scholarly journals Gaze-angle dependency of pupil-size measurements in head-mounted eye tracking

2021 ◽  
Author(s):  
Bernhard Petersch ◽  
Kai Dierkes
Keyword(s):  
Cognitive Processing ◽  
Data Aggregation ◽  
Pupil Size ◽  
Measurement Techniques ◽  
Population Level ◽  
Pupil Dilation ◽  
Optical Effects ◽  
Light Stimuli ◽  
Different Levels ◽  
Gaze Angle

AbstractPupillometry - the study of temporal changes in pupil diameter as a function of external light stimuli or cognitive processing - requires the accurate and gaze-angle independent measurement of pupil dilation. Expected response amplitudes often are only a few percent relative to a pre-stimulus baseline, thus demanding for sub-millimeter accuracy. Video-based approaches to pupil-size measurement aim at inferring pupil dilation from eye images alone. Eyeball rotation in relation to the recording camera as well as optical effects due to refraction at corneal interfaces can, however, induce so-called pupil foreshortening errors (PFE), i.e. systematic gaze-angle dependent changes of apparent pupil size that are on a par with typical response amplitudes. While PFE and options for its correction have been discussed for remote eye trackers, for head-mounted eye trackers such an assessment is still lacking. In this work, we therefore gauge the extent of PFE in three measurement techniques, all based on eye images recorded with a single near-eye camera. We present both real world experimental data as well as results obtained on synthetically generated eye images. We discuss PFE effects at three different levels of data aggregation: the sample, subject, and population level. In particular, we show that a recently proposed refraction-aware approach employing a mathematical 3D eye model is successful in providing pupil-size measurements which are gaze-angle independent at the population level.

scholarly journals Autobiographical memory increases pupil dilation

2019 ◽  
Vol 10 (1) ◽  
pp. 280-287
Author(s):  
Mohamad El Haj ◽  
Steve M. J. Janssen ◽  
Karim Gallouj ◽  
Quentin Lenoble
Keyword(s):  
Autobiographical Memory ◽  
Cognitive Processing ◽  
Memory Retrieval ◽  
Pupil Size ◽  
Pupil Diameter ◽  
Emotional Valence ◽  
Pupil Dilation ◽  
Control Task ◽  
Negative Memories

Abstract Background Pupil activity has been widely considered as a “summed index” of physiological activities during cognitive processing. Methodology We investigated pupil dilation during retrieval of autobiographical memory and compared pupil diameter with a control condition in which participants had to count aloud. We also measured pupil diameters retrieval of free (i.e., first memory that comes to mind), positive, and negative memories (memories associated, respectively, with the words “happy” and “sad”). Results Analyses demonstrated larger pupil diameters during the free, positive, and negative autobiographical memory retrieval than during the control task. Analyses also demonstrated no significant differences in pupil diameters across the three autobiographical memory conditions. Conclusion These outcomes demonstrate that, compared with counting, autobiographical retrieval results in a larger pupil size. However, the emotional valence of memories yields non-significant effect on pupil diameters. Our findings demonstrate how autobiographical memory retrieval yields pupil dilation.

scholarly journals Listener’s personality traits predict changes in pupil size during auditory language comprehension

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Isabell Hubert Lyall ◽  
Juhani Järvikivi
Keyword(s):  
Personality Traits ◽  
Language Processing ◽  
Language Comprehension ◽  
Pupil Size ◽  
Pupil Dilation ◽  
Systematic Research ◽  
Cognitive Resources ◽  
Personality Profiles ◽  
Pupillary Responses ◽  
Grammatical Errors

