The effects of visual and spatial interference on spatial working memory

Baddeley and Lieberman (1980) have shown that processing within spatial working memory is disrupted by a spatial secondary task, but not significantly by a visual processing secondary task. In the present study their experiment was replicated under broadly similar circumstances. The spatial and verbal primary tasks involved remembering descriptions of spatially arranged or nonsense sequences of digits, respectively. The secondary visual and spatial tasks involved either judging the level of brightness or pressing an unseen matrix of buttons in a predetermined sequence. In contrast to the finding of Baddeley and Lieberman, both the visual and spatial secondary tasks significantly impaired spatial working memory. Neither of these secondary tasks significantly interfered with concurrent verbal processing. The present findings suggest that spatial working memory draws from resources from both visual and spatial quarters.