Orienting of attention, pupil size, and the norepinephrine system.
Level 4 - case-series / case-control
Non-clinical laboratory psychophysiological experiment; graded by design analogy.
PubMed 21258914 · doi:10.3758/s13414-010-0015-4
What was done
Participants performed Posner exogenous visual cuing tasks under two levels of target processing demand: an easy localization task and a demanding discrimination task. Pupil diameter was continuously recorded as an indirect physiological proxy for locus coeruleus-norepinephrine (LC-NE) system activity modes (phasic versus tonic) to evaluate its relationship with the time course and magnitude of inhibition of return (IOR).
What was found
The abstract reports no numerical statistics, sample sizes, or effect sizes. Qualitatively, the authors reported a response-locked phasic dilation of the pupil during the discrimination task relative to the localization task, as well as a correlation between pupil size at cue presentation and the magnitude of IOR.
Why it matters
This study provides psychophysiological evidence linking LC-NE system activity states to reflexive spatial attention and the mechanisms governing inhibition of return.
Limits
The abstract does not provide the sample size, participant characteristics, task parameters, or numerical results. Additionally, pupil dilation is an indirect peripheral proxy for locus coeruleus activity that can be confounded by cognitive effort, luminance, or arousal.
Cited by
- supports Pupil dilation reflects underlying autonomic arousal that narrows visual focus and is mediated by norepinephrine, epinephrine, and dopamine.