AbstractResearch suggests that listeners’ comprehension of spoken language is concurrently affected by linguistic and non-linguistic factors, including individual difference factors. However, there is no systematic research on whether general personality traits affect language processing. We correlated 88 native English-speaking participants’ Big-5 traits with their pupillary responses to spoken sentences that included grammatical errors, "He frequently have burgers for dinner"; semantic anomalies, "Dogs sometimes chase teas"; and statements incongruent with gender stereotyped expectations, such as "I sometimes buy my bras at Hudson's Bay", spoken by a male speaker. Generalized additive mixed models showed that the listener's Openness, Extraversion, Agreeableness, and Neuroticism traits modulated resource allocation to the three different types of unexpected stimuli. No personality trait affected changes in pupil size across the board: less open participants showed greater pupil dilation when processing sentences with grammatical errors; and more introverted listeners showed greater pupil dilation in response to both semantic anomalies and socio-cultural clashes. Our study is the first one demonstrating that personality traits systematically modulate listeners’ online language processing. Our results suggest that individuals with different personality profiles exhibit different patterns of the allocation of cognitive resources during real-time language comprehension.

scholarly journals Priming Younger and Older Adults’ Sentence Comprehension: Insights from Dynamic Emotional Facial Expressions and Pupil Size Measures

2016 ◽  
Vol 9 (1) ◽  
pp. 129-148 ◽  
Author(s):  
Maria Nella Carminati ◽  
Pia Knoeferle
Keyword(s):  
Older Adults ◽  
Sentence Processing ◽  
Pupil Size ◽  
Sentence Comprehension ◽  
Cognitive Effort ◽  
Pupil Dilation ◽  
Emotional Facial Expressions ◽  
Visual World ◽  
Positivity Effect ◽  
Positive Valence

Background: Prior visual-world research has demonstrated that emotional priming of spoken sentence processing is rapidly modulated by age. Older and younger participants saw two photographs of a positive and of a negative event side-by-side and listened to a spoken sentence about one of these events. Older adults’ fixations to the mentioned (positive) event were enhanced when the still photograph of a previously-inspected positive-valence speaker face was (vs. wasn’t) emotionally congruent with the event/sentence. By contrast, the younger adults exhibited such an enhancement with negative stimuli only. Objective: The first aim of the current study was to assess the replicability of these findings with dynamic face stimuli (unfolding from neutral to happy or sad). A second goal was to assess a key prediction made by socio-emotional selectivity theory, viz. that the positivity effect (a preference for positive information) displayed by older adults involves cognitive effort. Method: We conducted an eye-tracking visual-world experiment. Results: Most priming and age effects, including the positivity effects, replicated. However, against our expectations, the positive gaze preference in older adults did not co-vary with a standard measure of cognitive effort - increased pupil dilation. Instead, pupil size was significantly bigger when (both younger and older) adults processed negative than positive stimuli. Conclusion: These findings are in line with previous research on the relationship between positive gaze preferences and pupil dilation. We discuss both theoretical and methodological implications of these results.

scholarly journals Human Papillomavirus Genotype Replacement: Still Too Early to Tell?

2020 ◽  
Author(s):  
Irene Man ◽  
Simopekka Vänskä ◽  
Matti Lehtinen ◽  
Johannes A Bogaards
Keyword(s):  
Human Papillomavirus ◽  
Hpv Vaccination ◽  
Population Level ◽  
Cross Protection ◽  
Transmission Model ◽  
Trade Off ◽  
Long Run ◽  
Vaccine Type ◽  
Cross Immunity ◽  
Different Levels

Abstract Background Although human papillomavirus (HPV) vaccines are highly efficacious in protecting against HPV infections and related diseases, vaccination may trigger replacement by nontargeted genotypes if these compete with the vaccine-targeted types. HPV genotype replacement has been deemed unlikely, based on the lack of systematic increases in the prevalence of nonvaccine-type (NVT) infection in the first decade after vaccination, and on the presence of cross-protection for some NVTs. Methods To investigate whether type replacement can be inferred from early postvaccination surveillance, we constructed a transmission model in which a vaccine type and an NVT compete through infection-induced cross-immunity. We simulated scenarios of different levels of cross-immunity and vaccine-induced cross-protection to the NVT. We validated whether commonly used measures correctly indicate type replacement in the long run. Results Type replacement is a trade-off between cross-immunity and cross-protection; cross-immunity leads to type replacement unless cross-protection is strong enough. With weak cross-protection, NVT prevalence may initially decrease before rebounding into type replacement, exhibiting a honeymoon period. Importantly, vaccine effectiveness for NVTs is inadequate for indicating type replacement. Conclusions Although postvaccination surveillance thus far is reassuring, it is still too early to preclude type replacement. Monitoring of NVTs remains pivotal in gauging population-level impacts of HPV vaccination.

