The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Elke Van Der Meer - One of the best experts on this subject based on the ideXlab platform.
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i spy with my little eye detection of temporal violations in event sequences and the Pupillary Response
International Journal of Psychophysiology, 2010Co-Authors: Susanne Raisig, Tinka Welke, Herbert Hagendorf, Elke Van Der MeerAbstract:Scripts of familiar activities store the temporal order of events. This enables us to generate predictions about which event will follow another. When an event does not unfold in the chronological order, a mismatch arises between the predictions and the external sensory input which is perceived as a conflict. The detection of this mismatch is accomplished by a comparison mechanism (Zacks et al., 2007; Barsalou, 2009). We have applied pupillometry to investigate the nature of this comparison process. We further tested for individual differences in the efficiency of the mismatch detection. Participants were presented the title of an event sequence to trigger predictions about the order in which events would unfold. Subsequently, three script events were presented one at a time. The events either unfolded in the correct chronological order or included temporal violations at different points within the event triplet. Violations of the temporal order had to be detected. As soon as it was detected, the trial had to be terminated. We found that a temporal violation elicited a large Pupillary Response in all individuals indicating that the comparison between the predictions and the external sensory input was accomplished online and worked equally well for all individuals. However, not all individuals terminated the trial after having detected the violation. Results showed that efficient individuals who responded adequately had a greater Pupillary Response than inefficient individuals suggesting that they invested more cognitive resources. The results are discussed in light of theories of behavioral performance and conflict-monitoring.
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investigating dimensional organization in scripts using the Pupillary Response
Psychophysiology, 2007Co-Authors: Susanne Raisig, Tinka Welke, Herbert Hagendorf, Elke Van Der MeerAbstract:Scripts are mental representations of activities in memory and are thought to be organized dimensionally in a temporal dimension. We investigated the cognitive strategies during the processing of temporal order of an event sequence to gain insight into the organization of scripts. Subjects were presented with triplets of script events (A - B - C). Fifty percent of the items included sequence violations at different positions within the triplet (late: A - C - B, or early: C - A - B). Reaction times indicate that subjects use an economical strategy by comparing the relative temporal positions of event pairs (e.g., A vs. B and if necessary B vs. C) and only attend to information that is necessary. Pupil data and error rates indicate that the temporal information of the complete sequence affects the decision process even if the first event pair indicates that temporal order has been violated. Results are seen as evidence of a dimensional structure of scripts.
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time s arrow and Pupillary Response
Psychophysiology, 2005Co-Authors: Antje Nuthmann, Elke Van Der MeerAbstract:Abstract The psychological arrow of time refers to our experience of the relentless forward temporal progression of all natural processes. To investigate whether and how time’s arrow is mentally coded in individual everyday events, a relatedness judgment task was used. The items each consisted of a verb (probe) and an adjective or participle (target). The temporal orientation between probe and target was varied either corresponding to the chronological orientation (e.g., shrinking – small) or corresponding to the reverse orientation (e.g., shrinking – large). In addition, the interval between probe and target presentation was varied (SOA: 250 ms vs. 1,000 ms). Reaction times, error rates, and Pupillary Responses were recorded. For both SOA-conditions, chronological items were processed faster than reverse items. These findings suggest that time’s arrow is mentally coded in single everyday events. Furthermore, pupil dilation and results of principal component analyses on mean Pupillary Responses suggest top-down influences in the processing of temporally related probe target pairs. Key Words: temporal orientation, events, Pupillary Response, cognitive load
Ted Maddess - One of the best experts on this subject based on the ideXlab platform.
