scholarly journals Pupillary Responses Obey Emmert’s Law and Co-vary with Autistic Traits

2020 ◽  
Author(s):  
Chiara Tortelli ◽  
Marco Turi ◽  
David C. Burr ◽  
Paola Binda
Keyword(s):  
Light Stimulus ◽  
Autistic Traits ◽  
Pupillary Response ◽  
Interindividual Differences ◽  
Pupil Response ◽  
Contextual Processing ◽  
Pupillary Responses ◽  
3D Information ◽  
Emmert’S Law

Abstract We measured the pupil response to a light stimulus subject to a size illusion and found that stimuli perceived as larger evoke a stronger pupillary response. The size illusion depends on combining retinal signals with contextual 3D information; contextual processing is thought to vary across individuals, being weaker in individuals with stronger autistic traits. Consistent with this theory, autistic traits correlated negatively with the magnitude of pupil modulations in our sample of neurotypical adults; however, psychophysical measurements of the illusion did not correlate with autistic traits, or with the pupil modulations. This shows that pupillometry provides an accurate objective index of complex perceptual processes, particularly useful for quantifying interindividual differences, and potentially more informative than standard psychophysical measures.

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.

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 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.

Abstract TMP97: Autonomic Nervous System Dysfunction Correlates With Increased Blood Pressure Variability After Acute Ischemic, But Not Hemorrhagic, Stroke

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Adam H de Havenon ◽  
Melissa Cortez ◽  
Cecilia Peterson ◽  
Fa Tuuhetaufa ◽  
Nils Petersen ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Blood Pressure Variability ◽  
Hemorrhagic Stroke ◽  
Light Stimulus ◽  
Pupillary Response ◽  
Autonomic Nervous System Dysfunction ◽  
Autonomic Nervous ◽  
The Mean

Background: Elevated blood pressure variability (BPV) in the days after acute stroke onset is associated with worse outcome. However, the mechanism of increased BPV remains unknown, but may be due to dysfunction of the autonomic nervous system, which can be measured by pupil response to a light stimulus. Methods: This is a retrospective study of 109 patients in a neurocritical care unit: 45 with acute ischemic stroke (AIS), 44 with intracerebral hemorrhage (ICH), and 20 with subarachnoid hemorrhage (SAH). The primary outcome is BPV, measured as standard deviation of SBP (SD), using all blood pressures from admission to 72 hours later. The primary predictors are pupillary light reflexes (PLR) from the same period, measured with a bedside pupilometer, the NPi-200. We used linear regression to evaluate the association between PLRs and BPV, and adjusted for patient age and gender. Results: The mean (SD) age was 60.7 (16.4) and 58.7% were male. The mean (SD) number of blood pressure and PLR measurements were 30.0 (9.0) and 10.4 (7.3). We found that parasympathetically mediated PLR measures were associated with BPV in AIS patients (Table 1), but no consistent pattern emerged in ICH or SAH patients (all p>0.05). The relationships between BPV and PLR for AIS patients were linear in nature (Figure 1), and were consistent with parasympathetic hypofunction in patients with the greatest BPV. Conclusions: Elevated BPV is associated with parasympathetic hypofunction, as measured by pupillary response to light, after acute ischemic, but not hemorrhagic, stroke. Further research is needed to better understand this relationship as it may represent a therapeutic target for BPV reduction.

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.

scholarly journals Modeling pupil responses to rapid sequential events

2019 ◽  
Author(s):  
Rachel N. Denison ◽  
Jacob A. Parker ◽  
Marisa Carrasco
Keyword(s):  
Pupil Size ◽  
Cognitive Task ◽  
Impulse Response Function ◽  
Parameter Estimates ◽  
Response Dynamics ◽  
Parameter Recovery ◽  
Pupil Response ◽  
Experimental Trial ◽  
Pupillary Responses ◽  
Model Fits

