MICRO-POSITION EFFECTS IN VISUAL SHORT-TERM-MEMORY

Short-term memory for visually presented eight-digit numbers was teste d in a forced recall, read-and-dial task. The digits were presented no n-grouped or grouped in 2 + 2 + 2 + 2 or 2 + 3 + 3 digit formats. Spat ial grouping enhanced memory performance and produced local discontinu ities in the serial position curves related to grouping format. These micro-position effects are explained in terms of the relative spatial distinctiveness of individual digits.