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Localization of Neuronal Gain Control in the Pupillary Response
Frontiers Media S.A., 2019Co-Authors: Corinne Frances Carle, Andrew Charles James, Yanti Rosli, Ted MaddessAbstract:Multifocal pupillographic objective perimetry (mfPOP) is being developed as an alternative to standard visual perimetry. In mfPOP, pupil Responses to sparse multifocal luminance stimuli are extracted from the overall composite Response. These individual test-region Responses are subject to gain-control which is dependent on the temporal and spatial density of stimuli. This study aimed to localize this gain within the pupil pathway. Pupil constriction amplitudes of 8 subjects (41.5 ±12.7 y, 4 male) were measured using a series of 14 mfPOP stimulus variants. The temporal density of stimulus signal at the levels of retina, pretectal olivary nuclei (PON), and Edinger-Westphal nuclei (EWN) were controlled using a combination of manipulation of the mean interval between stimulus presentations (3 or 6 stimuli/s/hemiretina) and the restriction of stimuli to specific subsets of the 24 visual field test-regions per eye (left or right eye, left or right hemifield, or nasal or temporal hemifield). No significant difference was observed between mfPOP variants with differing signal density at the retina or PON but matched density at the other levels. In contrast, where signal density differed at the EWN but was the same at the retinal and PON levels e.g., between 3 stim/s homonymous hemifield and all test-region variants, significant reductions in constriction amplitudes were observed [t(30) = −2.07 to −2.50, all p < 0.05]. Similar, although more variable, relationships were seen using nasal, and temporal hemifield stimuli. Results suggest that the majority of gain-control in the subcortical Pupillary pathway occurs at the level of the EWN
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Pupillary Response to sparse multifocal stimuli in multiple sclerosis patients
Multiple Sclerosis Journal, 2014Co-Authors: Eman Ali, Ted Maddess, A C James, Cristian Voicu, Christian J LueckAbstract:OBJECTIVES The objective of this paper is to investigate the pattern of abnormalities and establish the diagnostic power of multifocal objective pupil perimetry (mfPOP) in multiple sclerosis (MS). METHODS A prospective study enrolling 35 normal (47.9 ± 16.8 years, 22 females) and 85 MS subjects (49.8 ± 11.3 years, 62 females; 72 relapsing-remitting (RR), and 13 primary or secondary progressives (PorS)). EDSS scores for the RR and PorS groups were 3.53 ± 1.04 (mean ± SD), and 5.9 ± 1.43, respectively. mfPOP Responses were obtained from 44 regions/visual field. Each region was analysed according to Response time-to-peak and standardised amplitude (AmpStd). Predictive power was measured by percentage area under the receiver operator curve (%AUC). RESULTS mfPOP Responses showed a significant reduction of 0.69 ± 0.04 dB (mean ± SE) in AmpStd and significantly delayed time-to-peak of 25.95 ± 0.89 ms (mean ± SE) in MS subjects compared to control subjects (p<0.001). %AUC was greater for time-to-peak than AmpStd both for RR and PorS patients. Diagnostic power followed the EDSS scores but not a history of optic neuritis. CONCLUSIONS mfPOP is well tolerated and potentially has a role in the diagnosis and assessment of patients with MS.
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the Pupillary Response to color and luminance variant multifocal stimuli
Investigative Ophthalmology & Visual Science, 2013Co-Authors: Corinne F Carle, A C James, Ted MaddessAbstract:Supported by the Australian Research Council through the ARC Centre of Excellence in Vision Science (CE0561903), and Seeing Machines Ltd.
Hannes Devos - One of the best experts on this subject based on the ideXlab platform.
