How do we generalize?

TL;DR

This paper reviews and synthesizes different mechanisms of generalization in humans and animals, emphasizing the need for future collaborative research to understand how various processes operate and interact.

Contribution

It introduces candidate mechanisms of generalization, discusses current challenges in synthesizing research, and proposes future research directions for understanding generalization.

Findings

Both integration of experiences and on-the-fly computation are valid generalization mechanisms.

Research consensus suggests multiple mechanisms may operate simultaneously or under different conditions.

The paper highlights the importance of interdisciplinary collaboration to advance understanding of generalization.

Abstract

Humans and animals are able to generalize or transfer information from previous experience so that they can behave appropriately in novel situations. What mechanisms--computations, representations, and neural systems--give rise to this remarkable ability? The members of this Generative Adversarial Collaboration (GAC) come from a range of academic backgrounds but are all interested in uncovering the mechanisms of generalization. We started out this GAC with the aim of arbitrating between two alternative conceptual accounts: (1) generalization stems from integration of multiple experiences into summary representations that reflect generalized knowledge, and (2) generalization is computed on-the-fly using separately stored individual memories. Across the course of this collaboration, we found that--despite using different terminology and techniques, and although some of our specific papers may provide evidence one way or the other--we in fact largely agree that both of these broad accounts (as well as several others) are likely valid. We believe that future research and theoretical synthesis across multiple lines of research is necessary to help determine the degree to which different candidate generalization mechanisms may operate simultaneously, operate on different scales, or be employed under distinct conditions. Here, as the first step, we introduce some of these candidate mechanisms and we discuss the issues currently hindering better synthesis of generalization research. Finally, we introduce some of our own research questions that have arisen over the course of this GAC, that we believe would benefit from future collaborative efforts.