# Pupil size behavior during on line processing of sentences

## TL;DR

This study investigates how pupil size varies during sentence reading, revealing that pupil dilation reflects not only cognitive load but also recognition of familiar phrases like proverbs, indicating complex cognitive and memory processes.

## Contribution

It demonstrates that pupil size dynamics can serve as a reliable measure of cognitive and memory processes during sentence comprehension, extending beyond simple load assessment.

## Key findings

- Pupil size increases during reading of regular sentences.
- Pupil dilation strongly occurs when recognizing proverbs.
- Pupil size reflects cognitive recognition, not just difficulty.

## Abstract

In the present work we analyzed the pupil size behavior of forty subjects while they read well defined sentences with different contextual predictability (i.e., regular sentences and proverbs). In general, pupil size increased when reading regular sentences, but when readers realized that they were reading proverbs their pupils strongly increase until finishing proverbs' reading. Our results suggest that an increased pupil size is not limited to cognitive load (i.e., relative difficulty in processing) because when participants accurately recognized words during reading proverbs, theirs pupil size increased too. Our results show that pupil size dynamics may be a reliable measure to investigate the cognitive processes involved in sentence processing and memory functioning.