The pupil responds spontaneously to perceived numerosity

AbstractAlthough luminance is the main determinant of pupil size, the amplitude of the pupillary light response is also modulated by stimulus appearance and attention. Here we ask whether perceived numerosity modulates the pupillary light response. Participants passively observed arrays of black or white dots of matched physical luminance but different physical or illusory numerosity. In half the patterns, pairs of dots were connected by lines to create dumbbell-like shapes, inducing an illusory underestimation of perceived numerosity; in the other half, connectors were either displaced or removed. Constriction to white arrays and dilation to black were stronger for patterns with higher perceived numerosity, either physical or illusory, with the strength of the pupillary light response scaling with the perceived numerosity of the arrays. Our results show that even without an explicit task, numerosity modulates a simple automatic reflex, suggesting that numerosity is a spontaneously encoded visual feature.

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Altered pupillary light response scales with disease severity in migrainous photophobia

Cephalalgia ◽

10.1177/0333102416673205 ◽

2017 ◽

Vol 37 (8) ◽

pp. 801-811 ◽

Cited By ~ 19

Author(s):

Melissa M Cortez ◽

Natalie A Rea ◽

Lindsay A Hunter ◽

Kathleen B Digre ◽

KC Brennan

Keyword(s):

Disease Severity ◽

Pupil Size ◽

Light Response ◽

Light Sensitivity ◽

Light Responses ◽

Headache Severity ◽

Pupillary Light ◽

Affective Symptoms ◽

Infrared Pupillometry ◽

Diameter Change

Background Autonomic dysfunction and light sensitivity are core features of the migraine attack. Growing evidence also suggests changes in these parameters between attacks. Though sensory and autonomic responses likely interact, they have not been studied together across the spectrum of disease in migraine. Methods We performed digital infrared pupillometry while collecting interictal photophobia thresholds (PPT) in 36 migraineurs (14 episodic; 12 chronic; 10 probable) and 24 age and sex-matched non-headache controls. Quantitative pupillary light reflexes (PLR) were assessed in a subset of subjects, allowing distinction of sympathetic vs parasympathetic pupillary function. A structured questionnaire was used to ascertain migraine diagnosis, headache severity, and affective symptoms. Results Photophobia thresholds were significantly lower in migraineurs than controls, and were lowest in chronic migraine, consistent with a disease-related gradient. Lower PPT correlated with smaller dark-adapted pupil size and larger end pupil size at PPT, which corresponded to a reduced diameter change. On PLR testing, measures of both parasympathetic constriction and sympathetic re-dilation were reduced in migraineurs with clinically severe migraine. Conclusions In summary, we show that severity of photophobia in migraine scales with disease severity, in association with shifts in pupillary light responses. These alterations suggest centrally mediated autonomic adaptations to chronic light sensitivity.

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The Pupillary Light Response Reflects Visual Working Memory Content

10.1101/477562 ◽

2018 ◽

Cited By ~ 3

Author(s):

Cecília Hustá ◽

Edwin Dalmaijer ◽

Artem Belopolsky ◽

Sebastiaan Mathôt

Keyword(s):

Working Memory ◽

Visual Working Memory ◽

Pupil Size ◽

Light Response ◽

Memory Representation ◽

Brain Areas ◽

Active Memory ◽

Pupillary Light ◽

Memory Content ◽

Higher Cognitive Functions

AbstractRecent studies have shown that the pupillary light response (PLR) is modulated by higher cognitive functions, presumably through activity in visual sensory brain areas. Here we use the PLR to test the involvement of sensory areas in visual working memory (VWM). In two experiments, participants memorized either bright or dark stimuli. We found that pupils were smaller when a pre-stimulus cue indicated that a bright stimulus should be memorized; this reflects a covert shift of attention during encoding of items into VWM. Crucially, we obtained the same result with a post-stimulus cue, which shows that internal shifts of attention within VWM affect pupil size as well. Strikingly, pupil size reflected VWM content only briefly. This suggests that a shift of attention within VWM momentarily activates an “active” memory representation, but that this representation quickly transforms into a “hidden” state that does not rely on sensory areas.

