INTRODUCTION

At a time of increasing rapprochement between the analyses of local spatial properties and the global organization of Gestalt pattern relations, symmetry relations can provide a guiding principle to help connect the two. It therefore seems a good juncture to take stock of research in symmetry perception, which began over a century ago with the trenchant analysis of Mach (1886). The pace of investigation in the field has been accelerating over the past two decades and this collection provides a representative overview of current work.