scholarly journals Dissociable saccadic suppression of pupillary and perceptual responses to light

2016 ◽  
Vol 115 (3) ◽  
pp. 1243-1251 ◽  
Author(s):  
Alessandro Benedetto ◽  
Paola Binda
Keyword(s):  
Large Fraction ◽  
Pupillary Response ◽  
Visual Sensitivity ◽  
Saccadic Suppression ◽  
Light Responses ◽  
Pupillary Light ◽  
Relative Independence ◽  
Pupillary Responses ◽  
Full Screen ◽  
Flash Stimulus

We measured pupillary constrictions in response to full-screen flashes of variable luminance, occurring either at the onset of a saccadic eye movement or well before/after it. A large fraction of perisaccadic flashes were undetectable to the subjects, consistent with saccadic suppression of visual sensitivity. Likewise, pupillary responses to perisaccadic flashes were strongly suppressed. However, the two phenomena appear to be dissociable. Across subjects and luminance levels of the flash stimulus, there were cases in which conscious perception of the flash was completely depleted yet the pupillary response was clearly present, as well as cases in which the opposite occurred. On one hand, the fact that pupillary light responses are subject to saccadic suppression reinforces evidence that this is not a simple reflex but depends on the integration of retinal illumination with complex “extraretinal” cues. On the other hand, the relative independence of pupillary and perceptual responses suggests that suppression acts separately on these systems—consistent with the idea of multiple visual pathways that are differentially affected by saccades.

scholarly journals Elaborate pupils in skates may help camouflage the eye

2018 ◽  
Author(s):  
Sean Youn ◽  
Corey Okinaka ◽  
Lydia M Mäthger
Keyword(s):  
Light Intensity ◽  
Spatial Frequency ◽  
Experimental Evidence ◽  
Pupillary Response ◽  
Pupil Dilation ◽  
Primary Factor ◽  
Natural Substrate ◽  
Spatial Frequencies ◽  
Pupillary Responses ◽  
Changing Light

AbstractThe little skate Leucoraja erinacea has elaborately shaped pupils, whose characteristics and functions have not been studied extensively. It has been suggested that such pupil shapes may camouflage the eye; yet, no experimental evidence has been presented to support this claim. Skates are bottom-dwellers that often bury into the substrate with their eyes protruding. If these pupils serve any camouflage function, we expect there to be a pupillary response related to the spatial frequency (“graininess”) of the background against which the eye is viewed. Here, we tested whether skate pupils dilate or constrict in response to background spatial frequency. We placed skates on background substrates with different spatial frequencies and recorded pupillary responses at three light intensities. In experiment 1, the skates’ pupillary response to three artificial checkerboards of different spatial frequencies was recorded. Skates responded to changing light intensity with pupil dilation/constriction; yet, their pupils did not change in response to spatial frequency. In experiment 2, in which skates could bury into three natural substrates with different spatial frequencies, such that their eyes protruded above the substrate, the pupils showed a subtle but statistically significant response to changes in substrate spatial frequency. Given the same light intensity, the smaller the spatial frequency of the natural substrate, the more constricted the pupil. While light intensity is the primary factor determining pupil dilation, these experiments are the first to show that pupils also change in response to background spatial frequency, which suggests that the pupil may aid in camouflaging the eye.

Pupil Response: A Psychophysiological Measure of Fear during Analogue Desensitization,

1989 ◽  
Vol 69 (3-2) ◽  
pp. 1351-1367
Author(s):  
Robert S. Sturgeon ◽  
Leslie M. Cooper ◽  
Robert J. Howell
Keyword(s):  
Pupil Size ◽  
Pupillary Response ◽  
Pupil Response ◽  
Current Technology ◽  
Pupillary Responses

15 highly aroused snake phobics individually constructed fear hierarchies by selecting colored photographs of snakes. Subjects either imagined fear scenes based on their photographs or were exposed to duplicate projected slides during desensitization. Pupillary responses of the Slide Group were also recorded before, during, and after desensitization. Fear of snakes was significantly reduced for both groups within five or fewer desensitization sessions. Changes in pupil size of the Slide Group appear to reflect arousal of fear as well as reduction of fear after treatment. Current technology makes pupillary response a viable psychophysiological measure of fear.

scholarly journals Evaluation of Disk Halo Size after Implantation of a Collamer Lens with a Central Hole (ICL V4c)

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Xun Chen ◽  
Tian Han ◽  
Feng Zhao ◽  
Huamao Miao ◽  
Xiaoying Wang ◽  
...  
Keyword(s):  
Light Response ◽  
Pupillary Response ◽  
Central Hole ◽  
Implantable Collamer Lens ◽  
Contraction Amplitude ◽  
Pupillary Light ◽  
Significant Difference ◽  
Icl V4c ◽  
Latency Duration ◽  
Average Pupil

