EEG correlates of cognitive time scales in the Necker-Zeno model for bistable perception.

Science.gov (United States)

Kornmeier, J; Friedel, E; Wittmann, M; Atmanspacher, H

2017-08-01

The Necker-Zeno model of bistable perception provides a formal relation between the average duration of meta-stable percepts (dwell times T) of ambiguous figures and two other basic time scales (t 0 , ΔT) underlying cognitive processing. The model predicts that dwell times T covary with t 0 , ΔT or both. We tested this prediction by exploiting that observers, in particular experienced meditators, can volitionally control dwell times T. Meditators and non-meditators observed bistable Necker cubes either passively or tried to hold their current percept. The latencies of a centro-parietal event-related potential (CPP) were recorded as a physiological correlate of t 0 . Dwell times T and the CPP latencies, correlated with t 0 , differed between conditions and observer groups, while ΔT remained constant in the range predicted by the model. The covariation of CPP latencies and dwell times, as well as their quadratic functional dependence extends previous psychophysical confirmation of the Necker-Zeno model to psychophysiological measures. Copyright © 2017. Published by Elsevier Inc.

Time perception, pacing and exercise intensity: maximal exercise distorts the perception of time

OpenAIRE

Edwards, A. M.; McCormick, A.

2017-01-01

Introduction\\ud \\ud Currently there are no data examining the impact of exercise on the perception of time, which is surprising as optimal competitive performance is dependent on accurate pacing using knowledge of time elapsed.\\ud \\ud \\ud Methods\\ud \\ud With institutional ethics approval, 12 recreationally active adult participants (f = 7, m = 5) undertook both 30 s Wingate cycles and 20 min (1200 s) rowing ergometer bouts as short and long duration self-paced exercise trials, in each of thre...

Audience Perceptions of Family Viewing Time

Science.gov (United States)

Fontes, Brian F.; And Others

1977-01-01

Discusses a survey on Family Viewing Time designed to determine audience reactions to program content including violent and sexual content, audience perceptions of the suitability of program offerings for family viewing, and audience viewing habits with respect to Family Viewing Time. (MH)

Health risks occurring when color is percepted under led lighting

Directory of Open Access Journals (Sweden)

V.A. Kaptsov

2017-06-01

Full Text Available The article deals with problems of color perception under LED lighting. We revealed that inadequate perception of a signal color by a driver led to greater risks of transport accidents. We reviewed both Jung-Helmholtz three-color hypothesis and a modern one based on fiber-optical approach to functioning of "Mueller cells and cones" system. We made an attempt to explain a number of effects related to visibility curves and time delays when defining color of light signals. Our research on assessing influence exerted by LED lighting on functional state and working capacity of railway workers during which we applied occupational selection techniques revealed negative changes. We proved there was a decrease in functional resistance to color sense between red and green signals as well as longer response time for complicated sight-motor reaction and significant decrease in readiness to emergency actions (resistance to monotony in examined individuals. The article also contains data on time peculiarities which are characteristic for defining signals color in relation to red signal (650 nm. We showed that when red color LEDs with wave length much shorter than 650 nm were used in signaling devices it caused risks of inadequate color detection, longer reaction to inhibiting signals, and greater possibility of transport accidents and negative events in everyday life. These peculiarities should be taken into account when designing traffic lights and other signaling devices which provide transport safety. We also proved that signaling traffic lights for transport systems should be designed allowing for physiology of color perception by a human visual analyzer; application of LEDs with wave length shorter than 650 nm should be absolutely excluded

Oscillatory phase dynamics in neural entrainment underpin illusory percepts of time.

Science.gov (United States)

Herrmann, Björn; Henry, Molly J; Grigutsch, Maren; Obleser, Jonas

2013-10-02

Neural oscillatory dynamics are a candidate mechanism to steer perception of time and temporal rate change. While oscillator models of time perception are strongly supported by behavioral evidence, a direct link to neural oscillations and oscillatory entrainment has not yet been provided. In addition, it has thus far remained unaddressed how context-induced illusory percepts of time are coded for in oscillator models of time perception. To investigate these questions, we used magnetoencephalography and examined the neural oscillatory dynamics that underpin pitch-induced illusory percepts of temporal rate change. Human participants listened to frequency-modulated sounds that varied over time in both modulation rate and pitch, and judged the direction of rate change (decrease vs increase). Our results demonstrate distinct neural mechanisms of rate perception: Modulation rate changes directly affected listeners' rate percept as well as the exact frequency of the neural oscillation. However, pitch-induced illusory rate changes were unrelated to the exact frequency of the neural responses. The rate change illusion was instead linked to changes in neural phase patterns, which allowed for single-trial decoding of percepts. That is, illusory underestimations or overestimations of perceived rate change were tightly coupled to increased intertrial phase coherence and changes in cerebro-acoustic phase lag. The results provide insight on how illusory percepts of time are coded for by neural oscillatory dynamics.

On the Cyclotomic Quantum Algebra of Time Perception

OpenAIRE

Planat, Michel

2004-01-01

I develop the idea that time perception is the quantum counterpart to time measurement. Phase-locking and prime number theory were proposed as the unifying concepts for understanding the optimal synchronization of clocks and their 1/f frequency noise. Time perception is shown to depend on the thermodynamics of a quantum algebra of number and phase operators already proposed for quantum computational tasks, and to evolve according to a Hamiltonian mimicking Fechner's law. The mathematics is Bo...

Re-designing the everyday; The use and perception of time among cancer patients combining work and treatment

DEFF Research Database (Denmark)

Hauge, Bettina

2016-01-01

cancer patients performing their jobs while going through demanding treatment programs found time as their main motive for working while being seriously ill. Actions at work point to a time ahead, so by taking part in the time at the workplace they were inscribed in a future presently under pressure...... by their cancer diagnosis. The article describes how cancer struck women and men perceived time in their different life-worlds, at work, at home on temporary sick leave, and at the hospital, and it shows how these perceptions changed during the process of recovery.To these people time appeared in three forms......: A time beyond control, realizing that they had cancer; taking control of time, discovering that they could go to work; the time of the future, which was their new perception of time as cured. This new perception of time reflected the incidental discovery of the cancer, realizing life as coincidental...

The Neuromagnetic Dynamics of Time Perception

OpenAIRE

Carver, Frederick W.; Elvevåg, Brita; Altamura, Mario; Weinberger, Daniel R.; Coppola, Richard

2012-01-01

Examining real-time cortical dynamics is crucial for understanding time perception. Using magnetoencephalography we studied auditory duration discrimination of short (.5 s) versus a pitch control. Time-frequency analysis of event-related fields showed widespread beta-band (13-30 Hz) desynchronization during all tone presentations. Synthetic aperture magnetometry indicated automatic primarily sensorimotor responses in short and pitch conditions, with activation specific to timing in bilateral ...

Time perception in patients with major depressive disorder during vagus nerve stimulation.

Science.gov (United States)

Biermann, T; Kreil, S; Groemer, T W; Maihöfner, C; Richter-Schmiedinger, T; Kornhuber, J; Sperling, W

2011-07-01

Affective disorders may affect patients' time perception. Several studies have described time as a function of the frontal lobe. The activating eff ects of vagus nerve stimulation on the frontal lobe might also modulate time perception in patients with major depressive disorder (MDD). Time perception was investigated in 30 patients with MDD and in 7 patients with therapy-resistant MDD. In these 7 patients, a VNS system was implanted and time perception was assessed before and during stimulation. A time estimation task in which patients were asked "How many seconds have passed?" tested time perception at 4 defined time points (34 s, 77 s, 192 s and 230 s). The differences between the estimated and actual durations were calculated and used for subsequent analysis. Patients with MDD and healthy controls estimated the set time points relatively accurately. A general linear model revealed a significant main eff ect of group but not of age or sex. The passing of time was perceived as significantly slower in patients undergoing VNS compared to patients with MDD at all time points (T34: t = − 4.2; df = 35; p differences in time perception with regard to age, sex or polarity of depression (uni- or bipolar). VNS is capable of changing the perception of time. This discovery furthers the basic research on circadian rhythms in patients with psychiatric disorders.

Perception of Childhood Immunization among Mothers of Under ...

African Journals Online (AJOL)

This work is distributed under the terms of the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 59. Perception of. Childhood .... these successes, immunization is an unfinished agenda. An estimated 19.3 million ...

Odors Bias Time Perception in Visual and Auditory Modalities.

Science.gov (United States)

Yue, Zhenzhu; Gao, Tianyu; Chen, Lihan; Wu, Jiashuang

2016-01-01

Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal) were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor). The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a framework of

Perceptions of Time and Long Time Intervals

International Nuclear Information System (INIS)

Drottz-Sjoeberg, Britt-Marie

2006-01-01

There are certainly many perspectives presented in the literature on time and time perception. This contribution has focused on perceptions of the time frames related to risk and danger of radiation from a planned Swedish repository for spent nuclear fuel. Respondents from two municipalities judged SSI's reviews of the entrepreneur's plans and work of high importance, and more important the closer to our time the estimate was given. Similarly were the consequences of potential leakage from a repository perceived as more serious the closer it would be to our time. Judgements of risks related to the storage of spent nuclear fuel were moderately large on the used measurement scales. Experts are experts because they have more knowledge, and in this context they underlined e.g. the importance of reviews of the radiation situation of time periods up to 100,000 years. It was of interest to note that 55% of the respondents from the municipalities did not believe that the future repository would leak radioactivity. They were much more pessimistic with respect to world politics, i.e. a new world war. However, with respect to the seriousness of the consequences given a leakage from the repository, the public group consistently gave high risk estimates, often significantly higher than those of the expert group. The underestimations of time estimates, as seen in the tasks of pinpointing historic events, provide examples of the difficulty of making estimations involving long times. Similar results showed that thinking of 'the future' most often involved about 30 years. On average, people reported memories of about 2.5 generations back in time, and emotional relationships stretching approximately 2.5 generations into the future; 94% of the responses, with respect to how many future generations one had an emotional relationship, were given in the range of 1-5 generations. Similarly, Svenson and Nilsson found the opinion that the current generations' general responsibility for

Worker's perceptions of time, time-use-attitudes and productivity

Directory of Open Access Journals (Sweden)

E. Ben-Baruch

1991-06-01

Full Text Available Decreasing productivity and increasing wage demands are singled out as being crucial problems facing the economy of South Africa. Changes in the time perceptions and time-use-attitudes of workers could play a decisive role in increasing productivity. The relationships between time perception, needs, motivation and productivity are analysed. Culture, tradition, economy, and environment lend a specific significance to these variables. Workers in a technological society should be guided to adapt to and live by the value system needed to uphold productivity. Opsomming Voortdurende afnemende produktiwiteit teenoor looneise wat styg, is een van die kritieke probleme waarmee die Suid-Afrikaanse ekonomie gekonfronteer word. Die verandering van werkers se tydpersepsie en verandering van houdinge teenoor die benutting van tyd kan deurslaggewend in die verhoging van produktiwiteit wees. In die lig hiervan is die verwantskap tussen tydpersepsie, behoeftes, motivering en prodrktiwiteit ondersoek. In die ontleding word aandag geskenk aan die invloed wat kultuur, tradisie, ekonomie en die omgewing op hierdie veranderlikes het. Opieiding in 'n tegnologiese samelewmg behoort daarop gerig te wees om 'n waardesisteem by werkers te laat ontwikkel wat produktiwiteit kan bevorder.

Prospective and retrospective time perception are related to mental time travel: evidence from Alzheimer's disease.

Science.gov (United States)

El Haj, Mohamad; Moroni, Christine; Samson, Séverine; Fasotti, Luciano; Allain, Philippe

2013-10-01

Unlike prospective time perception paradigms, in which participants are aware that they have to estimate forthcoming time, little is known about retrospective time perception in normal aging and Alzheimer's disease (AD). Our paper addresses this shortcoming by comparing prospective and retrospective time estimation in younger adults, older adults, and AD patients. In four prospective tasks (lasting 30s, 60s, 90s, or 120s) participants were asked to read a series of numbers and to provide a verbal estimation of the reading time. In four other retrospective tasks, they were not informed about time judgment until they were asked to provide a verbal estimation of four elapsed time intervals (lasting 30s, 60s, 90s, or 120s). AD participants gave shorter verbal time estimations than older adults and younger participants did, suggesting that time is perceived to pass quickly in these patients. For all participants, the duration of the retrospective tasks was underestimated as compared to the prospective tasks and both estimations were shorter than the real time interval. Prospective time estimation was further correlated with mental time travel, as measured with the Remember/Know paradigm. Mental time travel was even higher correlated with retrospective time estimation. Our findings shed light on the relationship between time perception and the ability to mentally project oneself into time, two skills contributing to human memory functioning. Finally, time perception deficits, as observed in AD patients, can be interpreted in terms of dramatic changes occurring in frontal lobes and hippocampus. Copyright © 2013 Elsevier Inc. All rights reserved.

Temporal cognition: Connecting subjective time to perception, attention, and memory.

Science.gov (United States)

Matthews, William J; Meck, Warren H

2016-08-01

Time is a universal psychological dimension, but time perception has often been studied and discussed in relative isolation. Increasingly, researchers are searching for unifying principles and integrated models that link time perception to other domains. In this review, we survey the links between temporal cognition and other psychological processes. Specifically, we describe how subjective duration is affected by nontemporal stimulus properties (perception), the allocation of processing resources (attention), and past experience with the stimulus (memory). We show that many of these connections instantiate a "processing principle," according to which perceived time is positively related to perceptual vividity and the ease of extracting information from the stimulus. This empirical generalization generates testable predictions and provides a starting-point for integrated theoretical frameworks. By outlining some of the links between temporal cognition and other domains, and by providing a unifying principle for understanding these effects, we hope to encourage time-perception researchers to situate their work within broader theoretical frameworks, and that researchers from other fields will be inspired to apply their insights, techniques, and theorizing to improve our understanding of the representation and judgment of time. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Perceptions of Life Changes: An Alternate Measure of Aging through Time.

Science.gov (United States)

Suggs, Patricia K.; Kivett, Vira R.

Retrospective strategies measuring perceived life changes over time can further the advancement of life span developmental research. Researchers have neglected the individual's perception of his/her life changes over time. This study attempts to determine discriminators of change over time as operationalized by perceptions of change. Subjects…

Affective State Influences Perception by Affecting Decision Parameters Underlying Bias and Sensitivity

OpenAIRE

Lynn, Spencer K.; Zhang, Xuan; Barrett, Lisa Feldman

2012-01-01

Studies of the effect of affect on perception often show consistent directional effects of a person’s affective state on perception. Unpleasant emotions have been associated with a “locally focused” style of stimulus evaluation, and positive emotions with a “globally focused” style. Typically, however, studies of affect and perception have not been conducted under the conditions of perceptual uncertainty and behavioral risk inherent to perceptual judgments outside the laboratory. We investiga...

Odors bias time perception in visual and auditory modalities

Directory of Open Access Journals (Sweden)

Zhenzhu eYue

2016-04-01

Full Text Available Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 ms or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor. The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a

The Perception of Time While Perceiving Dynamic Emotional Faces

Directory of Open Access Journals (Sweden)

Wang On eLi

2015-08-01

Full Text Available Emotion plays an essential role in the perception of time such that time is perceived to fly when events are enjoyable, while unenjoyable moments are perceived to drag. Previous studies have reported a time-drag effect when participants are presented with emotional facial expressions, regardless of the emotion presented. This effect can hardly be explained by induced emotion given the heterogeneous nature of emotional expressions. We conducted two experiments (n=44 & n=39 to examine the cognitive mechanism underlying this effect by presenting dynamic sequences of emotional expressions to participants. Each sequence started with a particular expression, then morphed to another. The presentation of dynamic facial expressions allows a comparison between the time-drag effect of homogeneous pairs of emotional expressions sharing similar valence and arousal to heterogeneous pairs. Sequences of seven durations (400ms, 600ms, 800ms, 1,000ms, 1,200ms, 1,400ms, 1,600ms were presented to participants, who were asked to judge whether the sequences were closer to 400ms or 1,600ms in a two-alternative forced choice task. The data were then collated according to conditions and fit into cumulative Gaussian curves to estimate the point of subjective equivalence indicating the perceived duration of 1,000ms. Consistent with previous reports, a feeling of time dragging is induced regardless of the sequence presented, such that 1,000ms is perceived to be longer than 1,000ms. In addition, dynamic facial expressions exert a greater effect on perceived time drag than static expressions. The effect is most prominent when the dynamics involve an angry face or a change in valence. The significance of this sensitivity is discussed in terms of emotion perception and its evolutionary significance for our attention mechanism.

Perceptions of Time and Long Time Intervals

Energy Technology Data Exchange (ETDEWEB)

Drottz-Sjoeberg, Britt-Marie [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Psychology

2006-09-15

There are certainly many perspectives presented in the literature on time and time perception. This contribution has focused on perceptions of the time frames related to risk and danger of radiation from a planned Swedish repository for spent nuclear fuel. Respondents from two municipalities judged SSI's reviews of the entrepreneur's plans and work of high importance, and more important the closer to our time the estimate was given. Similarly were the consequences of potential leakage from a repository perceived as more serious the closer it would be to our time. Judgements of risks related to the storage of spent nuclear fuel were moderately large on the used measurement scales. Experts are experts because they have more knowledge, and in this context they underlined e.g. the importance of reviews of the radiation situation of time periods up to 100,000 years. It was of interest to note that 55% of the respondents from the municipalities did not believe that the future repository would leak radioactivity. They were much more pessimistic with respect to world politics, i.e. a new world war. However, with respect to the seriousness of the consequences given a leakage from the repository, the public group consistently gave high risk estimates, often significantly higher than those of the expert group. The underestimations of time estimates, as seen in the tasks of pinpointing historic events, provide examples of the difficulty of making estimations involving long times. Similar results showed that thinking of 'the future' most often involved about 30 years. On average, people reported memories of about 2.5 generations back in time, and emotional relationships stretching approximately 2.5 generations into the future; 94% of the responses, with respect to how many future generations one had an emotional relationship, were given in the range of 1-5 generations. Similarly, Svenson and Nilsson found the opinion that the current generations

A unified model of time perception accounts for duration-based and beat-based timing mechanisms

Directory of Open Access Journals (Sweden)

Sundeep eTeki

2012-01-01

Full Text Available Accurate timing is an integral aspect of sensory and motor processes such as the perception of speech and music and the execution of skilled movement. Neuropsychological studies of time perception in patient groups and functional neuroimaging studies of timing in normal participants suggest common neural substrates for perceptual and motor timing. A timing system is implicated in core regions of the motor network such as the cerebellum, inferior olive, basal ganglia, pre-supplementary and supplementary motor area, pre-motor cortex and higher regions such as the prefrontal cortex.In this article, we assess how distinct parts of the timing system subserve different aspects of perceptual timing. We previously established brain bases for absolute, duration-based timing and relative, beat-based timing in the olivocerebellar and striato-thalamo-cortical circuits respectively (Teki et al., 2011. However, neurophysiological and neuroanatomical studies provide a basis to suggest that timing functions of these circuits may not be independent.Here, we propose a unified model of time perception based on coordinated activity in the core striatal and olivocerebellar networks that are interconnected with each other and the cerebral cortex th

Engaging narratives evoke similar neural activity and lead to similar time perception.

Science.gov (United States)

Cohen, Samantha S; Henin, Simon; Parra, Lucas C

2017-07-04

It is said that we lose track of time - that "time flies" - when we are engrossed in a story. How does engagement with the story cause this distorted perception of time, and what are its neural correlates? People commit both time and attentional resources to an engaging stimulus. For narrative videos, attentional engagement can be represented as the level of similarity between the electroencephalographic responses of different viewers. Here we show that this measure of neural engagement predicted the duration of time that viewers were willing to commit to narrative videos. Contrary to popular wisdom, engagement did not distort the average perception of time duration. Rather, more similar brain responses resulted in a more uniform perception of time across viewers. These findings suggest that by capturing the attention of an audience, narrative videos bring both neural processing and the subjective perception of time into synchrony.

