Three-Dimensional Spatial Representation Of Number,Order And Magnitude

The SNARC effect refers to the association of smaller numbers with the left and of larger numbers with the right side in the space, suggesting that numbers may be represented on the horizontal dimensional internal mental number line(Dehaene, Bossini, & Giraux, 1993). Later, researchers found that the SNARC effect not only exist in the horizontal dimension, but also exist in the vertical dimension(Holmes & Lourenco, 2012; Schwarz & Keus, 2004). But until now, whether the SNARC effect exist in the front and rear dimension or not is still an open question. The first goal of the present study was to investigate whether the SNARC effect could be observed In the three-dimensional space. Numbers may tell us how many entities are in a set and convey quantity meaning(e.g., five apples in a basket), or they may refer to the relative position of an element within an ordered sequence and convey order information(e.g., page 5 comes after page4)(Turconi, Jemel, Rossion, & Seron, 2004). The second goal of the present study was to investigate whether the three-dimensional SNARC-like effect could be observed in the magnitude material and the ordinal material.The first experiment including 3 sub-experiments was to investigate the connections between numbers and space, magnitude and space, order and space in the horizontal dimension. The second and third experiment also including 3 Sub-experiments was to investigate the connections between numbers and space, magnitude and space, order and space in the vertical dimension and the front and rear dimension. The stimulus consisted of the Arabic numbers 3~7, Chinese characters “甲, 乙, 丙, 丁, 戊” which convey ordinal meanings as the ordinal material and 5 black round with different area as magnitude material. Participants were instructed to judge whether the Arabic number presented on the screen was greater than 5 or whether The ordinal stimuli was before 丙 or whether the magnitude stimuli was larger than the standard round, and press corresponding buttons which were placed in the horizontal dimension or vertical dimension or front and rear dimension。Each sub-experiment was a within-subject design of 2(Consistency : Consistent and Inconsistent) × 2(Distance to the Standard stimuli: 1 and 2). When Arabic number was greater than 5 /ordinal stimuli was after 丙/magnitude stimuli was larger than the Standard round, participants press the right button/top button/front button, otherwise, press the left button/bottom button/ rear button were defined as Consistent, and on the contrary, defined as inconsistent. All the participants were Han Chinese who read and write from left to right, from top to bottom.Results showed that in the horizontal dimension, the SNARC effect or SNARC-like effect appeared in all stimulus. Arabic number less than 5 /ordinal stimuli before 丙/magnitude stimuli less than the standard round were mapped to left side, Arabic number greater than 5 /ordinal stimuli after 丙/magnitude stimuli larger than the standard round were mapped to right side. In the vertical dimension the SNARC effect or SNARC-like effect appeared in all stimulus. Arabic number less than 5/ordinal stimuli after 丙/magnitude stimuli less than the standard round were mapped to bottom,Arabic number greater than 5 /ordinal stimuli before 丙/magnitude stimuli larger than the standard round were mapped to top. In the front and rear dimension the SNARC effect or SNARC-like effect appeared in ordinal stimulus and magnitude stimulus but not in the Arabic numbers. Ordinal stimuli after 丙/magnitude stimuli less than the standard round were mapped to rear, ordinal stimuli before 丙/magnitude stimuli larger than the standard round were mapped to front.Although, the SNARC effect in Arabic numbers was not observed in the front and rear dimension, we do found that the SNARC-like in Ordinal material and magnitude material not only could be observed in the horizontal and vertical dimension but also in the front and rear dimension for the first time. so, mental representation of order and magnitude may not on a mental number line(Dehaene, Bossini, & Giraux, 1993)or in a two-dimensional map(Schwarz & Keus, 2004),but in a three-dimensional space.