Pupils expand when memories are spoken

Autobiographical memory serves both private reflection and social communication, yet little is known about how these retrieval modes differ in physiological demands. We investigated whether overt (spoken) versus covert (silent) autobiographical retrieval differentially modulates pupil activity- a sensitive index of cognitive processing. Forty-four participants recalled personal memories under overt and covert conditions, alongside overt and covert counting control tasks, while pupil size was continuously recorded. Results revealed significantly larger pupil diameters during overt retrieval compared with covert retrieval, despite equivalent memory specificity and emotional intensity across conditions. Overt retrieval elicited greater dilation than overt counting, and covert retrieval elicited greater dilation than covert counting, confirming that autobiographical reconstruction itself imposes cognitive effort. The increased dilation during overt compared with covert retrieval may reflect additional demands related to narrative organization, social monitoring, emotional regulation, communicative processing, and other task-related cognitive processes. These findings suggest that speaking about personal memories engages additional cognitive and socio-cognitive demands beyond silent recollection and demonstrate that pupillometry provides a useful window into the processes supporting autobiographical retrieval. Overall, our results indicate that overt and covert autobiographical retrieval are associated with different pupillary responses, with overt retrieval eliciting greater dilation than covert retrieval.