scholarly journals The relationship between pupil diameter and decentration in myopia

Eye ◽  
1997 ◽  
Vol 11 (5) ◽  
pp. 729-732 ◽  
Author(s):  
R Nuzzi ◽  
C Finazzo ◽  
L Francone
2020 ◽  
Vol 8 (4) ◽  
pp. 70-79
Author(s):  
Shirin Vafaei ◽  
Reza Ebrahimpour ◽  
Sajjad Zabbah ◽  
◽  
◽  
...  

2019 ◽  
Vol 202 ◽  
pp. 111-114
Author(s):  
Cecilia L. Bergeria ◽  
Andrew S. Huhn ◽  
D. Andrew Tompkins ◽  
George E. Bigelow ◽  
Eric C. Strain ◽  
...  

2018 ◽  
Vol 18 (6) ◽  
pp. 7 ◽  
Author(s):  
Nina N. Thigpen ◽  
Margaret M. Bradley ◽  
Andreas Keil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sou Nobukawa ◽  
Aya Shirama ◽  
Tetsuya Takahashi ◽  
Toshinobu Takeda ◽  
Haruhisa Ohta ◽  
...  

AbstractAdult attention-deficit/hyperactivity disorder (ADHD) frequently leads to psychological/social dysfunction if unaddressed. Identifying a reliable biomarker would assist the diagnosis of adult ADHD and ensure that adults with ADHD receive treatment. Pupil diameter can reflect inherent neural activity and deficits of attention or arousal characteristic of ADHD. Furthermore, distinct profiles of the complexity and symmetricity of neural activity are associated with some psychiatric disorders. We hypothesized that analysing the relationship between the size, complexity of temporal patterns, and asymmetricity of pupil diameters will help characterize the nervous systems of adults with ADHD and that an identification method combining these features would ease the diagnosis of adult ADHD. To validate this hypothesis, we evaluated the resting state hippus in adult participants with or without ADHD by examining the pupil diameter and its temporal complexity using sample entropy and the asymmetricity of the left and right pupils using transfer entropy. We found that large pupil diameters and low temporal complexity and symmetry were associated with ADHD. Moreover, the combination of these factors by the classifier enhanced the accuracy of ADHD identification. These findings may contribute to the development of tools to diagnose adult ADHD.


2020 ◽  
Author(s):  
Sara LoTemplio ◽  
Jack Silcox ◽  
Brennan Payne ◽  
Kara D. Federmeier

Although the P3b component of the event-related brain potential is one of the most widely-studied components, its underlying generators are not currently well understood. Recent theories have suggested that the P3b is triggered by phasic activation of the locus-coeruleus norepinephrine (LC-NE) system, an important control center implicated in facilitating optimal task-relevant behavior. Previous research has reported strong correlations between pupil dilation and LC activity, suggesting that pupil diameter is a useful indicator for ongoing LC-NE activity. Given the strong relationship between LC activity and pupil dilation, if the P3b is driven by phasic LC activity, there should be a robust trial-to-trial relationship with the phasic pupillary dilation response (PDR). However, previous work examining relationships between concurrently recorded pupillary and P3b responses has not supported this. One possibility is that the relationship between the measures might be carried primarily by either inter-individual (i.e., between-participant) or intra-individual (i.e., within-participant) contributions to coupling, and prior work has not systematically delineated these relationships. Doing so in the current study, we do not find evidence for either inter-individual or intra-individual relationships between the PDR and P3b responses. However, baseline pupil dilation did predict the P3b. Interestingly, both the PDR and P3b independently predicted inter-individual and intra-individual variability in decision response time. Implications for the LC-P3b hypothesis are discussed.


2011 ◽  
Vol 23 (7) ◽  
pp. 1587-1596 ◽  
Author(s):  
Marieke Jepma ◽  
Sander Nieuwenhuis

The adaptive regulation of the balance between exploitation and exploration is critical for the optimization of behavioral performance. Animal research and computational modeling have suggested that changes in exploitative versus exploratory control state in response to changes in task utility are mediated by the neuromodulatory locus coeruleus–norepinephrine (LC–NE) system. Recent studies have suggested that utility-driven changes in control state correlate with pupil diameter, and that pupil diameter can be used as an indirect marker of LC activity. We measured participants' pupil diameter while they performed a gambling task with a gradually changing payoff structure. Each choice in this task can be classified as exploitative or exploratory using a computational model of reinforcement learning. We examined the relationship between pupil diameter, task utility, and choice strategy (exploitation vs. exploration), and found that (i) exploratory choices were preceded by a larger baseline pupil diameter than exploitative choices; (ii) individual differences in baseline pupil diameter were predictive of an individual's tendency to explore; and (iii) changes in pupil diameter surrounding the transition between exploitative and exploratory choices correlated with changes in task utility. These findings provide novel evidence that pupil diameter correlates closely with control state, and are consistent with a role for the LC–NE system in the regulation of the exploration–exploitation trade-off in humans.


2018 ◽  
Author(s):  
Jochem van Kempen ◽  
Gerard M. Loughnane ◽  
Daniel P. Newman ◽  
Simon P. Kelly ◽  
Alexander Thiele ◽  
...  

AbstractThe timing and accuracy of perceptual decision making is exquisitely sensitive to fluctuations in arousal. Although extensive research has highlighted the role of neural evidence accumulation in forming decisions, our understanding of how arousal impacts these processes remains limited. Here we isolated electrophysiological signatures of evidence accumulation alongside signals reflecting target selection, attentional engagement and motor output and examined their modulation as a function of both tonic and phasic arousal, indexed by baseline and task-evoked pupil diameter, respectively. For both pupillometric measures, the relationship with reaction time was best described by a second-order, U-shaped, polynomial. Additionally, the two pupil measures were predictive of a unique set of EEG signatures that together represent multiple information processing steps of perceptual decision-making, including evidence accumulation. Finally, we found that behavioural variability associated with fluctuations in both tonic and phasic arousal was largely mediated by variability in evidence accumulation.


2016 ◽  
Author(s):  
Indranil Sinharoy ◽  
Prasanna Rangarajan ◽  
Marc P. Christensen

We present a geometric model of image formation in Scheimpflug cameras that is most general. Scheimpflug imaging is commonly used is scientific and medical imaging either to increase the depth of field of the imager or to focus on tilted object surfaces. Existing Scheimpflug imaging models do not take into account the effect of pupil magnification (i.e. the ratio of the exit pupil diameter to the entrance pupil diameter), which we have found to affect the type of distortions experienced by the image-field upon lens rotations. In this work, we have also derived the relationship between the object, lens and sensor planes in Scheimpflug configuration, which is very similar in form with the standard Gaussian imaging equation, but applicable for imaging systems in which the lens plane and the sensor plane are arbitrarily oriented with respect to each other. Since the conventional rigid camera, in which the sensor and lens planes are constrained to be parallel to each other, is a special case of the Scheimpflug camera, our model also applies to imaging with conventional cameras.


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