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Pupillometry

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https://www.readbyqxmd.com/read/28107273/influence-of-depth-of-hypnosis-on-pupillary-reactivity-to-a-standardized-tetanic-stimulus-in-patients-under-propofol-remifentanil-target-controlled-infusion-a-crossover-randomized-pilot-study
#1
Nada Sabourdin, Jean-Baptiste Peretout, Eliane Khalil, Marie-Laurence Guye, Nicolas Louvet, Isabelle Constant
BACKGROUND: Pupillometry allows the measurement of pupillary diameter variations in response to nociceptive stimuli. This technique has been used to monitor the balance between analgesia and nociception. Under general anesthesia, the amplitude of pupillary dilation is related to the amount of administered opioids. The objective of this study was to determine whether at a constant infusion rate of opioids, the pupillary response was influenced by depth of hypnosis assessed by the bispectral index (BIS)...
January 19, 2017: Anesthesia and Analgesia
https://www.readbyqxmd.com/read/28089758/pupil-responses-and-pain-ratings-to-heat-stimuli-reliability-and-effects-of-expectations-and-a-conditioning-pain-stimulus
#2
James C Eisenach, Regina Curry, Carol A Aschenbrenner, Robert C Coghill, Timothy T Houle
BACKGROUND: The locus coeruleus (LC) signals salience to sensory stimuli and these responses can modulate the experience of pain stimuli. The pupil dilation response (PDR) to noxious stimuli is thought to be a surrogate for LC responses, but PDR response to Peltier-controlled noxious heat stimuli, the most commonly used method in experimental pain research, has not been described. NEW METHOD: Healthy volunteers were presented with randomly presented heat stimuli of 5 sec duration and provided pain intensity ratings to each stimulus...
January 12, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/28068124/cognitive-effort-is-modulated-outside-of-the-explicit-awareness-of-conflict-frequency-evidence-from-pupillometry
#3
Nathaniel T Diede, Julie M Bugg
Classic theories of cognitive control conceptualized controlled processes as slow, strategic, and willful, with automatic processes being fast and effortless. The context-specific proportion compatibility (CSPC) effect, the reduction in the compatibility effect in a context (e.g., location) associated with a high relative to low likelihood of conflict, challenged classic theories by demonstrating fast and flexible control that appears to operate outside of conscious awareness. Two theoretical questions yet to be addressed are whether the CSPC effect is accompanied by context-dependent variation in effort, and whether the exertion of effort depends on explicit awareness of context-specific task demands...
January 9, 2017: Journal of Experimental Psychology. Learning, Memory, and Cognition
https://www.readbyqxmd.com/read/28061512/assessment-of-rod-cone-and-intrinsically-photosensitive-retinal-ganglion-cell-contributions-to-the-canine-chromatic-pupillary-response
#4
Connie Y Yeh, Kristin L Koehl, Christine D Harman, Simone Iwabe, José M Guzman, Simon M Petersen-Jones, Randy H Kardon, András M Komáromy
Purpose: The purpose of this study was to evaluate a chromatic pupillometry protocol for specific functional assessment of rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs) in dogs. Methods: Chromatic pupillometry was tested and compared in 37 dogs in different stages of primary loss of rod, cone, and combined rod/cone and optic nerve function, and in 5 wild-type (WT) dogs. Eyes were stimulated with 1-s flashes of dim (1 cd/m2) and bright (400 cd/m2) blue light (for scotopic conditions) or bright red (400 cd/m2) light with 25-cd/m2 blue background (for photopic conditions)...
January 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28049026/memory-consolidation-of-socially-relevant-stimuli-during-sleep-in-healthy-children-and-children-with-attention-deficit-hyperactivity-disorder-and-oppositional-defiant-disorder-what-you-can-see-in-their-eyes
#5
Alexander Prehn-Kristensen, Ina Molzow, Alexandra Förster, Nadine Siebenhühner, Maxime Gesch, Christian D Wiesner, Lioba Baving
Children with attention-deficit/hyperactivity disorder (ADHD) display deficits in sleep-dependent memory consolidation, and being comorbid with oppositional defiant disorder (ODD), results in deficits in face processing. The aim of the present study was to investigate the role of sleep in recognizing faces in children with ADHD+ODD. Sixteen healthy children and 16 children diagnosed with ADHD+ODD participated in a sleep and a wake condition. During encoding (sleep condition at 8p.m.; wake condition at 8a.m...
