scholarly journals Early phase of pupil dilation is mediated by the peripheral parasympathetic pathway

2021 ◽  
Author(s):  
Chinatsu Marumo ◽  
Tamami Nakano
Keyword(s):  
Early Phase ◽  
Untreated Control ◽  
Pupil Size ◽  
Pupil Diameter ◽  
Pupil Dilation ◽  
Sphincter Muscle ◽  
Dilator Muscle ◽  
Brain States ◽  
Parasympathetic Pathway ◽  
Iris Sphincter

Pupil diameter fluctuates in association with changes in brain states induced by the neuromodulator systems. However, it remains unclear how the neuromodulator systems control the activity of the iris sphincter (constrictor) and dilator muscles to change the pupil size. The present study compared temporal patterns of pupil dilation during movement when each muscle was pharmacologically manipulated in the human eye. When the iris sphincter muscle was blocked with tropicamide, the latency of pupil dilation was delayed and the magnitude of pupil dilation was reduced during movement. In contrast, when the iris dilator muscle was continuously stimulated with phenylephrine, the latency and magnitude of rapid pupil dilation did not differ from the untreated control eye, but sustained pupil dilation was reduced until the end of movement. These results suggest that the iris sphincter muscle, which is under the control of the parasympathetic pathway, is quickly modulated by the neuromodulator system and plays a major role in rapid pupil dilation. However, the iris dilator muscle receives signals from the neuromodulator system with a slow latency and is involved in maintaining sustained pupil dilation.

scholarly journals Autobiographical memory increases pupil dilation

2019 ◽  
Vol 10 (1) ◽  
pp. 280-287
Author(s):  
Mohamad El Haj ◽  
Steve M. J. Janssen ◽  
Karim Gallouj ◽  
Quentin Lenoble
Keyword(s):  
Autobiographical Memory ◽  
Cognitive Processing ◽  
Memory Retrieval ◽  
Pupil Size ◽  
Pupil Diameter ◽  
Emotional Valence ◽  
Pupil Dilation ◽  
Control Task ◽  
Negative Memories

Abstract Background Pupil activity has been widely considered as a “summed index” of physiological activities during cognitive processing. Methodology We investigated pupil dilation during retrieval of autobiographical memory and compared pupil diameter with a control condition in which participants had to count aloud. We also measured pupil diameters retrieval of free (i.e., first memory that comes to mind), positive, and negative memories (memories associated, respectively, with the words “happy” and “sad”). Results Analyses demonstrated larger pupil diameters during the free, positive, and negative autobiographical memory retrieval than during the control task. Analyses also demonstrated no significant differences in pupil diameters across the three autobiographical memory conditions. Conclusion These outcomes demonstrate that, compared with counting, autobiographical retrieval results in a larger pupil size. However, the emotional valence of memories yields non-significant effect on pupil diameters. Our findings demonstrate how autobiographical memory retrieval yields pupil dilation.

A PRELIMINARY STUDY ON PUPIL SIZE CHANGES DETECTION ON MENTAL STRESS WITH MENTAL STRESSOR

2017 ◽  
Vol 29 (02) ◽  
pp. 1750011
Author(s):  
Poh Foong Lee ◽  
Khai Shan Lee
Keyword(s):  
Pupil Size ◽  
Pupil Diameter ◽  
Detection Algorithm ◽  
Pupil Dilation ◽  
Simple Tool ◽  
Pupil Detection ◽  
Acquisition Device ◽  
Changes Detection ◽  
Proportional Relationship ◽  
Preliminary Study

This is a study on measuring the effect of stress that stimulated by the different difficulty of game level on pupil dilation. Playing games are claimed a method to distress in the community, however, this activity is enhancing stress level? The effect of the game playing on the changes of pupil dilation is unknown. An investigation was conducted on relating the changes of pupil diameter measurement at the different difficulty levels of the game. A simple tool was developed by using a webcam as image acquisition device together with MATLAB Image Processing Tool to analyze the acquired images. Here, experiments on the pupil detection algorithm, which consisted of four different methods are to work alternatively with one another and to provide higher chances of pupil detection. 10 subjects were involved in the experiments, which they were requested to play a selected game with four different ascending increased in difficulties, meanwhile, pupil size changes were measured simultaneously. The selected game served as a stress stimulus to the subjects. The result showed a positive proportional relationship between increased in game difficulty levels and pupil dilation. The investigation reported that the pupil dilated when the difficulty of game level increased. Limitation of this study is the sample size on the prototype testing should be increased to concrete the outcome.

scholarly journals Pupil size dynamics predict dLGN firing mode over a wide range of timescales