Exploring the Effects of Working Memory on Time Perception in Attention Deficit Hyperactivity Disorder.

Science.gov (United States)

Lee, Hom-Yi; Yang, En-Lin

2018-01-01

Children with attention deficit hyperactivity disorder (ADHD) are often reported to have deficits of time perception. However, there is a strong relation between performance on tasks of working memory and time perception. Thus, it is possible that the poor performance of children with ADHD on time perception results from their deficit of working memory. In this study, the working memory of participants was separately assessed; therefore, we could explore the relationship between working memory and time perception of children with ADHD. Fifty-six children with ADHD and those of healthy controls completed tasks measuring working memory and time perception. The results showed that the time discrimination ability of children with ADHD was poorer than that of controls. However, there was a strong association between time perception and working memory. After controlling working memory and intelligence, the time discrimination ability of children with ADHD was not significantly poorer than that of controls. We suggest that there is an interdependent relationship between time perception and working memory for children with ADHD.

On the number of neurons and time scale of integration underlying the formation of percepts in the brain.

Science.gov (United States)

Wohrer, Adrien; Machens, Christian K

2015-03-01

All of our perceptual experiences arise from the activity of neural populations. Here we study the formation of such percepts under the assumption that they emerge from a linear readout, i.e., a weighted sum of the neurons' firing rates. We show that this assumption constrains the trial-to-trial covariance structure of neural activities and animal behavior. The predicted covariance structure depends on the readout parameters, and in particular on the temporal integration window w and typical number of neurons K used in the formation of the percept. Using these predictions, we show how to infer the readout parameters from joint measurements of a subject's behavior and neural activities. We consider three such scenarios: (1) recordings from the complete neural population, (2) recordings of neuronal sub-ensembles whose size exceeds K, and (3) recordings of neuronal sub-ensembles that are smaller than K. Using theoretical arguments and artificially generated data, we show that the first two scenarios allow us to recover the typical spatial and temporal scales of the readout. In the third scenario, we show that the readout parameters can only be recovered by making additional assumptions about the structure of the full population activity. Our work provides the first thorough interpretation of (feed-forward) percept formation from a population of sensory neurons. We discuss applications to experimental recordings in classic sensory decision-making tasks, which will hopefully provide new insights into the nature of perceptual integration.

As time goes by: Oxytocin influences the subjective perception of time in a social context.

Science.gov (United States)

Colonnello, Valentina; Domes, Gregor; Heinrichs, Markus

2016-06-01

Time perception depends on an event's emotional relevance to the beholder; a subjective time dilation effect is associated with self-relevant, emotionally salient stimuli. Previous studies have revealed that oxytocin modulates the salience of social stimuli and attention to social cues. However, whether the oxytocin system is involved in human subjective time perception is unknown. The aim of the present study was to investigate whether increased oxytocin levels would induce a time dilation effect for self-relevant, positive social cues. In a double-blind, placebo-controlled, between-subject design, heterosexual men were administered intranasal oxytocin or placebo. After about 50min, participants completed a time-bisection task in which they estimated lengths of exposure to happy female faces (self-relevant positive stimuli, based on sexual orientation), emotionally neutral and negative female faces (control), and happy, neutral, and negative male faces (control). Oxytocin induced a subjective time dilation effect for happy female faces and a time compression effect for happy male faces. Our results provide evidence that oxytocin influences time perception, a primary form of human subjectivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modelling travel time perception in transport mode choices

NARCIS (Netherlands)

Varotto, S.F.; Glerum, A.; Stathopoulos, A.; Bierlaire, M.; Longo, G.

2015-01-01

Travel behaviour models typically rely on data afflicted by errors, in perception (e.g., over/under-estimation by traveller) and measurement (e.g., software or researcher imputation error). Such errors are shown to have a relevant impact on model outputs. So far a comprehensive framework to deal

The influence of social stress on time perception and psychophysiological reactivity.

Science.gov (United States)

van Hedger, Kathryne; Necka, Elizabeth A; Barakzai, Anam K; Norman, Greg J

2017-05-01

Time perception is a fundamental component of everyday life. Although time can be measured using standard units, the relationship between an individual's experience of perceived time and a standard unit is highly sensitive to context. Stressful and threatening stimuli have been previously shown to produce time distortion effects, such that individuals perceive the stimuli as lasting for different amounts of time as compared to a standard unit. As a highly social species, humans are acutely sensitive to social stressors; however, time distortion effects have not been studied in the context of social stress. We collected psychophysiological (electrocardiogram and impedance cardiography) and time perception data before, during, and after a modified version of the Trier Social Stress Test for 42 participants. Based on prior theories and evidence from the time perception literature, we hypothesized that experiencing a stressful event would result in time distortion. This hypothesis was supported by the data, with individuals on average reproducing short and long duration negative and positive stimuli as lasting longer after experiencing social stress, t(41) = -3.55, p = .001, and t(41) = -4.12, p social stress. These findings are in line with some other studies of time distortion, and provide evidence for the interoceptive salience model of time perception. Implications for mechanisms of time distortion are discussed. © 2017 Society for Psychophysiological Research.

77 FR 7244 - Agency Information Collection (Supplier Perception Survey) Activity Under OMB Review

Science.gov (United States)

2012-02-10

... Perception Survey) Activity Under OMB Review AGENCY: Office of Acquisition, Logistics and Construction... Veterans Affairs Supplier Perception Survey. OMB Control Number: 2900-2900-0751. Type of Review: Extension... and logistics operations across VA enterprise. An agency may not conduct or sponsor, and a person is...

75 FR 1119 - Agency Information Collection (Supplier Perception Survey) Activity Under OMB Review

Science.gov (United States)

2010-01-08

... (Supplier Perception Survey) Activity Under OMB Review AGENCY: Office of Acquisition, Logistics and...).'' SUPPLEMENTARY INFORMATION: Title: Department of Veterans Affairs Supplier Perception Survey. OMB Control Number..., and a person is not required to respond to a collection of information unless it displays a currently...

Neural architecture underlying classification of face perception paradigms.

Science.gov (United States)

Laird, Angela R; Riedel, Michael C; Sutherland, Matthew T; Eickhoff, Simon B; Ray, Kimberly L; Uecker, Angela M; Fox, P Mickle; Turner, Jessica A; Fox, Peter T

2015-10-01

We present a novel strategy for deriving a classification system of functional neuroimaging paradigms that relies on hierarchical clustering of experiments archived in the BrainMap database. The goal of our proof-of-concept application was to examine the underlying neural architecture of the face perception literature from a meta-analytic perspective, as these studies include a wide range of tasks. Task-based results exhibiting similar activation patterns were grouped as similar, while tasks activating different brain networks were classified as functionally distinct. We identified four sub-classes of face tasks: (1) Visuospatial Attention and Visuomotor Coordination to Faces, (2) Perception and Recognition of Faces, (3) Social Processing and Episodic Recall of Faces, and (4) Face Naming and Lexical Retrieval. Interpretation of these sub-classes supports an extension of a well-known model of face perception to include a core system for visual analysis and extended systems for personal information, emotion, and salience processing. Overall, these results demonstrate that a large-scale data mining approach can inform the evolution of theoretical cognitive models by probing the range of behavioral manipulations across experimental tasks. Copyright © 2015 Elsevier Inc. All rights reserved.

Attention Switching during Scene Perception: How Goals Influence the Time Course of Eye Movements across Advertisements

Science.gov (United States)

Wedel, Michel; Pieters, Rik; Liechty, John

2008-01-01

Eye movements across advertisements express a temporal pattern of bursts of respectively relatively short and long saccades, and this pattern is systematically influenced by activated scene perception goals. This was revealed by a continuous-time hidden Markov model applied to eye movements of 220 participants exposed to 17 ads under a…

[Time perception, maternal tasks, and maternal role behavior among pregnant Japanese women].

Science.gov (United States)

Yamamoto, A

1996-01-01

The relationship of time perception, maternal tasks, and maternal role behavior was examined in 140 pregnant Japanese women with a short-term longitudinal design. A model developed by Rubin provided the conceptual framework for this research. The Time Perception Scale. Time Production Method, and the Prefatory Maternal Response measured the study variables. Study results revealed significant differences in duration of time, time production, maternal-fetal attachment, and maternal role behavior before and after quickening(fetal movement)occurred. Medium to strong positive relationships among time orientation, maternal-fetal attachment, gratification, and maternal role behavior were found before and after movement. After quickening, a weak relationship between time orientation and duration was found. After controlling maternal-fetal attachment and gratification in pregnancy and maternal role, orientation in time perception accounted for significant amounts of variance in maternal role behavior before and after fetal movement. Results show that the process of becoming a mother, which started before quickening, increased in magnitude after fetal movement. The function of fetal movement is important in developing motherhood. In the process of becoming a mother, cognitive, emotional, and behavioral aspects in becoming a mother are inseparable from each other. Future orientation of time perception contributes to development of maternal role behavior. Having a future orientation during pregnancy may indicate hope or positive expectation. Based on these findings, several recommendations were proposed: (a)to study further the general process of becoming a mother and the role of time perception in developing motherhood, (b)to disseminate information to the general public about the process in development of motherhood, (c)to construct theory to explain the process of becoming a mother, and(d)to conduct future research to clarify the construct of time perception and attachment.

A research on motion design for APP's loading pages based on time perception

Science.gov (United States)

Cao, Huai; Hu, Xiaoyun

2018-04-01

Due to restrictions caused by objective reasons like network bandwidth, hardware performance and etc., waiting is still an inevitable phenomenon that appears in our using mobile-terminal products. Relevant researches show that users' feelings in a waiting scenario can affect their evaluations on the whole product and services the product provides. With the development of user experience and inter-facial design subjects, the role of motion effect in the interface design has attracted more and more scholars' attention. In the current studies, the research theory of motion design in a waiting scenario is imperfect. This article will use the basic theory and experimental research methods of cognitive psychology to explore the motion design's impact on user's time perception when users are waiting for loading APP pages. Firstly, the article analyzes the factors that affect waiting experience of loading APP pages based on the theory of time perception, and then discusses motion design's impact on the level of time-perception when loading pages and its design strategy. Moreover, by the operation analysis of existing loading motion designs, the article classifies the existing loading motions and designs an experiment to verify the impact of different types of motions on the user's time perception. The result shows that the waiting time perception of mobile's terminals' APPs is related to the loading motion types, the combination type of loading motions can effectively shorten the waiting time perception as it scores a higher mean value in the length of time perception.

Time Slices: What Is the Duration of a Percept?

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Michael H Herzog

2016-04-01

Full Text Available We experience the world as a seamless stream of percepts. However, intriguing illusions and recent experiments suggest that the world is not continuously translated into conscious perception. Instead, perception seems to operate in a discrete manner, just like movies appear continuous although they consist of discrete images. To explain how the temporal resolution of human vision can be fast compared to sluggish conscious perception, we propose a novel conceptual framework in which features of objects, such as their color, are quasi-continuously and unconsciously analyzed with high temporal resolution. Like other features, temporal features, such as duration, are coded as quantitative labels. When unconscious processing is "completed," all features are simultaneously rendered conscious at discrete moments in time, sometimes even hundreds of milliseconds after stimuli were presented.

Children's GPS-determined versus self-reported transport in leisure time and associations with parental perceptions of the neighborhood environment

DEFF Research Database (Denmark)

Vanwolleghem, Griet; Schipperijn, Jasper; Gheysen, Freja

2016-01-01

measured transport in leisure time and filled out a diary to assess self-reported transport in leisure time. Parents completed a questionnaire to assess parental perceptions of the neighborhood environment. Pearson correlations and t-tests were used to test for concurrent validity and differences between...... GPS-determined and self-reported transport in leisure time. Generalized linear models were used to determine the associations between the parental perceptions of the neighborhood environment and GPS-determined transport in leisure time. RESULTS: Overall, children under-reported their walking......BACKGROUND: This study aimed to examine both GPS-determined and self-reported walking, cycling and passive transport in leisure time during week- and weekend-days among 10 to 12-year old children. Comparisons between GPS-determined and self-reported transport in leisure time were investigated...

Evaluation of thermal perception in schoolyards under Mediterranean climate conditions

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Antoniadis, D.; Katsoulas, N.; Papanastasiou, D.; Christidou, V.; Kittas, C.

2016-03-01

The aim of this paper was to study qualitatively and quantitatively the thermal perception and corresponding heat stress conditions that prevail in two schoolyards in a coastal city in central Greece. For this purpose, meteorological parameters (i.e., wind speed, temperature, relative humidity, solar radiation) were recorded at 70 and 55 measuring points in the schoolyards, from 14:00 to 15:30 local time, during May and June of 2011. The measuring points were distributed so as to get measurements at points (a) directly exposed to the sun, (b) under the shadow of trees and building structures, and (c) near building structures. Cluster analysis was applied to group observations and revealed places that are microclimatically homogeneous. Thermal perception and heat stress conditions were assessed by means of the physiologically equivalent temperature (PET, °C), and the results are presented in relevant charts. The impact of material's albedo, radiation's reflection by structures and obstacles, and different tree species on thermal perception and heat stress conditions was also assessed. The analysis showed that trees triggered a reduction of incident solar radiation that ranged between 79 and 94 % depending on tree's species, crown dimension, tree height, and leaf area. PET values were mainly affected by solar radiation and wind speed. Trees caused a reduction of up to 37 % in PET values, while a 1-m s-1 increase in wind speed triggered a reduction of 3.7-5.0 °C in PET value. The effective shading area in the two schoolyards was small, being 27.5 and 11 %. The results of this study could be exploited by urban planning managers when designing or improving the outdoor environment of a school complex.

Time-constrained mother and expanding market: emerging model of under-nutrition in India

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S. Chaturvedi

2016-07-01

Full Text Available Abstract Background Persistent high levels of under-nutrition in India despite economic growth continue to challenge political leadership and policy makers at the highest level. The present inductive enquiry was conducted to map the perceptions of mothers and other key stakeholders, to identify emerging drivers of childhood under-nutrition. Methods We conducted a multi-centric qualitative investigation in six empowered action group states of India. The study sample included 509 in-depth interviews with mothers of undernourished and normal nourished children, policy makers, district level managers, implementer and facilitators. Sixty six focus group discussions and 72 non-formal interactions were conducted in two rounds with primary caretakers of undernourished children, Anganwadi Workers and Auxiliary Nurse Midwives. Results Based on the perceptions of the mothers and other key stakeholders, a model evolved inductively showing core themes as drivers of under-nutrition. The most forceful emerging themes were: multitasking, time constrained mother with dwindling family support; fragile food security or seasonal food paucity; child targeted market with wide availability and consumption of ready-to-eat market food items; rising non-food expenditure, in the context of rising food prices; inadequate and inappropriate feeding; delayed recognition of under-nutrition and delayed care seeking; and inadequate responsiveness of health care system and Integrated Child Development Services (ICDS. The study emphasized that the persistence of child malnutrition in India is also tied closely to the high workload and consequent time constraint of mothers who are increasingly pursuing income generating activities and enrolled in paid labour force, without robust institutional support for childcare. Conclusion The emerging framework needs to be further tested through mixed and multiple method research approaches to quantify the contribution of time limitation of

Localization of Human Cortical Areas Underlying Glossiness Perception: An fMRI Study

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Yuichi Sakano

2011-05-01

Full Text Available We conducted two fMRI experiments to clarify what cortical areas are involved in perception of surface glossiness. To dissociate activations caused by glossiness from those caused by low-level features such as luminance and luminance contrast of the stimulus, we utilized the perceptual glossiness constancy (Experiment 1 and the selective attention technique (Experiment 2. In Experiment 1, subjects viewed glossy or matte objects under bright or dim illumination. The mean luminance and luminance RMS contrast of glossy objects under dim illumination were lower than those of matte objects under bright illumination. Thus, if certain areas are more activated by the former stimulus than the latter, the activation differences can be explained by the differences in surface glossiness but not by the differences in mean luminance or luminance RMS contrast of the stimulus. In Experiment 2, subjects judged whether the paired objects were the same or different in terms of glossiness, 3D form, or 3D orientation. If certain areas are more activated during the glossiness discrimination task than the other two tasks, it is suggested that the areas are involved in glossiness perception. Common areas identified as those involved in glossiness perception in both experiments are bilateral ventral occipital areas.

Academic Workload and Working Time: Retrospective Perceptions versus Time-Series Data

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Kyvik, Svein

2013-01-01

The purpose of this article is to examine the validity of perceptions by academic staff about their past and present workload and working hours. Retrospective assessments are compared with time-series data. The data are drawn from four mail surveys among academic staff in Norwegian universities undertaken in the period 1982-2008. The findings show…

Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research

OpenAIRE

Harper, Liam D.; Fothergill, Melissa; West, Daniel J.; Stevenson, Emma; Russell, Mark

2016-01-01

Qualitative research investigating soccer practitioners’ perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time reg...

Face processing pattern under top-down perception: a functional MRI study

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Li, Jun; Liang, Jimin; Tian, Jie; Liu, Jiangang; Zhao, Jizheng; Zhang, Hui; Shi, Guangming

2009-02-01

Although top-down perceptual process plays an important role in face processing, its neural substrate is still puzzling because the top-down stream is extracted difficultly from the activation pattern associated with contamination caused by bottom-up face perception input. In the present study, a novel paradigm of instructing participants to detect faces from pure noise images is employed, which could efficiently eliminate the interference of bottom-up face perception in topdown face processing. Analyzing the map of functional connectivity with right FFA analyzed by conventional Pearson's correlation, a possible face processing pattern induced by top-down perception can be obtained. Apart from the brain areas of bilateral fusiform gyrus (FG), left inferior occipital gyrus (IOG) and left superior temporal sulcus (STS), which are consistent with a core system in the distributed cortical network for face perception, activation induced by top-down face processing is also found in these regions that include the anterior cingulate gyrus (ACC), right oribitofrontal cortex (OFC), left precuneus, right parahippocampal cortex, left dorsolateral prefrontal cortex (DLPFC), right frontal pole, bilateral premotor cortex, left inferior parietal cortex and bilateral thalamus. The results indicate that making-decision, attention, episodic memory retrieving and contextual associative processing network cooperate with general face processing regions to process face information under top-down perception.

Nurses' perception of time availability in patient communication in Hong Kong.

