Using a Delayed Match-to-Samples Task to Investigate the Isolated Processing of Geometric Shapes and Their Corresponding Shape Words
Term of Award
Master of Science in Experimental Psychology (M.S.)
Document Type and Release Option
Thesis (open access)
Copyright Statement / License for Reuse
This work is licensed under a Creative Commons Attribution 4.0 License.
Department of Psychology
Bradley R. Sturz
Committee Member 1
Committee Member 2
Evidence suggests an isolated system dedicated to processing geometric information (Spelke, Lee, & Izard, 2010), but isolating geometric processing from semantic processing has remained difficult. Recently, Sturz, Edwards, and Boyer (2014) utilized a delayed match-to-sample (DMTS) task to present participants with a sample composed of a shape, shape word, or a bi-dimensional stimulus composed of a shape and a shape word. After a delay, participants were required to identify the sample shape or the sample word by selecting between two shapes or two shape words. Results suggested that sample shapes did not interfere with selecting a correct match in the presence of two shape words, but a sample shape word interfered with selecting a correct match in the presence of two shapes. Interference took the form of increased reaction times and increased errors in the presence of selecting between two shapes but not two words. Results were interpreted as suggesting that shapes do not activate a semantic representation of shape words, but shape words activate semantic and spatial representations of shapes. The present experiments attempted to replicate and extend these results. Experiment 1 included a condition that was identical to the original condition (Unfilled) and one condition in which the shapes were filled (Filled) to address a potential explanation based upon sample shape saliency. As predicted Experiment 1 replicated the asymmetrical results for both Filled and Unfilled conditions and undermine an explanation based upon saliency. Experiment 2 tested the assumption that shapes do not activate a semantic representation by reversing the matching criteria such that a sample shape word needed to be matched to its corresponding shape whereas a sample shape needed to be matched to its corresponding shape word. Such a reversal should require the semantic processing of shapes and result in increased reaction time and decreased accuracy. As predicted Experiment 2 produced a symmetrical pattern of results and indicated that word targets took a significantly longer time to match compared to shape targets. Collectively, results support an isolated system dedicated to processing geometric information by suggesting that both shapes and shape-words are automatically processed by two different psychological systems.
Edwards, Joshua E., "Using a Delayed Match-to-Samples Task to Investigate the Isolated Processing of Geometric Shapes and Their Corresponding Shape Words" (2015). Electronic Theses and Dissertations. 1218.