This study is an investigation of short term (STM) and long term (LTM) memory structure and its breakdown in aphasia. The STM studies are based on a Sternberg paradigm, employing semantically related and unrelated picturable nouns or pictures in the memory set with a probe item. The LTM studies are adaptations of existing semantic memory paradigms, assessing the extent to which aphasia disrupts the relationship between a superordinate category and its members, and the extent to which the typicality function is preserved. These studies will be correlated with performance on naming and comprehension tests, to determine the extent to which limitations in LTM and/or STM contribute to these aphasic deficits.