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Pupillary Response to postural demand in parkinson s disease
Frontiers in Bioengineering and Biotechnology, 2021Co-Authors: Melike Kahya, Abiodun Emmanuel Akinwuntan, Kelly E Lyons, Rajesh Pahwa, Hannes DevosAbstract:Background: Individuals with Parkinson's disease (PD) may need to spend more mental and physical effort (i.e., cognitive workload) to maintain postural control. Pupillary Response reflects cognitive workload during postural control tasks in healthy controls but has not been investigated as a measure of postural demand in PD. Objectives: To compare Pupillary Response during increased postural demand using vision occlusion and dual tasking between individuals with PD and healthy controls. Methods: Thirty-three individuals with PD and thirty-five healthy controls were recruited. The four conditions lasted 60 s and involved single balance task with eyes open; single balance task with eyes occluded; dual task with eyes open; dual task with eyes occluded. The dual task comprised the Auditory Stroop test. Pupillary Response was recorded using an eye tracker. The balance was assessed by using a force plate. Two-way Repeated Measures ANOVA and LSD post-hoc tests were employed to compare Pupillary Response and Center of Pressure (CoP) displacement across the four conditions and between individuals with PD and healthy controls. Results: Pupillary Response was higher in individuals with PD compared to healthy controls (p = 0.009) and increased with more challenging postural conditions in both groups (p < 0.001). The post-hoc analysis demonstrated increased Pupillary Response in the single balance eyes occluded (p < 0.001), dual task eyes open (p = 0.01), and dual task eyes occluded (p < 0.001) conditions compared to single task eyes open condition. Conclusion: Overall, the PD group had increased Pupillary Response with increased postural demand compared to the healthy controls. In the future, Pupillary Response can be a potential tool to understand the neurophysiological underpinnings of falls risk in the PD population.
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reliability and validity of Pupillary Response during dual task balance in parkinson disease
Archives of Physical Medicine and Rehabilitation, 2021Co-Authors: Melike Kahya, Abiodun Emmanuel Akinwuntan, Kelly E Lyons, Rajesh Pahwa, Hannes DevosAbstract:Abstract Objective To investigate the reliability and validity of Pupillary Response during dual-task balance conditions in individuals with Parkinson disease (PD). Design Cross-sectional study. Setting University of Kansas Medical Center Parkinson's Disease and Movement Disorder Center. Participants Participants (N=68) included individuals with PD (n=33) and healthy controls (n=35). Interventions Not applicable. Main Outcome Measures Pupillary Response was the main outcome measure that was measured during the following conditions: single-task balance eyes open, single-task balance eyes occluded, dual-task eyes open, and dual-task eyes occluded. After each condition, the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) was administered to assess self-reported cognitive workload. To examine the test-retest reliability of the Pupillary Response, the conditions were administered twice for each individual within 2 hours. Intraclass correlation coefficients (ICC) were used to analyze the test-retest reliability of Pupillary Response in each condition for both groups. Pearson’s r correlation was used to assess the convergent validity of Pupillary Response against the NASA-TLX. Results The test-retest reliability was excellent for both groups in almost all conditions (ICC>0.75). There were no correlations between Pupillary Response and the NASA-TLX. However, increased mental demand (a subitem of the NASA-TLX) significantly correlated with increased Pupillary Response in individuals with PD (r=0.38; P=.03). Conclusions Pupillary Response showed excellent test-retest reliability and validity during dual-task balance for individuals with PD and healthy controls. Overall, these results suggest that Pupillary Response represents a stable index of cognitive workload during dual-task balance in individuals with PD.
