Complexity factors in visuo-spatial working memory. 
Three experiments are presented that use a technique of selective interference--irrelevant pictures--to develop our understanding of visuo-spatial working memory.  Visual noise fields are used as the irrelevant pictures.  Using two related measures of simple visual complexity, the experiments demonstrate that the greater the complexity the greater the degree of interference, even within a paradigm where subjects are instructed to look at but otherwise ignore the irrelevant pictures.  Both the number of dots and the density of the dots comprising the visual noise fields affect the degree of interference in a concurrent memory task.  In addition, increasing the size of the field increases the amount of interference.  It is argued that the results give insight into the properties of visual working memory and contribute to its theoretical development.  For example, it is argued that the store is directly accessible by externally presented interference and that particular aspects of the noise displays cause interference with visual memory.