Abstract
The aperiodic exponent features signals in various neuroimaging modalities and has been linked to the excitation/inhibition balance of the neural system. Leveraging the rich temporal dynamics of resting-state pupil fluctuations, the present study investigated the association between the aperiodic exponent of pupil fluctuations and the neural excitation/inhibition balance in attentional processing. In separate phases, we recorded participants’ pupil size during resting state and assessed their attentional orienting using the Posner cueing tasks with different cue validities (i.e., 100% and 50%). We found significant correlations between the aperiodic exponent of resting pupil fluctuations and both the microsaccadic and behavioral cueing effects. Critically, this relationship was particularly evident in the 50% cue-validity condition rather than in the 100% cue-validity condition. The microsaccadic responses mediated the association between the aperiodic exponent and the behavioral response. Further analysis showed that the aperiodic exponent of pupil fluctuations predicted the self-rated hyperactivity/impulsivity trait across individuals, suggesting its potential as a marker of attentional deficits. These findings highlight the rich information contained in pupil fluctuations and provide a novel approach to assessing the neural excitation/inhibition balance in attentional processing.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Conflict of interest: The authors declare no competing financial interests.
First, more discussion of the relationships between cue validity, uncertainty, and neural E/I balance. Second, we recognize that the exogenous attention paradigm used in this study is an indirect measure of neural E/I balance. After careful consideration, we have changed the title to "Aperiodic pupil fluctuations at rest predict orienting of visual attention". At the same time, we have substantially revised the structure and content of the Introduction section to clarify the logical connection between the aperiodic exponent of pupil fluctuations and both neural E/I balance and attentional processing. Third, we have changed all median-split analyses to correlation analyses. Fourth, we have completely revised the description of ADHD in the manuscript. Finally, we have fixed minor grammatical issues and added the necessary control analysis to the data.