Capturing Interactions between Arousal and Cortical Dynamics with Simultaneous Pupillometry and EEG-fMRI

One of the two major axes for operationalizing emotion is arousal. While valence accounts for the positive or negative degree of a certain emotional state, arousal refers to the intensity of such a state. The locus coeruleus (LC), a small nucleus situated in the brainstem, is one of the key subcortical structures which plays a central role in regulating global arousal. In recent years, pupil diameter under constant luminance has also emerged as a widely used marker to index arousal. This study demonstrates how interactions between cortical processes and pupil/LC-linked arousal can be characterized with high temporal and spatial resolutions using a unique multi-modal approach. Specifically, we simultaneously recorded the participant’s pupillometry, EEG, and fMRI while they performed a simple auditory discrimination task. Our findings revealed that both pupil-and LC-linked arousal relate to a cascade of task-driven cognitive processes throughout the duration of the task. These neuroscientific findings can potentially be used to develop new human computer interfaces which utilize the dynamics of arousal to optimally deliver information, engage artificial intelligence and optimize human machine interaction.