Anticipation and Stuttering: A Pupillographic Study

1969 ◽  
Vol 12 (4) ◽  
pp. 833-839 ◽  
Author(s):  
Kenneth C. Gray ◽  
Dean E. Williams
Keyword(s):  
Auditory Stimulus ◽  
Pupil Size ◽  
Free Association ◽  
Pupil Dilation ◽  
Auditory Stimuli ◽  
Physiological Changes ◽  
Single Word ◽  
Pupil Response ◽  
Association Response ◽  
Pupil Reaction

Changes in pupil size were studied in 24 stuttering and 30 nonstuttering adults during a 4-sec period following the presentation of single-word auditory stimuli and before a signal to respond. Subjects were required first to respond with a single word which was the opposite of the word presented and later to give a one-word free-association response to words of both emotional and neutral connotations. Pupil size was measured also while subjects merely listened to the word stimuli. The process of attending to an auditory stimulus was associated with pupil dilation. Pupil response was significantly greater (in absolute diameter and in dilation) when subjects were required to give an oral response to the stimulus than when they simply listened to the stimulus. Furthermore, the extent of the pupil reaction was related to the nature of the stimulus presented. Such differences in arousal did not occur to any greater degree in stutterers than in nonstutterers. Moreover, among stutterers, measures of pupil size were not predictive of stuttering. Thus, the cues which the stutterer associates with the anticipation of stuttering do not appear to be reflected in the physiological changes associated with pupillary movement.

scholarly journals ENUMERASI DAN ANALISIS BAKTERI TANAH DI HUTAN LARANGAN ADAT RUMBIO (Enumeration And Bacteria Analysis of Soil on The Larangan Adat Rumbio Forest)

2017 ◽  
Vol 8 (1) ◽  
pp. 17
Author(s):  
Rahmi Fitrah ◽  
Mokhammad Irfan ◽  
Robbana Saragih
Keyword(s):  
Total Population ◽  
Soil Depth ◽  
Population Level ◽  
Bacterial Populations ◽  
Bacterial Morphology ◽  
Observation Method ◽  
Bacterial Cell Shape ◽  
Two Stages ◽  
Animal Sciences ◽  
Different Levels

One of indicator of soil fertility is the population level of microbial in the soil. This research aims to determine the number of bacterial populations in the soil on yhe Larangan Adat Rumbi Forest with different levels of depth. This research has been carried out on January-February 2015 in the Laboratory of Pathology, Entomology and Microbiology, Faculty of Agriculture and Animal Sciences of State Islamic University of Sultan Syarif Kasim Riau. The method that was used namely observation method by taking soil samples on the Larangan Adat Rumbio Forest then calculated the number of colonies of bacteria and analyze the morphology of the bacteria that was obtained macroscopically and microscopically. Parameters measured were pH of soil, the population of bacteria, bacterial morphology, gram stain, and bacterial cell shape based on soil depth of 0-10 cm, 11-20 cm, 21-30 cm. Observations carried out two stages macroscopic and microscopic observation. The results showed the soil pH on the Larangan Adat Rumbio Forest was 4,11. Total population of bacteria at depth of 0-10 cm namely 3,0 x 109 CFU, then at a depth of 11-20 cm namely of 2,2 x 109 CFU and at depth of 21-30 cm namely 1,6 x 108 CFU. The Results of purification of culture was obtained six isolat two coccus and four bacil consisting of five gram negative bacteria and one gram positive. Need to do further research on bacteria identification to genus or species level.

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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