Pupillometry as an objective measure of sustained attention in young and older listeners

Abstract

Acknowledgements: supported by funding from the BRC and the EC (Horizon2020 grant to MC). Initial pilot experiments were performed by Youna Cho. We are grateful to Mathilde Le Gal de Kerangal for helping recruit and screen the older listeners in Experiment 2. Data Availability Statement: Upon manuscript acceptance, data will be deposited in a suitable online depository and freely available. AbstractThe ability to sustain attention on a task-relevant sound-source whilst avoiding distraction from other concurrent sounds is fundamental to listening in crowded environments.To isolate this aspect of hearing we designed a paradigm that continuously measured behavioural and pupillometry responses during 25-second-long trials in young (18-35 yo) and older (63-79 yo) participants. The auditory stimuli consisted of a number (1, 2 or 3) of concurrent, spectrally distinct tone streams. On each trial, participants detected brief silent gaps in one of the streams whilst resisting distraction from the others. Behavioural performance demonstrated increasing difficulty with time-on-task and with number/proximity of distractor streams. In young listeners (N=20), pupillometry revealed that pupil diameter (on the group and individual level) was dynamically modulated by instantaneous task difficulty such that periods where behavioural performance revealed a strain on sustained attention, were also accompanied by increased pupil diameter. Only trials on which participants performed successfully were included in the pupillometry analysis. Therefore, the observed effects reflect consequences of task demands as opposed to failure to attend.In line with existing reports, we observed global changes to pupil dynamics in the older group, including decreased pupil diameter, a limited dilation range, and reduced temporal variability. However, despite these changes, the older group showed similar effects of attentive tracking to those observed in the younger listeners. Overall, our results demonstrate that pupillometry can be a reliable and time-sensitive measure of the effort associated with attentive tracking over long durations in both young and (with some caveats) older listeners.

Neural alpha oscillations and pupil size differentially index cognitive demand under competing audio-visual task conditions

“…Pupil size tracks cognitive demand in the auditory and visual tasks Pupil size increased with the degree of cognitive demand for both the auditory and the visual task (Figure 3). This increase in pupil size with cognitive demand is generally consistent with previous work (Kadem et al, 2020;Kahneman & Beatty, 1966;Koelewijn et al, 2012;Martin et al, 2020;Ohlenforst et al, 2018;Porter et al, 2007;Stolte et al, 2020;Wendt et al, 2016;Winn et al, 2018;Zekveld et al, 2010;Zekveld & Kramer, 2014;Zhao et al, 2019).…”

The effect of healthy aging on change detection and sensitivity to predictable sturcture in crowded acoustic scenes

“…Our results suggest that developing more sensitive auditory sustained attention tasks (e.g. Zhao et al, 2019) may be crucial for accurate assessment of older listeners' scene analysis ability.…”