scholarly journals Polarized light information modulates sensorimotor decision making in goldfish

2018 ◽  
Author(s):  
Santiago Otero Coronel ◽  
Martín Berón de Astrada ◽  
Violeta Medan
Keyword(s):  
Decision Making ◽  
Polarized Light ◽  
Polarization Sensitivity ◽  
Polarization Angle ◽  
Threat Detection ◽  
Low Contrast ◽  
Low Intensity ◽  
Wide Range ◽  
Visual Tasks ◽  
Intensity Contrast

AbstractAnimal survival relays on environmental information gathered by their sensory systems. In invertebrates the polarization angle of light is known to provide vital information for a wide range of visual tasks. However, the role of polarization sensitivity in vertebrates remains poorly understood. Here we study if polarization vision enhances threat detection in goldfish. We found that adding a polarization cue to a low intensity contrast looming stimulus biases the type of evasive behavior the animals perform. While low contrast looms mostly evoke subtle alarm reactions, the addition of a polarized cue dramatically increases the probability of eliciting a fast escape maneuver, the C-start response. Goldfish can be startled by polarized light stimuli coming not only from above but also from the sides indicating that polarization sensitivity spans large areas of the retina. In addition, we observed that while low intensity contrast looms preferentially elicit alarm behaviours, high intensity contrast looms rarely induced them, but elicited C-start responses with a high probability. Together, our results show that the addition of a polarized light cue to a low intensity contrast stimulus shifts animal’s decision making from low threshold alarm responses to the higher threshold C-start escape behaviour. This additional visual cue, thus, might aid underwater threat detection and predator avoidance in the animal’s natural environment.Summary statementThis study gives the first compelling evidence that fish can use polarized light information to improve their decision making in the context of visual threat detection.

Polarization analysis in the crayfish visual system

2001 ◽  
Vol 204 (14) ◽  
pp. 2383-2390 ◽  
Author(s):  
Raymon M. Glantz
Keyword(s):  
Visual System ◽  
Motor Neurons ◽  
Polarized Light ◽  
Cell Types ◽  
Afferent Input ◽  
Polarization Sensitivity ◽  
Polarization Analysis ◽  
Low Contrast ◽  
Motion Responses ◽  
Light Flashes

SUMMARY It is proposed that polarization sensitivity at the most peripheral stages of the crayfish visual system (lamina ganglionaris and medulla externa) is used to enhance contrast and thus may contribute to motion detection in low contrast environments. The four classes of visual interneurons that exhibit polarization sensitivity (lamina monopolar cells, tangential cells, sustaining fibers and dimming fibers) are not sensitive exclusively to polarized light but also respond to unpolarized contrast stimuli. Furthermore, many of these cells and the sustaining fibers in particular exhibit a greater differential e-vector responsiveness to a changing e-vector than to e-vector variations among steady-state stimuli. While all four cell types respond modestly to light flashes at an e-vector of 90° to the preferred orientation, the dynamic response to a changing e-vector is small or absent at this orientation. Because the sustaining fibers exhibit polarization sensitivity, and they provide afferent input to a subset of optomotor neurons, the latter were also tested for polarization sensitivity. The optomotor neurons involved in compensatory reflexes for body pitch were differentially sensitive to the e-vector angle of a flash of light, with maximum responses for e-vectors near the vertical. The motor neurons also exhibited a maximum response near the vertical e-vector to a continuously rotating polarizer. Two scenarios are described in which the sensitivity to a changing e-vector can produce motion responses in the absence of intensity contrast.