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Pupillary Response to cognitive demand in parkinson s disease a pilot study
Frontiers in Aging Neuroscience, 2018Co-Authors: Melike Kahya, Sanghee Moon, Abiodun Emmanuel Akinwuntan, Kelly E Lyons, Rajesh Pahwa, Hannes DevosAbstract:Previous studies have shown that Pupillary Response, a physiological measure of cognitive workload, reflects cognitive demand in healthy younger and older adults. However, the relationship between cognitive workload and cognitive demand in Parkinson's disease (PD) remains unclear. The aim of this pilot study was to examine the Pupillary Response to cognitive demand in a letter-number sequencing (LNS) task between 16 non-demented individuals with PD (age, median (Q1-Q3): 68 (62-72); 10 males) and 10 control participants (age: 63 (59-67); 2 males), matched for age, education, and Montreal Cognitive Assessment (MOCA) scores. A mixed model analysis was employed to investigate cognitive workload changes as a result of incremental cognitive demand for both groups. As expected, no differences were found in cognitive scores on the LNS between groups. Cognitive workload, exemplified by greater pupil dilation, increased with incremental cognitive demand in both groups (p = 0.003). No significant between-group (p = 0.23) or interaction effects were found (p = 0.45). In addition, individuals who achieved to complete the task at higher letter-number (LN) load responded differently to increased cognitive demand compared with those who completed at lower LN load (p < 0.001), regardless of disease status. Overall, the findings indicated that Pupillary Response reflects incremental cognitive demand in non-demented people with PD and healthy controls. Further research is needed to investigate the Pupillary Response to incremental cognitive demand of PD patients with dementia compared to non-demented PD and healthy controls. Highlights -Pupillary Response reflects cognitive demand in both non-demented people with PD and healthy controls-Although not significant due to insufficient power, non-demented individuals with PD had increased cognitive workload compared to the healthy controls throughout the testing-Pupillary Response may be a valid measure of cognitive demand in non-demented individuals with PD-In future, Pupillary Response might be used to detect cognitive impairment in individuals with PD.
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Pupillary Response to cognitive workload during saccadic tasks in parkinson s disease
Behavioural Brain Research, 2017Co-Authors: Maud Ranchet, Abiodun Emmanuel Akinwuntan, Jason Orlosky, John C Morgan, Siraj Qadir, Hannes DevosAbstract:The relationship between cognitive workload and cognitive impairments in Parkinson's disease (PD) is currently not well known. This study compared cognitive workload during saccadic tasks between patients with PD and controls. Sixteen controls, 11 patients with no obvious cognitive impairment (PD-NCI) (MOCA score≥26), and 10 PD patients with cognitive impairment (PD-CI) (MOCA score<26) performed prosaccade and antisaccade tasks. Cognitive workload, extracted via pupil recording, and other eye metrics were compared between the three groups. PD-NCI patients exhibited greater cognitive workload than controls in the prosaccade task. PD-CI patients also showed more cognitive workload in the prosaccade task than PD-NCI patients and controls. No other differences in eye metrics were found between the three groups. Cognitive workload could be used to differentiate between different cognitive states in PD. The causal relationship between increased cognitive workload and cognitive decline in PD-NCI should be the focus of future studies.
Abiodun Emmanuel Akinwuntan - One of the best experts on this subject based on the ideXlab platform.
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Pupillary Response to postural demand in parkinson s disease
Frontiers in Bioengineering and Biotechnology, 2021Co-Authors: Melike Kahya, Abiodun Emmanuel Akinwuntan, Kelly E Lyons, Rajesh Pahwa, Hannes DevosAbstract:Background: Individuals with Parkinson's disease (PD) may need to spend more mental and physical effort (i.e., cognitive workload) to maintain postural control. Pupillary Response reflects cognitive workload during postural control tasks in healthy controls but has not been investigated as a measure of postural demand in PD. Objectives: To compare Pupillary Response during increased postural demand using vision occlusion and dual tasking between individuals with PD and healthy controls. Methods: Thirty-three individuals with PD and thirty-five healthy controls were recruited. The four conditions lasted 60 s and involved single balance task with eyes open; single balance task with eyes occluded; dual task with eyes open; dual task with eyes occluded. The dual task comprised the Auditory Stroop test. Pupillary Response was recorded using an eye tracker. The balance was assessed by using a force plate. Two-way Repeated Measures ANOVA and LSD post-hoc tests were employed to compare Pupillary Response and Center of Pressure (CoP) displacement across the four conditions and between individuals with PD and healthy controls. Results: Pupillary Response was higher in individuals with PD compared to healthy controls (p = 0.009) and increased with more challenging postural conditions in both groups (p < 0.001). The post-hoc analysis demonstrated increased Pupillary Response in the single balance eyes occluded (p < 0.001), dual task eyes open (p = 0.01), and dual task eyes occluded (p < 0.001) conditions compared to single task eyes open condition. Conclusion: Overall, the PD group had increased Pupillary Response with increased postural demand compared to the healthy controls. In the future, Pupillary Response can be a potential tool to understand the neurophysiological underpinnings of falls risk in the PD population.
