Is elapsing time really recoded into spatial linear representation in working memory?

A growing body of evidence suggested that elapsing time is tightly associated with space in a specific way (e.g., Spatial Temporal Association of Response Codes or STARC effect). However, existing findings cannot justify a hypothesis that elapsing time is recoded directly into a spatial linear representation in working memory. The present study addresses this fundamental question by using three modified STARC-related working memory paradigms. In different experiments, participants were asked to give order judgment, order-irrelevant STM recognition judgment, or motor-related free-choice judgment, immediately after successive presentation of a set of disparate stimuli. Results show that responses to early stimuli were faster or more often with the left key and responses to late stimuli were faster or more often with the right key. These findings clearly support the hypothesis that elapsing time is directly and automatically recoded into a spatial linear representation in working memory.