POST-CATEGORICAL PROCESSING AND ATTENUATION OF THE AUDITORY SUFFIX - EVIDENCE FROM BOTH IMMEDIATE AND DELAYED SUFFIXES

Recall of the final item in a spoken list is impaired by the presentat ion of a spoken to-be-ignored item following the list. The nature of t he processes responsible for the stimulus suffix effect (as well as it s magnitude) can be varied by manipulating the intrinsic characteristi cs of the relationship between the final list (target) item and suffix . A series of experiments show that systematic manipulation of both ty picality of same-category membership of target-item and suffix (Experi ment 1), and degree of synonymity between target-item and suffix (Expe riment 2) result in differential attenuation in the magnitude of the s uffix effect. The effect of the synonymity manipulation persists for u p to twenty seconds after the presentation of the target-item (Experim ent 3). That post-categorical processing of the suffix occurs provides direct support for semantic coding in short-term memory and contradic ts models arguing that short-term memory is organised according to the principle of physical similarity (e.g., LeCompte and Watkins, 1993).