Parts of Speech Shape Reading-Time Variability in Brazilian Portuguese

Proceedings fo the Second International Workshop on Eye-Tracking Resources and Evaluation for Human-Aligned NLP

Abstract

This study uses regression analysis of Brazilian Portuguese eye-tracking data to examine variability in reading times across grammatical categories. Mixed-effects models reveal distinct patterns: numerals elicit high individual variability in early-stage reading, while function words (e.g., adpositions, determiners) drive differences in late-stage integration. In contrast, nouns show stable effects. These findings demonstrate that individual differences in reading are systematically linked to specific parts of speech, with numerals and function words as key loci of variability.