2021 ◽  
Author(s):  
Davide Crombie ◽  
Martin A Spacek ◽  
Christian Leibold ◽  
Laura Busse
Keyword(s):  
Visual Cortex ◽  
Pupil Size ◽  
Sensory Input ◽  
Pupil Dilation ◽  
Multiple Timescales ◽  
Sensory Signals ◽  
Wide Range ◽  
Firing Mode ◽  
Brain States ◽  
Per Se

Pupil size is a commonly used proxy for waking brain states such as arousal, and has been related to activity modulations in cortical sensory areas. Here, we asked whether the dorsolateral geniculate nucleus (dLGN), which provides sensory input to the visual cortex, is modulated by pupil-indexed arousal. Observing that the pupil size oscillates at multiple timescales, we developed a method to show that the spiking mode of the dLGN is predicted by pupil size oscillations over several of these timescales. Overall, we found that tonic spikes preferentially occurred during pupil dilation, while bursts occurred during contraction. These preferences could not be explained solely by pupil size per se or by the locomotion of the animal, and were also present during periods of stimulus viewing. We conclude that dLGN spiking activity is modulated by pupil-indexed arousal processes on various timescales, influencing the mode in which sensory signals are passed on to the cortex.

scholarly journals Listener’s personality traits predict changes in pupil size during auditory language comprehension

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Isabell Hubert Lyall ◽  
Juhani Järvikivi
Keyword(s):  
Personality Traits ◽  
Language Processing ◽  
Language Comprehension ◽  
Pupil Size ◽  
Pupil Dilation ◽  
Systematic Research ◽  
Cognitive Resources ◽  
Personality Profiles ◽  
Pupillary Responses ◽  
Grammatical Errors

AbstractResearch suggests that listeners’ comprehension of spoken language is concurrently affected by linguistic and non-linguistic factors, including individual difference factors. However, there is no systematic research on whether general personality traits affect language processing. We correlated 88 native English-speaking participants’ Big-5 traits with their pupillary responses to spoken sentences that included grammatical errors, "He frequently have burgers for dinner"; semantic anomalies, "Dogs sometimes chase teas"; and statements incongruent with gender stereotyped expectations, such as "I sometimes buy my bras at Hudson's Bay", spoken by a male speaker. Generalized additive mixed models showed that the listener's Openness, Extraversion, Agreeableness, and Neuroticism traits modulated resource allocation to the three different types of unexpected stimuli. No personality trait affected changes in pupil size across the board: less open participants showed greater pupil dilation when processing sentences with grammatical errors; and more introverted listeners showed greater pupil dilation in response to both semantic anomalies and socio-cultural clashes. Our study is the first one demonstrating that personality traits systematically modulate listeners’ online language processing. Our results suggest that individuals with different personality profiles exhibit different patterns of the allocation of cognitive resources during real-time language comprehension.

scholarly journals Pupil Dilation with Intracameral Epinephrine Hydrochloride during Phacoemulsification and Intraocular Lens Implantation

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
A-Yong Yu ◽  
Hua Guo ◽  
Qin-Mei Wang ◽  
Fang-Jun Bao ◽  
Jing-Hai Huang
Keyword(s):  
Intraocular Lens ◽  
Pupil Diameter ◽  
Pupil Dilation ◽  
Surgical Performance ◽  
Corneal Incision ◽  
Iol Implantation ◽  
The Mean ◽  
Contralateral Eye ◽  
To Receive ◽  
Time Point

Objective. To investigate mydriatic effect of intracamerally injected epinephrine hydrochloride during phacoemulsification and intraocular lens (IOL) implantation.Methods. Eighteen cataract patients for bilateral phacoemulsification were enrolled. To dilate pupil, one eye was randomly selected to receive intracamerally 1 mL epinephrine hydrochloride 0.001% for 1 minute after corneal incision (intracameral group), and the contralateral eye received 3 drops of compound tropicamide 0.5% and phenylephrine 0.5% at 5-minute intervals 30 minutes before surgery (topical group). Pupil diameters were measured before corneal incision, before ophthalmic viscoelastic device (OVD) injection, after OVD injection, before IOL implantation, and at the end of surgery.Results. At each time point, the mean pupil diameter in the intracameral group was2.20±0.08,5.09±0.20,6.76±0.19,6.48±0.18, and5.97±0.24 mm, respectively, and in the topical group it was7.98±0.15,7.98±0.15,8.53±0.14,8.27±0.16, and7.93±0.20 mm, respectively. The topical group consistently had larger mydriatic effects than the intracameral group (P<0.05). The onset of mydriatic effect was rapid in the intracameral group. There was no difference in surgical performance or other parameters between groups.Conclusions. Intracameral epinephrine hydrochloride appears to be an alternative to the mydriatic modalities for phacoemulsification and IOL implantation. In comparison with topical mydriatics, intracameral epinephrine hydrochloride offers easier preoperative preparation, more rapid pupil dilation, and comparable surgical performance.