Science.gov (United States)

Chan, Engle A; Jones, Aled; Fung, Sylvia; Wu, Sui Chu

2012-04-01

To explore nurses' perceptions of their patient communication in practice and to identify their ways of communicating. Nurse theorists and clinicians are aware of the importance of nurse-patient communication in providing patient-centred care. However, barriers remain that prevent nurses from implementing quality/effective communication, and time is often viewed as a critical variable. Continuous emphasis on efficiency contravenes patient-centred care, warranting a re-examination of nurses' perception of time in nurse-patient communication. Focus group interviews were adopted. Thirty-nine registered nurses participated. Interviews were tape-recorded, transcribed and translated, and data were analysed using thematic analysis to identify codes, categories and themes/patterns. Three themes were identified regarding nurses' perception of communication with time: (1) Patterns of communication. (2) Routine scheduled communication vs. meeting individuals' needs. (3) Saving time through communication. Patterns of communication, based on participants' criteria such as the purpose, who initiated it, the nature of communication, expectation to perform, therapeutic value and relation with time were explicated. By integrating communication into routines as intended actions, nurses demonstrate that communication and relationship building with patients take no extra time. Good communication and good relationships help nurses save time. Nurses' communication behaviour is closely related to their perception of communication. This study suggests the need for a paradigm shift in thinking about communication as requiring time. Additionally, nurses should recognise the value of short, iterative interaction and chit-chat as quality communication for knowing their patients and providing patient-centred care. Nurses should think beyond time in the discourse of effective nurse-patient communication, as it often relates to manpower. An understanding of how nurses perceive their time

Time perception among the youth and its implication for industry: An exploratory study

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GG Rousseau

2004-04-01

Full Text Available The main objective of this exploratory study was to investigate perceived cultural differences in the perception of time among the youth and its implications for time management and productivity regarding future employment in industry. The study further sought to develop a reliable instrument for measuring time perception across cultures.  A non-probability convenience sample (N=467 was drawn from English, Afrikaans and Xhosa speaking respondents, aged 13 to 18 years.  Results confirmed four factors: time allocation, time economy, time attitudes and scheduling of tasks.  Significant differences between age, language and gender groups on time perception were observed.  These findings have implications for time management training among the youth as well as for industry seeking employees who can perform tasks with speed and efficiency.  Further refinement of the instrument in follow-up studies is essential.

Perceptions of work-time and leisure-time among managers and field staff in a UK primary health care trust.

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Brown, Reva Berman; Adebayo, Shirley A

2004-09-01

The aims of the research were to explore the issues around the perception of District Nurses in an inner London Primary Health Care Trust of their use of work-time and leisure-time, and to reveal how the boundaries between these two aspects can become blurred and impinge on each other. Time use is helpful in considerations of wider issues such as satisfaction at work and work-life balance. The data were collected by a questionnaire to seek the views of managers and field staff on issues such as the impact on the quality of patient care of the nurses' perception of work-time and leisure-time. The research identified the different perception of "work-time" that employees have in relation to their place within the hierarchical structure. The findings answered the question of whether time is perceived differently, dependent on one's occupation within the Trust.

Changes in risk perception over time

International Nuclear Information System (INIS)

Gomez, L.S.; Jenkins-Smith, H.C.; Miller, K.W.

1992-01-01

The focus of this paper is on changes in perceptions of the risks associated with nuclear waste management over time. In particular, we are interested in the kinds of change that take place when the management programs, and those who are charged with implementing them, are subject to intensive public debate over an extended period of time. We are undertaken an over-time study of perceived risks in Colorado and New Mexico by implementing sequential random household surveys in each state, timed at six month intervals. This study employs three of these surveys, spanning the period from summer, 1990 to summer, 1991. Using these data, we examine the dynamics that may underlie variations in perceived risks over time. In particular, our analysis is focused on changes in the roles played by (1) basic political orientations (i.e. political ideology) and (2) trust in those who advocate conflicting policy positions

A general theory of intertemporal decision-making and the perception of time

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Vijay Mohan eK Namboodiri

2014-02-01

Full Text Available Animals and humans make decisions based on their expected outcomes. Since relevant outcomes are often delayed, perceiving delays and choosing between earlier versus later rewards (intertemporal decision-making is an essential component of animal behavior. The myriad observations made in experiments studying intertemporal decision-making and time perception have not yet been rationalized within a single theory. Here we present a theory—Training-Integrated Maximized Estimation of Reinforcement Rate (TIMERR—that explains a wide variety of behavioral observations made in intertemporal decision-making and the perception of time. Our theory postulates that animals make intertemporal choices to optimize expected reward rates over a limited temporal window which includes a past integration interval—over which experienced reward rate is estimated—as well as the expected delay to future reward. Using this theory, we derive mathematical expressions for both the subjective value of a delayed reward and the subjective representation of the delay. A unique contribution of our work is in finding that the past integration interval directly determines the steepness of temporal discounting and the nonlinearity of time perception. In so doing, our theory provides a single framework to understand both intertemporal decision-making and time perception.

A general theory of intertemporal decision-making and the perception of time.

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Namboodiri, Vijay M K; Mihalas, Stefan; Marton, Tanya M; Hussain Shuler, Marshall G

2014-01-01

Animals and humans make decisions based on their expected outcomes. Since relevant outcomes are often delayed, perceiving delays and choosing between earlier vs. later rewards (intertemporal decision-making) is an essential component of animal behavior. The myriad observations made in experiments studying intertemporal decision-making and time perception have not yet been rationalized within a single theory. Here we present a theory-Training-Integrated Maximized Estimation of Reinforcement Rate (TIMERR)-that explains a wide variety of behavioral observations made in intertemporal decision-making and the perception of time. Our theory postulates that animals make intertemporal choices to optimize expected reward rates over a limited temporal window which includes a past integration interval-over which experienced reward rate is estimated-as well as the expected delay to future reward. Using this theory, we derive mathematical expressions for both the subjective value of a delayed reward and the subjective representation of the delay. A unique contribution of our work is in finding that the past integration interval directly determines the steepness of temporal discounting and the non-linearity of time perception. In so doing, our theory provides a single framework to understand both intertemporal decision-making and time perception.

Career Expectations and Perceptions of Part-Time MBA Students

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Fish, Lynn A.; Fish, Lauren A.

2010-01-01

In the U.S., part-time MBA students regard work/life balance as the critical factor that drives career expectations and perceptions. Job aspects and benefits/compensation closely follow in importance, while employee relations are valued less. Within work/life balance, students value job location, travel time, and telecommuting. Promotional…

Why do unusual novel foods like insects lack sensory appeal? Investigating the underlying sensory perceptions

NARCIS (Netherlands)

Tan Hui Shan, Grace; Tibboel, Claudia Joyce; Stieger, Markus

2017-01-01

Unusual novel foods like insects generally hold little sensory appeal for consumers, but little is known about the underlying sensory perceptions and how the properties of the food contribute to acceptance. This study examined the sensory perceptions of 3 unusual novel foods (lamb brain, frog

Values underlying perceptions of breach of the psychological contract

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Leon Botha

2010-10-01

Research purpose: The study identifies the most important breaches and investigates which values underlie employee perceptions of breach of the psychological contract. It also addresses values that lead to employees interpreting incidents as breaches. Motivation for the study: The study calls on the fact that employees make inconsequential contributions to the terms of many formal employment contracts may imply that such contracts cannot be viewed as documents between equals. Research design, approach and method: The study identifies the most prominent breaches of the psychological contract and the values underlying the perceptions that violations have occurred. Main findings: The data revealed lack of promotion, poor interpersonal relations between colleagues and bad treatment by seniors as three main breaches of the contract, and social recognition, world of peace and sense of accomplishment as three dominant values that underlie perceptions of contract violation. Practical/managerial implications: The competent and intelligent manner in which lack of promotion is handled and communicated to employees is vital because it has implications for their willingness to contribute, their career prospects and their intention to stay in the organisation. Contribution/value-add: This research can serve as the basis for the development of survey or research instruments that are appropriate and relevant to the population.

Speech perception under adverse conditions: Insights from behavioral, computational and neuroscience research

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Sara eGuediche

2014-01-01

Full Text Available Adult speech perception reflects the long-term regularities of the native language, but it is also flexible such that it accommodates and adapts to adverse listening conditions and short-term deviations from native-language norms. The purpose of this review article is to examine how the broader neuroscience literature can inform and advance research efforts in understanding the neural basis of flexibility and adaptive plasticity in speech perception. In particular, we consider several domains of neuroscience research that offer insight into how perception can be adaptively tuned to short-term deviations while also maintaining without affecting the long-term learned regularities for mapping sensory input. We review several literatures to highlight the potential role of learning algorithms that rely on prediction error signals and discuss specific neural structures that are likely to contribute to such learning. Already, a few studies have alluded to a potential role of these mechanisms in adaptive plasticity in speech perception. Better understanding the application and limitations of these algorithms for the challenges of flexible speech perception under adverse conditions promises to inform theoretical models of speech.

Gender differences in emotion experience perception under different facial muscle manipulations.

Science.gov (United States)

Wang, Yufeng; Zhang, Dongjun; Zou, Feng; Li, Hao; Luo, Yanyan; Zhang, Meng; Liu, Yijun

2016-04-01

According to embodied emotion theory, facial manipulations should modulate and initiate particular emotions. However, whether there are gender differences in emotion experience perception under different facial muscle manipulations is not clear. Therefore, we conducted two behavioral experiments to examine gender differences in emotional perception in response to facial expressions (sad, neutral, and happy) under three conditions: (1) holding a pen using only the teeth (HPT), which facilitates the muscles typically associated with smiling; (2) holding a pen using only the lips (HPL), which inhibits the muscles typically associated with smiling; and (3) a control condition--hold no pen (HNP). We found that HPT made the emotional feelings more positive, and that the change degree of female's ratings of sad facial expressions between conditions (HPL to HPT) was larger than males'. These results suggested cognition can be affected by the interaction of the stimuli and the body, especially the female. Copyright © 2016 Elsevier Inc. All rights reserved.

The hunt for the perfect discounting function and a reckoning of time perception.

Science.gov (United States)

Namboodiri, Vijay Mk; Hussain Shuler, Marshall G

2016-10-01

Making decisions that factor the cost of time is fundamental to survival. Yet, while it is readily appreciated that our perception of time is intimately involved in this process, theories regarding intertemporal decision-making and theories regarding time perception are treated, largely, independently. Even within these respective domains, models providing good fits to data fail to provide insight as to why, from a normative sense, those fits should take their apparent form. Conversely, normative models that proffer a rationalization for why an agent should weigh options in a particular way, or to perceive time in a particular way, fail to account for the full body of well-established experimental evidence. Here we review select, yet key advances in our understanding, identifying conceptual breakthroughs in the fields of intertemporal decision-making and in time perception, as well as their limits and failings in the face of hard-won experimental observation. On this background of accrued knowledge, a new conception unifying the domains of decision-making and time perception is put forward (Training-Integrated Maximization of Reinforcement Rate, TIMERR) to provide a better fit to observations and a more parsimonious reckoning of why we make choices, and thereby perceive time, the way we do. Copyright © 2016 Elsevier Ltd. All rights reserved.

Affective state influences perception by affecting decision parameters underlying bias and sensitivity.

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Lynn, Spencer K; Zhang, Xuan; Barrett, Lisa Feldman

2012-08-01

Studies of the effect of affect on perception often show consistent directional effects of a person's affective state on perception. Unpleasant emotions have been associated with a "locally focused" style of stimulus evaluation, and positive emotions with a "globally focused" style. Typically, however, studies of affect and perception have not been conducted under the conditions of perceptual uncertainty and behavioral risk inherent to perceptual judgments outside the laboratory. We investigated the influence of perceivers' experienced affect (valence and arousal) on the utility of social threat perception by combining signal detection theory and behavioral economics. We compared 3 perceptual decision environments that systematically differed with respect to factors that underlie uncertainty and risk: the base rate of threat, the costs of incorrect identification threat, and the perceptual similarity of threats and nonthreats. We found that no single affective state yielded the best performance on the threat perception task across the 3 environments. Unpleasant valence promoted calibration of response bias to base rate and costs, high arousal promoted calibration of perceptual sensitivity to perceptual similarity, and low arousal was associated with an optimal adjustment of bias to sensitivity. However, the strength of these associations was conditional upon the difficulty of attaining optimal bias and high sensitivity, such that the effect of the perceiver's affective state on perception differed with the cause and/or level of uncertainty and risk.

Time perception, impulsivity, emotionality, and personality in self-harming borderline personality disorder patients.

Science.gov (United States)

Berlin, Heather A; Rolls, Edmund T

2004-08-01

To investigate how time perception may contribute to the symptoms of self-harming Borderline Personality Disorder (BPD) patients, 19 self-harming BPD inpatients and 39 normal controls were given measures of time perception, impulsivity, personality, emotion, and BPD characteristics. A test sensitive to orbitofrontal cortex (OFC) function ("Frontal" Behavior Questionnaire) was also administered, as the OFC has been associated with impulsivity and time perception. BPD patients produced less time than controls, and this correlated with impulsiveness and other characteristics commonly associated with BPD. BPD patients were also less conscientious, extraverted, and open to experience, as well as more impulsive (self-report and behaviorally), emotional, neurotic, and reported more BPD characteristics, compared to controls. The results suggest that some of these core characteristics of BPD may be on a continuum with the normal population and, impulsivity in particular, may be related to time perception deficits (i.e., a faster subjective sense of time). Finally, BPD patients scored higher on the Frontal Behavior Questionnaire, suggesting that some symptoms of the BPD syndrome may be related to problems associated with the OFC. A control spatial working memory task (SWM) revealed that SWM deficits could not explain any of the BPD patients' poor performance. While impulsivity was correlated with time perception across all participants, emotionality, introversion, and lack of openness to experience were not. This suggests that different symptoms of the borderline personality syndrome may be separable, and therefore, related to different cognitive deficits, and potentially to different brain systems. This may have important implications for treatment strategies for BPD.

Time Perception and the Experience of Time When Immersed in an Altered Sensory Environment.

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Glicksohn, Joseph; Berkovich-Ohana, Aviva; Mauro, Federica; Ben-Soussan, Tal D

2017-01-01

The notion that exposure to a monotonous sensory environment could elicit reports indicating aberrant subjective experience and altered time perception is the impetus for the present report. Research has looked at the influence of exposure to such environments on time perception, reporting that the greater the environmental variation, the shorter is the time estimation obtained by the method of production. Most conditions for creating an altered sensory environment, however, have not facilitated an immersive experience, one that directly impacts both time perception and subjective experience. In this study, we invited our participants to enter a whole-body altered sensory environment for a 20-min session, wherein they were asked to relax without falling asleep. The session included white-colored illumination of the chamber with eyes closed (5 min), followed by 10 min of illuminating the room with color, after which a short report of subjective experience was collected using a brief questionnaire; this was followed by an additional 5 min of immersion in white light with closed eyes. The participants were then interviewed regarding their subjective experience, including their experience of time within the chamber. Prior to entering the chamber, the participants completed a time-production (TP) task. One group of participants then repeated the task within the chamber, at the end of the session; a second group of participants repeated the task after exiting the chamber. We shall report on changes in TP, and present data indicating that when produced time is plotted as a function of target duration, using a log-log plot, the major influence of sensory environment is on the intercept of the psychophysical function. We shall further present data indicating that for those participants reporting a marked change in time experience, such as "the sensation of time disappeared," their TP data could not be linearized using a log-log plot, hence indicating that for these

Time Perception and the Experience of Time When Immersed in an Altered Sensory Environment

Directory of Open Access Journals (Sweden)

Joseph Glicksohn

2017-10-01

Full Text Available The notion that exposure to a monotonous sensory environment could elicit reports indicating aberrant subjective experience and altered time perception is the impetus for the present report. Research has looked at the influence of exposure to such environments on time perception, reporting that the greater the environmental variation, the shorter is the time estimation obtained by the method of production. Most conditions for creating an altered sensory environment, however, have not facilitated an immersive experience, one that directly impacts both time perception and subjective experience. In this study, we invited our participants to enter a whole-body altered sensory environment for a 20-min session, wherein they were asked to relax without falling asleep. The session included white-colored illumination of the chamber with eyes closed (5 min, followed by 10 min of illuminating the room with color, after which a short report of subjective experience was collected using a brief questionnaire; this was followed by an additional 5 min of immersion in white light with closed eyes. The participants were then interviewed regarding their subjective experience, including their experience of time within the chamber. Prior to entering the chamber, the participants completed a time-production (TP task. One group of participants then repeated the task within the chamber, at the end of the session; a second group of participants repeated the task after exiting the chamber. We shall report on changes in TP, and present data indicating that when produced time is plotted as a function of target duration, using a log–log plot, the major influence of sensory environment is on the intercept of the psychophysical function. We shall further present data indicating that for those participants reporting a marked change in time experience, such as “the sensation of time disappeared,” their TP data could not be linearized using a log–log plot, hence

When Time Flies: How Abstract and Concrete Mental Construal Affect the Perception of Time

Science.gov (United States)

Hansen, Jochim; Trope, Yaacov

2013-01-01

Time is experienced as passing more quickly the more changes happen in a situation. The present research tested the idea that time perception depends on the level of construal of the situation. Building on previous research showing that concrete rather than abstract mental construal causes people to perceive more variations in a given situation,…

Time Spent, Workload, and Student and Faculty Perceptions in a Blended Learning Environment

Science.gov (United States)

Schumacher, Christie; Arif, Sally

2016-01-01

Objective. To evaluate student perception and time spent on asynchronous online lectures in a blended learning environment (BLE) and to assess faculty workload and perception. Methods. Students (n=427) time spent viewing online lectures was measured in three courses. Students and faculty members completed a survey to assess perceptions of a BLE. Faculty members recorded time spent creating BLEs. Results. Total time spent in the BLE was less than the allocated time for two of the three courses by 3-15%. Students preferred online lectures for their flexibility, students’ ability to apply information learned, and congruence with their learning styles. Faculty members reported the BLE facilitated higher levels of learning during class sessions but noted an increase in workload. Conclusion. A BLE increased faculty workload but was well received by students. Time spent viewing online lectures was less than what was allocated in two of the three courses. PMID:27667839

Investigating Gender Differences under Time Pressure in Financial Risk Taking.

Science.gov (United States)

Xie, Zhixin; Page, Lionel; Hardy, Ben

2017-01-01

There is a significant gender imbalance on financial trading floors. This motivated us to investigate gender differences in financial risk taking under pressure. We used a well-established approach from behavior economics to analyze a series of risky monetary choices by male and female participants with and without time pressure. We also used second to fourth digit ratio (2D:4D) and face width-to-height ratio (fWHR) as correlates of pre-natal exposure to testosterone. We constructed a structural model and estimated the participants' risk attitudes and probability perceptions via maximum likelihood estimation under both expected utility (EU) and rank-dependent utility (RDU) models. In line with existing research, we found that male participants are less risk averse and that the gender gap in risk attitudes increases under moderate time pressure. We found that female participants with lower 2D:4D ratios and higher fWHR are less risk averse in RDU estimates. Males with lower 2D:4D ratios were less risk averse in EU estimations, but more risk averse using RDU estimates. We also observe that men whose ratios indicate a greater prenatal exposure to testosterone exhibit a greater optimism and overestimation of small probabilities of success.

First-time mothers' breast-feeding maintenance: role of experiences and changes in maternal perceptions.

Science.gov (United States)

Schafer, Ellen J; Campo, Shelly; Colaizy, Tarah T; Mulder, Pamela J; Breheny, Patrick; Ashida, Sato

2017-12-01

Breast-feeding initiation rates have increased in the USA; however, maintenance of breast-feeding for recommended durations is low. The objective of the present study was to identify factors that may facilitate breast-feeding for longer durations among first-time mothers, including physiological and social experiences and changes in maternal perceptions. Survival analysis and linear regression methods were used to explore the relationship between experiences and breast-feeding duration, and the possible mediating effect of changes in maternal perceptions. Secondary data from the Infant Feeding Practices Study II, conducted in the USA between 2005 and 2007. Data from 762 first-time mothers who ever breast-fed were analysed. Experiencing trouble with baby's latch, problems with milk flow/supply and painful breast-feeding were significantly associated with breast-feeding duration (64, 26 and 36 % shorter duration, respectively). Meanwhile, positive changes in perception with respect to breast-feeding self-efficacy, opinion about infant feeding and belief about breast milk were associated with 16-27 % longer duration. Furthermore, changes in perception were observed to partially mediate the impact of physiological experiences on breast-feeding duration. Perceptions of breast-feeding self-efficacy, beliefs and opinions can change over time and are influenced by breast-feeding experiences. The combined effect of experience and perception plays a key role in influencing breast-feeding duration. Future research should explore interventions to maintain or improve these perceptions while accounting for physiological experiences to support breast-feeding for recommended durations among first-time mothers.

