I’m Trying to Read Here! How Does Irrelevant Speech Affect How You Read?

Purpose: Reading involves a remarkable coordination of perceptual and linguistic processes. This coordination is reflected by a close coupling between reading eye movements and lexical properties of words, such as word frequency and predictability, as well as morpho-syntactic and semantic regularities. Yet, reading is also subject to interference, and a common source of interference is when others are speaking nearby. Then, how does irrelevant speech affect reading as reflected in eye movements? Method: Fifty-nine participants (mean age: 19, 25 females, 34 males, primary language: English) read passages from the PROVO corpus (Luke & Christianson, 2018) under intelligible irrelevant speech or silence, with eye movements recorded. We investigated how irrelevant speech influences the link between eye movements and several indicators of lexical difficulty: word frequency, cloze probability (exact-word predictability), large-language-model-generated surprisal, morpho-syntactic predictability (part-of-speech and inflection), and semantic predictability (general meaning). Results: Relationships between these lexical variables and eye movements remained robust during first-pass reading and were unaffected by irrelevant speech, suggesting intact lexical and syntactic processing during early stages of reading. However, disruption emerged in later eye-movement measures (i.e., total viewing time), where low-frequency and semantically unpredictable words prompted increased re-reading under irrelevant speech. Conclusion: These results indicate that intelligible irrelevant speech selectively interferes with post-lexical, higher-order semantic integration. The increased re-reading of rare and semantically unpredictable words suggests that readers compensate by revisiting these words to repair difficulties in integrating their meanings into a coherent understanding of the text.