Pupil is controlled by the activity of the autonomous system. Under constant light and visual stimulus, it performs complex size oscillations and movements. Here, it is assumed that pupil behavior can be described by some unknown nonlinear deterministic rules. The techniques of time series embedding are applied to pupil size, obtaining a trajectory in the phase space. A trajectory is also obtai...

The adaptive gain theory highlights the pivotal role of the locus coeruleus-noradrenergic (LC-NE) system in regulating task engagement. In humans, however, LC-NE functional dynamics remain largely unknown. We evaluated the utility of two candidate psychophysiological markers of LC-NE activity: the P3 event-related potential and pupil diameter. Electroencephalogram and pupillometry data were col...

Degree of pupil dilation has been shown to be a valid and reliable measure of cognitive load, but the effect of aural versus visual task presentation on pupil dilation is unknown. To evaluate effects of presentation mode, pupil dilation was measured in three tasks spanning a range of cognitive activities: mental multiplication, digit sequence recall, and vigilance. Stimuli were presented both a...

We describe a surgical technique for management of zonular instability and pupillary miosis using a pupil expansion device (Malyugin ring) in patients who need cataract surgery. In this technique, the pupil expansion device is first used in the usual fashion. After a capsulorhexis has been created, lateral scrolls of the pupil expansion device are released and repositioned to entrap both the an...

In this paper, an alternative to the classical pupil apodization techniques (use of an amplitude pupil mask) is proposed. It is shown that an apodized pupil suitable for imaging of Extrasolar planets can be obtained by reflection of an unapodized flat wavefront on 2 mirrors. By carefully choosing the shape of these 2 mirrors, it is possible to obtain a contrast better than 109 at a distance sma...

Pupil cycling was produced using an electronic circuit so that the retina was illuminated in Maxwellian view only when pupil area exceeded an adjustable area threshold, Aref. The maximum (Amax) and minimum (Amin) amplitude of the oscillations varied linearly with Aref. These observations are described by a delay-differential equation. The Aref-dependent changes in Amax, Amin were used, respecti...

INtrODUctION The goal of educational methods is to allow the pupil the acquisition of knowledge. Even so, the way in which this aim is pursued originates four different currents of methods sorted by two criteria: (1) who leads the educational process and (2) requirement of pupil physical attendance. Regarding the former criterion, the process may be conducted either by the teacher—Teaching-Orie...

Our daily experience of time is strongly influenced by internal states, such as arousal, attention, and mood. However, the underlying neuronal mechanism remains largely unknown. To investigate this, we recorded pupil diameter, which is closely linked to internal factors and neuromodulatory signaling, in monkeys performing the oculomotor version of the time production paradigm. In the self-timed...

Introduction: Pupil and iris disorders form an important category of eye diseases. Accurate segmentation the pupil is first most step in automatic diagnosis diseases related to iris. Most existing methods do not have enough accuracy are sensitive effects noise specular spot reflection. In addition, images used these usually limitations, such as viewing angle . Method: proposed algorithm, a stab...