Timing in audiovisual speech perception: A mini review and new psychophysical data.

Science.gov (United States)

Venezia, Jonathan H; Thurman, Steven M; Matchin, William; George, Sahara E; Hickok, Gregory

2016-02-01

Recent influential models of audiovisual speech perception suggest that visual speech aids perception by generating predictions about the identity of upcoming speech sounds. These models place stock in the assumption that visual speech leads auditory speech in time. However, it is unclear whether and to what extent temporally-leading visual speech information contributes to perception. Previous studies exploring audiovisual-speech timing have relied upon psychophysical procedures that require artificial manipulation of cross-modal alignment or stimulus duration. We introduce a classification procedure that tracks perceptually relevant visual speech information in time without requiring such manipulations. Participants were shown videos of a McGurk syllable (auditory /apa/ + visual /aka/ = perceptual /ata/) and asked to perform phoneme identification (/apa/ yes-no). The mouth region of the visual stimulus was overlaid with a dynamic transparency mask that obscured visual speech in some frames but not others randomly across trials. Variability in participants' responses (~35 % identification of /apa/ compared to ~5 % in the absence of the masker) served as the basis for classification analysis. The outcome was a high resolution spatiotemporal map of perceptually relevant visual features. We produced these maps for McGurk stimuli at different audiovisual temporal offsets (natural timing, 50-ms visual lead, and 100-ms visual lead). Briefly, temporally-leading (~130 ms) visual information did influence auditory perception. Moreover, several visual features influenced perception of a single speech sound, with the relative influence of each feature depending on both its temporal relation to the auditory signal and its informational content.

Timing in Audiovisual Speech Perception: A Mini Review and New Psychophysical Data

Science.gov (United States)

Venezia, Jonathan H.; Thurman, Steven M.; Matchin, William; George, Sahara E.; Hickok, Gregory

2015-01-01

Recent influential models of audiovisual speech perception suggest that visual speech aids perception by generating predictions about the identity of upcoming speech sounds. These models place stock in the assumption that visual speech leads auditory speech in time. However, it is unclear whether and to what extent temporally-leading visual speech information contributes to perception. Previous studies exploring audiovisual-speech timing have relied upon psychophysical procedures that require artificial manipulation of cross-modal alignment or stimulus duration. We introduce a classification procedure that tracks perceptually-relevant visual speech information in time without requiring such manipulations. Participants were shown videos of a McGurk syllable (auditory /apa/ + visual /aka/ = perceptual /ata/) and asked to perform phoneme identification (/apa/ yes-no). The mouth region of the visual stimulus was overlaid with a dynamic transparency mask that obscured visual speech in some frames but not others randomly across trials. Variability in participants' responses (∼35% identification of /apa/ compared to ∼5% in the absence of the masker) served as the basis for classification analysis. The outcome was a high resolution spatiotemporal map of perceptually-relevant visual features. We produced these maps for McGurk stimuli at different audiovisual temporal offsets (natural timing, 50-ms visual lead, and 100-ms visual lead). Briefly, temporally-leading (∼130 ms) visual information did influence auditory perception. Moreover, several visual features influenced perception of a single speech sound, with the relative influence of each feature depending on both its temporal relation to the auditory signal and its informational content. PMID:26669309

A neuroeconomic theory of rational addiction and nonlinear time-perception.

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Takahashi, Taiki

2011-01-01

Neuroeconomic conditions for "rational addiction" (Becker & Murphy 1988) have been unknown. This paper derived the conditions for "rational addiction" by utilizing a nonlinear time-perception theory of "hyperbolic" discounting, which is mathematically equivalent to the q-exponential intertemporal choice model based on Tsallis' statistics. It is shown that (i) Arrow-Pratt measure for temporal cognition corresponds to the degree of irrationality (i.e., Prelec's "decreasing impatience" parameter of temporal discounting) and (ii) rationality in addicts is controlled by a nondimensionalization parameter of the logarithmic time-perception function. Furthermore, the present theory illustrates the possibility that addictive drugs increase impulsivity via dopaminergic neuroadaptation without increasing irrationality. Future directions in the application of the model to studies in neuroeconomics are discussed.

Self-motion perception: assessment by real-time computer-generated animations

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Parker, D. E.; Phillips, J. O.

2001-01-01

We report a new procedure for assessing complex self-motion perception. In three experiments, subjects manipulated a 6 degree-of-freedom magnetic-field tracker which controlled the motion of a virtual avatar so that its motion corresponded to the subjects' perceived self-motion. The real-time animation created by this procedure was stored using a virtual video recorder for subsequent analysis. Combined real and illusory self-motion and vestibulo-ocular reflex eye movements were evoked by cross-coupled angular accelerations produced by roll and pitch head movements during passive yaw rotation in a chair. Contrary to previous reports, illusory self-motion did not correspond to expectations based on semicircular canal stimulation. Illusory pitch head-motion directions were as predicted for only 37% of trials; whereas, slow-phase eye movements were in the predicted direction for 98% of the trials. The real-time computer-generated animations procedure permits use of naive, untrained subjects who lack a vocabulary for reporting motion perception and is applicable to basic self-motion perception studies, evaluation of motion simulators, assessment of balance disorders and so on.

Linguistic Means of Depersonalization and Dematerialization in the Descriptions of Subjective Perception of Time

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Ella V. Nesterik

2013-01-01

Full Text Available This article analyses linguistic means of depersonalization and dematerialization in the descriptions of subjective perception of time by characters, detects functions, fulfilled by them in such contexts. Subjective perception of time is considered as a text category and is studied in terms of text linguistics

Opposite Distortions in Interval Timing Perception for Visual and Auditory Stimuli with Temporal Modulations.

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Yuasa, Kenichi; Yotsumoto, Yuko

2015-01-01

When an object is presented visually and moves or flickers, the perception of its duration tends to be overestimated. Such an overestimation is called time dilation. Perceived time can also be distorted when a stimulus is presented aurally as an auditory flutter, but the mechanisms and their relationship to visual processing remains unclear. In the present study, we measured interval timing perception while modulating the temporal characteristics of visual and auditory stimuli, and investigated whether the interval times of visually and aurally presented objects shared a common mechanism. In these experiments, participants compared the durations of flickering or fluttering stimuli to standard stimuli, which were presented continuously. Perceived durations for auditory flutters were underestimated, while perceived durations of visual flickers were overestimated. When auditory flutters and visual flickers were presented simultaneously, these distortion effects were cancelled out. When auditory flutters were presented with a constantly presented visual stimulus, the interval timing perception of the visual stimulus was affected by the auditory flutters. These results indicate that interval timing perception is governed by independent mechanisms for visual and auditory processing, and that there are some interactions between the two processing systems.

The Influence of Odors on Time Perception

OpenAIRE

Millot, Jean-Louis; Laurent, Lucie; Casini, Laurence

2016-01-01

International audience; The effect of an olfactory stimulation on the perception of time was investigated through two different experiments based on temporal bisection tasks. In experiment 1, the durations to be classified as either short or long were centered on 400 ms while in Experiment 2 there were centered on 2000 ms. The participants were different in the two experiments (36 subjects in each one). In each experiment, half of the subjects learnt the anchor durations when smelling an unpl...

Exploring implicit dimensions underlying risk perception of waste from mining and milling of uranium ores in France

International Nuclear Information System (INIS)

Guillaume, B.; Charron, S.

2000-01-01

Understanding public perceptions of risks is increasingly considered to be important in order to make sound policy decisions. For many years, social scientists have been working to understand why the public is so concerned about nuclear energy and radioactive waste. Indeed, risk perception studies have essentially focused on high-level nuclear waste. As a result, there is now a fair understanding of what determines public support or opposition to high-level nuclear waste storage and disposal facilities. However, to date, little research has been conducted into radioactive waste from mining and milling of uranium ores. In France, such waste have a much debated legal status, which illustrates their ambiguous origin (natural versus artificial) and the manner people can perceive them. Therefore, it seems relevant to explore the individual judgements, attitudes and beliefs towards risk associated with uranium mill tailings. The present study provides a structural model based on both the identification and analysis of implicit dimensions underlying risk perception (psychological, cultural, moral...) applied to the case of french uranium mill tailings. One objective of the research has been to develop an interview grid based on this conceptual model in order to elicit social demand beyond public attitudes. Semi-structured interviews have been conducted on site in french uranium bearing areas. The relationships inferred between identified risk characteristics and contextual risk perceptions suggest that five majors thematics (time, space, nature, ethics and trust) build determinants of the public's perceptions of risk related to waste from mining and milling of uranium ores. (author)

No Correlation between Distorted Body Representations Underlying Tactile Distance Perception and Position Sense

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Matthew R. Longo

2016-11-01

Full Text Available Both tactile distance perception and position sense are believed to require that immediate afferent signals be referenced to a stored representation of body size and shape (the body model. For both of these abilities, recent studies have reported that the stored body representations involved are highly distorted, at least in the case of the hand, with the hand dorsum represented as wider and squatter than it actually is. Here, we investigated whether individual differences in the magnitude of these distortions are shared between tactile distance perception and position sense, as would be predicted by the hypothesis that a single distorted body model underlies both tasks. We used established task to measure distortions of the represented shape of the hand dorsum. Consistent with previous results, in both cases there were clear biases to overestimate distances oriented along the medio-lateral axis of the hand compared to the proximo-distal axis. Moreover, within each task there were clear split-half correlations, demonstrating that both tasks show consistent individual differences. Critically, however, there was no correlation between the magnitudes of distortion in the two tasks. This casts doubt on the proposal that a common body model underlies both tactile distance perception and position sense.

Perception is more than time delays

NARCIS (Netherlands)

Pala, O.; Rouwette, E.A.J.A.

2013-01-01

In this paper, we look at the way perceptions – a vital component of any decision-making process – are modeled in System Dynamics (SD) models. SD models include perceptions as a factor translating actual into observed conditions. System dynamicists assume that true conditions are not available to

A Perceptual Pathway to Bias: Interracial Exposure Reduces Abrupt Shifts in Real-Time Race Perception That Predict Mixed-Race Bias.

Science.gov (United States)

Freeman, Jonathan B; Pauker, Kristin; Sanchez, Diana T

2016-04-01

In two national samples, we examined the influence of interracial exposure in one's local environment on the dynamic process underlying race perception and its evaluative consequences. Using a mouse-tracking paradigm, we found in Study 1 that White individuals with low interracial exposure exhibited a unique effect of abrupt, unstable White-Black category shifting during real-time perception of mixed-race faces, consistent with predictions from a neural-dynamic model of social categorization and computational simulations. In Study 2, this shifting effect was replicated and shown to predict a trust bias against mixed-race individuals and to mediate the effect of low interracial exposure on that trust bias. Taken together, the findings demonstrate that interracial exposure shapes the dynamics through which racial categories activate and resolve during real-time perceptions, and these initial perceptual dynamics, in turn, may help drive evaluative biases against mixed-race individuals. Thus, lower-level perceptual aspects of encounters with racial ambiguity may serve as a foundation for mixed-race prejudice. © The Author(s) 2016.

Time, costs and farmers’ perceptions: The case of livestock service delivery in tamilnadu

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G kathiravan

2011-10-01

Full Text Available A study was undertaken in southern peninsular State of India, the Tamil Nadu State, (i to ascertain the time costs of animal health care and bovine breeding services, and (ii to comprehend the perceptions of farmers on the livestock services rendered by different service providers. The districts of the state were categorized as 'Livestock Developed' (LD and 'Livestock Under Developed' (LUD based on initial base line developed. Travel, waiting and service time were among the primary non-price factors that affected service quality. Average travel time was highest for visiting the public veterinary centre in both LUD (23.05 min. and LD (21.32 min. districts. Waiting time with regard to veterinarians providing home services in LUD districts was highest (23.01 min., followed by public veterinary centre services at LUD districts (22.35 min., home services by para-veterinarians (22.01 min. and public veterinary centre services at LD districts (20.10 min.. Both travel and waiting time were much higher in case of breeding services compared to curative services, which could be due to the fact that the farmers preferred Artificial Insemination (AI over its close substitute, the natural service. However, the service time was relatively less in case of insemination services vis-à-vis curative services both in LUD and LD districts. The quality perceptions of farmers on livestock services revealed that the home services rendered by veterinarians as the best one (0.83, followed by private veterinary clinics (0.75, home services by para-veterinarians (0.74, public veterinary centres (0.64 and co-operative veterinary centres (0.48. [Vet. World 2011; 4(5.000: 209-212

[Newborn children under phototherapy: the mother's perception].

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Campos, Antonia do Carmo Soares; Cardoso, Maria Vera Lúcia Moreira Leitão

2004-01-01

Since 1958, phototherapy has been used as a method to cure jaundice, which is still an important disease in newborn children. Supported by a phenomenological and qualitative approach, this study aims to investigate the mothers' perception of the phototherapy treatment their children are submitted to. Research subjects were ten mothers of newborns under phototherapy treatment at the Neonatological Hospitalization Unit of a public maternity in Fortaleza-CE, Brazil. Data were collected between May and July 2002. We used group meetings with the mothers as suggested by Carl Rogers. Discourse was organized into categories according to Bardin, which revealed themes that were analyzed in view of Paterson's and Zderad's humanistic nursing theory, as follows: mothers' knowledge on phototherapy and concerns about the treatment. We concluded that the analyzed mothers' major concern is related to the babies' vision.

Perception of CPR quality: Influence of CPR feedback, Just-in-Time CPR training and provider role.

Science.gov (United States)

Cheng, Adam; Overly, Frank; Kessler, David; Nadkarni, Vinay M; Lin, Yiqun; Doan, Quynh; Duff, Jonathan P; Tofil, Nancy M; Bhanji, Farhan; Adler, Mark; Charnovich, Alex; Hunt, Elizabeth A; Brown, Linda L

2015-02-01

Many healthcare providers rely on visual perception to guide cardiopulmonary resuscitation (CPR), but little is known about the accuracy of provider perceptions of CPR quality. We aimed to describe the difference between perceived versus measured CPR quality, and to determine the impact of provider role, real-time visual CPR feedback and Just-in-Time (JIT) CPR training on provider perceptions. We conducted secondary analyses of data collected from a prospective, multicenter, randomized trial of 324 healthcare providers who participated in a simulated cardiac arrest scenario between July 2012 and April 2014. Participants were randomized to one of four permutations of: JIT CPR training and real-time visual CPR feedback. We calculated the difference between perceived and measured quality of CPR and reported the proportion of subjects accurately estimating the quality of CPR within each study arm. Participants overestimated achieving adequate chest compression depth (mean difference range: 16.1-60.6%) and rate (range: 0.2-51%), and underestimated chest compression fraction (0.2-2.9%) across all arms. Compared to no intervention, the use of real-time feedback and JIT CPR training (alone or in combination) improved perception of depth (pCPR quality was poor for chest compression depth (0-13%), rate (5-46%) and chest compression fraction (60-63%). Perception of depth is more accurate in CPR providers versus team leaders (27.8% vs. 7.4%; p=0.043) when using real-time feedback. Healthcare providers' visual perception of CPR quality is poor. Perceptions of CPR depth are improved by using real-time visual feedback and with prior JIT CPR training. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Action and Perception Are Temporally Coupled by a Common Mechanism That Leads to a Timing Misperception

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Astefanoaei, Corina; Daye, Pierre M.; FitzGibbon, Edmond J.; Creanga, Dorina-Emilia; Rufa, Alessandra; Optican, Lance M.

2015-01-01

We move our eyes to explore the world, but visual areas determining where to look next (action) are different from those determining what we are seeing (perception). Whether, or how, action and perception are temporally coordinated is not known. The preparation time course of an action (e.g., a saccade) has been widely studied with the gap/overlap paradigm with temporal asynchronies (TA) between peripheral target onset and fixation point offset (gap, synchronous, or overlap). However, whether the subjects perceive the gap or overlap, and when they perceive it, has not been studied. We adapted the gap/overlap paradigm to study the temporal coupling of action and perception. Human subjects made saccades to targets with different TAs with respect to fixation point offset and reported whether they perceived the stimuli as separated by a gap or overlapped in time. Both saccadic and perceptual report reaction times changed in the same way as a function of TA. The TA dependencies of the time change for action and perception were very similar, suggesting a common neural substrate. Unexpectedly, in the perceptual task, subjects misperceived lights overlapping by less than ∼100 ms as separated in time (overlap seen as gap). We present an attention-perception model with a map of prominence in the superior colliculus that modulates the stimulus signal's effectiveness in the action and perception pathways. This common source of modulation determines how competition between stimuli is resolved, causes the TA dependence of action and perception to be the same, and causes the misperception. PMID:25632126

Perception of short time scale intervals in a hypnotic virtuoso

NARCIS (Netherlands)

Noreika, Valdas; Falter, Christine M.; Arstila, Valtteri; Wearden, John H.; Kallio, Sakari

2012-01-01

Previous studies showed that hypnotized individuals underestimate temporal intervals in the range of several seconds to tens of minutes. However, no previous work has investigated whether duration perception is equally disorderly when shorter time intervals are probed. In this study, duration

Spike Timing Matters in Novel Neuronal Code Involved in Vibrotactile Frequency Perception.

Science.gov (United States)

Birznieks, Ingvars; Vickery, Richard M

2017-05-22

Skin vibrations sensed by tactile receptors contribute significantly to the perception of object properties during tactile exploration [1-4] and to sensorimotor control during object manipulation [5]. Sustained low-frequency skin vibration (perception of frequency is still unknown. Measures based on mean spike rates of neurons in the primary somatosensory cortex are sufficient to explain performance in some frequency discrimination tasks [7-11]; however, there is emerging evidence that stimuli can be distinguished based also on temporal features of neural activity [12, 13]. Our study's advance is to demonstrate that temporal features are fundamental for vibrotactile frequency perception. Pulsatile mechanical stimuli were used to elicit specified temporal spike train patterns in tactile afferents, and subsequently psychophysical methods were employed to characterize human frequency perception. Remarkably, the most salient temporal feature determining vibrotactile frequency was not the underlying periodicity but, rather, the duration of the silent gap between successive bursts of neural activity. This burst gap code for frequency represents a previously unknown form of neural coding in the tactile sensory system, which parallels auditory pitch perception mechanisms based on purely temporal information where longer inter-pulse intervals receive higher perceptual weights than short intervals [14]. Our study also demonstrates that human perception of stimuli can be determined exclusively by temporal features of spike trains independent of the mean spike rate and without contribution from population response factors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Functional development of fronto-striato-parietal networks associated with time perception

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Anna eSmith

2011-11-01

Full Text Available Compared to our understanding of the functional maturation of executive functions, little is known about the neurofunctional development of perceptive functions. Time perception develops during late adolescence, underpinning many functions including motor and verbal processing, as well as late maturing higher order cognitive skills such as forward planning and future-related decision-making. Nothing, however, is known about the neurofunctional changes associated with time perception from childhood to adulthood. Using functional magnetic resonance imaging we explored the effects of age on the brain activation and functional connectivity of 32 male participants from 10 to 53 years of age during a time discrimination task that required the discrimination of temporal intervals of seconds differing by several hundred milliseconds. Increasing development was associated with progressive activation increases within left lateralised dorsolateral and inferior fronto-parieto-striato-thalamic brain regions. Furthermore, despite comparable task performance, adults showed increased functional connectivity between inferior/dorsolateral interhemispheric fronto-frontal activation as well as between inferior fronto-parietal regions compared with adolescents. Activation in caudate, specifically, was associated with both increasing age and better temporal discrimination. Progressive decreases in activation with age were observed in ventromedial prefrontal cortex, limbic regions and cerebellum. The findings demonstrate age-dependent developmentally dissociated neural networks for time discrimination. With increasing age there is progressive recruitment of later maturing left hemispheric and lateralised fronto-parieto-striato-thalamic networks, known to mediate time discrimination in adults, while earlier developing brain regions such as ventromedial prefrontal cortex, limbic and paralimbic areas and cerebellum subserve fine-temporal processing functions in children

State estimation bias induced by optimization under uncertainty and error cost asymmetry is likely reflected in perception.

