Although mental fatigue is a complex, multi-facetted state that involves changes in motivation, cognition, and mood, one of its main characteristics is reduced task engagement. Despite its relevance for performance and safety, knowledge about the underlying neurocognitive processes in mental fatigue is still limited. Inspired by the idea that central norepinephrine plays an important role in re...

The difference in pupil diameter between monocular and binocular viewing conditions was used as a measure of binocular luminance summation in 97 infants aged 0 to 12 months. No significant difference in pupil diameter under monocular versus binocular viewing conditions was found until the end of the fourth month of life. The age of onset was positively correlated with the age of onset for stere...

In this paper we use pupil diameter as an indicator for measuring cognitive load for six different tasks on common web maps. Two eye tracking data sets were collected for different basemaps (37 participants and 1,328 trials in total). We found significant differences in mean pupil diameter between tasks, indicating low cognitive load for free exploration, medium cognitive load for search, polyg...

Changes in pupil diameter that reflect effort and other cognitive factors are often interpreted in terms of the activity of norepinephrine-containing neurons in the brainstem nucleus locus coeruleus (LC), but there is little direct evidence for such a relationship. Here, we show that LC activation reliably anticipates changes in pupil diameter that either fluctuate naturally or are driven by ex...

purpose: to report tonic pupil in a patient with ocular siderosis. case report: a 12-year-old male patient presented with over-sized right pupil from two weeks before. visual acuity (va) was 10/10 in both eyes without afferent pupillary defect. anisocoria was present with the right and left pupils, measuring 5 and 3 mm in diameter, respectively. anisocoria was greater in bright light and there ...

PURPOSE To evaluate a new disposable, small-pupil expansion device in tamsulosin patients with intraoperative floppy-iris syndrome (IFIS) having cataract surgery. SETTING Private practice, Los Altos, California, USA. METHODS The 5-0 polypropylene Malyugin pupil expansion device (MicroSurgical Technology) was used in 30 eyes from 21 tamsulosin patients having routine cataract surgery. The pu...

BACKGROUND Studies suggest that the pain response may be evaluated using pupillometry and is influenced by factors such as gender and anxiety. OBJECTIVES The aim of this study was to use pupillometry to observe the effects of gender and anxiety on the pain response. STUDY DESIGN A randomized, prospective, clinical and interventional study. SETTING Center for Research on Pain at the Federa...