Pupil dilation and its relationship to information processing during reading and listening

Abstract

Investigated whether pupil diameter indicates information-processing load during reading in 3 experiments involving 24 undergraduates reading passages of varying difficulty. A TV camera and monitor and a video recorder were used to measure the diameter of the pupil under a reading condition and 3 control conditions. No evidence was obtained that the pupil dilates while reading. Results were investigated by measuring the pupil size of 20 undergraduates while listening to tape recordings of the reading passages. No evidence was obtained that the pupil dilates while listening. Results suggest that pupil size cannot be used as an objective indication of whether or not an S is processing the information contained in connected discourse while he is engaged in reading or listening activities. The possibilities that the dilations occurred but were too small to be detected with the methods used is discussed. (PsycInfo Database Record (c) 2025 APA, all rights reserved)