The typical pattern of results in divided attention experiments is that subjects in a full attention (FA) condition perform markedly better on tests of memory than subjects in a divided attention (DA) condition which forces subjects to split their attention between studying to-be-remembered stimuli and completing some peripheral task. Nevertheless, recent research has revealed an exception wherein stimuli presented concurrently with targets in a detection task are better remembered than stimuli which co-occur with distractors. Research on this phenomenon--the Attentional Boost Effect (ABE)--has demonstrated that the ABE is reduced or eliminated for words made distinct by their word frequency or orthographic properties--forms of secondary distinctiveness. However, it is unclear how primary distinctiveness effects may interact with the ABE. The current study observed how perceptual and semantic manipulations of primary distinctiveness via the isolation paradigm interact with the ABE, and revealed these interactions to be fundamentally different than those of secondary distinctiveness. Specifically, whereas the effects of secondary distinctiveness in earlier studies were found to be redundant with the ABE, the current study demonstrated that items characterized by primary distinctiveness enhanced memory performance independently of the ABE.