Exploring the suffix effect in serial visuospatial short-term memory

The suffix effect—the loss of recency induced by a redundant end-of-list item—was studied in a visuospatial serial recall task involving the memory for the position of dots on a screen. A visuospatial suffix markedly impaired recall of the last to-be-remembered dot. The impact on recall was roughly of equal magnitude whether the suffix shared attributes with the to-be-remembered dots (Experiment 1) or was visually distinct (Experiments 2 and 3). Although the presence of a tone suffix also impaired serial memory for the last items in the sequence, the impact of a visuospatial suffix was more marked, implying a specific as well as a possible general effect of suffix in the visuospatial domain (Experiment 4). The suffix effect seems not to be a phenomenon confined to verbal material but rather a universal phenomenon possibly related to grouping.