Lexical connectivity effects in immediate serial recall of words

In four experiments, we tested whether immediate serial recall is influenced by a word’s degree centrality, an index of lexical connectivity. Words of high degree centrality are associated with more words in free association norms than those of low degree centrality. Experiment 1 reanalysed four existing datasets (collected for other purposes) to explore the effect of degree centrality in scrambled wordlists. Results indicated that high-degree (vs. low-degree) words are advantaged across all serial positions, independently of other variables including word frequency. Experiment 2 replicated this finding using an expanded stimulus set. Experiment 3 used pure lists with each list containing high- or low-degree words only. Once again, high-degree words were better recalled across all serial positions, and this could not be explained by other psycholinguistic variables. Experiment 4 used alternating lists, within which high- and low-degree words alternated. High-degree words were no longer advantaged overall. Instead, recall of low-degree words was facilitated when neighboured by high-degree words. We conclude that degree centrality is a distinct variable that affects serial recall and consider its influence both as an item-level characteristic that reflects how accessible a word is and as an inter-item property that captures how well associative links can be formed between words.