Investigating the effects of prolonged exposure to textual enhancement on attention and learning: a pre-posttest measures eye-tracking study

Research on the effects of textually enhanced (TE) subtitles on vocabulary acquisition through audiovisual input has yielded mixed results, primarily focusing on short viewing interventions. This study investigates the impact of TE on vocabulary meaning recall among 22 international students with limited knowledge of L3 Dutch. Participants watched an entire season of a comedy TV series in L2 English, accompanied by L3 Dutch subtitles as it would be broadcast on television. Using a within-subjects design, we assessed learning outcomes for 16 enhanced target words, 16 unenhanced target words, and 16 filler words absent from the subtitles. Two eye-tracking sessions were employed to measure participants’ attention to both enhanced and unenhanced target words during the first and last episodes, addressing the limitations of previous studies that only included a single eye-tracking session and could not capture shifts in processing at pre- and posttest. The findings reveal that TE significantly increases fixations on enhanced words compared to unenhanced ones, with this difference remaining significant over the duration of the intervention, resulting in greater learning gains. Overall, the results highlight the potential of TE to facilitate vocabulary acquisition through subtitled audiovisual input.