本研究采用眼动仪直接记录40名在校大学生及研究生(平均年龄21.9岁,SD=1.8)自由观看实景图片的眼动情况,考察自然状态下视觉注意在真实场景中的空间偏向。为了控制图片不同区域刺激特征显著性对结果的影响,将被试随机分为两组,一组观看正向图片,一组观看倒置图片。对图片四个象限上的首次注视概率、首次眼跳方向和注视时间百分比分别进行2(水平方向)×2(垂直方向)×2(呈现方式)的重复测量方差分析,结果表明,存在独立于刺激特征的空间注意偏向,表现在水平方向具有左侧注意偏向,垂直方向具有上侧注意偏向。
There are two main types of visual-field asymmetries : right/left hemi-field asymmetries and upper/lower hemi-field asymmetries. In view of scenes differing from other types of visual stimuli chosen by previous papers in a number of important ways, it is still an open question whether there is an overall attentional bias of horizontal and vertical visual fields in viewing natural scenes. 40 college students (20 females) viewed 40 real-world pictures with free viewing allowed, and their eye movements were monitored by Tobii TI20. In order to control the effect of feature saliency, half of the participants viewed the normal picture while the other half viewed its mirror reversed in the horizontal and vertical orientation. The dependent variables were locations of the first fixation, as a measure of endogenous attentional bias before the pictures showed up ( to make sure of that, there was a 600-800ms blank screen between the central fixation cross and picture) ; initial saccade direction, as a survey of the initial distribution of attention during observers' first fixations on pictures ; and fixation duration, as a reflection of visual asymmetries in the whole process. To determine whether the presence of pictures would affect the result, a repeated measure analysis of variance (ANOVA) with horizontal ( left and right) and vertical( upper and lower) bias as the within-subject factors and the presence mode (normal and reversed) as a between-group factor was designed. With regard to locations of first fixation, there was a significant main effect of horizontal bias, F( 1,38) = 10. 437, p 〈 . 01, ηp2 =. 215, sp =. 883. However, there was no vertical bias differences, and no significant interaction was found between any two or among three variables except the one between vertical bias and presence mode, F( 1,38) =4. 123, p 〈. 05, ηp2 =. 098, sp =. 508. The simple effect test demonstrated that when the observers viewed the normal pictures, they showed a striking upward bias, F?