Université de Munich
Can we use psycholinguistic marker effects to study individual differences in lexical processing ability?
To become fluent readers, children need to develop the ability to activate a word’s pronunciation and meaning quickly and automatically. In shallow orthographies, where the print-to-speech correspondences are relatively easy to learn, the main hallmark of developmental dyslexia is slow reading speed. This is likely to be a consequence of poor lexical processing skills. Despite the practical importance of lexical processing, little is known about the best way to measure individual differences in this ability. In psycholinguistics, numerous marker effects have been used to measure lexical processing on the group level, including the frequency effect, regularity effect, and word superiority effect. We aimed to test to what extent these group-level marker effects can be used to measure individual differences, and whether the strength of the effects is correlated across individuals. We tested 85 Italian native speakers on 9 tests which have been used in the literature to measure lexical processing on the group level. We used both linear mixed effect models and standard linear regression to calculate each participant’s slopes associated with each marker effect. We found little correlation between these different measures, suggesting that, at least in Italian adult native speakers, there may be insufficient inter-individual variability to meaningfully assess individual differences.