Science.gov (United States)

Shimansky, Y P

2011-05-01

It is well known from numerous studies that perception can be significantly affected by intended action in many everyday situations, indicating that perception and related decision-making is not a simple, one-way sequence, but a complex iterative cognitive process. However, the underlying functional mechanisms are yet unclear. Based on an optimality approach, a quantitative computational model of one such mechanism has been developed in this study. It is assumed in the model that significant uncertainty about task-related parameters of the environment results in parameter estimation errors and an optimal control system should minimize the cost of such errors in terms of the optimality criterion. It is demonstrated that, if the cost of a parameter estimation error is significantly asymmetrical with respect to error direction, the tendency to minimize error cost creates a systematic deviation of the optimal parameter estimate from its maximum likelihood value. Consequently, optimization of parameter estimate and optimization of control action cannot be performed separately from each other under parameter uncertainty combined with asymmetry of estimation error cost, thus making the certainty equivalence principle non-applicable under those conditions. A hypothesis that not only the action, but also perception itself is biased by the above deviation of parameter estimate is supported by ample experimental evidence. The results provide important insights into the cognitive mechanisms of interaction between sensory perception and planning an action under realistic conditions. Implications for understanding related functional mechanisms of optimal control in the CNS are discussed.

Time perception impairment in early-to-moderate stages of Huntington's disease is related to memory deficits.

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Righi, Stefania; Galli, Luca; Paganini, Marco; Bertini, Elisabetta; Viggiano, Maria Pia; Piacentini, Silvia

2016-01-01

Huntington's disease (HD) primarily affects striatum and prefrontal dopaminergic circuits which are fundamental neural correlates of the timekeeping mechanism. The few studies on HD mainly investigated motor timing performance in second durations. The present work explored time perception in early-to-moderate symptomatic HD patients for seconds and milliseconds with the aim to clarify which component of the scalar expectancy theory (SET) is mainly responsible for HD timing defect. Eleven HD patients were compared to 11 controls employing two separate temporal bisection tasks in second and millisecond ranges. Our results revealed the same time perception deficits for seconds and milliseconds in HD patients. Time perception impairment in early-to-moderate stages of Huntington's disease is related to memory deficits. Furthermore, both the non-systematical defect of temporal sensitivity and the main impairment of timing performance in the extreme value of the psychophysical curves suggested an HD deficit in the memory component of the SET. This result was further confirmed by the significant correlations between time perception performance and long-term memory test scores. Our findings added important preliminary data for both a deeper comprehension of HD time-keeping deficits and possible implications on neuro-rehabilitation practices.

A hierarchical stochastic model for bistable perception.

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Stefan Albert

2017-11-01

Full Text Available Viewing of ambiguous stimuli can lead to bistable perception alternating between the possible percepts. During continuous presentation of ambiguous stimuli, percept changes occur as single events, whereas during intermittent presentation of ambiguous stimuli, percept changes occur at more or less regular intervals either as single events or bursts. Response patterns can be highly variable and have been reported to show systematic differences between patients with schizophrenia and healthy controls. Existing models of bistable perception often use detailed assumptions and large parameter sets which make parameter estimation challenging. Here we propose a parsimonious stochastic model that provides a link between empirical data analysis of the observed response patterns and detailed models of underlying neuronal processes. Firstly, we use a Hidden Markov Model (HMM for the times between percept changes, which assumes one single state in continuous presentation and a stable and an unstable state in intermittent presentation. The HMM captures the observed differences between patients with schizophrenia and healthy controls, but remains descriptive. Therefore, we secondly propose a hierarchical Brownian model (HBM, which produces similar response patterns but also provides a relation to potential underlying mechanisms. The main idea is that neuronal activity is described as an activity difference between two competing neuronal populations reflected in Brownian motions with drift. This differential activity generates switching between the two conflicting percepts and between stable and unstable states with similar mechanisms on different neuronal levels. With only a small number of parameters, the HBM can be fitted closely to a high variety of response patterns and captures group differences between healthy controls and patients with schizophrenia. At the same time, it provides a link to mechanistic models of bistable perception, linking the group

A hierarchical stochastic model for bistable perception.

Science.gov (United States)

Albert, Stefan; Schmack, Katharina; Sterzer, Philipp; Schneider, Gaby

2017-11-01

Viewing of ambiguous stimuli can lead to bistable perception alternating between the possible percepts. During continuous presentation of ambiguous stimuli, percept changes occur as single events, whereas during intermittent presentation of ambiguous stimuli, percept changes occur at more or less regular intervals either as single events or bursts. Response patterns can be highly variable and have been reported to show systematic differences between patients with schizophrenia and healthy controls. Existing models of bistable perception often use detailed assumptions and large parameter sets which make parameter estimation challenging. Here we propose a parsimonious stochastic model that provides a link between empirical data analysis of the observed response patterns and detailed models of underlying neuronal processes. Firstly, we use a Hidden Markov Model (HMM) for the times between percept changes, which assumes one single state in continuous presentation and a stable and an unstable state in intermittent presentation. The HMM captures the observed differences between patients with schizophrenia and healthy controls, but remains descriptive. Therefore, we secondly propose a hierarchical Brownian model (HBM), which produces similar response patterns but also provides a relation to potential underlying mechanisms. The main idea is that neuronal activity is described as an activity difference between two competing neuronal populations reflected in Brownian motions with drift. This differential activity generates switching between the two conflicting percepts and between stable and unstable states with similar mechanisms on different neuronal levels. With only a small number of parameters, the HBM can be fitted closely to a high variety of response patterns and captures group differences between healthy controls and patients with schizophrenia. At the same time, it provides a link to mechanistic models of bistable perception, linking the group differences to

A diagnostic tool on time perception of children with ADHD

NARCIS (Netherlands)

Gongsook, P.; Peijnenborgh, J.; Sallustro, C.; Spek, van der E.D.; Hu, J.; Bellotti, F.; Rauterberg, G.W.M.; Hendriksen, J.G.M.; De Gloria, A.

2014-01-01

ADHD is among the most common childhood developmental disorder which may affect the school achievements. Children with ADHD may show symptoms of time perception problems. Although ADHD is a clinical diagnosis with several approaches, no diagnostic tool has been designed to detect the symptoms of

Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity.

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Meredith S Berry

Full Text Available Impulsivity in delay discounting is associated with maladaptive behaviors such as overeating and drug and alcohol abuse. Researchers have recently noted that delay discounting, even when measured by a brief laboratory task, may be the best predictor of human health related behaviors (e.g., exercise currently available. Identifying techniques to decrease impulsivity in delay discounting, therefore, could help improve decision-making on a global scale. Visual exposure to natural environments is one recent approach shown to decrease impulsive decision-making in a delay discounting task, although the mechanism driving this result is currently unknown. The present experiment was thus designed to evaluate not only whether visual exposure to natural (mountains, lakes relative to built (buildings, cities environments resulted in less impulsivity, but also whether this exposure influenced time perception. Participants were randomly assigned to either a natural environment condition or a built environment condition. Participants viewed photographs of either natural scenes or built scenes before and during a delay discounting task in which they made choices about receiving immediate or delayed hypothetical monetary outcomes. Participants also completed an interval bisection task in which natural or built stimuli were judged as relatively longer or shorter presentation durations. Following the delay discounting and interval bisection tasks, additional measures of time perception were administered, including how many minutes participants thought had passed during the session and a scale measurement of whether time "flew" or "dragged" during the session. Participants exposed to natural as opposed to built scenes were less impulsive and also reported longer subjective session times, although no differences across groups were revealed with the interval bisection task. These results are the first to suggest that decreased impulsivity from exposure to natural as

The influence of hallucination proneness and social threat on time perception.

Science.gov (United States)

Coy, Abbie L; Hutton, Samuel B

2013-01-01

Individuals with schizophrenia frequently report disturbances in time perception, but the precise nature of such deficits and their relation to specific symptoms of the disorder is unclear. We sought to determine the relationship between hallucination proneness and time perception in healthy individuals, and whether this relationship is moderated by hypervigilance to threat-related stimuli. 206 participants completed the Revised Launay-Slade Hallucination Scale (LSHS-R) and a time reproduction task in which, on each trial, participants viewed a face (happy, angry, neutral, or fearful) for between 1 and 5 s and then reproduced the time period with a spacebar press. High LSHS-R scores were associated with longer time estimates, but only during exposure to angry faces. A factor analysis of LSHS-R scores identified a factor comprising items related to reality monitoring, and this factor was most associated with the longer time estimates. During exposure to potential threat in the environment, duration estimates increase with hallucination proneness. The experience of feeling exposed to threat for longer may serve to maintain a state of hypervigilance which has been shown previously to be associated with positive symptoms of schizophrenia.

Speech perception in older listeners with normal hearing:conditions of time alteration, selective word stress, and length of sentences.

Science.gov (United States)

Cho, Soojin; Yu, Jyaehyoung; Chun, Hyungi; Seo, Hyekyung; Han, Woojae

2014-04-01

Deficits of the aging auditory system negatively affect older listeners in terms of speech communication, resulting in limitations to their social lives. To improve their perceptual skills, the goal of this study was to investigate the effects of time alteration, selective word stress, and varying sentence lengths on the speech perception of older listeners. Seventeen older people with normal hearing were tested for seven conditions of different time-altered sentences (i.e., ±60%, ±40%, ±20%, 0%), two conditions of selective word stress (i.e., no-stress and stress), and three different lengths of sentences (i.e., short, medium, and long) at the most comfortable level for individuals in quiet circumstances. As time compression increased, sentence perception scores decreased statistically. Compared to a natural (or no stress) condition, the selectively stressed words significantly improved the perceptual scores of these older listeners. Long sentences yielded the worst scores under all time-altered conditions. Interestingly, there was a noticeable positive effect for the selective word stress at the 20% time compression. This pattern of results suggests that a combination of time compression and selective word stress is more effective for understanding speech in older listeners than using the time-expanded condition only.

“Childhood overweight and obesity: maternal perceptions of the time for engaging in child weight management”

OpenAIRE

Warschburger, Petra; Kröller, Katja

2012-01-01

Abstract Background There is an increasing awareness of the impact of parental risk perception on the weight course of the child and the parent’s readiness to engage in preventive efforts, but only less is known about factors related to the parental perception of the right time for the implementation of preventive activities. The aim of this study was to examine parental perceptions of the appropriate time to engage in child weight management strategies, and the factors associated with differ...

Toward a model of phoneme perception.

Science.gov (United States)

Ardila, A

1993-05-01

Hemisphere asymmetry in phoneme perception was analyzed. Three basic mechanisms underlying phoneme perception are proposed. Left temporal lobe would be specialized in: (1) ultrashort auditory (echoic) memory; (2) higher resolution power for some language frequencies; and (3) recognition of rapidly changing and time-dependent auditory signals. An attempt was made to apply some neurophysiological mechanisms described for the visual system to phoneme recognition in the auditory system.

Evaluation of ceiling lifts: transfer time, patient comfort and staff perceptions.

Science.gov (United States)

Alamgir, Hasanat; Li, Olivia Wei; Yu, Shicheng; Gorman, Erin; Fast, Catherine; Kidd, Catherine

2009-09-01

Mechanical lifting devices have been developed to reduce healthcare worker injuries related to patient handling. The purpose of this study was to evaluate ceiling lifts in comparison to floor lifts based on transfer time, patient comfort and staff perceptions in three long-term care facilities with varying ceiling lift coverage. The time required to transfer or reposition patients along with patient comfort levels were recorded for 119 transfers. Transfers performed with ceiling lifts required on average less time (bed to chair transfers: 156.9 seconds for ceiling lift, 273.6 seconds for floor lift) and were found to be more comfortable for patients. In the three facilities, 143 healthcare workers were surveyed on their perceptions of patient handling tasks and equipment. For both transferring and repositioning tasks, staff preferred to use ceiling lifts and also found them to be less physically demanding. Further investigation is needed on repositioning tasks to ensure safe practice.

Evidence for distinct mechanisms underlying attentional priming and sensory memory for bistable perception.

Science.gov (United States)

Brinkhuis, M A B; Kristjánsson, Á; Brascamp, J W

2015-08-01

Attentional selection in visual search paradigms and perceptual selection in bistable perception paradigms show functional similarities. For example, both are sensitive to trial history: They are biased toward previously selected targets or interpretations. We investigated whether priming by target selection in visual search and sensory memory for bistable perception are related. We did this by presenting two trial types to observers. We presented either ambiguous spheres that rotated over a central axis and could be perceived as rotating in one of two directions, or search displays in which the unambiguously rotating target and distractor spheres closely resembled the two possible interpretations of the ambiguous stimulus. We interleaved both trial types within experiments, to see whether priming by target selection during search trials would affect the perceptual outcome of bistable perception and, conversely, whether sensory memory during bistable perception would affect target selection times during search. Whereas we found intertrial repetition effects among consecutive search trials and among consecutive bistable trials, we did not find cross-paradigm effects. Thus, even though we could ascertain that our experiments robustly elicited processes of both search priming and sensory memory for bistable perception, these same experiments revealed no interaction between the two.

Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research.

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Liam D Harper

Full Text Available Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: 'importance of extra-time', 'rule changes', 'efficacy of extra-time hydro-nutritional provision', 'nutritional timing', 'future research directions', 'preparatory modulations' and 'recovery'. The majority of practitioners (63% either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50% and do not (50% account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk

Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research.

Science.gov (United States)

Harper, Liam D; Fothergill, Melissa; West, Daniel J; Stevenson, Emma; Russell, Mark

2016-01-01

Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: 'importance of extra-time', 'rule changes', 'efficacy of extra-time hydro-nutritional provision', 'nutritional timing', 'future research directions', 'preparatory modulations' and 'recovery'. The majority of practitioners (63%) either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50%) and do not (50%) account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority) were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk, recovery

Effects of psilocybin on time perception and temporal control of behaviour in humans.

Science.gov (United States)

Wittmann, Marc; Carter, Olivia; Hasler, Felix; Cahn, B Rael; Grimberg, Ulrike; Spring, Philipp; Hell, Daniel; Flohr, Hans; Vollenweider, Franz X

2007-01-01

Hallucinogenic psilocybin is known to alter the subjective experience of time. However, there is no study that systematically investigated objective measures of time perception under psilocybin. Therefore, we studied dose-dependent effects of the serotonin (5-HT)2A/1A receptor agonist psilocybin (4-phosphoryloxy-N, N-dimethyltryptamine) on temporal processing, employing tasks of temporal reproduction, sensorimotor synchronization and tapping tempo. To control for cognitive and subjective changes, we assessed spatial working memory and conscious experience. Twelve healthy human volunteers were tested under placebo, medium (115 microg/kg), and high (250 microg/kg) dose conditions, in a double-blind experimental design. Psilocybin was found to significantly impair subjects' ability to (1) reproduce interval durations longer than 2.5 sec, (2) to synchronize to inter-beat intervals longer than 2 sec and (3) caused subjects to be slower in their preferred tapping rate. These objective effects on timing performance were accompanied by working-memory deficits and subjective changes in conscious state, namely increased reports of 'depersonalization' and 'derealization' phenomena including disturbances in subjective 'time sense.' Our study is the first to systematically assess the impact of psilocybin on timing performance on standardized measures of temporal processing. Results indicate that the serotonin system is selectively involved in duration processing of intervals longer than 2 to 3 seconds and in the voluntary control of the speed of movement. We speculate that psilocybin's selective disruption of longer intervals is likely to be a product of interactions with cognitive dimensions of temporal processing -presumably via 5-HT2A receptor stimulation.

Perception, time of perception, perception of the time

OpenAIRE

Barata, André

2009-01-01

From a conceptual point of view, time is independent of its experience. That is: it can be given a conceptual description of time without any reference to terms related to the subjective consciousness of time. But concerning a phenomenology of that subjective experience of time, it can it be showed that such experience of time is, in itself, temporal. The very same terms employed in a conceptual description of time – terms like “change” and “duration”– are implied in the phenomenological desc...

Is the perception of time pressure a barrier to healthy eating and physical activity among women?

Science.gov (United States)

Welch, Nicky; McNaughton, Sarah A; Hunter, Wendy; Hume, Clare; Crawford, David

2009-07-01

To describe the proportion of women reporting time is a barrier to healthy eating and physical activity, the characteristics of these women and the perceived causes of time pressure, and to examine associations between perceptions of time as a barrier and consumption of fruit, vegetables and fast food, and physical activity. A cross-sectional survey of food intake, physical activity and perceived causes of time pressure. A randomly selected community sample. A sample of 1580 women self-reported their food intake and their perceptions of the causes of time pressure in relation to healthy eating. An additional 1521 women self-reported their leisure-time physical activity and their perceptions of the causes of time pressure in relation to physical activity. Time pressure was reported as a barrier to healthy eating by 41% of the women and as a barrier to physical activity by 73%. Those who reported time pressure as a barrier to healthy eating were significantly less likely to meet fruit, vegetable and physical activity recommendations, and more likely to eat fast food more frequently. Women reporting time pressure as a barrier to healthy eating and physical activity are less likely to meet recommendations than are women who do not see time pressure as a barrier. Further research is required to understand the perception of time pressure issues among women and devise strategies to improve women's food and physical activity behaviours.

Multimodal sensory integration during sequential eating--linking chewing activity, aroma release, and aroma perception over time.

Science.gov (United States)

Leclercq, Ségolène; Blancher, Guillaume

2012-10-01

The respective effects of chewing activity, aroma release from a gelled candy, and aroma perception were investigated. Specifically, the study aimed at 1) comparing an imposed chewing and swallowing pattern (IP) and free protocol (FP) on panelists for in vivo measurements, 2) investigating carryover effects in sequential eating, and 3) studying the link between instrumental data and their perception counterpart. Chewing activity, in-nose aroma concentration, and aroma perception over time were measured by electromyography, proton transfer reaction-mass spectrometry, and time intensity, respectively. Model gel candies were flavored at 2 intensity levels (low-L and high-H). The panelists evaluated 3 sequences (H then H, H then L, and L then H) in duplicates with both IP and FP. They scored aroma intensity over time while their in-nose aroma concentrations and their chewing activity were measured. Overall, only limited advantages were found in imposing a chewing and swallowing pattern for instrumental and sensory data. In addition, the study highlighted the role of brain integration on perceived intensity and dynamics of perception, in the framework of sequential eating without rinsing. Because of the presence of adaptation phenomena, contrast effect, and potential taste and texture cross-modal interaction with aroma perception, it was concluded that dynamic in-nose concentration data provide only one part of the perception picture and therefore cannot be used alone in prediction models.

