| Readers routinely draw inferences with remarkable efficiency and seemingly little cognitive effort. The present study was designed to explore the processing of different types of inferences during the course of reading. In addition we explored the potential effects of differing levels of working memory capacity on the likelihood that inferences would be made. The EEG was recorded from five scalp sites (Cz, Pz, Oz, C3, C4) while subjects read ninety paragraphs, comprised of sixty experimental paragraphs and thirty filler paragraphs. There were four types of experimental paragraphs: (1) Bridging inference, (2) Elaborative inference, (3) Word-Based Priming, and (4) No Inference. Each paragraph was four sentences long, and the final sentence stated explicitly the inference which readers did or did not make. Results, using the average peaks of the N400 component of the ERP as a measure of semantic priming and integration, indicated that readers with greater working memory capacity (as measured by the Daneman and Carpenter (1980) Reading Span Task) made both bridging and elaborative inferences during reading, whereas readers with lower working memory capacity made only the necessary bridging inferences during reading. Data from the Word-Based Priming control condition rule out semantic priming between words as the sole cause of the N400 differences observed. |
