Do magnitude estimation and lexical decision tap similar processes?

Young adults (n = 54 for Exp. 1, n = 50 for Exp. 2) and elderly adults (the same n = 40 in each experiment) participated in studies that required nonspeeded magnitude estimation scaling in response to words that varied in frequency and number of meanings. Across both experiments and across both groups, subject and item analyses indicated significant word frequency effects (low-frequency words were judged more difficult to process than high-frequency words) and significant word meaning effects (unambiguous words were judged to be more difficult to process than ambiguous words). Mean magnitude estimate values were significantly and positively correlated with mean lexical-decision task values obtained from the same subjects on the same stimuli based on data from a previous experiment. Results suggest that processes required for magnitude estimation are similar to those measured with the lexical decision task in word-recognition studies involving young and elderly adults.