Semantic contribution to immediate serial recall using an unlimited set of items: Evidence for a multi-level capacity view of short-term memory

The purpose of this study was to assess the respective roles of lexical and semantic levels of representations in immediate serial recall, by testing participants with items that varied on both these dimensions. Contrary to most studies where a small fixed set of words are repeated over trials, the current items were tested once by sampling them from an unlimited set of items without replacement. Participants recalled three classes of words under articulatory suppression: nonwords, function words, and content words. Results indicated an advantage for function words over nonwords, confirming a specifically lexical contribution to immediate serial recall. Additionally, content words were more frequently recalled than function words, confirming a semantic contribution. These results imply that nonphonological factors influence immediate serial recall and are consistent with a multi-level capacity view of short-term memory.