scholarly journals Electrodermal Response Ratios: Scoring Against the Stronger of Two Comparison Questions in Search of an Optimal Minimum Threshold

2020 ◽  
Vol 14 (2) ◽  
pp. 9-16
Author(s):  
Donald J. Krapohl
Keyword(s):  
Ground Truth ◽  
Electrodermal Response ◽  
Minimum Threshold ◽  
Optimal Ratio ◽  
Relevant Question ◽  
Electrodermal Responses ◽  
Minimum Ratio

Abstract Previously, Krapohl (2020) evaluated the Bigger-Is-Better Rule (BIBR) on the polygraph electrodermal channel to assess whether there was a best minimum ratio between response sizes for assigning a score. Performance peaked at a minimum ratio between 10% and 20%. The ratios had been calculated by comparing the electrodermal responses for each relevant question against those of the immediately preceding comparison question. The analysis did not consider whether the same optimal ratio would be found if the relevant question electrodermal responses are compared to those of the stronger of two adjacent comparison questions. To investigate we analyzed responses from an independent sample of 255 laboratory cases. The data from those cases found the highest correlation between scores and ground truth occurred when the minimum difference between two electrodermal responses was 30%.

Brainstem loci for activation of electrodermal response in the cat

1975 ◽  
Vol 229 (4) ◽  
pp. 930-934 ◽  
Author(s):  
MA Davison ◽  
MC Koss
Keyword(s):  
Reticular Formation ◽  
Posterior Hypothalamus ◽  
Cervical Cord ◽  
Electrodermal Response ◽  
Posterior Commissure ◽  
Direct Stimulation ◽  
Electrodermal Responses ◽  
Decerebrate Cats ◽  
Dorsal Medulla ◽  
Stimulation Of

Brainstem loci from which electrodermal responses could be elicited were systematically explored by direct-stimulation techniques in chloralose-anesthetized and decerebrate cats. Reactive sites of the greatest amplitude were found to extend from the rostral border of the posterior hypothalamus, through the ventrolateral reticular formation of the pons and the medulla, to the cervical cord. Stimulation of these sites elicited stable, reproducible electrodermal responses of 10-30 mV in amplitude. In addition, it was found that stimulation of the ventrolateral extent of the lower brainstem evoked similar responses in the decerebrate preparation. Electrodermal responses could not be elicited from the dorsal medulla, the posterior commissure, or the midline region. The electrodermal response could be elicited from an apparently hypothalamus through the ventrolateral brainstem.

Saccadic and Electrodermal Responses to Television Violence

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 198-198
Author(s):  
A D Kalamas ◽  
A L Gruber
Keyword(s):  
Statistical Evaluation ◽  
Emotional Responses ◽  
Auditory Stimuli ◽  
Electrodermal Response ◽  
Corneal Reflection ◽  
Gun Shot ◽  
Electrodermal Responses ◽  
Tv Shows ◽  
Television Violence ◽  
Saccadic Responses

The concern for TV violence has not been followed by any way to discriminate one type of violent show from another. To ascertain which stimulus elements of TV violence elicit emotional responses we attempted to correlate the electrodermal response with the general saccadic responses. The simultaneous electrodermal and saccadic responses of children watching violent TV shows were analysed. The saccadic movements were derived from the corneal reflection, computer enhanced, and superimposed on the violent video. Allowing for the individualised response latency, the analog recording of the electrodermal response (as well as an audiometric response) was also superimposed. We found that most electrodermal responses (41%) actually occurred to nonviolent but frightening stimuli (eg villain's face; grave). Few responses (8%) occurred to actual violent stimuli (eg stabbing). Auditory stimuli (eg gun shot) elicited intense electrodermal responses, the correlation being positively associated with the audiometric level. Statistical evaluation by Anova confirmed the significance of the above findings at p<0.01. We conclude that (1) actual violence may provoke less electrodermal responses than implied violence; and (2) sound potentiates the electrodermal response to elements of violence. We hope that this computer superimposition technique will make it easier to discriminate one violent show from another.

Factors Influencing Electrophysiologic Responsivity in Normal Adults

1965 ◽  
Vol 8 (4) ◽  
pp. 323-347
Author(s):  
Robert Goldstein ◽  
Benjamin RosenblÜt
Keyword(s):  
Conditioned Stimulus ◽  
White Light ◽  
Pure Tone ◽  
Alpha Rhythm ◽  
White Women ◽  
White Men ◽  
Inverse Relation ◽  
Factors Influencing ◽  
Electrodermal Responses ◽  
Normal Adults

Electrodermal and electroencephalic responsivity to sound and to light was studied in 96 normal-hearing adults in three separate sessions. The subjects were subdivided into equal groups of white men, white women, colored men, and colored women. A 1 000 cps pure tone was the conditioned stimulus in two sessions and white light was used in a third session. Heat was the unconditioned stimulus in all sessions. Previously, an inverse relation had been found in white men between the prominence of alpha rhythm in the EEG and the ease with which electrodermal responses could be elicited. This relation did not hold true for white women. The main purpose of the present study was to answer the following questions: (1) are the previous findings on white subjects applicable to colored subjects? (2) are subjects who are most (or least) responsive electrophysiologically on one day equally responsive (or unresponsive) on another day? and (3) are subjects who are most (or least) responsive to sound equally responsive (or unresponsive) to light? In general, each question was answered affirmatively. Other factors influencing responsivity were also studied.

