Visual distraction and visuo-spatial memory: a sandwich effect

The functional characteristics of visuo-spatial serial memory and its sensitivity to irrelevant visual information are examined in the present study, through the investigation of the sandwich effect (e.g., Hitch, 1975). The memory task was one of serial recall for the position of a sequence of seven spatially and temporally separated dots. The presence of irrelevant dots interpolated with to-be-remembered dots affected performance over most serial positions (Experiment 1) but that effect was significantly reduced when the interpolated dots were distinct from the to-be-remembered dots by colour and shape (Experiment 2). Parallels are made between verbal and spatial serial memory, and the reduction of the sandwich effect is discussed in terms of the contribution of perceptual organisation and attentional factors in short-term memory.