The compound eyes of mantis shrimps (Crustacea, Hoplocarida, Stomatopoda). I. Compound eye structure: the detection of polarized light

1991 ◽  
Vol 334 (1269) ◽  
pp. 33-56 ◽  
Keyword(s):  
Compound Eye ◽  
Polarized Light ◽  
Structural Features ◽  
Polarization Sensitivity ◽  
Compound Eyes ◽  
Visual Tasks ◽  
Retinular Cells ◽  
High Degree ◽  
Structural Adaptations ◽  
Parallel Sampling

Stomatopod crustaceans possess compound eyes divided into three distinct regions: two peripheral retinae - the dorsal and ventral hemispheres — and the mid-band. Throughout the eye, in particular in the midband, there are many structural adaptations that potentially enable different portions of the eye to perform different visual tasks. A high degree of optical overlap between these eye regions allows the parallel sampling of various parameters of light from one direction in space. In consecutive papers, we present structural evidence that stomatopods have the receptors necessary for colour and polarization vision. The first paper describes the retinal structures that suggest the existence of polarization sensitivity in stomatopods. mid-band rows five and six, together with the hemispheres, are probably involved in this visual process. By using two strategies, rhabdomal modification and varying the orientation of similar ommatidial units in the three eye regions, stomatopods have the capacity to analyse polarized light in a very detailed manner. All the species included in this study live in shallow, tropical waters where polarized light signals are abundant. It therefore seems likely that their eyes have evolved to take advantage of such environmental cues. Structural evidence also suggests that all retinular cells in rows one to four of the mid-band, and the distal most retinular cells (R8) over most of the retina, are not sensitive to polarized light. These mid-band rows are instead adapted for colour detection. This function of the stomatopod retina and structural features concerned with colour sensitivity are described in paper II ( Phil. Trans. R. Soc. Lond. B 334, 57—84 (1991)).

scholarly journals Perceiving polarization with the naked eye: characterization of human polarization sensitivity

2015 ◽  
Vol 282 (1811) ◽  
pp. 20150338 ◽  
Author(s):  
Shelby E. Temple ◽  
Juliette E. McGregor ◽  
Camilla Miles ◽  
Laura Graham ◽  
Josie Miller ◽  
...  
Keyword(s):  
Light Field ◽  
Polarized Light ◽  
Age Related Macular Degeneration ◽  
Polarization Sensitivity ◽  
Polarization Angle ◽  
Self Assessment ◽  
Age Related ◽  
Polarization Of Light ◽  
Lower Limits

Like many animals, humans are sensitive to the polarization of light. We can detect the angle of polarization using an entoptic phenomenon called Haidinger's brushes, which is mediated by dichroic carotenoids in the macula lutea. While previous studies have characterized the spectral sensitivity of Haidinger's brushes, other aspects remain unexplored. We developed a novel methodology for presenting gratings in polarization-only contrast at varying degrees of polarization in order to measure the lower limits of human polarized light detection. Participants were, on average, able to perform the task down to a threshold of 56%, with some able to go as low as 23%. This makes humans the most sensitive vertebrate tested to date. Additionally, we quantified a nonlinear relationship between presented and perceived polarization angle when an observer is presented with a rotatable polarized light field. This result confirms a previous theoretical prediction of how uniaxial corneal birefringence impacts the perception of Haidinger's brushes. The rotational dynamics of Haidinger's brushes were then used to calculate corneal retardance. We suggest that psychophysical experiments, based upon the perception of polarized light, are amenable to the production of affordable technologies for self-assessment and longitudinal monitoring of visual dysfunctions such as age-related macular degeneration.

scholarly journals A survey of methods for evaluating mini-publics

2021 ◽  
Author(s):  
Takeuchi Ayano
Keyword(s):  
Decision Making ◽  
Academic Research ◽  
Future Research ◽  
The Political ◽  
Decision Making Process ◽  
Sufficient Information ◽  
Practical Case ◽  
Political Decision ◽  
Wide Range ◽  
Political Decision Making

