- Location: Wilson Hall • 111 21St Ave S • Nashville, TN 37240
- Room: 115
- Contact: Angel Gaither
- Email: email@example.com
- Phone: 615-322-0080
- Website: https://www.vanderbilt.edu/psychological_sciences/events/index.php
- Audience: Free and Open to the Public
Philip L. Smith, PhD
Melbourne School of Psychological Sciences
The University of Melbourne
"Modeling Speeded Decision Making as Diffusion in Circles, Spheres, and Hyperspheres"
Evidence-accumulation models of decision making provide a powerful and flexible theoretical framework for representing the cognitive and neural processes involved in translating perception into action. The diffusion decision model, in particular, has provided a unified theory of the response time and accuracy data from a wide variety of experimental tasks. In this talk, I will present work that generalizes the diffusion model to higher dimensions. In the first part of the talk, I will present an application of a 2D version of the model that models continuous-outcome decisions as diffusions on the interior of a circle. The model provides a successful account of data from an eye-movement decision task about the hues of noisy color patches, including the decision biases associated with nameable colors. In the second part of the talk, I will present a 4D generalization of the model that models decisions as diffusions on the interior of a hypersphere. The model provides a successful account of performance in a double-target detection task, in which people identified the presence of one or two target stimuli in brief four-element displays. Together, these applications represent a significant generalization of the diffusion model and highlight its utility as a unifying framework for speeded simple decisions.