Abstract: Introduction: Researchers have recently paid attention to individual differences in visuo-spatial working memory. An important issue is the influence of several individual difference variables, such as gender, age, study difficulty, spatial ability, on visuo-spatial working memory. In the present study, we investigated whether there were differences on visuo-spatial working memory among individuals of different cognitive styles when the memory materials were different in difficulty.
Method：Experiment 1: (1) Participants: Fifty-six graduates participated in the GEFT. Among them, 16 (top 30%) with highest scores were defined as field-independent, and 16 (bottom 30%) as field-dependent. The final sample consisted of 32 participants (14 males, 18 females; mean age = 20.2 years). (2) Experimental design: This was a mixed design of two factors which were cognitive style (between-group) and path complexity (within-group). The cognitive style included field-independence and field-dependence, whereas the path complexity included simple path and complex path. The dependent variable was the span of visuo-spatial working memory which could be obtained when the total sum of the three biggest spatial orders was divided by three. (3) Materials and equipments: There were 25 cubes used in Corsi block-tapping task, which were presented on the computer screen with a blue background (23×25cm) in the shape of a 5×5 matrix. Experiment 2: (1) Participants: Fifty-five graduates participated initially in the GEFT. The method used was the same as that of Experiment 1. The final sample included 16 field-independent and 16 field-dependent students (15 males, 17 females; mean age = 20.8 years). (2) Experimental design: This was a mixed design of three factors which were cognitive style (between-group ), structural complexity (within-group) and quantitative complexity (within-group). The cognitive style included field-independent and field-dependent, the structural complexity included the matrix shape and random shape, and quantitative complexity included the small quantity and the large quantity. The dependent variable was the same as that in experiment 1. (3) Materials and equipments: In Corsi block-tapping task, the cubes were the same as those in experiment 1. Quantitative complexity included both the small quantity (9 cubes) and the large quantity (16 cubes). The structural complexity included matrix shape and random shape. We used SPSS11.5 to analyze the data of the two experiments.
Results:
Table 1
The span of memory of different cognitive style in different path complexity tasks （M±SD）

cognitive style simple path complex path
field independence 6.146±1.068 5.020±1.013 field dependence 5.751±1.118 3.895±0.665
An MANOVA was administered on the span of visuo-spatial working memory. The results indicated that the main effect of path complexity was significant , F（1，30）=73.612， p<0.001;under the simpler path, the span of memory was significantly higher than that of the complex path; the main effect of cognitive style was significant , F（1，30）=6.392， p<0.05; the field-independent subjects’ span of visuo-spatial working memory was significantly higher than that of the field-dependent subjects; the interaction between cognitive style and path complexity was significant , F（1，30）=4.410， p<0.05.
Table2.
The span of memory of different cognitive style under different experiment conditions（M±SD）

experiment small quantity large quantityconditions matrix random matrix random
field independence 6.125±1.039 6.271±1.063 5.771±0.757 5.917±1.145
field dependence 6.083±1.000 5.167±0.699 5.396±0.743 4.875±0.383
After an MANOVA test on the span of visuo-spatial working memory, we obtained the following results. The main effect of quantitative complexity was significant ,F（1，30）=8.129， p<0.01; under the small quantity condition, the span of visuo-spatial working memory was significantly higher than that of the large quantity; the main effect of cognitive style was significant, F（1，30）=9.816， p<0.01; the field-independent subjects’ span of visuo-spatial working memory was significantly higher than that of the field-dependent subjects; the interaction between cognitive style and structural complexity was significant , F（1，30）=9.317，

Key words: cognitive style, visuo-spatial working memory, structural complexity, quantitative complexity, path complexity