The Type of Response Codes on Time-Space Association: Visuospatial Coding Not Verbal-Spatial Coding

Abstract

It has been well known that a tight association exists between time and space. The Spatial-Temporal association of response codes (STEARC) effect, which reports the observation that individual respond is faster with left-hand side to short duration or past information and with right-hand side to long duration or future information, is regarded as strong evidence for this association. But, the explanation of the STEARC effect is on debates, that is visuospatial coding or verbal-spatial coding. With respect to visuospatial coding, the STEARC effect can result from a correspondence between the position of the effector and the position of the temporal information in the mental time line. With respect to verbal-spatial coding, the STEARC effect results from a correspondence between the polarity of the verbally coding temporal information and the polarity of response as left and right. These two accounts were supported by the mental time line hypothesis and polarity correspondence hypothesis respectively. In order to resolve this debate, this study employed binary classification task and manipulated the form of the response to explore the type of response code on time-space association. Subjects judged whether a cross lasted for a short (1 s) or long (2 s) duration. The reaction times (RTs) of correct reaction were served as measurement index. In experiment 1, subjects judged the duration of a cross by pressing the left key "C" and right key "M" of the computer keyboard. A STEARC effect indicated by the significant interaction between time and response as usual was found. It suggests that adopting short duration to explore the STEARC effect is efficient in contest of Chinese. In the experiment 2, Given that visuospatial coding did not exist in the verbal condition, these results suggested that the verbal-spatial coding is not sufficient to obtain a regular STEARC effect. In the experiment 3, we used a manipulation to prevent verbalspatial coding of the response and only exist visuospatial coding. The results showed that a regular STEARC effect is still obtained; this proved that visuospatial coding is sufficient to obtain an association of time and space. These results suggest that cognitive representation of elapsing time is likely to be visuospatial in nature. The findings support the hypothesis that the representation of time is spatially organized, with short durations represented on the left space and longer ones