Purpose. To investigate disk halo size changes produced by a glare source after surgical insertion of an implantable collamer lens with a central hole (ICL V4c) for myopia correction. Methods. In this prospective study, disk halo size and pupillary light response with a vision monitor were measured preoperatively and at 1 week, 1 month, and 3 months postoperatively. Pupillary light response parameters included contraction amplitude, latency, duration, and velocity; dilation latency, duration, and velocity; and initial, maximum, minimum, and average pupil diameters. Results. Forty-two right eyes of 42 patients were enrolled. Postoperative uncorrected distance visual acuity was better than or equal to 20/20 in all eyes. Compared to preoperative values, disk halo size showed no significant difference at 1 week postoperatively (P>0.05) and then decreased significantly at 1 and 3 months postoperatively (both P<0.001). Contraction amplitude and velocity, as well as dilation velocity, decreased significantly at all postoperative time points (all P<0.001). Disk halo size at 3 months postoperatively was significantly correlated with initial (r = 0.446, P=0.003), maximum (r = 0.483, P=0.001), minimum (r = 0.425, P=0.005), and average pupil diameters (r = 0.474, P=0.002). Conclusions. After ICL V4c implantation, disk halo size was reduced in the short term. Patients with smaller pupil sizes during pupillary response to light experienced smaller halos after ICL V4c implantation.

scholarly journals A neural locus for spatial-frequency specific saccadic suppression in visual-motor neurons of the primate superior colliculus

2017 ◽  
Vol 117 (4) ◽  
pp. 1657-1673 ◽  
Author(s):  
Chih-Yang Chen ◽  
Ziad M. Hafed
Keyword(s):  
Spatial Frequency ◽  
Superior Colliculus ◽  
Motor Neurons ◽  
Motor Command ◽  
Visual Sensitivity ◽  
Saccadic Suppression ◽  
Behavioral Measure ◽  
Visual Responses ◽  
Spatial Frequencies ◽  
Visual Motor

Saccades cause rapid retinal-image shifts that go perceptually unnoticed several times per second. The mechanisms for saccadic suppression have been controversial, in part because of sparse understanding of neural substrates. In this study we uncovered an unexpectedly specific neural locus for spatial frequency-specific saccadic suppression in the superior colliculus (SC). We first developed a sensitive behavioral measure of suppression in two macaque monkeys, demonstrating selectivity to low spatial frequencies similar to that observed in earlier behavioral studies. We then investigated visual responses in either purely visual SC neurons or anatomically deeper visual motor neurons, which are also involved in saccade generation commands. Surprisingly, visual motor neurons showed the strongest visual suppression, and the suppression was dependent on spatial frequency, as in behavior. Most importantly, suppression selectivity for spatial frequency in visual motor neurons was highly predictive of behavioral suppression effects in each individual animal, with our recorded population explaining up to ~74% of behavioral variance even on completely different experimental sessions. Visual SC neurons had mild suppression, which was unselective for spatial frequency and thus only explained up to ~48% of behavioral variance. In terms of spatial frequency-specific saccadic suppression, our results run contrary to predictions that may be associated with a hypothesized SC saccadic suppression mechanism, in which a motor command in the visual motor and motor neurons is first relayed to the more superficial purely visual neurons, to suppress them and to then potentially be fed back to cortex. Instead, an extraretinal modulatory signal mediating spatial-frequency-specific suppression may already be established in visual motor neurons. NEW & NOTEWORTHY Saccades, which repeatedly realign the line of sight, introduce spurious signals in retinal images that normally go unnoticed. In part, this happens because of perisaccadic suppression of visual sensitivity, which is known to depend on spatial frequency. We discovered that a specific subtype of superior colliculus (SC) neurons demonstrates spatial-frequency-dependent suppression. Curiously, it is the neurons that help mediate the saccadic command itself that exhibit such suppression, and not the purely visual ones.

Pupil Response: A Psychophysiological Measure of Fear during Analogue Desensitization

1989 ◽  
Vol 69 (3_suppl) ◽  
pp. 1351-1367 ◽  
Author(s):  
Robert S. Sturgeon ◽  
Leslie M. Cooper ◽  
Robert J. Howell
Keyword(s):  
Pupil Size ◽  
Pupillary Response ◽  
Pupil Response ◽  
Current Technology ◽  
Pupillary Responses

15 highly aroused snake phobics individually constructed fear hierarchies by selecting colored photographs of snakes. Subjects either imagined fear scenes based on their photographs or were exposed to duplicate projected slides during desensitization. Pupillary responses of the Slide Group were also recorded before, during, and after desensitization. Fear of snakes was significantly reduced for both groups within five or fewer desensitization sessions. Changes in pupil size of the Slide Group appear to reflect arousal of fear as well as reduction of fear after treatment. Current technology makes pupillary response a viable psychophysiological measure of fear.

scholarly journals Foveal vision at the time of microsaccades

2021 ◽  
Author(s):  
Naghmeh Mostofi ◽  
Janis Intoy ◽  
Michele Rucci
Keyword(s):  
Eye Movements ◽  
Contrast Sensitivity ◽  
Time Course ◽  
Visual Sensitivity ◽  
Saccadic Suppression ◽  
Visual Exploration ◽  
Social Grooming ◽  
Foveal Vision ◽  
High Acuity ◽  
Display Control

