Phonological similarity in the serial recall task hinders item recall, not just order

The phonological similarity effect in short-term memory (STM) is the finding that serial recall of lists of similar sounding items is poorer than that of dissimilar sounding items. This is traditionally argued to be due to a detrimental effect on memory for the order of the words in the list and not on memory for the words themselves. Models that propose forgetting from STM is due to interference must invoke an additional compensatory process where the shared element of the words acts as a cue to recall, in order to account for the lack of an effect on memory for the words. However, the possibility of a detrimental effect of phonological similarity on item memory when these compensatory processes are not available has not been investigated. Two experiments (n = 60 and n = 57) in which similarity is operationalized in a way that precludes usage of compensatory processes are reported. The results clearly demonstrate that item recall is poorer for similar lists than dissimilar lists when similarity is defined in this way.