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Pupil responses to hidden photoreceptor–specific modulations in movies

10.1101/440040 ◽

2018 ◽

Author(s):

Manuel Spitschan ◽

Marina Gardasevic ◽

Franck P. Martial ◽

Robert J. Lucas ◽

Annette E. Allen

Keyword(s):

Real World ◽

Pupil Size ◽

Ganglion Cells ◽

Low Frequency ◽

Light Response ◽

Silent Substitution ◽

Precise Control ◽

Light Levels ◽

Pupillary Light ◽

Stimulation Of

AbstractUnder typical daytime light levels, the human pupillary light response (PLR) is driven by the activity of the L, M, and S cones, and melanopsin expressed in the so-called intrinsically photosensitive retinal ganglion cells (ipRGCs). However, the importance of each of these photoreceptive mechanisms in defining pupil size under real-world viewing conditions remains to be established. To address this question, we embedded photoreceptor-specific modulations in a movie displayed using a novel projector-based five-primary spatial stimulation system, which allowed for the precise control of photoreceptor activations in time and space. We measured the pupillary light response in eleven observers, who viewed short cartoon movies which contained hidden low-frequency (0.25 Hz) silent-substitution modulations of the L, M and S cones (no stimulation of melanopsin), melanopsin (no stimulation of L, M and S cones), both L, M, and S cones and melanopsin or no modulation at all. We find that all photoreceptors active at photopic light levels regulate pupil size under this condition. Our data imply that embedding modulations in photoreceptor contrast could provide a method to manipulate key adaptive aspects of the human visual system in everyday, real-world activities such as watching a movie.

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Exploring the interaction between the pupillary light response after exogenous attentional cueing and detection performance

10.1101/2020.04.08.032060 ◽

2020 ◽

Author(s):

Tiemen J. Wagenvoort ◽

Rosanne H. Timmerman ◽

Stefan Van der Stigchel ◽

Jasper H. Fabius

Keyword(s):

Visual Information ◽

Pupil Size ◽

Light Response ◽

Detection Performance ◽

Covert Attention ◽

Cognitive Factors ◽

Dark Side ◽

Light Conditions ◽

Pupillary Light ◽

Bright Side

AbstractPupil size changes under different light conditions. Whereas this pupillary light response (PLR) has long been regarded to be influenced by luminance only, recent studies indicated the PLR is also modulated by cognitive factors such as the allocation of spatial attention. This attentional modulation of the PLR has previously been hypothesized to facilitate detection and discrimination of visual information. Here, we replicated the finding that the pupil dilates when a cue is presented at the dark side of a screen and constricts when the cue is presented at the bright side, even when the eyes are fixated at the center. Furthermore, we investigated whether this modulation of the PLR, evoked by exogenous shifts of covert attention, facilitates perception operationalized as detection performance for threshold stimuli. Results showed that a larger pupil was indeed related to increased detection performance, although this effect was restricted to conditions in which both cue and target appeared on a dark surface. Our findings are in line with the notion that pupil dilations improve detectability, whereas pupil constrictions enhance discriminability of small stimuli.

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The pupillary light response reflects encoding, but not maintenance, in visual working memory.

Journal of Experimental Psychology Human Perception & Performance ◽

10.1037/xhp0000252 ◽

2016 ◽

Vol 42 (11) ◽

pp. 1716-1723 ◽

Cited By ~ 9

Author(s):

Tessel Blom ◽

Sebastiaan Mathôt ◽

Christian N. L. Olivers ◽

Stefan Van der Stigchel

Keyword(s):

Working Memory ◽

Visual Working Memory ◽

Light Response ◽

Pupillary Light

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Pupillary Light Response, Pupillary Response

10.1007/springerreference_183088 ◽

2012 ◽

Keyword(s):

Light Response ◽

Pupillary Response ◽

Pupillary Light

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Effects of stimulus size, eccentricity, luminance, and attention on pupillary light response examined by concentric stimulus

Vision Research ◽

10.1016/j.visres.2020.03.008 ◽

2020 ◽

Vol 170 ◽

pp. 35-45 ◽

Cited By ~ 1

Author(s):

Xiaofei Hu ◽

Rumi Hisakata ◽

Hirohiko Kaneko

Keyword(s):

Light Response ◽

Stimulus Size ◽

Pupillary Light

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Quantitative Pupillometry in the Intensive Care Unit

Journal of Intensive Care Medicine ◽

10.1177/0885066619881124 ◽

2019 ◽

pp. 088506661988112

Author(s):

Matthew M. Bower ◽

Alexander J. Sweidan ◽

Jordan C. Xu ◽

Sara Stern-Nezer ◽

Wengui Yu ◽

...

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Objective Assessment ◽

Light Response ◽

Pressure Monitoring ◽

Neurological Intensive Care Unit ◽

Neurological Intensive Care ◽

Pupillary Light ◽

Pupillary Reactivity ◽

Neurological Pupil Index

Quantitative pupillometry provides a noninvasive and objective assessment within the neurological examination. This review details the physiology of the pupillary light response, the clinical significance of changes in pupillary reactivity, and the variables that compose the Neurological Pupil index or NPi are discussed. This article reviews the most recent applications and advances in quantitative pupillometry for noninvasive intracranial pressure monitoring, postcardiac arrest prognostication, and subarachnoid hemorrhage. Also discussed are the limitations and confounders of quantitative pupillometry in the modern neurological intensive care unit.

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