AbstractHumans use rapid eye movements (saccades) to inspect stimuli with the foveola, the region of the retina where receptors are most densely packed. It is well established that visual sensitivity is generally attenuated during these movements, a phenomenon known as saccadic suppression. This effect is commonly studied with large, often peripheral, stimuli presented during instructed saccades. However, little is known about how saccades modulate the foveola and how the resulting dynamics unfold during natural visual exploration. Here we measured the foveal dynamics of saccadic suppression in a naturalistic high-acuity task, a task designed after primate’s social grooming, which—like most explorations of fine patterns—primarily elicits minute saccades (microsaccades). Leveraging on recent advances in gaze-contingent display control, we were able to systematically map the peri-saccadic time-course of sensitivity across the foveola. We show that contrast sensitivity is not uniform across this region and that both the extent and dynamics of saccadic suppression vary within the foveola. Suppression is stronger and faster in the most central portion, where sensitivity is generally higher and selectively rebounds at the onset of a new fixation. These results shed new light on the modulations experienced by foveal vision during the saccade-fixation cycle and explain some of the benefits of microsaccades.

scholarly journals Suppression without inhibition: A novel mechanism in the retina accounts for saccadic suppression

2020 ◽  
Author(s):  
Saad Idrees ◽  
Matthias-Philipp Baumann ◽  
Maria M. Korympidou ◽  
Timm Schubert ◽  
Alexandra Kling ◽  
...  
Keyword(s):  
Eye Movements ◽  
Visual Perception ◽  
Receptive Field ◽  
Calcium Imaging ◽  
Ganglion Cells ◽  
Saccadic Eye Movements ◽  
Visual Sensitivity ◽  
Saccadic Suppression ◽  
Retinal Processing ◽  
Retinal Pathways

AbstractVisual perception remains stable across saccadic eye movements, despite the concurrent strongly disruptive visual flow. This stability is partially associated with a reduction in visual sensitivity, known as saccadic suppression, which already starts in the retina with reduced ganglion cell sensitivity. However, the retinal circuit mechanisms giving rise to such suppression remain unknown. Here, we describe these mechanisms using electrophysiology in mouse, pig, and macaque retina, 2-photon calcium imaging, computational modeling, and human psychophysics. We find a novel retinal processing motif underlying retinal saccadic suppression, “dynamic reversal suppression”, which is triggered by sequential stimuli containing contrast reversals. This motif does not involve inhibition but relies on nonlinear transformation of the inherently slow responses of cone photoreceptors by downstream retinal pathways. Two further components of suppression are present in ON ganglion cells and originate in the cells’ receptive field surround, highlighting a novel disparity between ON and OFF ganglion cells. Our results are relevant for any sequential stimulation encountered frequently in naturalistic scenarios.

scholarly journals Disentangling listening effort and memory load beyond behavioural evidence: Pupillary response to listening effort during a concurrent memory task

2020 ◽  
Author(s):  
Yue Zhang ◽  
Alexandre Lehmann ◽  
Mickael Deroche
Keyword(s):  
Speech Intelligibility ◽  
Memory Load ◽  
Pupil Diameter ◽  
Memory Task ◽  
Pupillary Response ◽  
Pupil Dilation ◽  
Growth Patterns ◽  
Listening Effort ◽  
Pupillary Responses ◽  
Behavioural Evidence

AbstractRecent research has demonstrated that pupillometry is a robust measure for quantifying listening effort. However, pupillary responses in listening situations where multiple cognitive functions are engaged and sustained over a period of time remain hard to interpret. This limits our conceptualisation and understanding of listening effort in realistic situations, because rarely in everyday life are people challenged by one task at a time. Therefore, the purpose of this experiment was to reveal the dynamics of listening effort in a sustained listening condition using a word repeat and recall task.Words were presented in quiet and speech-shaped noise at different signal-to-noise ratios (SNR). Participants were presented with lists of 10 words, and required to repeat each word after its presentation. At the end of the list, participants either recalled as many words as possible or moved on to the next list. Simultaneously, their pupil dilation was recorded throughout the whole experiment.When only word repeating was required, peak pupil dilation (PPD) was bigger in 0dB versus other conditions; whereas when recall was required, PPD showed no difference among SNR levels and PPD in 0dB was smaller than repeat-only condition. Baseline pupil diameter and PPD followed different growth patterns across the 10 serial positions in conditions requiring recall: baseline pupil diameter built up progressively and plateaued in the later positions (but shot up at the onset of recall, i.e. the end of the list); PPD decreased at a pace quicker than in repeat-only condition.The current findings concur with the recent literature in showing that additional cognitive load during a speech intelligibility task could disturb the well-established relation between pupillary response and listening effort. Both the magnitude and temporal pattern of task-evoked pupillary response differ greatly in complex listening conditions, urging for more listening effort studies in complex and realistic listening situations.

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