Lay summary
The project aims at validating a new model of working memory (WM), that is the central construct which enables us to maintain and manipulate information for goal-directed processing. We assume that WM consists of two separate parts: a declarative WM that maintains informations and a procedural WM that undertakes operations on these informations. Furthermore we aim at bridging the gap between two research traditions addressing cognitive capacity limits, namely research on WM (such as the maintenance of briefly presented lists) and research on action control in multitasking situations (such as task switching and the psychological refractory period paradigm). Please note that research on WM so far has mainly focused on the declarative side, that is investigating working memory capacity and material-dependent storage (i.e., verbal working memory, spatial or visual working memory). We plan to explore the concept of a procedural WM next to declarative WM as a further capacity limited system. Though our new model of working memory conceptualize WM as a mechanism that evolved for the selection and the processing of goal-relevant information in two separate subsystems. This view is in line with recent reviews of studies using neuroimaging data, suggesting that WM is an emergent property of different sites in the brain acting together to ensure goal-directed processing (D'Esposito, 2007). The heuristic theoretical framework of two different sub-systems, declarative (dWM) and procedural WM (pWM), raises two general questions that we want to address with our project. First, we aim at investigating the relationship between the two sub-systems by testing for shared or independent capacity limits (Experiments 1-6) and testing for shared or independent representations, that is action-guiding ideas subjects develop after instructions (Experiments 7 & 8). Second, we want to test the assumption that declarative and procedural WM solve the problem of selecting relevant representations for goal-directed processing in analogous ways. With this project we hope to shed further lights on the mechanisms that enable goal-directed processing and circumvent capacity-limits for error-less and efficient processing of information.