Perceptions of public transport travel time and their effect on choice-sets among car drivers

NARCIS (Netherlands)

N.J.A. van Exel (Job); P. Rietveld (Piet)

2010-01-01

textabstractCar drivers' perceptions of the quality of alternative travel modes have been identified as a barrier for including these alternatives in their choice sets. The present study investigated the accuracy of car drivers' perceptions of public transport (PT) travel time and the potential

An Algorithm of Traffic Perception of DDoS Attacks against SOA Based on Time United Conditional Entropy

Directory of Open Access Journals (Sweden)

Yuntao Zhao

2016-01-01

Full Text Available DDoS attacks can prevent legitimate users from accessing the service by consuming resource of the target nodes, whose availability of network and service is exposed to a significant threat. Therefore, DDoS traffic perception is the premise and foundation of the whole system security. In this paper the method of DDoS traffic perception for SOA network based on time united conditional entropy was proposed. According to many-to-one relationship mapping between the source IP address and destination IP addresses of DDoS attacks, traffic characteristics of services are analyzed based on conditional entropy. The algorithm is provided with perception ability of DDoS attacks on SOA services by introducing time dimension. Simulation results show that the novel method can realize DDoS traffic perception with analyzing abrupt variation of conditional entropy in time dimension.

Time perception, attention, and memory: a selective review.

Science.gov (United States)

Block, Richard A; Gruber, Ronald P

2014-06-01

This article provides a selective review of time perception research, mainly focusing on the authors' research. Aspects of psychological time include simultaneity, successiveness, temporal order, and duration judgments. In contrast to findings at interstimulus intervals or durations less than 3.0-5.0 s, there is little evidence for an "across-senses" effect of perceptual modality (visual vs. auditory) at longer intervals or durations. In addition, the flow of time (events) is a pervasive perceptual illusion, and we review evidence on that. Some temporal information is encoded All rights reserved. relatively automatically into memory: People can judge time-related attributes such as recency, frequency, temporal order, and duration of events. Duration judgments in prospective and retrospective paradigms reveal differences between them, as well as variables that moderate the processes involved. An attentional-gate model is needed to account for prospective judgments, and a contextual-change model is needed to account for retrospective judgments. Copyright © 2013 Elsevier B.V. All rights reserved.

[Dynamic Attending Binds Time and Rhythm Perception].

Science.gov (United States)

Kuroda, Tsuyoshi; Ono, Fuminori; Kadota, Hiroshi

2017-11-01

Relations between time and rhythm perception are discussed in this review of psychophysical research relevant to the multiple-look effect and dynamic-attending theory. Discrimination of two neighboring intervals that are marked by three successive sounds is improved when the presentation of the first (standard, S) interval is repeated before that of the second (comparison, C), as SSSSC. This improvement in sensitivity, called the multiple-look effect, occurs because listeners (1) perceive regular rhythm during the repetition of the standard interval, (2) predict the timing of subsequent sounds, and (3) detect sounds that are deviated from the predicted timing. The dynamic-attending theory attributes such predictions to the entrainment of attentional rhythms. An endogenous attentional rhythm is synchronized with the periodic succession of sounds marking the repeated standard. The standard and the comparison are discriminated on the basis of whether the ending marker of the comparison appears at the peak of the entrained attentional rhythm. This theory is compatible with the findings of recent neurophysiological studies that relate temporal prediction to neural oscillations.

Teachers' Perceptions of Full- and Part-Time Nurses at School

Science.gov (United States)

Biag, Manuelito; Srivastava, Ashini; Landau, Melinda; Rodriguez, Eunice

2015-01-01

Teachers and school nurses partner together to help ensure students stay healthy and engaged in school. The purpose of this study is to generate a deeper understanding of teachers' perceptions on the benefits and challenges of working with full- or part-time school nurses. We conducted a qualitative analysis of open-ended survey responses from 129…

Action during body perception: processing time affects self-other correspondences.

Science.gov (United States)

Reed, Catherine L; McGoldrick, John E

2007-01-01

The accurate perception of other people and their postures is essential for functioning in a social world. Our own bodies organize information from others to help us respond appropriately by creating self-other mappings between bodies. In this study, we investigated mechanisms involved in the processing of self-other correspondences. Reed and Farah (1995) showed that a multimodal, articulated body representation containing the spatial relations among parts of the human body was accessed by both viewing another's body and moving one's own. Use of one part of the body representation facilitated the perception of homologous areas of other people's bodies, suggesting that inputs from both the self and other activated the shared body representation. Here we investigated whether this self-other correspondence produced rapid facilitation or required additional processing time to resolve competing inputs for a shared body representation. Using a modified Reed and Farah dual-task paradigm, we found that processing time influenced body-position memory: an interaction between body-part moved and body-part attended revealed a relative facilitation effect at the 5 s ISI, but interference at the 2 s ISI. Our results suggest that effective visual-motor integration from the self and other requires time to activate shared portions of the spatial body representation.

Timescale- and Sensory Modality-Dependency of the Central Tendency of Time Perception.

Science.gov (United States)

Murai, Yuki; Yotsumoto, Yuko

2016-01-01

When individuals are asked to reproduce intervals of stimuli that are intermixedly presented at various times, longer intervals are often underestimated and shorter intervals overestimated. This phenomenon may be attributed to the central tendency of time perception, and suggests that our brain optimally encodes a stimulus interval based on current stimulus input and prior knowledge of the distribution of stimulus intervals. Two distinct systems are thought to be recruited in the perception of sub- and supra-second intervals. Sub-second timing is subject to local sensory processing, whereas supra-second timing depends on more centralized mechanisms. To clarify the factors that influence time perception, the present study investigated how both sensory modality and timescale affect the central tendency. In Experiment 1, participants were asked to reproduce sub- or supra-second intervals, defined by visual or auditory stimuli. In the sub-second range, the magnitude of the central tendency was significantly larger for visual intervals compared to auditory intervals, while visual and auditory intervals exhibited a correlated and comparable central tendency in the supra-second range. In Experiment 2, the ability to discriminate sub-second intervals in the reproduction task was controlled across modalities by using an interval discrimination task. Even when the ability to discriminate intervals was controlled, visual intervals exhibited a larger central tendency than auditory intervals in the sub-second range. In addition, the magnitude of the central tendency for visual and auditory sub-second intervals was significantly correlated. These results suggest that a common modality-independent mechanism is responsible for the supra-second central tendency, and that both the modality-dependent and modality-independent components of the timing system contribute to the central tendency in the sub-second range.

Timescale- and Sensory Modality-Dependency of the Central Tendency of Time Perception.

Directory of Open Access Journals (Sweden)

Yuki Murai

Full Text Available When individuals are asked to reproduce intervals of stimuli that are intermixedly presented at various times, longer intervals are often underestimated and shorter intervals overestimated. This phenomenon may be attributed to the central tendency of time perception, and suggests that our brain optimally encodes a stimulus interval based on current stimulus input and prior knowledge of the distribution of stimulus intervals. Two distinct systems are thought to be recruited in the perception of sub- and supra-second intervals. Sub-second timing is subject to local sensory processing, whereas supra-second timing depends on more centralized mechanisms. To clarify the factors that influence time perception, the present study investigated how both sensory modality and timescale affect the central tendency. In Experiment 1, participants were asked to reproduce sub- or supra-second intervals, defined by visual or auditory stimuli. In the sub-second range, the magnitude of the central tendency was significantly larger for visual intervals compared to auditory intervals, while visual and auditory intervals exhibited a correlated and comparable central tendency in the supra-second range. In Experiment 2, the ability to discriminate sub-second intervals in the reproduction task was controlled across modalities by using an interval discrimination task. Even when the ability to discriminate intervals was controlled, visual intervals exhibited a larger central tendency than auditory intervals in the sub-second range. In addition, the magnitude of the central tendency for visual and auditory sub-second intervals was significantly correlated. These results suggest that a common modality-independent mechanism is responsible for the supra-second central tendency, and that both the modality-dependent and modality-independent components of the timing system contribute to the central tendency in the sub-second range.

Reliability of Interaural Time Difference-Based Localization Training in Elderly Individuals with Speech-in-Noise Perception Disorder.

Science.gov (United States)

Delphi, Maryam; Lotfi, M-Yones; Moossavi, Abdollah; Bakhshi, Enayatollah; Banimostafa, Maryam

2017-09-01

Previous studies have shown that interaural-time-difference (ITD) training can improve localization ability. Surprisingly little is, however, known about localization training vis-à-vis speech perception in noise based on interaural time difference in the envelope (ITD ENV). We sought to investigate the reliability of an ITD ENV-based training program in speech-in-noise perception among elderly individuals with normal hearing and speech-in-noise disorder. The present interventional study was performed during 2016. Sixteen elderly men between 55 and 65 years of age with the clinical diagnosis of normal hearing up to 2000 Hz and speech-in-noise perception disorder participated in this study. The training localization program was based on changes in ITD ENV. In order to evaluate the reliability of the training program, we performed speech-in-noise tests before the training program, immediately afterward, and then at 2 months' follow-up. The reliability of the training program was analyzed using the Friedman test and the SPSS software. Significant statistical differences were shown in the mean scores of speech-in-noise perception between the 3 time points (P=0.001). The results also indicated no difference in the mean scores of speech-in-noise perception between the 2 time points of immediately after the training program and 2 months' follow-up (P=0.212). The present study showed the reliability of an ITD ENV-based localization training in elderly individuals with speech-in-noise perception disorder.

Determinants and stability over time of perception of health risks related to mobile phone base stations

DEFF Research Database (Denmark)

Kowall, Bernd; Breckenkamp, Jürgen; Blettner, Maria

2012-01-01

about other environmental and health risks, is associated with psychological strain, and is stable on the individual level over time. METHODS: Self-administered questionnaires filled in by 3,253 persons aged 15-69 years in 2004 and 2006 in Germany. RESULTS: Risk perception of MPBS was strongly......OBJECTIVE: Perception of possible health risks related to mobile phone base stations (MPBS) is an important factor in citizens' opposition against MPBS and is associated with health complaints. The aim of the present study is to assess whether risk perception of MPBS is associated with concerns...... in 2004 expressed these concerns again 2 years later, the corresponding figure for attribution of health complaints to MPBS was 31.3%. CONCLUSION: Risk perception of MPBS is strongly associated with general concern, anxiety, depression, and stress, and rather instable over time....

Motion makes sense: an adaptive motor-sensory strategy underlies the perception of object location in rats.

Science.gov (United States)

Saraf-Sinik, Inbar; Assa, Eldad; Ahissar, Ehud

2015-06-10

Tactile perception is obtained by coordinated motor-sensory processes. We studied the processes underlying the perception of object location in freely moving rats. We trained rats to identify the relative location of two vertical poles placed in front of them and measured at high resolution the motor and sensory variables (19 and 2 variables, respectively) associated with this whiskers-based perceptual process. We found that the rats developed stereotypic head and whisker movements to solve this task, in a manner that can be described by several distinct behavioral phases. During two of these phases, the rats' whiskers coded object position by first temporal and then angular coding schemes. We then introduced wind (in two opposite directions) and remeasured their perceptual performance and motor-sensory variables. Our rats continued to perceive object location in a consistent manner under wind perturbations while maintaining all behavioral phases and relatively constant sensory coding. Constant sensory coding was achieved by keeping one group of motor variables (the "controlled variables") constant, despite the perturbing wind, at the cost of strongly modulating another group of motor variables (the "modulated variables"). The controlled variables included coding-relevant variables, such as head azimuth and whisker velocity. These results indicate that consistent perception of location in the rat is obtained actively, via a selective control of perception-relevant motor variables. Copyright © 2015 the authors 0270-6474/15/358777-13$15.00/0.

Time flies faster under time pressure.

Science.gov (United States)

Rattat, Anne-Claire; Matha, Pauline; Cegarra, Julien

2018-04-01

We examined the effects of time pressure on duration estimation in a verbal estimation task and a production task. In both temporal tasks, participants had to solve mazes in two conditions of time pressure (with or without), and with three different target durations (30 s, 60 s, and 90 s). In each trial of the verbal estimation task, participants had to estimate in conventional time units (minutes and seconds) the amount of time that had elapsed since they started to solve the maze. In the production task, they had to press a key while solving the maze when they thought that the trial's duration had reached a target value. Results showed that in both tasks, durations were judged longer with time pressure than without it. However, this temporal overestimation under time pressure did not increase with the length of the target duration. These results are discussed within the framework of scalar expectancy theory. Copyright © 2018 Elsevier B.V. All rights reserved.

Changes in health perceptions after exposure to human suffering: using discrete emotions to understand underlying processes.

Directory of Open Access Journals (Sweden)

Antonia A Paschali

Full Text Available BACKGROUND: The aim of this study was to examine whether exposure to human suffering is associated with negative changes in perceptions about personal health. We further examined the relation of possible health perception changes, to changes in five discrete emotions (i.e., fear, guilt, hostility/anger, and joviality, as a guide to understand the processes underlying health perception changes, provided that each emotion conveys information regarding triggering conditions. METHODOLOGY/FINDINGS: An experimental group (N = 47 was exposed to images of human affliction, whereas a control group (N = 47 was exposed to relaxing images. Participants in the experimental group reported more health anxiety and health value, as well as lower health-related optimism and internal health locus of control, in comparison to participants exposed to relaxing images. They also reported more fear, guilt, hostility and sadness, as well as less joviality. Changes in each health perception were related to changes in particular emotions. CONCLUSION: These findings imply that health perceptions are shaped in a constant dialogue with the representations about the broader world. Furthermore, it seems that the core of health perception changes lies in the acceptance that personal well-being is subject to several potential threats, as well as that people cannot fully control many of the factors the determine their own well-being.

Reliability of Interaural Time Difference-Based Localization Training in Elderly Individuals with Speech-in-Noise Perception Disorder

Directory of Open Access Journals (Sweden)

Maryam Delphi

2017-09-01

Full Text Available Background: Previous studies have shown that interaural-time-difference (ITD training can improve localization ability. Surprisingly little is, however, known about localization training vis-à-vis speech perception in noise based on interaural time difference in the envelope (ITD ENV. We sought to investigate the reliability of an ITD ENV-based training program in speech-in-noise perception among elderly individuals with normal hearing and speech-in-noise disorder. Methods: The present interventional study was performed during 2016. Sixteen elderly men between 55 and 65 years of age with the clinical diagnosis of normal hearing up to 2000 Hz and speech-in-noise perception disorder participated in this study. The training localization program was based on changes in ITD ENV. In order to evaluate the reliability of the training program, we performed speech-in-noise tests before the training program, immediately afterward, and then at 2 months’ follow-up. The reliability of the training program was analyzed using the Friedman test and the SPSS software. Results: Significant statistical differences were shown in the mean scores of speech-in-noise perception between the 3 time points (P=0.001. The results also indicated no difference in the mean scores of speech-in-noise perception between the 2 time points of immediately after the training program and 2 months’ follow-up (P=0.212. Conclusion: The present study showed the reliability of an ITD ENV-based localization training in elderly individuals with speech-in-noise perception disorder.

FIRST TIME ONLINE LEARNERS’ PERCEPTIONS OF SUPPORT SERVICES PROVIDED

Directory of Open Access Journals (Sweden)

Stephanie HUNTE

2012-04-01

Full Text Available The number of online continuous education and training initiatives continues to increase in Caribbean Small Island Developing States (SIDS and by extension, the number of adult learners who are unfamiliar with the peculiarities of the online teaching and learning environment. The extent to which these learners can derive maximum benefit from these initiatives depends on the rate at which they can adapt to the new circumstances and, as a result, function effectively in this type of teaching and learning environment. To this end, while supporting learners is recognized as a critical success factor little has been explored or documented specific to the Caribbean-SIDS context. The purpose of this study therefore was to describe the support services provided first time online learners in the context of Caribbean-SIDS and examine what if any benefit learners derived from them through their perceptions of these services. The findings reveal that participants’ overall perception of the support services was high. They also reveal that although participants’ awareness of ongoing support services was variable, their rating of the need for and importance of this type of support was also high. The findings suggest that providing support for first time online learners in the context of Caribbean SIDS positively impacts their performance in the online teaching and learning environment.

Temporal ventriloquism along the path of apparent motion: speed perception under different spatial grouping principles.

Science.gov (United States)

Ogulmus, Cansu; Karacaoglu, Merve; Kafaligonul, Hulusi

2018-03-01

The coordination of intramodal perceptual grouping and crossmodal interactions plays a critical role in constructing coherent multisensory percepts. However, the basic principles underlying such coordinating mechanisms still remain unclear. By taking advantage of an illusion called temporal ventriloquism and its influences on perceived speed, we investigated how audiovisual interactions in time are modulated by the spatial grouping principles of vision. In our experiments, we manipulated the spatial grouping principles of proximity, uniform connectedness, and similarity/common fate in apparent motion displays. Observers compared the speed of apparent motions across different sound timing conditions. Our results revealed that the effects of sound timing (i.e., temporal ventriloquism effects) on perceived speed also existed in visual displays containing more than one object and were modulated by different spatial grouping principles. In particular, uniform connectedness was found to modulate these audiovisual interactions in time. The effect of sound timing on perceived speed was smaller when horizontal connecting bars were introduced along the path of apparent motion. When the objects in each apparent motion frame were not connected or connected with vertical bars, the sound timing was more influential compared to the horizontal bar conditions. Overall, our findings here suggest that the effects of sound timing on perceived speed exist in different spatial configurations and can be modulated by certain intramodal spatial grouping principles such as uniform connectedness.

Person perception precedes theory of mind: an event related potential analysis.

Science.gov (United States)

Wang, Y W; Lin, C D; Yuan, B; Huang, L; Zhang, W X; Shen, D L

2010-09-29

Prior to developing an understanding of another person's mental state, an ability termed "theory of mind" (ToM), a perception of that person's appearance and actions is required. However the relationship between this "person perception" and ToM is unclear. To investigate the time course of ToM and person perception, event-related potentials (ERP) were recorded while 17 normal adults received three kinds of visual stimuli: cartoons involving people (person perception cartoons), cartoons involving people and also requiring ToM for comprehension (ToM cartoons), and scene cartoons. We hypothesized that the respective patterns of brain activation would be different under these three stimuli, at different stages in time. Our findings supported this proposal: the peak amplitudes of P200 for scene cartoons were significantly lower than for person perception or ToM cartoons, while there were no significant differences between the latter two for P200. During the 1000-1300 ms epoch, the mean amplitudes of the late positive components (LPC) for person perception were more positive than for scene representation, while the mean amplitudes of the LPC for ToM were more positive than for person perception. The present study provides preliminary evidence of the neural dynamic that underlies the dissociation between person perception and ToM. Copyright 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Time Perception in Severe Traumatic Brain Injury Patients: A Study Comparing Different Methodologies

Science.gov (United States)

Mioni, G.; Mattalia, G.; Stablum, F.

2013-01-01

In this study, we investigated time perception in patients with traumatic brain injury (TBI). Fifteen TBI patients and 15 matched healthy controls participated in the study. Participants were tested with durations above and below 1s on three different temporal tasks that involved time reproduction, production, and discrimination tasks. Data…

Passive perception system for day/night autonomous off-road navigation

Science.gov (United States)

Rankin, Arturo L.; Bergh, Charles F.; Goldberg, Steven B.; Bellutta, Paolo; Huertas, Andres; Matthies, Larry H.

2005-05-01

Passive perception of terrain features is a vital requirement for military related unmanned autonomous vehicle operations, especially under electromagnetic signature management conditions. As a member of Team Raptor, the Jet Propulsion Laboratory developed a self-contained passive perception system under the DARPA funded PerceptOR program. An environmentally protected forward-looking sensor head was designed and fabricated in-house to straddle an off-the-shelf pan-tilt unit. The sensor head contained three color cameras for multi-baseline daytime stereo ranging, a pair of cooled mid-wave infrared cameras for nighttime stereo ranging, and supporting electronics to synchronize captured imagery. Narrow-baseline stereo provided improved range data density in cluttered terrain, while wide-baseline stereo provided more accurate ranging for operation at higher speeds in relatively open areas. The passive perception system processed stereo images and outputted over a local area network terrain maps containing elevation, terrain type, and detected hazards. A novel software architecture was designed and implemented to distribute the data processing on a 533MHz quad 7410 PowerPC single board computer under the VxWorks real-time operating system. This architecture, which is general enough to operate on N processors, has been subsequently tested on Pentium-based processors under Windows and Linux, and a Sparc based-processor under Unix. The passive perception system was operated during FY04 PerceptOR program evaluations at Fort A. P. Hill, Virginia, and Yuma Proving Ground, Arizona. This paper discusses the Team Raptor passive perception system hardware and software design, implementation, and performance, and describes a road map to faster and improved passive perception.

