Manipulation of Filled and Unfilled Shapes and Shape Words Confirms Saliency Manipulation in a Delayed Match-to-Sample Task

The extent to which geometric processing is isolated from other processes remains a long-standing question. Sturz, Edwards, and Boyer (2014) developed a delayed match-to-sample task that presented a sample of a shape, shape word, or bi-dimensional stimulus (shape and shape word). Post delay, participants identified the sample shape or the sample word by selecting between two shapes or two shape words. An asymmetrical pattern of interference emerged with increased reaction times and errors occurring in matching shape targets but not word targets. This was interpreted as shape words activating a semantic and spatial representation of shapes, but shapes only activating a spatial representation; however, such a pattern of results could have resulted from the shape word being more salient than the shape. The present experiments replicated and extended these results by manipulating figure-ground relations to contrast the original condition with an alternative to address an explanation based upon sample shape saliency (Experiment 1) and by confirming the effectiveness of the saliency manipulation (Experiment 2). Experiment 1 replicated the asymmetrical pattern of results for both conditions, and Experiment 2 confirmed the saliency manipulation. Collectively, these results undermine a pure saliency explanation and have comparative implications for the isolation of geometric processing.