An implicit representation of stimulus ambiguity in pupil size

2021 ◽  
Vol 118 (48) ◽  
pp. e2107997118
Author(s):  
Jackson E. Graves ◽  
Paul Egré ◽  
Daniel Pressnitzer ◽  
Vincent de Gardelle
Keyword(s):  
Pupil Size ◽  
Behavioral Responses ◽  
Pupil Dilation ◽  
Specific Situation ◽  
Implicit Representation ◽  
Stimulus Ambiguity ◽  
Two Measures ◽  
Perceptual Systems ◽  
Physiological Correlate ◽  
Pitch Shift

To guide behavior, perceptual systems must operate on intrinsically ambiguous sensory input. Observers are usually able to acknowledge the uncertainty of their perception, but in some cases, they critically fail to do so. Here, we show that a physiological correlate of ambiguity can be found in pupil dilation even when the observer is not aware of such ambiguity. We used a well-known auditory ambiguous stimulus, known as the tritone paradox, which can induce the perception of an upward or downward pitch shift within the same individual. In two experiments, behavioral responses showed that listeners could not explicitly access the ambiguity in this stimulus, even though their responses varied from trial to trial. However, pupil dilation was larger for the more ambiguous cases. The ambiguity of the stimulus for each listener was indexed by the entropy of behavioral responses, and this entropy was also a significant predictor of pupil size. In particular, entropy explained additional variation in pupil size independent of the explicit judgment of confidence in the specific situation that we investigated, in which the two measures were decoupled. Our data thus suggest that stimulus ambiguity is implicitly represented in the brain even without explicit awareness of this ambiguity.

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.

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 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 Early phase of pupil dilation is mediated by the peripheral parasympathetic pathway

2021 ◽  
Author(s):  
Chinatsu Marumo ◽  
Tamami Nakano
Keyword(s):  
Early Phase ◽  
Untreated Control ◽  
Pupil Size ◽  
Pupil Diameter ◽  
Pupil Dilation ◽  
Sphincter Muscle ◽  
Dilator Muscle ◽  
Brain States ◽  
Parasympathetic Pathway ◽  
Iris Sphincter

Pupil diameter fluctuates in association with changes in brain states induced by the neuromodulator systems. However, it remains unclear how the neuromodulator systems control the activity of the iris sphincter (constrictor) and dilator muscles to change the pupil size. The present study compared temporal patterns of pupil dilation during movement when each muscle was pharmacologically manipulated in the human eye. When the iris sphincter muscle was blocked with tropicamide, the latency of pupil dilation was delayed and the magnitude of pupil dilation was reduced during movement. In contrast, when the iris dilator muscle was continuously stimulated with phenylephrine, the latency and magnitude of rapid pupil dilation did not differ from the untreated control eye, but sustained pupil dilation was reduced until the end of movement. These results suggest that the iris sphincter muscle, which is under the control of the parasympathetic pathway, is quickly modulated by the neuromodulator system and plays a major role in rapid pupil dilation. However, the iris dilator muscle receives signals from the neuromodulator system with a slow latency and is involved in maintaining sustained pupil dilation.

scholarly journals Is categorization in visual working memory a way to reduce mental effort? A pupillometry study

2021 ◽  
Author(s):  
Cherie Zhou ◽  
Monicque M. Lorist ◽  
Sebastiaan Mathot
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Information ◽  
Pupil Size ◽  
Mental Effort ◽  
Pupil Dilation ◽  
General Category ◽  
Set Size ◽  
Memory Precision ◽  
Continuous Representations

Recent studies on visual working memory (VWM) have shown that visual information can be stored in VWM as continuous (e.g., a specific shade of red) as well as categorical representations (e.g., the general category red). It has been widely assumed, yet never directly tested, that continuous representations require more VWM mental effort than categorical representations; given limited VWM capacity, this would mean that fewer continuous, as compared to categorical, representations can be maintained simultaneously. We tested this assumption by measuring pupil size, as a proxy for mental effort, in a delayed estimation task. Participants memorized one to four ambiguous (boundaries between adjacent color categories) or prototypical colors to encourage continuous or categorical representations, respectively; after a delay, a probe indicated the location of the to-be-reported color. We found that, for set size 1, pupil size was larger while maintaining ambiguous as compared to prototypical colors, but without any difference in memory precision; this suggests that participants relied on an effortful continuous representation to maintain a single ambiguous color, thus resulting in pupil dilation while preserving precision. In contrast, for set size 2 and higher, pupil size was equally large while maintaining ambiguous and prototypical colors, but memory precision was now substantially reduced for ambiguous colors; this suggests that participants now also relied on categorical representations for ambiguous colors (which are by definition a poor fit to any category), thus reducing memory precision but not resulting in pupil dilation. Taken together, our results suggest that continuous representations are more effortful than categorical representations, and that very few continuous representations (perhaps only one) can be maintained simultaneously.