The Perception of Time: Influences on Physical and Mental Health

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Cristián Rodrigo Oyanadel Véliz

2011-01-01

Full Text Available With a broad understanding of time perception, the dimensions positive past, negative past, fatalistic present, hedonistic present and future were grouped in profiles to assess relations with physical and mental health. Using a quasi-experimental design, 50 subjects matched for age and sex completed the Zimbardo Time Perspective Inventory and the SF-36, with 3 measures of time estimation. Pearson correlations and ANOVA showed significant relationships between dimensions, physical and mental health, and estimation. Three profiles were obtained, with the balanced one (BTP having the best health indicators. These results support the idea that it is good to have a balanced profile that implies a positive attitude to the past, future orientation, and enjoying pleasant experiences. Also, health is influenced by time estimation

The Perception of Time: Basic Research and Some Potential Links to the Study of Language

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Wearden, J. H.

2008-01-01

The article first discusses some recent work in time perception--in particular the distinction among prospective timing, retrospective timing, and passage of time judgments. The history and application of an "internal clock" model as an explanation of prospective timing performance is reviewed and contrasted with the different mechanisms needed…

Different Perceptions of Time Passage Among Older People: A Comparative Study in Terms of Age and Gender

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Mohammad Ali Nazari

2016-04-01

Conclusion: Research findings indicate that age affects time perception so that perceived time in the elderly people is shorter than the real physical time. Our findings also showed that if sources pay less attention to the passage of time or the memory capacity declines, the time estimation will be less. Based on cognitive changes in old age, the cognitive abilities of older people were found to decrease with increasing age. As the accurate processing of time intervals relates to memory capacity and attention, the changes in any cognitive process could affect the differences in the perception of time. Probably due to these factors, the reproduction of time in the older people shortens.

Brain networks underlying bistable perception.

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Baker, Daniel H; Karapanagiotidis, Theodoros; Coggan, David D; Wailes-Newson, Kirstie; Smallwood, Jonathan

2015-10-01

Bistable stimuli, such as the Necker Cube, demonstrate that experience can change in the absence of changes in the environment. Such phenomena can be used to assess stimulus-independent aspects of conscious experience. The current study used resting state functional magnetic resonance imaging (rs-fMRI) to index stimulus-independent changes in neural activity to understand the neural architecture that determines dominance durations during bistable perception (using binocular rivalry and Necker cube stimuli). Anterior regions of the Superior Parietal Lobule (SPL) exhibited robust connectivity with regions of primary sensorimotor cortex. The strength of this region's connectivity with the striatum predicted shorter dominance durations during binocular rivalry, whereas its connectivity to pre-motor cortex predicted longer dominance durations for the Necker Cube. Posterior regions of the SPL, on the other hand, were coupled to associative cortex in the temporal and frontal lobes. The posterior SPL's connectivity to the temporal lobe predicted longer dominance during binocular rivalry. In conjunction with prior work, these data suggest that the anterior SPL contributes to perceptual rivalry through the inhibition of incongruent bottom up information, whereas the posterior SPL influences rivalry by supporting the current interpretation of a bistable stimulus. Our data suggests that the functional connectivity of the SPL with regions of sensory, motor, and associative cortex allows it to regulate the interpretation of the environment that forms the focus of conscious attention at a specific moment in time. Copyright © 2015. Published by Elsevier Inc.

Time Perception: Modality and Duration Effects in Attention-Deficit/Hyperactivity Disorder (ADHD)

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Toplak, Maggie E.; Tannock, Rosemary

2005-01-01

Time perception performance was systematically investigated in adolescents with and without attention-deficit/hyperactivity disorder (ADHD). Specifically, the effects of manipulating modality (auditory and visual) and length of duration (200 and 1000 ms) were examined. Forty-six adolescents with ADHD and 44 controls were administered four duration…

Job quality of short-time workers and perception and support from their managers

OpenAIRE

坂爪, 洋美

2017-01-01

The purpose of this study was to clarify the relationship between the characteristics of job quality that short-time workers occupied and the managers’ perception and support whose member has used short-time working hour system. A total of 559 first-line managers who has a member using short-time working hour system completed a web-based survey assessing job quality of short-time workers , the risk of using short-timeworking hour system, career perspective of short-time workers, and the suppo...

Consumer sensory and hedonic perception of sheep meat coppa under blind and informed conditions.

Science.gov (United States)

de Andrade, Juliana Cunha; Nalério, Elen Silveira; Giongo, Citieli; de Barcellos, Marcia Dutra; Ares, Gastón; Deliza, Rosires

2018-03-01

The development of air-dried cured sheep meat products represents an interesting option to add value to the meat of adult animals. In this context, the aim of the present study was to evaluate consumer sensory and hedonic perception of sheep meat coppa, an innovative product. Four sheep meat coppa samples were formulated by varying smoking (smoked vs. non-smoked) and salt content (4.5% vs. 3.4%), and compared with two commercial samples of regular pork meat coppa. Samples were evaluated under blind or informed conditions by 202 consumers, who had to rate their liking and to answer a check-all-that-apply question. Sheep and pork meat coppa samples did not largely differ in their overall liking in both experimental conditions. Smoking and high salt content significantly increased consumers' hedonic perception of sheep meat coppa. The information included in the labels did not modify consumer hedonic perception but influenced their sensory description, particularly for the terms related to the type of meat used in their manufacture. Results indicate positive market opportunities for sheep meat coppa in the Brazilian market. Copyright © 2017 Elsevier Ltd. All rights reserved.

Motion perception and driving: predicting performance through testing and shortening braking reaction times through training.

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Wilkins, Luke; Gray, Rob; Gaska, James; Winterbottom, Marc

2013-12-30

A driving simulator was used to examine the relationship between motion perception and driving performance. Although motion perception test scores have been shown to be related to driving safety, it is not clear which combination of tests are the best predictors and whether motion perception training can improve driving performance. In experiment 1, 60 younger drivers (22.4 ± 2.5 years) completed three motion perception tests (2-dimensional [2D] motion-defined letter [MDL] identification, 3D motion in depth sensitivity [MID], and dynamic visual acuity [DVA]) followed by two driving tests (emergency braking [EB] and hazard perception [HP]). In experiment 2, 20 drivers (21.6 ± 2.1 years) completed 6 weeks of motion perception training (using the MDL, MID, and DVA tests), while 20 control drivers (22.0 ± 2.7 years) completed an online driving safety course. The EB performance was measured before and after training. In experiment 1, MDL (r = 0.34) and MID (r = 0.46) significantly correlated with EB score. The change in DVA score as a function of target speed (i.e., "velocity susceptibility") was correlated most strongly with HP score (r = -0.61). In experiment 2, the motion perception training group had a significant decrease in brake reaction time on the EB test from pre- to posttreatment, while there was no significant change for the control group: t(38) = 2.24, P = 0.03. Tests of 3D motion perception are the best predictor of EB, while DVA velocity susceptibility is the best predictor of hazard perception. Motion perception training appears to result in faster braking responses.

General anesthesia alters time perception by phase shifting the circadian clock.

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Cheeseman, James F; Winnebeck, Eva C; Millar, Craig D; Kirkland, Lisa S; Sleigh, James; Goodwin, Mark; Pawley, Matt D M; Bloch, Guy; Lehmann, Konstantin; Menzel, Randolf; Warman, Guy R

2012-05-01

Following general anesthesia, people are often confused about the time of day and experience sleep disruption and fatigue. It has been hypothesized that these symptoms may be caused by general anesthesia affecting the circadian clock. The circadian clock is fundamental to our well-being because it regulates almost all aspects of our daily biochemistry, physiology, and behavior. Here, we investigated the effects of the most common general anesthetic, isoflurane, on time perception and the circadian clock using the honeybee (Apis mellifera) as a model. A 6-h daytime anesthetic systematically altered the time-compensated sun compass orientation of the bees, with a mean anticlockwise shift in vanishing bearing of 87° in the Southern Hemisphere and a clockwise shift in flight direction of 58° in the Northern Hemisphere. Using the same 6-h anesthetic treatment, time-trained bees showed a delay in the start of foraging of 3.3 h, and whole-hive locomotor-activity rhythms were delayed by an average of 4.3 h. We show that these effects are all attributable to a phase delay in the core molecular clockwork. mRNA oscillations of the central clock genes cryptochrome-m and period were delayed by 4.9 and 4.3 h, respectively. However, this effect is dependent on the time of day of administration, as is common for clock effects, and nighttime anesthesia did not shift the clock. Taken together, our results suggest that general anesthesia during the day causes a persistent and marked shift of the clock effectively inducing "jet lag" and causing impaired time perception. Managing this effect in humans is likely to help expedite postoperative recovery.

Computer/Mobile Device Screen Time of Children and Their Eye Care Behavior: The Roles of Risk Perception and Parenting.

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Chang, Fong-Ching; Chiu, Chiung-Hui; Chen, Ping-Hung; Miao, Nae-Fang; Chiang, Jeng-Tung; Chuang, Hung-Yi

2018-03-01

This study assessed the computer/mobile device screen time and eye care behavior of children and examined the roles of risk perception and parental practices. Data were obtained from a sample of 2,454 child-parent dyads recruited from 30 primary schools in Taipei city and New Taipei city, Taiwan, in 2016. Self-administered questionnaires were collected from students and parents. Fifth-grade students spend more time on new media (computer/smartphone/tablet: 16 hours a week) than on traditional media (television: 10 hours a week). The average daily screen time (3.5 hours) for these children exceeded the American Academy of Pediatrics recommendations (≤2 hours). Multivariate analysis results showed that after controlling for demographic factors, the parents with higher levels of risk perception and parental efficacy were more likely to mediate their child's eye care behavior. Children who reported lower academic performance, who were from non-intact families, reported lower levels of risk perception of mobile device use, had parents who spent more time using computers and mobile devices, and had lower levels of parental mediation were more likely to spend more time using computers and mobile devices; whereas children who reported higher academic performance, higher levels of risk perception, and higher levels of parental mediation were more likely to engage in higher levels of eye care behavior. Risk perception by children and parental practices are associated with the amount of screen time that children regularly engage in and their level of eye care behavior.

Brain mechanisms for simple perception and bistable perception.

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Wang, Megan; Arteaga, Daniel; He, Biyu J

2013-08-27

When faced with ambiguous sensory inputs, subjective perception alternates between the different interpretations in a stochastic manner. Such multistable perception phenomena have intrigued scientists and laymen alike for over a century. Despite rigorous investigations, the underlying mechanisms of multistable perception remain elusive. Recent studies using multivariate pattern analysis revealed that activity patterns in posterior visual areas correlate with fluctuating percepts. However, increasing evidence suggests that vision--and perception at large--is an active inferential process involving hierarchical brain systems. We applied searchlight multivariate pattern analysis to functional magnetic resonance imaging signals across the human brain to decode perceptual content during bistable perception and simple unambiguous perception. Although perceptually reflective activity patterns during simple perception localized predominantly to posterior visual regions, bistable perception involved additionally many higher-order frontoparietal and temporal regions. Moreover, compared with simple perception, both top-down and bottom-up influences were dramatically enhanced during bistable perception. We further studied the intermittent presentation of ambiguous images--a condition that is known to elicit perceptual memory. Compared with continuous presentation, intermittent presentation recruited even more higher-order regions and was accompanied by further strengthened top-down influences but relatively weakened bottom-up influences. Taken together, these results strongly support an active top-down inferential process in perception.

Uncertainty Expressions in Accounting Standards: is there any effect of time in the differences of perception?

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Rodrigo Fernandes Malaquias

2017-04-01

Full Text Available This paper examines whether differences in the perception of uncertainty expressions persist over time. The empirical analysis of this question involved two approaches: quantitative (with tests to compare means, medians, regression analysis with ordinary least squares and quantile regression, and qualitative, with interviews. Principal findings are that the differences in the perceptions of participants with respect to uncertainty expressions were not statistically significant, which differs from the findings reported in previous studies. This may be indicative of a tendency toward elimination of potential differences in the interpretation of accounting standards over time.

Analysis of bus passenger comfort perception based on passenger load factor and in-vehicle time.

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Shen, Xianghao; Feng, Shumin; Li, Zhenning; Hu, Baoyu

2016-01-01

Although bus comfort is a crucial indicator of service quality, existing studies tend to focus on passenger load and ignore in-vehicle time, which can also affect passengers' comfort perception. Therefore, by conducting surveys, this study examines passengers' comfort perception while accounting for both factors. Then, using the survey data, it performs a two-way analysis of variance and shows that both in-vehicle time and passenger load significantly affect passenger comfort. Then, a bus comfort model is proposed to evaluate comfort level, followed by a sensitivity analysis. The method introduced in this study has theoretical implications for bus operators attempting to improve bus service quality.

The neural time course of art perception: an ERP study on the processing of style versus content in art.

Science.gov (United States)

Augustin, M Dorothee; Defranceschi, Birgit; Fuchs, Helene K; Carbon, Claus-Christian; Hutzler, Florian

2011-06-01

A central prerequisite to understand the phenomenon of art in psychological terms is to investigate the nature of the underlying perceptual and cognitive processes. Building on a study by Augustin, Leder, Hutzler, and Carbon (2008) the current ERP study examined the neural time course of two central aspects of representational art, one of which is closely related to object- and scene perception, the other of which is art-specific: content and style. We adapted a paradigm that has repeatedly been employed in psycholinguistics and that allows one to examine the neural time course of two processes in terms of when sufficient information is available to allow successful classification. Twenty-two participants viewed pictures that systematically varied in style and content and conducted a combined go/nogo dual choice task. The dependent variables of interest were the Lateralised Readiness Potential (LRP) and the N200 effect. Analyses of both measures support the notion that in the processing of art style follows content, with style-related information being available at around 224 ms or between 40 and 94 ms later than content-related information. The paradigm used here offers a promising approach to further explore the time course of art perception, thus helping to unravel the perceptual and cognitive processes that underlie the phenomenon of art and the fascination it exerts. Copyright © 2011 Elsevier Ltd. All rights reserved.

Who is on the primary care team? Professionals' perceptions of the conceptualization of teams and the underlying factors: a mixed-methods study.

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Doekhie, Kirti D; Buljac-Samardzic, Martina; Strating, Mathilde M H; Paauwe, Jaap

2017-12-28

Due to the growing prevalence of elderly patients with multi-morbidity living at home, there is an increasing need for primary care professionals from different disciplinary backgrounds to collaborate as primary care teams. However, it is unclear how primary care professionals conceptualize teams and what underlying factors influence their perception of being part of a team. Our research question is: What are primary care professionals' perceptions of teams and team membership among primary care disciplines and what factors influence their perceptions? We conducted a mixed-methods study in the Dutch primary care setting. First, a survey study of 152 professionals representing 12 primary care disciplines was conducted, focusing on their perceptions of which disciplines are part of the team and the degree of relational coordination between professionals from different disciplinary backgrounds. Subsequently, we conducted semi-structured interviews with 32 professionals representing 5 primary care disciplines to gain a deeper understanding of the underlying factors influencing their perceptions and the (mis)alignment between these perceptions. Misalignments were found between perceptions regarding which disciplines are members of the team and the relational coordination between disciplines. For example, general practitioners were viewed as part of the team by helping assistants, (district) nurses, occupational therapists and geriatric specialized practice nurses, whereas the general practitioners themselves only considered geriatric specialized practice nurses to be part of their team. Professionals perceive multidisciplinary primary care teams as having multiple inner and outer layers. Three factors influence their perception of being part of a team and acting accordingly: a) knowing the people you work with, b) the necessity for knowledge exchange and c) sharing a holistic view of caregiving. Research and practice should take into account the misalignment between

Exploring the effects of driving experience on hazard awareness and risk perception via real-time hazard identification, hazard classification, and rating tasks.

Science.gov (United States)

Borowsky, Avinoam; Oron-Gilad, Tal

2013-10-01

This study investigated the effects of driving experience on hazard awareness and risk perception skills. These topics have previously been investigated separately, yet a novel approach is suggested where hazard awareness and risk perception are examined concurrently. Young, newly qualified drivers, experienced drivers, and a group of commercial drivers, namely, taxi drivers performed three consecutive tasks: (1) observed 10 short movies of real-world driving situations and were asked to press a button each time they identified a hazardous situation; (2) observed one of three possible sub-sets of 8 movies (out of the 10 they have seen earlier) for the second time, and were asked to categorize them into an arbitrary number of clusters according to the similarity in their hazardous situation; and (3) observed the same sub-set for a third time and following each movie were asked to rate its level of hazardousness. The first task is considered a real-time identification task while the other two are performed using hindsight. During it participants' eye movements were recorded. Results showed that taxi drivers were more sensitive to hidden hazards than the other driver groups and that young-novices were the least sensitive. Young-novice drivers also relied heavily on materialized hazards in their categorization structure. In addition, it emerged that risk perception was derived from two major components: the likelihood of a crash and the severity of its outcome. Yet, the outcome was rarely considered under time pressure (i.e., in real-time hazard identification tasks). Using hindsight, when drivers were provided with the opportunity to rate the movies' hazardousness more freely (rating task) they considered both components. Otherwise, in the categorization task, they usually chose the severity of the crash outcome as their dominant criterion. Theoretical and practical implications are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

On the perception and operationalization of risk perception

Directory of Open Access Journals (Sweden)

Yoav Ganzach

2008-04-01

Full Text Available We compare and critique two measures of risk perception. We suggest that a single question --- ``How risky is the situation?'' --- captures the concept of risk perception more accurately than the multiple-item measure used by Sitkin and Weingart (1995. In fact, this latter measure inadvertently captures notions of attractiveness or expected return, rather than risk perception. We further propose that the error underlying the construction of Sitkin and Weingart's measure is explained in terms of a top-down model of risk perception, in which perceived risk and perceived return are consequences, rather than determinants, of attractiveness. Two studies compare the validity of the two alternative measures.

Time perception and dynamics of facial expressions of emotions.

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Sophie L Fayolle

Full Text Available Two experiments were run to examine the effects of dynamic displays of facial expressions of emotions on time judgments. The participants were given a temporal bisection task with emotional facial expressions presented in a dynamic or a static display. Two emotional facial expressions and a neutral expression were tested and compared. Each of the emotional expressions had the same affective valence (unpleasant, but one was high-arousing (expressing anger and the other low-arousing (expressing sadness. Our results showed that time judgments are highly sensitive to movements in facial expressions and the emotions expressed. Indeed, longer perceived durations were found in response to the dynamic faces and the high-arousing emotional expressions compared to the static faces and low-arousing expressions. In addition, the facial movements amplified the effect of emotions on time perception. Dynamic facial expressions are thus interesting tools for examining variations in temporal judgments in different social contexts.

Associations of American Indian children's screen-time behavior with parental television behavior, parental perceptions of children's screen time, and media-related resources in the home.