AbstractPublic participation has become increasingly necessary to connect a wide range of knowledge and various values to agenda setting, decision-making and policymaking. In this context, deliberative democratic concepts, especially “mini-publics,” are gaining attention. Generally, mini-publics are conducted with randomly selected lay citizens who provide sufficient information to deliberate on issues and form final recommendations. Evaluations are conducted by practitioner researchers and independent researchers, but the results are not standardized. In this study, a systematic review of existing research regarding practices and outcomes of mini-publics was conducted. To analyze 29 papers, the evaluation methodologies were divided into 4 categories of a matrix between the evaluator and evaluated data. The evaluated cases mainly focused on the following two points: (1) how to maintain deliberation quality, and (2) the feasibility of mini-publics. To create a new path to the political decision-making process through mini-publics, it must be demonstrated that mini-publics can contribute to the decision-making process and good-quality deliberations are of concern to policy-makers and experts. Mini-publics are feasible if they can contribute to the political decision-making process and practitioners can evaluate and understand the advantages of mini-publics for each case. For future research, it is important to combine practical case studies and academic research, because few studies have been evaluated by independent researchers.

scholarly journals Results of the Behavioral Health Readiness Evaluation and Decision-Making Instrument Study

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 142-152
Author(s):  
Justin M Curley ◽  
Katie L Nugent ◽  
Kristina M Clarke-Walper ◽  
Elizabeth A Penix ◽  
James B Macdonald ◽  
...  
Keyword(s):  
Decision Making ◽  
Behavioral Health ◽  
User Satisfaction ◽  
Safety Issue ◽  
Walter Reed Army Institute ◽  
End User ◽  
Chi Square ◽  
Proficiency Level ◽  
Wide Range ◽  
Decision Making Support

ABSTRACT Introduction Recent reports have demonstrated behavioral health (BH) system and individual provider challenges to BH readiness success. These pose a risk to winning on the battlefield and present a significant safety issue for the Army. One of the most promising areas for achieving better BH readiness results lies in improving readiness decision-making support for BH providers. The Walter Reed Army Institute of Research (WRAIR) has taken the lead in addressing this challenge by developing and empirically testing such tools. The results of the Behavioral Health Readiness Evaluation and Decision-Making Instrument (B-REDI) field study are herein described. Methods The B-REDI study received WRAIR Institutional Review Board approval, and BH providers across five U.S. Army Forces Command installations completed surveys from September 2018 to March 2019. The B-REDI tools/training were disseminated to 307 providers through random clinic assignments. Of these, 250 (81%) providers consented to participate and 149 (60%) completed both initial and 3-month follow-up surveys. Survey items included a wide range of satisfaction, utilization, and proficiency-level outcome measures. Analyses included examinations of descriptive statistics, McNemar’s tests pre-/post-B-REDI exposure, Z-tests with subgroup populations, and chi-square tests with demographic comparisons. Results The B-REDI resulted in broad, statistically significant improvements across the measured range of provider proficiency-level outcomes. Net gains in each domain ranged from 16.5% to 22.9% for knowledge/awareness (P = .000), from 11.1% to 15.8% for personal confidence (P = .001-.000), and from 6.2% to 15.1% for decision-making/documentation (P = .035-.002) 3 months following B-REDI initiation, and only one (knowledge) failed to maintain a statistically significant improvement in all of its subcategories. The B-REDI also received high favorability ratings (79%-97% positive) across a wide array of end-user satisfaction measures. Conclusions The B-REDI directly addresses several critical Army BH readiness challenges by providing tangible decision-making support solutions for BH providers. Providers reported high degrees of end-user B-REDI satisfaction and significant improvements in all measured provider proficiency-level domains. By effectively addressing the readiness decision-making challenges Army BH providers encounter, B-REDI provides the Army BH health care system with a successful blueprint to set the conditions necessary for providers to make more accurate and timely readiness determinations. This may ultimately reduce safety and mission failure risks enterprise-wide, and policymakers should consider formalizing and integrating the B-REDI model into current Army BH practice.