scholarly journals Synergistic Signaling by Light and Acetylcholine in Mouse Iris Sphincter Muscle

2017 ◽  
Vol 27 (12) ◽  
pp. 1791-1800.e5 ◽  
Author(s):  
Qian Wang ◽  
Wendy Wing Sze Yue ◽  
Zheng Jiang ◽  
Tian Xue ◽  
Shin H. Kang ◽  
...  
Keyword(s):  
Sphincter Muscle ◽  
Iris Sphincter

scholarly journals Direct Action of Light in Naturally Pigmented Muscle Fibers

1962 ◽  
Vol 46 (2) ◽  
pp. 333-342 ◽  
Author(s):  
Howard H. Seliger
Keyword(s):  
Visual Pigment ◽  
Absorption Maximum ◽  
Pupil Diameter ◽  
Direct Action ◽  
Pigment Epithelium ◽  
Action Spectrum ◽  
Square Root ◽  
Light Reaction ◽  
First Order ◽  
Iris Sphincter

Contraction due to light in excised eel irises appears to follow a simple first order law. The action spectrum for contraction has a maximum which agrees with the eel rhodopsin absorption maximum. Inasmuch as rhodopsin is the rod pigment-opsin complex and the iris sphincter pupillae evolves from the pigment epithelium of the retina in the region of the iris, the muscle pigment might be the same as the visual pigment. In the human eye the contraction of the iris sphincter is activated only by light incident on the retina and the pupil diameter varies inversely with the square root of the light intensity. The inverse first power relation observed in the present experiments suggests a more primitive origin for the light reaction in eel irises. Relaxation is a much slower process and can be approximated as the sum of two first order processes.

Clinical evaluation of the repeatability of ocular aberrometry obtained with a new pyramid wavefront sensor

2018 ◽  
Vol 29 (6) ◽  
pp. 585-592 ◽  
Author(s):  
Ana B Plaza-Puche ◽  
Liberdade C Salerno ◽  
Francesco Versaci ◽  
Daniel Romero ◽  
Jorge L Alio
Keyword(s):  
Standard Deviation ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Pupil Size ◽  
Pupil Diameter ◽  
Intraclass Correlation ◽  
Wavefront Sensor ◽  
Mean Square ◽  
The Subject ◽  
Healthy Eyes

Purpose:To evaluate the intrasubject repeatability of the ocular aberrometry obtained with a new ocular pyramidal aberrometer technology in a sample of normal eyes.Methods:A total of 53 healthy eyes of 53 subjects with ages ranging from 18 to 45 years were included in this study. In all cases, three consecutive acquisitions were obtained. Intrasubject repeatability of the measurements with a pyramidal aberrometer was calculated. Intrasubject repeatability for 4.0- and 6.0-mm pupils was evaluated within the subject standard deviation (Sw) and intraclass correlation coefficient.Results:Low values of the Swand intraclass correlation coefficient outcomes close to 1 were observed for the sphere and cylinder at 3.0-mm pupil size. Most low Swand intraclass correlation coefficient values close to 1 were observed for total, low-order aberrations and higher-order aberrations root mean square and for each Zernike coefficient analysis (intraclass correlation coefficient ⩾0.798) at 4.0-mm pupil size, with more limited outcomes for the aberrometric coefficient of Z(4, 4) with an intraclass correlation coefficient of 0.683. For a 6.0 mm pupil diameter, low Swand intraclass correlation coefficient values close to 1 were observed for all aberrometric parameters or Zernike coefficients analyzed (intraclass correlation coefficient ⩾0.850).Conclusion:The new pyramidal aberrometer Osiris provides repeatable and consistent measurements of ocular aberrometry measurements in normal eyes.

scholarly journals Levels of IMeurokinin A, Neurokinin B and Substance P in Rabbit Iris Sphincter Muscle

1986 ◽  
Vol 42 (4) ◽  
pp. 590-593 ◽  
Author(s):  
Takashi TANIGUCHI ◽  
Motohatsu FUJIWARA ◽  
Yoshinori MASUO ◽  
Ichiro KANAZAWA
Keyword(s):  
Substance P ◽  
Sphincter Muscle ◽  
Neurokinin B ◽  
Rabbit Iris Sphincter Muscle ◽  
Rabbit Iris Sphincter ◽  
Rabbit Iris ◽  
Iris Sphincter
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