Manipulation of Interference in the Passive Visual Store

Three experiments are reported that examine the circumstances under which irrelevant material causes interference with visual memory. Experiment 1 indicates that the amount of interference is related to the extent of the dynamic aspect within a visual noise field when the field is used as the irrelevant material. When the dynamic aspect comprises only a single dot changing within a field of 80 x 80 dots, interference is significant. Experiments 2 and 3 indicate that when the dot is extracted from the noise field and presented against a uniform plain background interference crucially depends on whether the dot is presented and re-presented at the same spatial location or at different locations. Only when the dot occupies successively different locations is interference caused. It is argued that the results are to be understood in terms of the two component parts of the VSSP. When the dot is presented against a uniform field and in different spatial locations, interference acts through the active spatial component. When the dot occupies a single position, interference acts through the passive visual store. The passive visual store only is sensitive to the visual noise background.