Ocular and Attentional Pursuit Tracking in Visuo-Spatial Working Memory

Despite evidence of interference between spatial working memory and ocular control (e.g., Baddeley, 1986; Lawrence et al, 2001; Pearson & Sahraie, 2003; Postle et al., 2006) an equivalent interference to visual working memory has never been carefully examined. In Experiment 1 (n=18), participants made either pursuit eye movements or equivalent shifts of attention during the retention of visual information. Visual working memory was disrupted by both conditions but eye movements produced a larger impairment. In Experiment 2 (n=12), a novel paradigm for investigating the effects of eye movements and shifts of attention on visuo-spatial encoding processes was used. Discrimination performance was better when visuo-spatial representations were encoded using attentional tracking than when encoded using eye movements. The results suggest that visual and spatial working memory encoding and maintenance processes are impaired by concurrent tasks that require spatial attention and ocular motor processing.