected by the interaction between memory load and SOA. The effect of SOA was likely related to task switch. The finding implies that time perception and retention of objects is also modulated by working memory especially central executive resources.

Key words: object stimuli, retention stage, time perception, working memory resources

摘要： 初步探讨毫秒范围内，客体信息保持对时间知觉的影响。实验一发现，知觉到的时间不受记忆负荷的影响，但当保持时间短时，低负荷的反应时低于高负荷的反应时；实验二仅要求被试完成时间知觉任务，发现知觉负荷异于记忆负荷对时间知觉的影响。结果说明，客体工作记忆保持对时间知觉的影响受到工作记忆资源的调节。

关键词: 客体图形, 保持过程, 时间知觉, 工作记忆资源