Elemental Representations of Stimuli in Associative Learning

14 October 2011

This paper reviews evidence and theories concerning the nature of stimulus representations in Pavlovian conditioning. It focuses on the elemental approach developed in Stimulus Sampling Theory (Atkinson & Estes, 1963; Bush & Mosteller, 1951b) and extended by McLaren and Mackintosh (2000; 2002), and contrasts this with models that that invoke notions of configural representations that uniquely code for different patterns of stimulus inputs (e.g., Pearce, 1987, 1994; Rescorla & Wagner, 1972; Wagner & Brandon, 2001). The paper then presents a new elemental model that emphasizes interactions between stimulus elements. This model is shown to explain a range of behavioral findings, including those (e.g., negative patterning and biconditional discriminations) traditionally thought beyond the explanatory capabilities of elemental models. Moreover, the model offers a ready explanation for recent findings reported by Rescorla (2000; 2001; 2002b) concerning the way that stimuli with different conditioning histories acquire associative strength when conditioned in compound