December 31, 2016: Biological Psychology
https://www.readbyqxmd.com/read/28007522/the-pupillary-light-reflex-for-predicting-the-risk-of-hypotension-after-spinal-anaesthesia-for-elective-caesarean-section
#6
Céline Riffard, Truong Quoc Viêt, François-Pierrick Desgranges, Lionel Bouvet, Bernard Allaouchiche, Adrienne Stewart, Dominique Chassard
INTRODUCTION: The balance between the sympathetic and parasympathetic systems could be used to predict the onset of hypotension following spinal anaesthesia. The autonomic innervation of the pupil may reflect this balance. The aim of this study was to evaluate the ability of pupillometry to predict the risk of hypotension after spinal anaesthesia for caesarean section. METHODS: Two hundred patients receiving spinal anaesthesia for caesarean section were recruited...
December 19, 2016: Anaesthesia, Critical Care & Pain Medicine
https://www.readbyqxmd.com/read/28004334/noninvasive-neuromonitoring-current-utility-in-subarachnoid-hemorrhage-traumatic-brain-injury-and-stroke
#7
Luisa Vinciguerra, Julian Bösel
Noninvasive neuromonitoring is increasingly being used to monitor the course of primary brain injury and limit secondary brain damage of patients in the neurocritical care unit. Proposed advantages over invasive neuromonitoring methods include a lower risk of infection and bleeding, no need for surgical installation, mobility and portability of some devices, and safety. The question, however, is whether noninvasive neuromonitoring is practical and trustworthy enough already. We searched the recent literature and reviewed English-language studies on noninvasive neuromonitoring in subarachnoid hemorrhage, traumatic brain injury, and ischemic and hemorrhagic stroke between the years 2010 and 2015...
December 21, 2016: Neurocritical Care
https://www.readbyqxmd.com/read/27981704/the-eye-of-the-retriever-developing-episodic-memory-mechanisms-in-preverbal-infants-assessed-through-pupil-dilation
#8
Kahl Hellmer, Hedvig Söderlund, Gustaf Gredebäck
Studying memory in infants can be challenging, as they cannot express their subjective recollection verbally. In this study we use a novel method with which we can assess episodic recognition memory through pupillometry, using identical procedures and stimuli for infants and adults. In three experiments of 4- and 7-month-old infants, and adults we show that the adult pupillary response is larger to previously seen than to never seen items (old/new effect). Pupil dilations index subjective memory experience in adults, producing distinct pupil dilations to items judged as remembered, familiar, and new, regardless of actual previous exposure (Experiment 1)...
December 15, 2016: Developmental Science
https://www.readbyqxmd.com/read/27966269/the-effect-of-blue-blocking-and-neutral-intraocular-lenses-on-circadian-photoentrainment-and-sleep-one-year-after-cataract-surgery
#9
Adam Elias Brøndsted, Birgitte Haargaard, Birgit Sander, Henrik Lund-Andersen, Poul Jennum, Line Kessel
PURPOSE: To compare the long-term effect on circadian photoentrainment and sleep in patients implanted with neutral and blue-blocking intraocular lenses 1 year after cataract surgery. METHODS: Randomized, controlled trial involving 67 patients with age-related cataract. Intervention was cataract surgery with implantation of either a neutral or a blue-blocking intraocular lens (IOL). Main outcome was activation of the intrinsically photosensitive retinal ganglion cells (ipRGC) measured by chromatic pupillometry...
December 14, 2016: Acta Ophthalmologica
https://www.readbyqxmd.com/read/27928748/pupillary-response-to-complex-interdependent-tasks-a-cognitive-load-theory-perspective
#10
Ritayan Mitra, Karen S McNeal, Howard D Bondell
Pupil dilation is known to indicate cognitive load. In this study, we looked at the average pupillary responses of a cohort of 29 undergraduate students during graphical problem solving. Three questions were asked, based on the same graphical input. The questions were interdependent and comprised multiple steps. We propose a novel way of analyzing pupillometry data for such tasks on the basis of eye fixations, a commonly used eyetracking parameter. We found that pupil diameter increased during the solution process...