A Comparison of Simple Structure Rotation Criteria in Temporal Exploratory Factor Analysis for Event-Related Potential Data

Methodology ◽  
2019 ◽  
Vol 15 (Supplement 1) ◽  
pp. 43-60 ◽  
Author(s):  
Florian Scharf ◽  
Steffen Nestler
Keyword(s):  
Factor Analysis ◽  
Exploratory Factor Analysis ◽  
Simple Structure ◽  
Ground Truth ◽  
Event Related Potential ◽  
Suitable Alternative ◽  
Factor Rotation ◽  
Rotation Methods ◽  
Simple Structure Rotation ◽  
Temporal Overlap

Abstract. It is challenging to apply exploratory factor analysis (EFA) to event-related potential (ERP) data because such data are characterized by substantial temporal overlap (i.e., large cross-loadings) between the factors, and, because researchers are typically interested in the results of subsequent analyses (e.g., experimental condition effects on the level of the factor scores). In this context, relatively small deviations in the estimated factor solution from the unknown ground truth may result in substantially biased estimates of condition effects (rotation bias). Thus, in order to apply EFA to ERP data researchers need rotation methods that are able to both recover perfect simple structure where it exists and to tolerate substantial cross-loadings between the factors where appropriate. We had two aims in the present paper. First, to extend previous research, we wanted to better understand the behavior of the rotation bias for typical ERP data. To this end, we compared the performance of a variety of factor rotation methods under conditions of varying amounts of temporal overlap between the factors. Second, we wanted to investigate whether the recently proposed component loss rotation is better able to decrease the bias than traditional simple structure rotation. The results showed that no single rotation method was generally superior across all conditions. Component loss rotation showed the best all-round performance across the investigated conditions. We conclude that Component loss rotation is a suitable alternative to simple structure rotation. We discuss this result in the light of recently proposed sparse factor analysis approaches.

Brain FDG PET for the Etiological Diagnosis of Clinically Uncertain Cognitive Impairment During Delirium in Remission

2020 ◽  
Vol 77 (4) ◽  
pp. 1609-1622
Author(s):  
Franziska Mathies ◽  
Catharina Lange ◽  
Anja Mäurer ◽  
Ivayla Apostolova ◽  
Susanne Klutmann ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Fdg Pet ◽  
False Negative ◽  
Ground Truth ◽  
Etiological Diagnosis ◽  
Geriatric Unit ◽  
Positron Emission ◽  
The Brain ◽  
Hospitalized Geriatric Patients

Background: Positron emission tomography (PET) of the brain with 2-[F-18]-fluoro-2-deoxy-D-glucose (FDG) is widely used for the etiological diagnosis of clinically uncertain cognitive impairment (CUCI). Acute full-blown delirium can cause reversible alterations of FDG uptake that mimic neurodegenerative disease. Objective: This study tested whether delirium in remission affects the performance of FDG PET for differentiation between neurodegenerative and non-neurodegenerative etiology of CUCI. Methods: The study included 88 patients (82.0±5.7 y) with newly detected CUCI during hospitalization in a geriatric unit. Twenty-seven (31%) of the patients were diagnosed with delirium during their current hospital stay, which, however, at time of enrollment was in remission so that delirium was not considered the primary cause of the CUCI. Cases were categorized as neurodegenerative or non-neurodegenerative etiology based on visual inspection of FDG PET. The diagnosis at clinical follow-up after ≥12 months served as ground truth to evaluate the diagnostic performance of FDG PET. Results: FDG PET was categorized as neurodegenerative in 51 (58%) of the patients. Follow-up after 16±3 months was obtained in 68 (77%) of the patients. The clinical follow-up diagnosis confirmed the FDG PET-based categorization in 60 patients (88%, 4 false negative and 4 false positive cases with respect to detection of neurodegeneration). The fraction of correct PET-based categorization did not differ between patients with delirium in remission and patients without delirium (86% versus 89%, p = 0.666). Conclusion: Brain FDG PET is useful for the etiological diagnosis of CUCI in hospitalized geriatric patients, as well as in patients with delirium in remission.

A Flying Gray Ball Multi-illuminant Image Dataset for Color Research

2020 ◽  
Vol 64 (5) ◽  
pp. 50411-1-50411-8
Author(s):  
Hoda Aghaei ◽  
Brian Funt
Keyword(s):  
Machine Vision ◽  
Spectral Reflectance ◽  
Color Constancy ◽  
Ground Truth ◽  
Practical Approach ◽  
Post Processing ◽  
Illumination Estimation ◽  
Processing Step ◽  
Image Dataset

Abstract For research in the field of illumination estimation and color constancy, there is a need for ground-truth measurement of the illumination color at many locations within multi-illuminant scenes. A practical approach to obtaining such ground-truth illumination data is presented here. The proposed method involves using a drone to carry a gray ball of known percent surface spectral reflectance throughout a scene while photographing it frequently during the flight using a calibrated camera. The captured images are then post-processed. In the post-processing step, machine vision techniques are used to detect the gray ball within each frame. The camera RGB of light reflected from the gray ball provides a measure of the illumination color at that location. In total, the dataset contains 30 scenes with 100 illumination measurements on average per scene. The dataset is available for download free of charge.

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