Pupil-linked phasic arousal relates to the reduction of response inhibition: inferences from a simultaneous pupillometry and EEG-fMRI study

Abstract

Attention reorienting is a critical cognitive function which drives how we respond to novel and unexpected stimuli. In recent years, arousal has been linked to attention reorienting. The timing and spatial organization of the interactions between the arousal and reorienting systems, however, remain only partially revealed. Here, we investigate the dynamics between the two systems through simultaneous recordings of pupillometry, EEG, and fMRI of healthy human subjects while they performed an auditory target detection task. We used pupil diameter and activity in the noradrenergic locus coeruleus to infer arousal, and found these measures linked to distinct cortical activity at various temporal stages of the reorienting response. Specifically, our results provide the first demonstration in humans of how phasic pupil-linked arousal relates to the reduction of response inhibition, an inference which otherwise would remain hidden without the help of simultaneous multi-modal acquisitions.

Pupillary response is associated with the reset and switching of functional brain networks during salience processing

“…In addition to the other work from our group where we used this multi-modal approach to examine the relationship between LC activity, pupillary response, and cortical dynamics [ 82 ], there are two other very recent instances where this simultaneous triple-modality data acquisition was reported [ 83 , 84 ]. Together with the work presented here, all four studies showcase unique analyses and insights that could be harnessed from simultaneous pupillometry-EEG-fMRI.…”

“…Descriptions of pupillometry, EEG and fMRI data preprocessing are included in S1 Text . Data acquisition specifications (along with the rigorous measures taken to ensure data quality) were described in detail in [ 82 ]. Specifically, proper synchronization between EEG recording and MR imaging was ensured via Brain Products’ SyncBox.…”

“…Additionally, the present study did not examine the relationship between the LC activity and pupillary response, as well as its relationship to the EEG measurement of cortex processes. Another study from our group highlighted these additional analyses and comprehensive examinations of LC activity and their associations [82,86]. In this study, we examined the relationship between effective connectivity and pupil measurement at the inter-individual level as shown in Fig 5 . Future studies are needed to replicate our results at the intra-individual level.…”