December 7, 2016: Behavior Research Methods
https://www.readbyqxmd.com/read/27924440/is-pupillary-response-a-reliable-index-of-word-recognition-evidence-from-a-delayed-lexical-decision-task
#11
Juan Haro, Marc Guasch, Blanca Vallès, Pilar Ferré
Previous word recognition studies have shown that the pupillary response is sensitive to a word's frequency. However, such a pupillary effect may be due to the process of executing a response, instead of being an index of word processing. With the aim of exploring this possibility, we recorded the pupillary responses in two experiments involving a lexical decision task (LDT). In the first experiment, participants completed a standard LDT, whereas in the second they performed a delayed LDT. The delay in the response allowed us to compare pupil dilations with and without the response execution component...
December 6, 2016: Behavior Research Methods
https://www.readbyqxmd.com/read/27915119/neural-correlates-of-pupil-dilation-during-human-fear-learning
#12
Laura Leuchs, Max Schneider, Michael Czisch, Victor I Spoormaker
BACKGROUND: Fear conditioning and extinction are prevailing experimental and etiological models for normal and pathological anxiety. Pupil dilations in response to conditioned stimuli are increasingly used as a robust psychophysiological readout of fear learning, but their neural correlates remain unknown. We aimed at identifying the neural correlates of pupil responses to threat and safety cues during a fear learning task. METHODS: Thirty-four healthy subjects underwent a fear conditioning and extinction paradigm with simultaneous functional magnetic resonance imaging (fMRI) and pupillometry...
December 1, 2016: NeuroImage
https://www.readbyqxmd.com/read/27858935/multiethnic-involvement-in-autosomal-dominant-optic-atrophy-in-singapore
#13
J L Loo, S Singhal, A V Rukmini, S Tow, P Amati-Bonneau, V Procaccio, D Bonneau, J J Gooley, P Reynier, M Ferré, D Milea
PurposeAutosomal-dominant optic atrophy (ADOA), often associated with mutations in the OPA1 gene (chromosome 3q28-q29) is rarely reported in Asia. Our aim was to identify and describe this condition in an Asian population in Singapore.Patients and methodsPreliminary cross-sectional study at the Singapore National Eye Centre, including patients with clinical suspicion of ADOA, who subsequently underwent genetic testing by direct sequencing of the OPA1 gene.ResultsAmong 12 patients (10 families) with clinically suspected ADOA, 7 patients (5 families) from 3 different ethnic origins (Chinese, Indian, and Malay) carried a heterozygous pathogenic variant in the OPA1 gene...
November 18, 2016: Eye
https://www.readbyqxmd.com/read/27843292/topography-modified-refraction-tmr-adjustment-of-treated-cylinder-amount-and-axis-to-the-topography-versus-standard-clinical-refraction-in-myopic-topography-guided-lasik
#14
Anastasios John Kanellopoulos
PURPOSE: To evaluate the safety, efficacy, and contralateral eye comparison of topography-guided myopic LASIK with two different refraction treatment strategies. SETTING: Private clinical ophthalmology practice. PATIENTS AND METHODS: A total of 100 eyes (50 patients) in consecutive cases of myopic topography-guided LASIK procedures with the same refractive platform (FS200 femtosecond and EX500 excimer lasers) were randomized for treatment as follows: one eye with the standard clinical refraction (group A) and the contralateral eye with the topographic astigmatic power and axis (topography-modified treatment refraction; group B)...
2016: Clinical Ophthalmology
https://www.readbyqxmd.com/read/27821359/pupillary-response-abnormalities-in-depressive-disorders
#15
Scott A Laurenzo, Randy Kardon, Johannes Ledolter, Pieter Poolman, Ashley M Schumacher, James B Potash, Jan M Full, Olivia Rice, Anna Ketcham, Cole Starkey, Jess G Fiedorowicz
Depressive disorders lack objective physiological measurements to characterize the affected population and facilitate study of relevant mechanisms. The melanopsin-mediated light signaling pathway may contribute to seasonal variation and can be measured non-invasively by pupillometry. We prospectively studied changes in melanopsin-mediated pupillary constriction in 19 participants with major depressive disorder (MDD) and 10 control across the summer and winter solstices. The melanopsin-mediated response, as measured by the pupil's sustained constriction six s after a high intensity blue light stimulus, was marginally attenuated in those with MDD relative to controls (p=0...