The Application of Multicriteria Decision Analysis Methods in Health Care: A Literature Review

2021 ◽  
pp. 0272989X2110190
Author(s):  
Ilyas Khan ◽  
Liliane Pintelon ◽  
Harry Martin
Keyword(s):  
Health Care ◽  
Decision Making ◽  
Decision Analysis ◽  
Medical Devices ◽  
Hybrid Methods ◽  
Multicriteria Decision Analysis ◽  
Multicriteria Decision ◽  
Health Care Decision ◽  
Wide Range ◽  
Care Decision

Objectives The main objectives of this article are 2-fold. First, we explore the application of multicriteria decision analysis (MCDA) methods in different areas of health care, particularly the adoption of various MCDA methods across health care decision making problems. Second, we report on the publication trends on the application of MCDA methods in health care. Method PubMed was searched for literature from 1960 to 2019 in the English language. A wide range of keywords was used to retrieve relevant studies. The literature search was performed in September 2019. Articles were included only if they have reported an MCDA case in health care. Results and Conclusion The search yielded 8,318 abstracts, of which 158 fulfilled the inclusion criteria and were considered for further analysis. Hybrid methods are the most widely used methods in health care decision making problems. When it comes to single methods, analytic hierarchy process (AHP) is the most widely used method followed by TOPSIS (technique for order preference by similarity to ideal solution), multiattribute utility theory, goal programming, EVIDEM (evidence and value: impact on decision making), evidential reasoning, discrete choice experiment, and so on. Interestingly, the usage of hybrid methods has been high in recent years. AHP is most widely applied in screening and diagnosing and followed by treatment, medical devices, resource allocation, and so on. Furthermore, treatment, screening and diagnosing, medical devices, and drug development and assessment got more attention in the MCDA context. It is indicated that the application of MCDA methods to health care decision making problem is determined by the nature and complexity of the health care problem. However, guidelines and tools exist that assist in the selection of an MCDA method.

scholarly journals Goal-driven active learning

2021 ◽  
Vol 35 (2) ◽  
Author(s):  
Nicolas Bougie ◽  
Ryutaro Ichise
Keyword(s):  
Decision Making ◽  
Reinforcement Learning ◽  
Learning Process ◽  
Real World ◽  
Imitation Learning ◽  
Learning Approaches ◽  
Wide Range ◽  
Fixed Set ◽  
Complex Decision Making ◽  
Complex Decision

AbstractDeep reinforcement learning methods have achieved significant successes in complex decision-making problems. In fact, they traditionally rely on well-designed extrinsic rewards, which limits their applicability to many real-world tasks where rewards are naturally sparse. While cloning behaviors provided by an expert is a promising approach to the exploration problem, learning from a fixed set of demonstrations may be impracticable due to lack of state coverage or distribution mismatch—when the learner’s goal deviates from the demonstrated behaviors. Besides, we are interested in learning how to reach a wide range of goals from the same set of demonstrations. In this work we propose a novel goal-conditioned method that leverages very small sets of goal-driven demonstrations to massively accelerate the learning process. Crucially, we introduce the concept of active goal-driven demonstrations to query the demonstrator only in hard-to-learn and uncertain regions of the state space. We further present a strategy for prioritizing sampling of goals where the disagreement between the expert and the policy is maximized. We evaluate our method on a variety of benchmark environments from the Mujoco domain. Experimental results show that our method outperforms prior imitation learning approaches in most of the tasks in terms of exploration efficiency and average scores.

scholarly journals Ultraviolet polarization vision in fishes: possible mechanisms for coding e–vector

2000 ◽  
Vol 355 (1401) ◽  
pp. 1187-1190 ◽  
Author(s):  
Craig W. Hawryshyn
Keyword(s):  
Polarized Light ◽  
Spatial Arrangement ◽  
Short Review ◽  
Research Problem ◽  
Polarization Sensitivity ◽  
Polarization Vision ◽  
Selective Reflection ◽  
Mosaic Pattern ◽  
Cone Mosaic ◽  
Biophysical Mechanism