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reliability and validity of Pupillary Response during dual task balance in parkinson disease
Archives of Physical Medicine and Rehabilitation, 2021Co-Authors: Melike Kahya, Abiodun Emmanuel Akinwuntan, Kelly E Lyons, Rajesh Pahwa, Hannes DevosAbstract:Abstract Objective To investigate the reliability and validity of Pupillary Response during dual-task balance conditions in individuals with Parkinson disease (PD). Design Cross-sectional study. Setting University of Kansas Medical Center Parkinson's Disease and Movement Disorder Center. Participants Participants (N=68) included individuals with PD (n=33) and healthy controls (n=35). Interventions Not applicable. Main Outcome Measures Pupillary Response was the main outcome measure that was measured during the following conditions: single-task balance eyes open, single-task balance eyes occluded, dual-task eyes open, and dual-task eyes occluded. After each condition, the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) was administered to assess self-reported cognitive workload. To examine the test-retest reliability of the Pupillary Response, the conditions were administered twice for each individual within 2 hours. Intraclass correlation coefficients (ICC) were used to analyze the test-retest reliability of Pupillary Response in each condition for both groups. Pearson’s r correlation was used to assess the convergent validity of Pupillary Response against the NASA-TLX. Results The test-retest reliability was excellent for both groups in almost all conditions (ICC>0.75). There were no correlations between Pupillary Response and the NASA-TLX. However, increased mental demand (a subitem of the NASA-TLX) significantly correlated with increased Pupillary Response in individuals with PD (r=0.38; P=.03). Conclusions Pupillary Response showed excellent test-retest reliability and validity during dual-task balance for individuals with PD and healthy controls. Overall, these results suggest that Pupillary Response represents a stable index of cognitive workload during dual-task balance in individuals with PD.
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Pilot Feasibility Study Examining Pupillary Response During Driving Simulation as a Measure of Cognitive Load in Breast Cancer Survivors.
Oncology Nursing Forum, 2020Co-Authors: Jamie S. Myers, Nesreen Alissa, Melissa P. Mitchell, Junqiang Dai, Sanghee Moon, Anne O'dea, Jennifer R. Klemp, Monica Kurylo, Abiodun Emmanuel AkinwuntanAbstract:Objectives To test the feasibility of adding driving simulation tasks to measure visuospatial ability and processing speed to an existing neurocognitive battery for breast cancer survivors (BCSs). Sample & setting 38 BCSs and 17 healthy controls from a cross-sectional pilot study conducted at the University of Kansas Medical Center. Methods & variables Exploratory substudy measuring Pupillary Response, visuospatial ability, and processing speed during two 10-minute driving simulations (with or without n-back testing) in a sample of BCSs with self-reported cognitive complaints and healthy controls. Results Feasibility of measurement of Pupillary Response during driving simulation was demonstrated. No between-group differences were noted for Pupillary Response during driving simulation. BCSs had greater visuospatial ability and processing speed performance difficulties than healthy controls during driving simulation without n-back testing and slower n-back Response time. Implications for nursing Preliminary evidence showed a possible link between cancer/treatment on visuospatial ability and processing speed in BCSs.
