Effects of speaker deviation on interpreters’ cognitive processes during simultaneous interpreting with text: evidence from eye-tracking, output analysis, and retrospective interview

Speaker deviations from prepared scripts present a significant cognitive challenge during simultaneous interpreting with text (SIMTXT), as audio-visual incongruence intensifies cross-modal interference and increases demands on attention management. This study investigates how student interpreters process and respond to such incongruence, combining eye-tracking, target output analysis, and retrospective interviews. Twenty-three student interpreters performed a Chinese-to-English SIMTXT task in which the source speech and script were presented simultaneously. Two variables were manipulated: congruence (congruent vs. incongruent) and deviation type (ideational vs. appraisal meaning). Eye-tracking results revealed significantly higher second-pass dwell time proportions for incongruent than congruent items, indicating that incongruence triggered late-stage reprocessing. Output analysis revealed a predominant text-following tendency, with over half of rendered items based on the script; however, considerable individual variation was observed, moderated by real-time cognitive demand and training experience. Appraisal deviations were more frequently resolved in favour of the auditory input than were ideational deviations, suggesting that the heavier cognitive load associated with propositional items reinforced script reliance. Interview data identified four script engagement strategies and revealed broadly positive but partly ambivalent attitudes towards script use. Together, the findings offer converging evidence on the cognitive management of speaker deviation in SIMTXT, with implications for interpreter training.