Polarization vision in vertebrates has been marked with significant controversy over recent decades. In the last decade, however, models from two laboratories have indicated that the spatial arrangement of photoreceptors provides the basis for polarization sensitivity.Work in my laboratory, in collaboration with I. Novales Flamarique and F. I. Harosi, has shown that polarization sensitivity depends on a well–defined square cone mosaic pattern and that the biophysical properties of the square cone mosaic probably account for polarization vision in the ultraviolet spectrum. The biophysical mechanism appears to be based on the selective reflection of axial–polarized light by the partitioning membrane, formed along the contact zone between the members of the double cones, onto neighbouring ultraviolet–sensitive cones. In this short review, I discuss the historical development of this research problem.

Effects of a Brief Transdiagnostic Cognitive Behavioural Group Therapy on Disorder Specific Symptoms

2018 ◽  
Vol 47 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Hafrún Kristjánsdóttir ◽  
Baldur Heiðar Sigurðsson ◽  
Paul Salkovskis ◽  
Engilbert Sigurðsson ◽  
Magnús Blöndahl Sighvatsson ◽  
...  
Keyword(s):  
Anxiety Disorders ◽  
Treatment Effects ◽  
Mental Health Problems ◽  
Effect Sizes ◽  
Low Intensity ◽  
Cognitive Behavioural ◽  
Wide Range ◽  
Common Mental Health Problems ◽  
Specific Symptoms ◽  
Group Therapies

Background:In recent years, cognitive behavioural group therapies (CBGT) have been increasingly deployed as a strategy to increase the efficiency and cost-effectiveness in treatment of common mental health problems. The vast majority of these therapies are disorder specific, but in the last few years there has been growing interest in transdiagnostic CBGT.Aims:The aim of this study was twofold: to evaluate the treatment effects of transdiagnostic CBGT on disorder specific symptoms and what (if any) differences would be observed in the treatment effects with regard to general as opposed to disorder specific symptoms measured pre- and post-treatment.Method:The participants were 233 adult patients diagnosed with depression and/or anxiety disorders. They underwent a 6-week transdiagnostic CBGT. To compare treatment effects on general and disorder specific symptoms, raw scores on all measures were converted to standardized scores.Results:Pre–post differences were significant and there was no evidence that treatment was differentially effective for general and disorder specific symptoms. Effect sizes ranged from medium to large.Conclusion:The 6-week transdiagnostic CBGT is feasible for a wide range of mood and anxiety disorders. The results indicate that low-intensity transdiagnostic group therapies may have similar effects on both general and disorder specific symptoms.

Perceived Affordances and Regret in Online Travel Agencies

2021 ◽  
pp. 004728752110149
Author(s):  
Hwirim Jo ◽  
Namho Chung ◽  
Sunyoung Hlee ◽  
Chulmo Koo
Keyword(s):  
Decision Making ◽  
Regulatory Focus ◽  
Group Analysis ◽  
Cognitive Effort ◽  
Wide Range ◽  
Impulsive Buying ◽  
Travel Agencies ◽  
Effective Decision Making ◽  
Online Travel ◽  
Online Travel Agencies

Despite the revolutionary system of online booking, the decision-making process for booking hotels is still very stressful for customers, who face much uncertainty. The wide range of products and great volume of information result in significant cognitive overload. Therefore, online travel agencies (OTAs) try to reduce customers’ cognitive effort requirements and to induce effective decision making by triggering potential actions through perceived affordance. This study aims to explore the influence of perceived affordance on purchase decisions and postpurchase emotion in the context of OTAs. The findings show that explicit affordance and hidden affordance significantly affect impulsive buying, thus resulting in postpurchase discomfort and regret. Additionally, the outcomes of a multiple group analysis revealed a significant moderating effect of regulatory focus orientation on impulsive buying and postpurchase regret during an overall purchase process involving OTAs.

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