Lexical-semantic support of verbal short-term memory under phonological demand: evidence for persistent imageability effects in immediate serial recall under rapid presentation and in dyslexic adults.

Verbal short-term memory (vSTM) draws on both phonological and lexical-semantic systems. This study examined whether vSTM support from semantic properties - specifically word imageability - varies with phonological ability and whether it endures rapid encoding conditions. Two auditory immediate serial recall (ISR) experiments tested recall for high - and low-imageability word lists in adults with and without developmental dyslexia. In Experiment 1, word imageability effects in standard presentation ISR were robust and equivalent across groups, despite the context of lower nonword recall in dyslexic participants. Experiment 2 used speeded presentation to limit rehearsal and reduce strategic encoding. Imageability effects were still observed, and a moderate association emerged between imageability benefit and nonword recall, which had not been observed with standard rate presentation. However, there remained no group-level differences in word recall. These findings indicate that imageability supports vSTM performance across individuals and task conditions. They do not provide strong evidence for compensatory mechanisms but rather highlight the general stability of semantic support in verbal memory across conditions.