scholarly journals Central sensitization increases the pupil dilation elicited by mechanical pinprick stimulation

2018 ◽  
Author(s):  
E.N. van den Broeke ◽  
D.M. Hartgerink ◽  
J Butler ◽  
J Lambert ◽  
A Mouraux
Keyword(s):  
Electrical Stimulation ◽  
Central Sensitization ◽  
High Frequency ◽  
Similar Pattern ◽  
Pupil Size ◽  
Pupil Dilation ◽  
Negative Wave ◽  
Brain Potentials ◽  
Stimulation Intensity ◽  
Brain Responses

ABSTRACTHigh frequency electrical stimulation (HFS) of skin nociceptors triggers central sensitization, manifested as increased pinprick sensitivity of the skin surrounding the site at which HFS was applied. The aim of the present study was to compare the effects of HFS on pupil dilation and brain responses elicited by pinprick stimulation delivered in the area of increased pinprick sensitivity. In fourteen healthy volunteers HFS was applied to one of the two forearms. Before and twenty minutes after applying HFS, mechanical pinprick stimuli (64 mN and 96 mN) were delivered to the area surrounding the site at which HFS was applied as well as the contralateral control arm. During pinprick stimulation both the pupil size and electroencephalogram were recorded. HFS induced a clear and comparable increase in pinprick sensitivity for both the 64 and 96 mN stimulation intensity. Both pinprick stimulation intensities elicited a greater pupil dilation response when delivered to the area of increased pinprick sensitivity. However, this greater pupil dilation response was larger for the 64 mN compared to the 96 mN stimulation intensity. A similar pattern was observed for the negative wave of the pinprick-evoked brain potentials (PEPs), however, the increase was not significant for the 96 mN and showed only a trend towards significance for the 64 mN. These results show that there is a correspondence between the increase in pupil dilation and the increase in PEPs, but that pupil size is a more sensitive measure for detecting the effects of central sensitization than PEPs.

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.

Pupil Dilation as a Measure of Processing Load in Simultaneous Interpretation and Other Language Tasks

1995 ◽  
Vol 48 (3) ◽  
pp. 598-612 ◽  
Author(s):  
Jukka Hyönä ◽  
Jorma Tommola ◽  
Anna-Mari Alaja
Keyword(s):  
Pupil Size ◽  
Native Language ◽  
Pupillary Response ◽  
Pupil Dilation ◽  
Global Processing ◽  
Processing Load ◽  
Simultaneous Interpretation ◽  
Task Effect ◽  
Good Support ◽  
Average Pupil

The present study tested whether the pupillary response can be applied to study the variation in processing load during simultaneous interpretation. In Experiment 1, the global processing load in simultaneous interpretation as reflected in the average pupil size was compared to that in two other language tasks, listening to and repeating back an auditorily presented text. Experiment 1 showed clear differences between the experimental tasks. In Experiment 2, the task effect was replicated using single words as stimuli. Experiment 2 showed that momentary variations in processing load during a lexical translation task are reflected in pupil size. Words that were chosen to be more difficult to translate induced higher levels of pupil dilation than did easily translatable words. Moreover, repeating back words in a non-native language was accompanied by increased pupil dilations, in comparison to repetition in the subject's native language. In sum, the study lends good support to the use of the pupillary response as an indicator of processing load.

Effects of Continuity or Discontinuity in Actual Film Editing

2017 ◽  
Vol 36 (2) ◽  
pp. 222-246 ◽  
Author(s):  
Thorbjörn Swenberg ◽  
Per Erik Eriksson
Keyword(s):  
Pupil Size ◽  
Documentary Film ◽  
Pupil Dilation ◽  
The Other ◽  
Cognitive Effects ◽  
Film Editing ◽  
Significant Difference ◽  
Areas Of Interest

The film editor’s task in refining film edits by frame-by-frame matching is an important undertaking in perceptual precision. This article investigates whether the failure of a few frames jeopardizes the perceived continuity of a film. Thirty-three Swedish students were eye-tracked while watching two versions of the same documentary film sequence; one version was completed to continuity satisfaction by a film editor, while the other had some frames altered toward discontinuity. Gaze hits in Areas-of-Interest appointed by the film editor, saccade frequency, and pupil dilation after edit points were measured. No significant difference was found for hits in Areas-of-Interest, whereas saccade frequency and relative pupil size increased after edits in the altered version of the film sequence. Results indicate that the altered film sequence constrained viewers with possible cognitive effects, implying that frame-by-frame matching of film edits achieved by film editors is crucial to film continuity.

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