Analogous selection processes in declarative and procedural working memory : N-2 list-repetition and task-repetition costs

Kurzfassung/Abstract

Abstract Working memory (WM) holds and manipulates
representations for ongoing cognition. Oberauer (Psychology
of Learning and Motivation, 51, 45–100, 2009) distinguishes
between two analogous WM sub-systems: a declarative WM
which handles the objects of thought, and a procedural WM
which handles the representations of (cognitive) actions. Here,
we assessed whether analogous effects are observed when
participants switch between memory sets (declarative representations) and when they switch between task sets (procedural representations). One mechanism assumed to facilitate
switching in procedural WM is the inhibition of previously
used, but currently irrelevant task sets, as indexed by n-2 taskrepetition costs (Mayr & Keele, Journal of Experimental
Psychology: General, 129(1), 4–26, 2000). In this study we
tested for an analogous effect in declarative WM. We assessed
the evidence for n-2 list-repetition costs across eight experiments in which participants switched between memory lists to
perform speeded classifications, mental arithmetic, or a local
recognition test. N-2 list-repetition costs were obtained consistently in conditions assumed to increase interference between memory lists, and when lists formed chunks in longterm memory. Further analyses across experiments revealed a
substantial contribution of episodic memory to n-2 listrepetition costs, thereby questioning the interpretation of n-2
repetition costs as reflecting inhibition. We reanalyzed the data
of eight task-switching experiments, and observed that episodic memory also contributes to n-2 task-repetition costs. Taken
together, these results show analogous processing principles
in declarative and procedural WM, and question the relevance
of inhibitory processes for efficient switching between mental
sets.