ABSTRACT

This paper presents a memory-based model of direct psychophysical scaling.

The model is based on an extension of the cognitive architecture ACT-R and

uses anchors that serve as prototypes for the stimuli classified within each

response category. Using the ANCHOR model as a specific example, a general

Bayesian framework is introduced. It provides principled methods for making

data-based inferences about models of this kind. The internal representations in

the model are analyzed as hidden variables that are constructed from the stimuli

according to probabilistic representation rules. In turn, the hidden

representations produce overt responses via probabilistic performance rules.

Incremental learning rules transform the model into a dynamic system. A

parameter-fitting algorithm is formulated and tested on experimental data.