This note is a tribute to Garth J. Thomas (1916-2008), late Professor of Brain Research at the University of Rochester, New York. Thomas was an influential psychologist, albeit for his research in learning and memory, as much as for his work as editor of the Journal of Comparative and Physiological Psychology. In his studies, he combined experimental lesions with behavioral analyses. He introduced the terms "dispositional" and "representational" to describe the 2 different types of memory function, and emphasized that memory must be studied not only through behavioristic psychology, but also in a molecular and physiological context. Through his experimentation in rodents, Thomas concluded that distinct neural mechanisms underpin dispositional and representational memory. Prompted by Thomas' remarks on the future evolution of research techniques, we touch upon some ideas on the engram and the glial theory in a modern perspective.
Keywords: Behavioral analysis; Delayed alternation; Dispositional and representational memory; Hippocampal and related structures; Learning and memory.