AbstractPupil size is an easily accessible, noninvasive online indicator of various perceptual and cognitive processes. Pupil measurements have the potential to reveal continuous processing dynamics throughout an experimental trial, including anticipatory responses. However, the relatively sluggish (∼2 s) response dynamics of pupil dilation make it challenging to connect changes in pupil size to events occurring close together in time. Researchers have used models to link changes in pupil size to specific trial events, but such methods have not been systematically evaluated. Here we developed and evaluated a general linear model (GLM) pipeline that estimates pupillary responses to multiple rapid events within an experimental trial. We evaluated the modeling approach using a sample dataset in which multiple sequential stimuli were presented within 2-s trials. We found: (1) Model fits improved when the pupil impulse response function (puRF) was fit for each observer. PuRFs varied substantially across individuals but were consistent for each individual. (2) Model fits also improved when pupil responses were not assumed to occur simultaneously with their associated trial events, but could have non-zero latencies. For example, pupil responses could anticipate predictable trial events. (3) Parameter recovery confirmed the validity of the fitting procedures, and we quantified the reliability of the parameter estimates for our sample dataset. (4) A cognitive task manipulation modulated pupil response amplitude. We provide our pupil analysis pipeline as open-source software (Pupil Response Estimation Toolbox: PRET) to facilitate the estimation of pupil responses and the evaluation of the estimates in other datasets.

scholarly journals Cross-species convergence in pupillary response: understanding human anxiety via non-human primate amygdala lesion

2019 ◽  
Vol 14 (6) ◽  
pp. 591-599 ◽  
Author(s):  
David Pagliaccio ◽  
Daniel S Pine ◽  
Ellen Leibenluft ◽  
O Dal Monte ◽  
Bruno B Averbeck ◽  
...  
Keyword(s):  
Anxiety Disorders ◽  
Pupillary Response ◽  
Distractor Task ◽  
Opposite Pattern ◽  
Pupillary Constriction ◽  
Pupillary Responses ◽  
Pupil Constriction ◽  
Amygdala Lesions ◽  
Anxious Youth ◽  
Human Primate

Abstract Few studies have used matched affective paradigms to compare humans and non-human primates. In monkeys with amygdala lesions and youth with anxiety disorders, we examined cross-species pupillary responses during a saccade-based, affective attentional capture task. Given evidence of enhanced amygdala function in anxiety, we hypothesized that opposite patterns would emerge in lesioned monkeys and anxious participants. A total of 53 unmedicated youths (27 anxious, 26 healthy) and 8 adult male rhesus monkeys (Macaca mulatta) completed matched behavioral paradigms. Four monkeys received bilateral excitotoxic amygdala lesions and four served as unoperated controls. Compared to healthy youth, anxious youth exhibited increased pupillary constriction in response to emotional and non-emotional distractors (F(1,48) = 6.28, P = 0.02, η2p = 0.12). Pupillary response was associated significantly with anxiety symptoms severity (F(1,48) = 5.59, P = 0.02, η2p = 0.10). As hypothesized, lesioned monkeys exhibited the opposite pattern i.e. decreased pupillary constriction in response to distractors, compared to unoperated control monkeys (F(1,32) = 24.22, P < 0.001, η2 = 0.33). Amygdala lesioned monkeys and youth with anxiety disorders show opposite patterns of pupil constriction in the context of an affective distractor task. Such findings suggest the presence of altered amygdala circuitry functioning in anxiety. Future lesion and human neuroimaging work might examine the way in which specific amygdala sub-nuclei and downstream circuits mediate these effects.

scholarly journals Background luminance effects on pupil size associated with emotion and saccade preparation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yih-Giun Cherng ◽  
Talia Baird ◽  
Jui-Tai Chen ◽  
Chin-An Wang
Keyword(s):  
Cognitive Processing ◽  
Luminance Level ◽  
Pupillary Response ◽  
Pupil Dilation ◽  
Auditory Stimuli ◽  
Background Luminance ◽  
Sympathetic Activation ◽  
Dark Background ◽  
Pupillary Responses ◽  
Saccade Preparation

Abstract Pupil dilation is consistently evoked by affective and cognitive processing, and this dilation can result from sympathetic activation or parasympathetic inhibition. The relative contributions of the sympathetic and parasympathetic systems on the pupillary response induced by emotion and cognition may be different. Sympathetic and parasympathetic activity is regulated by global luminance level. Higher luminance levels lead to greater activation of the parasympathetic system while lower luminance levels lead to greater activation of the sympathetic system. To understand the contributions of the sympathetic and parasympathetic nervous systems to pupillary responses associated with emotion and saccade preparation, emotional auditory stimuli were presented following the fixation cue whose color indicated instruction to perform a pro- or anti-saccade while varying the background luminance level. Pupil dilation was evoked by emotional auditory stimuli and modulated by arousal level. More importantly, greater pupil dilation was observed with a dark background, compared to a bright background. In contrast, pupil dilation responses associated with saccade preparation were larger with the bright background than the dark background. Together, these results suggest that arousal-induced pupil dilation was mainly mediated by sympathetic activation, but pupil dilation related to saccade preparation was primarily mediated by parasympathetic inhibition.

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