09:00 - 10:30
Parallel sessions 4
09:00 - 10:30
Room: HSZ - N4
Chair/s:
Nicola Schneider
The diffusion decision model (DDM) is a mathematical framework that jointly describes choice behavior and response time distributions, offering a process-level account of decision-making. Conceptualizing decisions as the accumulation of noisy evidence, the DDM has provided insights into the cognitive mechanisms underlying perception, attention, memory, and higher-order decision-making. Its flexibility and explanatory power have made it one of the most widely used tools in experimental psychology, bridging cognitive theory, mathematical modeling, and empirical research.
The increasing prominence of DDMs has spurred both conceptual and methodological developments. This symposium focuses on recent theoretical and computational advancements in the modeling of DDMs, including advances in estimation techniques, alternative stochastic dynamics to the Wiener process, and integrations with other modeling frameworks. Together, we aim to highlight new directions for enhancing theoretical and conceptual precision, modeling flexibility, and computational efficiency.
This symposium is the first part of a two-part series on DDMs at TeaP. While Part I emphasizes model development, theoretical extensions, and computational innovation, Part II turns to applied research, demonstrating how DDMs can help us better understand cognitive processes across different populations and domains. By being open to scholars from all areas of experimental psychology, the series offers a forum for presenting new ideas, establishing collaborations, and identifying future directions in the modeling of human cognition.
Submission 698
Lévy Flights vs. Self-Elicitation: Competing Accounts of Speed–Accuracy Trade-Offs in Evidence-Accumulation Models
SymposiumTalk-02
Presented by: Andreas Voss
Andreas Voss
Heidelberg University, Germany
In evidence-accumulation models, speed–accuracy settings are typically modeled by adjusting boundary separation. Numerous studies have shown that speed instructions lead to lower boundaries, indicating that decisions are made based on smaller amounts of accumulated information (i.e., liberal settings), whereas accuracy instructions lead to higher boundaries, requiring more information for a decision (i.e., conservative settings). However, recent research challenges the idea that boundary separation alone is sufficient to explain behavior under speed versus accuracy instructions. The Lévy Flight Model assumes more pronounced guessing tendencies—reflecting less stable evidence accumulation—under speed instructions. Another approach, based on an Ornstein–Uhlenbeck process, suggests a tendency toward self-elicitation in evidence accumulation following speed instructions.

In the present talk, I will compare both accounts and test whether they can be empirically distinguished.