Experimental Designs for Understanding Symbolic Learning

By Madeleine Mason, 2022 awardee of a Sidney W. & Janet R. Bijou Grant

Madeleine Mason is a doctoral student at the University of North Carolina Wilmington studying applied behavior analysis under the mentorship of Dr. Mark Galizio. She received her MA in psychology from UNCW and worked for several years as a BCBA serving individuals with autism before returning to UNCW for her doctoral studies. Her research interests include stimulus equivalence and emergent behavior. The Bijou Grant will support her doctoral research into an innovative rodent model of functional equivalence class formation.

The ability to relate symbols and their meanings is fundamental to complex cognition and language. The development of symbolic behavior, however, is difficult to study in human children as their rich natural learning history acts as a confound to experimental preparations. An animal model would be a useful tool, but there have been only a handful of demonstrations of symbolic-like processes in a limited number of species (Galizio & Bruce, 2018; Lionello-DeNolf, 2021). A simple discrimination reversal procedure originally developed in pigeons (Vaughan, 1988) has recently yielded some of the first evidence of functional equivalence in rats (Mason et al., 2021). In this procedure, rats are trained respond to olfactory stimuli arbitrarily assigned to one of two sets. The contingencies associated with each set are repeatedly reversed such that on some sessions responding to members of Set 1 is reinforced while on other sessions responding to members of Set 2 is reinforced. If subjects shift responding to be consistent with the newly reversed contingency after only a few trials, before contacting each individual stimulus, this is considered evidence for transfer of function across class members.

Madeleine and her team will extend previous research by assessing the extent to which functional classes formed by rats reliably model those formed by humans. To assess class expansion, a novel odor discrimination will be trained with just one member of each class, followed by a test of function transfer between the novel odor and remaining class members. In another set of experiments, a novel response or Pavlovian function will be trained to just one member of a class, then tested for transfer to remaining class members. This research will provide valuable insight how symbols acquire meaning, how we learn from symbols, and potentially how interventions can be designed to promote symbolic learning in individuals with developmental disabilities.