An important dimension of cognitive control is the adaptive regulation of the balance between exploitation (pursuing known sources of reward) and exploration (seeking new ones) in response to changes in task utility. Recent studies have suggested that the locus coeruleus-norepinephrine system may play an important role in this function and that pupil diameter can be used to index locus coeruleu...

Clinical assessment of pupil appearance and pupillary light reflex (PLR) may inform us the integrity of the autonomic nervous system (ANS). Current clinical pupil assessment is limited to qualitative examination, and relies on clinical judgment. Infrared (IR) video pupillography combined with image processing software offer the possibility of recording quantitative parameters. In this study we ...

The locus coeruleus-noradrenergic (LC-NA) neuromodulatory system has been implicated in a broad array of cognitive processes, yet scope for investigating this system's function in humans is currently limited by an absence of reliable non-invasive measures of LC activity. Although pupil diameter has been employed as a proxy measure of LC activity in numerous studies, empirical evidence for a rel...

Convergence, accommodation and pupil diameter were measured simultaneously while subjects were watching 3D images. The subjects were middle-aged and had weak hyperopia. WAM-5500 and EMR-9 were combined to make an original apparatus for the measurements. It was confirmed that accommodation and pupil diameter changed synchronously with convergence. These findings suggest that with naked vision th...

We measured tracking performance in two groups while either the target or the manual cursor was suppressed for a brief period during each trial. We have used this approach to investigate the internal models used during tracking, and their updating during motor learning. We have simultaneously measured tracking performance and pupil dilation as a measure of cognitive load. The results showed tha...

PURPOSE To prospectively compare the scotopic pupil size between emmetropes and myopes using a Colvard pupillometer. METHODS The pupil diameters of 55 normal subjects and 55 healthy myopic subjects were measured with the Colvard pupillometer in a low-light situation that simulated the level of light encountered while driving at night. RESULTS The mean (+/- SD) age of the emmetropic subjects...

Rods, cones and melanopsin containing intrinsically photosensitive retinal ganglion cells (ipRGCs) operate in concert to regulate pupil diameter. The temporal properties of intrinsic ipRGC signalling are distinct to those of rods and cones, including longer latencies and sustained signalling after light offset. We examined whether the melanopsin mediated post-illumination pupil response (PIPR) ...

OBJECTIVES To determine if there is any difference in pupillary response among different acupuncture stimulation sites. METHODS The subjects were 14 healthy males who had no known eye diseases or abnormality in their pupils. They received five different interventions: no acupuncture stimulation (hereinafter 'no-stimulation') and acupuncture stimulation at four sites (TE5, ST7, CV12 and ST36)....

BACKGROUND The purpose of this study was to evaluate the effect of OMS302 on intraoperative pupil diameter and early postoperative ocular pain when administered during intraocular lens replacement surgery. METHODS Four hundred and six patients (406 study eyes; 202 in the OMS302 group and 204 in the placebo group) were entered into this randomized, double-masked, placebo-controlled, multicente...

Pupillometry has long been used as a measure of brain state. Changes in pupil diameter are thought to coincide with the activity of neuromodulators, including noradrenaline and acetylcholine, producing alterations in the brain state and corresponding changes in behavior. Here we review mechanisms underlying the control of pupil diameter and how these mechanisms are correlated with changes in co...