Phasic LC-NE firing and attentional profiles: a pupillometric study.
Level 4 - case-series / case-control
Cross-sectional laboratory experimental and correlational study in humans (graded by design analogy)
PubMed 42139840 · doi:10.1016/j.concog.2026.104072
What was done
Participants completed two visual-input-matched tasks to evaluate task-evoked phasic pupil responses: a high-demand discrimination task and a low-demand localization task. The difference in response-locked peak pupil dilation between tasks served as a pupillometric proxy for phasic locus coeruleus-norepinephrine (LC-NE) activity. Participants also performed the MOXO-d-CPT, a continuous performance task with visual and auditory distractors measuring attentiveness, impulsivity, hyperactivity, and timeliness. Correlations between the isolated pupil metric and MOXO performance indices were examined.
What was found
The abstract reports no exact numerical values, sample sizes, correlation coefficients, or p-values. Discrimination conditions elicited greater pupil dilation than localization conditions. Exploratory correlation analysis revealed a significant association between response-locked phasic pupil responses and the MOXO attentiveness index, but no significant associations with the timeliness, hyperactivity, or impulsivity indices. The correlation with attentiveness differed significantly from timeliness and hyperactivity correlations, but not from the impulsivity correlation.
Why it matters
The findings provide preliminary evidence that phasic LC-NE activity specifically supports momentary attentional filtering against distractors rather than broad behavioral regulation.
Limits
The abstract omits sample size, participant characteristics, and all numerical statistics. The study was powered only to detect large effects, pupillometry is an indirect proxy for central noradrenergic firing, and the correlational design cannot establish causality.
Cited by
- supports Pupil dilation reflects underlying autonomic arousal that narrows visual focus and is mediated by norepinephrine, epinephrine, and dopamine.