Individual determinants of response strategy formation in voluntary task switching

• Applicants: Dr. Jovita Brüning; Professor Dr. Dirk Ostwald
• Subject Area: General, Cognitive and Mathematical Psychology
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564829065

Our project focuses on interindividual differences in task switching decisions. In previous research, the Free Concurrent Dual-Tasking (FCDT) paradigm has identified individual preferences for three response strategies-blocking, switching, and response grouping-that are characterized by distinct response patterns in voluntary task-switching (VTS) situations. These strategies represent stable individual biases, unaffected by task variations, but differ in performance efficiency (i.e., the number of correct responses when performing two versus one task). Individuals who prefer a blocking strategy show moderate efficiency, whereas individuals who prefer switching or response grouping strategies show higher multi-tasking efficiency under favorable conditions. However, it remains unclear how short-term task engagement and long-term psychological traits influence the development of these strategies. Thus, our project contributes to this research unit by investigating the individual determinants of response strategy formation in task choice behavior and their interaction with other performance-based and extrinsic factors. By integrating behavioral experiments, electrophysiological recordings, and agent-based behavioral modeling, we investigate response strategy formation in relation to three possible mechanisms: (1) learning ability and error sensitivity, (2) motivation and reward sensitivity, and (3) personality traits and cognitive abilities. We pursue two main lines of research: an empirical line investigating task-switching decisions in the FCDT paradigm, and a theoretical line developing a computational framework for analyzing behavioral and neurophysiological data. Empirically, we analyze performance indicators (reaction times, errors) alongside electroencephalographic markers such as error-related negativity to understand how learning ability and error sensitivity shape strategy formation. We also examine interactions between response strategies, reward, and reward sensitivity by manipulating task-independent and task-dependent rewards. In addition, we examine the role of psychological traits using a comprehensive test battery that assesses motivation-related personality traits and working memory. Theoretical objectives focus on conceptualizing FCDT response strategies using Markov decision processes, embedding optimal decision policies in a statistical inference framework for validation, and extending this approach with a dipole-based ERP forward model. Through collaborations within the research unit, we are also exploring correspondences between response strategies, past performance, and reward sensitivity across projects. By contributing this perspective, we aim to offer key insights into the costs and benefits that drive VTS decisions, refine decision-theoretic frameworks for modeling task-switching decisions, and support the development of a unified theoretical framework.

• DFG Programme: Research Units
• Subproject of: FOR 6047: Voluntary task switching: Cognitive processes and models to account for task choices
• Co-Investigator: Professor Dr. Markus Ullsperger