CHARACTERISTICS OF VISUAL INTERFERENCE WITH VISUOSPATIAL WORKING-MEMORY

Recent discussions of visuospatial working memory have suggested that this subsystem may incorporate a visual buffer which holds Visuospatia l information relatively passively. Empirical investigations of visual interference with information held within a visuospatial subsystem ha ve yielded somewhat equivocal results. Nonetheless, evidence from Logi c (1986) has indicated that visuospatial processing can be disrupted b y passive exposure to irrelevant visual material in a manner analogous to the disruption of serial verbal recall by exposure to irrelevant s peech. This paper reports two experiments which explore whether such i rrelevant visual input is disruptive to storage of imaginal informatio n in a primarily spatial task-the Brooks spatial matrix task. Experime nt 1 shows that exposure to irrelevant visual input during encoding se lectively disrupts performance on a spatial, but not a verbal, version of the task. The extent of such disruption is shown to be independent of the visual complexity of the material, its similarity to the to-be -remembered information, or a change in state, with a static white squ are pattern yielding equivalent disruption to that produced by changin g matrix patterns. The second experiment indicates that this pattern o f effects is robust, and that such disruption is evident at an equival ent level when the visual material is present only during a 20-second retention interval. These results are interpreted as evidence of oblig atory access of external visual material to a passive visual buffer. I mplications for the nature of a visuospatial subsystem in working memo ry are discussed.