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Pupillary Response to cognitive demand in parkinson s disease a pilot study
Frontiers in Aging Neuroscience, 2018Co-Authors: Melike Kahya, Sanghee Moon, Abiodun Emmanuel Akinwuntan, Kelly E Lyons, Rajesh Pahwa, Hannes DevosAbstract:Previous studies have shown that Pupillary Response, a physiological measure of cognitive workload, reflects cognitive demand in healthy younger and older adults. However, the relationship between cognitive workload and cognitive demand in Parkinson's disease (PD) remains unclear. The aim of this pilot study was to examine the Pupillary Response to cognitive demand in a letter-number sequencing (LNS) task between 16 non-demented individuals with PD (age, median (Q1-Q3): 68 (62-72); 10 males) and 10 control participants (age: 63 (59-67); 2 males), matched for age, education, and Montreal Cognitive Assessment (MOCA) scores. A mixed model analysis was employed to investigate cognitive workload changes as a result of incremental cognitive demand for both groups. As expected, no differences were found in cognitive scores on the LNS between groups. Cognitive workload, exemplified by greater pupil dilation, increased with incremental cognitive demand in both groups (p = 0.003). No significant between-group (p = 0.23) or interaction effects were found (p = 0.45). In addition, individuals who achieved to complete the task at higher letter-number (LN) load responded differently to increased cognitive demand compared with those who completed at lower LN load (p < 0.001), regardless of disease status. Overall, the findings indicated that Pupillary Response reflects incremental cognitive demand in non-demented people with PD and healthy controls. Further research is needed to investigate the Pupillary Response to incremental cognitive demand of PD patients with dementia compared to non-demented PD and healthy controls. Highlights -Pupillary Response reflects cognitive demand in both non-demented people with PD and healthy controls-Although not significant due to insufficient power, non-demented individuals with PD had increased cognitive workload compared to the healthy controls throughout the testing-Pupillary Response may be a valid measure of cognitive demand in non-demented individuals with PD-In future, Pupillary Response might be used to detect cognitive impairment in individuals with PD.
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Pupillary Response to cognitive workload during saccadic tasks in parkinson s disease
Behavioural Brain Research, 2017Co-Authors: Maud Ranchet, Abiodun Emmanuel Akinwuntan, Jason Orlosky, John C Morgan, Siraj Qadir, Hannes DevosAbstract:The relationship between cognitive workload and cognitive impairments in Parkinson's disease (PD) is currently not well known. This study compared cognitive workload during saccadic tasks between patients with PD and controls. Sixteen controls, 11 patients with no obvious cognitive impairment (PD-NCI) (MOCA score≥26), and 10 PD patients with cognitive impairment (PD-CI) (MOCA score<26) performed prosaccade and antisaccade tasks. Cognitive workload, extracted via pupil recording, and other eye metrics were compared between the three groups. PD-NCI patients exhibited greater cognitive workload than controls in the prosaccade task. PD-CI patients also showed more cognitive workload in the prosaccade task than PD-NCI patients and controls. No other differences in eye metrics were found between the three groups. Cognitive workload could be used to differentiate between different cognitive states in PD. The causal relationship between increased cognitive workload and cognitive decline in PD-NCI should be the focus of future studies.
Joost C F De Winter - One of the best experts on this subject based on the ideXlab platform.
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workload assessment for mental arithmetic tasks using the task evoked Pupillary Response
PeerJ, 2015Co-Authors: Gerhard Marquart, Joost C F De WinterAbstract:Pupillometry is a promising method for assessing mental workload and could be helpful in the optimization of systems that involve human-computer interaction. The present study focuses on replicating the pupil diameter study by Ahern (1978) for mental multiplications of varying difficulty, using an automatic remote eye tracker. Our results showed that the findings of Ahern were replicated and that the mean pupil diameter and mean pupil diameter change (MPDC) discriminated just as well between the three difficulty levels as did a self-report questionnaire of mental workload (NASA-TLX). A higher mean blink rate was observed during the multiplication period for the highest level of difficulty in comparison with the other two levels. Moderate to strong correlations were found between the MPDC and the proportion of incorrect Responses, indicating that the MPDC was higher for participants with a lower performance. For practical applications, validity could be improved by combining pupillometry with other physiological techniques.
