Recursive self-feedback enables target language production in aphasia with pathological language mixing

Stroke in bilingual adults can lead to aphasia with pathological language mixing (PLM), a rare neurological condition with limited treatment options. Recursive self-feedback (RSF) offers a self-directed approach, allowing individuals with PLM to iteratively self-monitor and correct their language mixing independently. We demonstrated the effects of RSF in a 59-year-old female bilingual speaker of Spanish and English (Patient P3) with severe Broca's aphasia and PLM, 67-months poststroke. Over 14 intensive RSF sessions (2 h/day, 5 days/week, for 3 weeks), P3 used a mobile app to self-correct her mixing errors and increase the proportion of English words in her spontaneous speech. Post-treatment assessments showed improvements across both treated and untreated narrative prompts, with an 11-point increase in her Aphasia Quotient on the English version of the Western Aphasia Battery-Revised. These findings demonstrate that RSF enables target language production, yielding clinically meaningful language recovery in P3 without external cueing, modelling or feedback. RSF is a promising procedure for aphasia therapy, opening new pathways for targeting language access, control and recovery in aphasia and PLM.