December 30, 2016: Psychiatry Research
https://www.readbyqxmd.com/read/27787677/measuring-physician-cognitive-load-validity-evidence-for-a-physiologic-and-a-psychometric-tool
#16
Adam Szulewski, Andreas Gegenfurtner, Daniel W Howes, Marco L A Sivilotti, Jeroen J G van Merriënboer
In general, researchers attempt to quantify cognitive load using physiologic and psychometric measures. Although the construct measured by both of these metrics is thought to represent overall cognitive load, there is a paucity of studies that compares these techniques to one another. The authors compared data obtained from one physiologic tool (pupillometry) to one psychometric tool (Paas scale) to explore whether they actually measured the construct of cognitive load as purported. Thirty-two participants with a range of resuscitation medicine experience and expertise completed resuscitation-medicine based multiple-choice-questions as well as arithmetic questions...
October 27, 2016: Advances in Health Sciences Education: Theory and Practice
https://www.readbyqxmd.com/read/27753579/objective-pupillary-correlates-of-photosensitivity-in-the-normal-and-mild-traumatic-brain-injury-populations
#17
James Q Truong, Kenneth J Ciuffreda
OBJECTIVE: No objective vision biomarker for photosensitivity currently exists. The present study sought to uncover potential biomarkers for photosensitivity within the pupillary light reflex. METHODS: The pupillary light reflex was evaluated in those with mild traumatic brain injury (mTBI) and in normal individuals, with and without photosensitivity, under a range of test conditions. The Neuroptics DP-2000, infrared, binocular pupillometer was used for both binocular stimulation and recording...
October 2016: Military Medicine
https://www.readbyqxmd.com/read/27731503/pupillometry-reveals-changes-in-physiological-arousal-during-a-sustained-listening-task
#18
Ronan McGarrigle, Piers Dawes, Andrew J Stewart, Stefanie E Kuchinsky, Kevin J Munro
Hearing loss is associated with anecdotal reports of fatigue during periods of sustained listening. However, few studies have attempted to measure changes in arousal, as a potential marker of fatigue, over the course of a sustained listening task. The present study aimed to examine subjective, behavioral, and physiological indices of listening-related fatigue. Twenty-four normal-hearing young adults performed a speech-picture verification task in different signal-to-noise ratios (SNRs) while their pupil size was monitored and response times recorded...
October 12, 2016: Psychophysiology
https://www.readbyqxmd.com/read/27712127/quantifying-pupillary-asymmetry-through-objective-binocular-pupillometry-in-the-normal-and-mild-traumatic-brain-injury-mtbi-populations
#19
James Q Truong, Kenneth J Ciuffreda
INTRODUCTION: Little is known about human inter-ocular pupillary asymmetry (IOPA). Thus, the purpose of the present investigation was to assess objectively static and dynamic IOPA in normals and in individuals with mild traumatic brain injury (mTBI). METHODS: The pupillary light reflex (PLR) was assessed in an adult population of normals and in those with mTBI using the Neuroptics DP-2000 binocular pupillometer. Four stimulus conditions were used to optimize the assessment...
August 11, 2016: Brain Injury: [BI]
https://www.readbyqxmd.com/read/27712047/coupling-between-spontaneous-pupillary-fluctuations-and-brain-activity-relates-to-inattentiveness
#20
A L Breeden, G J Siegle, M E Norr, E M Gordon, C J Vaidya
Autonomic activity in neurological and psychiatric disorders is often dysregulated, particularly in the context of attentional behaviors. This suggests that interplay between the autonomic nervous system and aspects of the central nervous system subserving attention may be disrupted in these conditions. Better understanding these interactions and their relationship with individual variation in attentional behaviors could facilitate development of mechanistic biomarkers. We identified brain regions defined by trait-sensitive central-autonomic coupling as a first step in this process...
January 2017: European Journal of Neuroscience
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