Science.gov (United States)

Barr-Anderson, Daheia J; Fulkerson, Jayne A; Smyth, Mary; Himes, John H; Hannan, Peter J; Holy Rock, Bonnie; Story, Mary

2011-09-01

American Indian children have high rates of overweight and obesity, which may be partially attributable to screen-time behavior. Young children's screen-time behavior is strongly influenced by their environment and their parents' behavior. We explored whether parental television watching time, parental perceptions of children's screen time, and media-related resources in the home are related to screen time (ie, television, DVD/video, video game, and computer use) among Oglala Lakota youth residing on or near the Pine Ridge Reservation in South Dakota. We collected baseline data from 431 child and parent/caregiver pairs who participated in Bright Start, a group-randomized, controlled, school-based obesity prevention trial to reduce excess weight gain. Controlling for demographic characteristics, we used linear regression analysis to assess associations between children's screen time and parental television watching time, parental perceptions of children's screen time, and availability of media-related household resources. The most parsimonious model for explaining child screen time included the children's sex, parental body mass index, parental television watching time, how often the child watched television after school or in the evening, parental perception that the child spent too much time playing video games, how often the parent limited the child's television time, and the presence of a VCR/DVD player or video game player in the home (F(7,367) = 14.67; P strategy for reducing overweight and obesity in American Indian children.

Information dynamics of boundary perception

DEFF Research Database (Denmark)

Kragness, Haley; Hansen, Niels Christian; Vuust, Peter

It has long been noted that expert musicians lengthen notes at phrase boundaries in expressive performance. Recently, we have extended research on this phenomenon by showing that undergraduates with no formal musical training and children as young as 3 years lengthen phrase boundaries during self...... uncertain than low-entropy contexts. Because phrase boundaries tend to afford high-entropy continuations, thus generating uncertain expectations in the listener, one possibility is that boundary perception is directly related to entropy. In other words, it may be hypothesized that entropy underlies...... on predictive uncertainty to the timing domain, as well as potentially answer key questions relating to boundary perception in musical listening....

Decreased pain perception by unconscious emotional pictures

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Irene Peláez

2016-10-01

Full Text Available Pain perception arises from a complex interaction between a nociceptive stimulus and different emotional and cognitive factors, which appear to be mediated by both automatic and controlled systems. Previous evidence has shown that whereas conscious processing of unpleasant stimuli enhances pain perception, emotional influences on pain under unaware conditions are much less known. The aim of the present study was to investigate the modulation of pain perception by unconscious emotional pictures through an emotional masking paradigm. Two kinds of both somatosensory (painful and non-painful and emotional stimulation (negative and neutral pictures were employed. Fifty pain-free participants were asked to rate the perception of pain they were feeling in response to laser-induced somatosensory stimuli as faster as they can. Data from pain intensity and reaction times were measured. Statistical analyses revealed a significant effect for the interaction between pain and emotional stimulation, but surprisingly this relationship was opposite to expected. In particular, lower pain intensity scores and longer reaction times were found in response to negative images being strengthened this effect for painful stimulation. Present findings suggest a clear pain perception modulation by unconscious emotional contexts. Attentional capture mechanisms triggered by unaware negative stimulation could explain this phenomenon leading to a withdrawal of processing resources from pain.

Perception of Time, Creative Attitudes, and Adoption of Innovations: A Cross-Cultural Study from Chinese and US College Students

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Seung-Hee Lee

2016-11-01

Full Text Available This study explores how earlier (vs. later adopters of innovation differ in time perception and creative attitudes, comparing Chinese and US college students. Research on the perception of time and creative attitudes is useful to understand how sustainability and creative collaboration might work together. Various relationships exist between different levels of innovation adoption groups and creative attitudes or perceptions of time. We found that earlier adopters scored higher on economic time and future time orientation. This may indicate that earlier adopters are sensitive about their planned schedule. Also, earlier adopters with a future time orientation are forward-thinking and anticipate the introduction of new styles, items, or events in the future. We also find that Chinese (vs. US participants scored higher on creative capacity and creative collaboration but did not differ in general creative attitudes or creative risk-taking. For all participants from these two countries, earlier adopters (vs. later scored higher on all aspects of creative attitudes. This study suggests academic and practical implications regarding sustainability issues. From an academic perspective, this study adds a new perspective to the literature about the relationships among time of adoption, time perception, creative attitudes, and cultural values, and is especially useful for how these four variables influence sustainability. From a practitioner perspective, this study provides information of how consumer values and attitudes in a developing economy (China and a developed economy (US might facilitate open innovation and induce sustainability.

Exploring the effects of adolescent perceptions of parenting in free time and gender on adolescent motivation in free time

Science.gov (United States)

Clifton E., Jr. Watts; Linda L. Caldwell

2007-01-01

This study examined how gender and perceptions of parenting related to adolescent motivation during free-time. The sample consisted of 377 ninthgraders from high schools in eastern Massachusetts. Significant gender differences were found for rules enacted, with females reporting more rules in place than males. When examining the relationship between parenting practices...

Towards a neural basis of music perception.

Science.gov (United States)

Koelsch, Stefan; Siebel, Walter A

2005-12-01

Music perception involves complex brain functions underlying acoustic analysis, auditory memory, auditory scene analysis, and processing of musical syntax and semantics. Moreover, music perception potentially affects emotion, influences the autonomic nervous system, the hormonal and immune systems, and activates (pre)motor representations. During the past few years, research activities on different aspects of music processing and their neural correlates have rapidly progressed. This article provides an overview of recent developments and a framework for the perceptual side of music processing. This framework lays out a model of the cognitive modules involved in music perception, and incorporates information about the time course of activity of some of these modules, as well as research findings about where in the brain these modules might be located.

Is seeing believing? Perceptions of wildfire risk over time

Science.gov (United States)

Patricia A. Champ; Hannah Brenkert-Smith

2016-01-01

Ongoing challenges to understanding how hazard exposure and disaster experiences influence perceived risk lead us to ask: Is seeing believing? We approach risk perception by attending to two components of overall risk perception: perceived probability of an event occurring and perceived consequences if an event occurs. Using a two-period longitudinal data set...

When and How-long: A unified approach for time perception

Directory of Open Access Journals (Sweden)

Michail eManiadakis

2016-03-01

Full Text Available The representation of the environment assumes the encoding of four basic dimensions in the brain, that is the 3D space and time. The vital role of time for cognition is a topic that recently attracted gradually increasing research interest. Surprisingly, the scientific community investigating mind-time interactions has mainly focused on interval timing, paying less attention on the encoding and processing of distant moments. The present work highlights two basic capacities that are necessary for developing temporal cognition in artificial systems. In particular, the seamless integration of agents in the environment assumes they are able to consider when events have occurred and how long they have lasted. This information, although rather standard in humans, is largely missing from artificial cognitive systems. In the present work we consider how a time perception model that is based on neural networks and the Streatal Beat Frequency (SBF theory is extended in a way that besides the duration of events, facilitates the encoding of the time of occurrence in memory. The extended model is capable to support skills assumed in temporal cognition and answer time-related questions about the unfolded events.

Time perception and psychopathology: Influence of time perspective on quality of life of severe mental illness.

Science.gov (United States)

Oyanadel, Cristián; Buela-Casal, Gualberto

2014-01-01

The study of time perception and mental illness has given priority to time estimation over time perspective. Considering Zimbardo’s theory on five dimensions of time perspective, and balanced time perspective profile, this study has aimed to compare people with severe mental illness (SMI) and healthy people, with measurements of time perspective and time estimation and to assess whether the time perspective profile influences the quality of life in people with SMI. Using a quasi-experimental design, a clinical group (n=167) corresponding to four samples of severe mental disorders (major depression, bipolar disorder, schizophrenia and personality disorders) and healthy people (n=167) were compared in their performance regarding time perspective and time estimation. After, the clinical sample was grouped according to their deviation from the balanced time perspective profile (DBTP) and negative profile (DNTP). These groups were evaluated with health measures and time estimation tasks. Through the ANOVA, it can be seen that the time perspective profile affects health measurements. There are significant differences between the clinical sample and controls regarding time perspective and time estimation. Within the group of patients, it was observed that those who were closer to the BTP profile had better physical health, and less hopelessness (ptime perspective in the assessment, treatment and quality of life of people with SMI.

Treatment comfort, time perception, and preference for conventional and digital impression techniques: A comparative study in young patients.

Science.gov (United States)

Burhardt, Lukasz; Livas, Christos; Kerdijk, Wouter; van der Meer, Wicher Joerd; Ren, Yijin

2016-08-01

The aim of this crossover study was to assess perceptions and preferences for impression techniques in young orthodontic patients receiving alginate and 2 different digital impressions. Thirty-eight subjects aged 10 to 17 years requiring impressions for orthodontic treatment were randomly allocated to 3 groups that differed in the order that an alginate impressions and 2 different intraoral scanning procedures were administered. After each procedure, the patients were asked to score their perceptions on a 5-point Likert scale for gag reflex, queasiness, difficulty to breathe, uncomfortable feeling, perception of the scanning time, state of anxiety, and use of a powder, and to select the preferred impression system. Chairside time and maximal mouth opening were also registered. More queasiness (P = 0.00) and discomfort (P = 0.02) during alginate impression taking of the maxilla were perceived compared with the scans with the CEREC Omnicam (Sirona Dental Systems, Bensheim, Germany). There were no significant differences in perceptions between the alginate impressions and the Lava C.O.S. (3M ESPE, St Paul, Minn) and between the 2 scanners. Chairside times for the alginate impressions (9.7 ± 1.8 minutes) and the CEREC Omnicam (10.7 ± 1.8 minutes) were significantly lower (P <0.001) than for the Lava C.O.S. (17.8 ± 4.0 minutes). Digital impressions were favored by 51% of the subjects, whereas 29% chose alginate impressions, and 20% had no preference. Regardless of the significant differences in the registered times among the 3 impression-taking methods, the distributions of the Likert scores of time perception and maximal mouth opening were similar in all 3 groups. Young orthodontic patients preferred the digital impression techniques over the alginate method, although alginate impressions required the shortest chairside time. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

LWIR passive perception system for stealthy unmanned ground vehicle night operations

Science.gov (United States)

Lee, Daren; Rankin, Arturo; Huertas, Andres; Nash, Jeremy; Ahuja, Gaurav; Matthies, Larry

2016-05-01

Resupplying forward-deployed units in rugged terrain in the presence of hostile forces creates a high threat to manned air and ground vehicles. An autonomous unmanned ground vehicle (UGV) capable of navigating stealthily at night in off-road and on-road terrain could significantly increase the safety and success rate of such resupply missions for warfighters. Passive night-time perception of terrain and obstacle features is a vital requirement for such missions. As part of the ONR 30 Autonomy Team, the Jet Propulsion Laboratory developed a passive, low-cost night-time perception system under the ONR Expeditionary Maneuver Warfare and Combating Terrorism Applied Research program. Using a stereo pair of forward looking LWIR uncooled microbolometer cameras, the perception system generates disparity maps using a local window-based stereo correlator to achieve real-time performance while maintaining low power consumption. To overcome the lower signal-to-noise ratio and spatial resolution of LWIR thermal imaging technologies, a series of pre-filters were applied to the input images to increase the image contrast and stereo correlator enhancements were applied to increase the disparity density. To overcome false positives generated by mixed pixels, noisy disparities from repeated textures, and uncertainty in far range measurements, a series of consistency, multi-resolution, and temporal based post-filters were employed to improve the fidelity of the output range measurements. The stereo processing leverages multi-core processors and runs under the Robot Operating System (ROS). The night-time passive perception system was tested and evaluated on fully autonomous testbed ground vehicles at SPAWAR Systems Center Pacific (SSC Pacific) and Marine Corps Base Camp Pendleton, California. This paper describes the challenges, techniques, and experimental results of developing a passive, low-cost perception system for night-time autonomous navigation.

Faraday waves under time-reversed excitation.

Science.gov (United States)

Pietschmann, Dirk; Stannarius, Ralf; Wagner, Christian; John, Thomas

2013-03-01

Do parametrically driven systems distinguish periodic excitations that are time mirrors of each other? Faraday waves in a Newtonian fluid are studied under excitation with superimposed harmonic wave forms. We demonstrate that the threshold parameters for the stability of the ground state are insensitive to a time inversion of the driving function. This is a peculiarity of some dynamic systems. The Faraday system shares this property with standard electroconvection in nematic liquid crystals [J. Heuer et al., Phys. Rev. E 78, 036218 (2008)]. In general, time inversion of the excitation affects the asymptotic stability of a parametrically driven system, even when it is described by linear ordinary differential equations. Obviously, the observed symmetry has to be attributed to the particular structure of the underlying differential equation system. The pattern selection of the Faraday waves above threshold, on the other hand, discriminates between time-mirrored excitation functions.

Research on intelligent machine self-perception method based on LSTM

Science.gov (United States)

Wang, Qiang; Cheng, Tao

2018-05-01

In this paper, we use the advantages of LSTM in feature extraction and processing high-dimensional and complex nonlinear data, and apply it to the autonomous perception of intelligent machines. Compared with the traditional multi-layer neural network, this model has memory, can handle time series information of any length. Since the multi-physical domain signals of processing machines have a certain timing relationship, and there is a contextual relationship between states and states, using this deep learning method to realize the self-perception of intelligent processing machines has strong versatility and adaptability. The experiment results show that the method proposed in this paper can obviously improve the sensing accuracy under various working conditions of the intelligent machine, and also shows that the algorithm can well support the intelligent processing machine to realize self-perception.

Just-in-Time Teaching in undergraduate physics courses: Implementation, learning, and perceptions

Science.gov (United States)

Dwyer, Jessica Hewitt

Regardless of discipline, a decades-long battle has ensued within nearly every classroom in higher education: instructors getting students to come to class prepared to learn. In response to this clash between teacher expectations and frequent student neglect, a group of four physics education researchers developed a reformed instructional strategy called Just-in-Time Teaching (JiTT). This dissertation investigates the following three areas: 1) the fidelity with which undergraduate physics instructors implement JiTT, 2) whether student performance predicts student perception of their instructor's fidelity of JiTT implementation, and 3) whether student perception of their instructor's fidelity of JiTT implementation correlates with student views of their physics course. A blend of quantitative data (e.g., students grades, inventory scores, and questionnaire responses) are integrated with qualitative data (e.g., individual faculty interviews, student focus group discussions, and classroom observations). This study revealed no statistically significant relationship between instructors who spent time on a predefined JiTT critical component and their designation as a JiTT user or non-user. While JiTT users implemented the pedagogy in accordance with the creators' intended ideal vision, many also had trouble reconciling personal concerns about their role as a JiTT adopter and the anticipated demand of the innovation. I recommend that this population of faculty members can serve as a JiTT model for other courses, disciplines, and/or institutions. Student performance was not a predictor of student perception instructor fidelity of JiTT implementation. Additionally, the majority of students in this study reported they read their textbook prior to class and that JiTT assignments helped them prepare for in-class learning. I found evidence that exposure to the JiTT strategy may correlate with a more favorable student view of their physics course. Finally, according to students

Self-Motion Perception: Assessment by Real-Time Computer Generated Animations

Science.gov (United States)

Parker, Donald E.

1999-01-01

Our overall goal is to develop materials and procedures for assessing vestibular contributions to spatial cognition. The specific objective of the research described in this paper is to evaluate computer-generated animations as potential tools for studying self-orientation and self-motion perception. Specific questions addressed in this study included the following. First, does a non- verbal perceptual reporting procedure using real-time animations improve assessment of spatial orientation? Are reports reliable? Second, do reports confirm expectations based on stimuli to vestibular apparatus? Third, can reliable reports be obtained when self-motion description vocabulary training is omitted?

Delay-enhanced stability and stochastic resonance in perception bistability under non-Gaussian noise

International Nuclear Information System (INIS)

Yang, Tao; Zeng, Chunhua; Liu, Ruifen; Wang, Hua; Mei, Dongcheng

2015-01-01

In this paper we investigate the effect of time delay in an attractor network model of perception bistability driven by non-Gaussian noise. Using delay Langevin and Fokker–Planck approaches, the theoretical analysis of the model is presented. It is found that the mean first-passage time (MFPT) as a function of the time delay exhibits a maximum, which is identified as the characteristic of the delay-enhanced stability of the system. This is different to the case of noise-enhanced stability. The non-Gaussian noise-enhanced stability of the system is also analyzed. The signal-to-noise ratio (SNR) as a function of the noise intensity exhibits a maximum. This maximum implies the identifying characteristic of stochastic resonance (SR), and the time delay and non-Gaussian noise can enhance the SR phenomenon. (paper)

Abrupt category shifts during real-time person perception.

Science.gov (United States)

Freeman, Jonathan B

2014-02-01

Previous studies have suggested that real-time person perception relies on continuous competition, in which partially active categories smoothly compete over time. Here, two studies demonstrated the involvement of a different kind of competition. In Study 1, before participants selected the correct sex category for morphed faces, their mouse trajectories often exhibited a continuous attraction toward the incorrect category that increased with sex-category ambiguity, indicating continuous competition. On other trials, however, trajectories initially pursued the incorrect category and then abruptly redirected toward the correct category, suggesting early incorrect category activation that was rapidly reversed later in processing. These abrupt category reversals also increased with ambiguity. In Study 2, participants were presented with faces containing a sex-typical or sex-atypical hair cue, in a context in which the norm was either sex-typical targets (normative context) or sex-atypical targets (counternormative context). Sex-atypical targets induced greater competition in the normative context, but sex-typical targets induced greater competition in the counternormative context. Together, these results demonstrate that categorizing others involves both smooth competition and abrupt category shifts, and that these flexibly adapt to the social context.

Face perception is tuned to horizontal orientation in the N170 time window.

Science.gov (United States)

Jacques, Corentin; Schiltz, Christine; Goffaux, Valerie

2014-02-07

The specificity of face perception is thought to reside both in its dramatic vulnerability to picture-plane inversion and its strong reliance on horizontally oriented image content. Here we asked when in the visual processing stream face-specific perception is tuned to horizontal information. We measured the behavioral performance and scalp event-related potentials (ERP) when participants viewed upright and inverted images of faces and cars (and natural scenes) that were phase-randomized in a narrow orientation band centered either on vertical or horizontal orientation. For faces, the magnitude of the inversion effect (IE) on behavioral discrimination performance was significantly reduced for horizontally randomized compared to vertically or nonrandomized images, confirming the importance of horizontal information for the recruitment of face-specific processing. Inversion affected the processing of nonrandomized and vertically randomized faces early, in the N170 time window. In contrast, the magnitude of the N170 IE was much smaller for horizontally randomized faces. The present research indicates that the early face-specific neural representations are preferentially tuned to horizontal information and offers new perspectives for a description of the visual information feeding face-specific perception.

Visual Timing of Structured Dance Movements Resembles Auditory Rhythm Perception

Science.gov (United States)

Su, Yi-Huang; Salazar-López, Elvira

2016-01-01

Temporal mechanisms for processing auditory musical rhythms are well established, in which a perceived beat is beneficial for timing purposes. It is yet unknown whether such beat-based timing would also underlie visual perception of temporally structured, ecological stimuli connected to music: dance. In this study, we investigated whether observers extracted a visual beat when watching dance movements to assist visual timing of these movements. Participants watched silent videos of dance sequences and reproduced the movement duration by mental recall. We found better visual timing for limb movements with regular patterns in the trajectories than without, similar to the beat advantage for auditory rhythms. When movements involved both the arms and the legs, the benefit of a visual beat relied only on the latter. The beat-based advantage persisted despite auditory interferences that were temporally incongruent with the visual beat, arguing for the visual nature of these mechanisms. Our results suggest that visual timing principles for dance parallel their auditory counterparts for music, which may be based on common sensorimotor coupling. These processes likely yield multimodal rhythm representations in the scenario of music and dance. PMID:27313900

Bullying Behavior, Parents' Work Hours and Early Adolescents' Perceptions of Time Spent with Parents

Science.gov (United States)

Christie-Mizell, C. Andre; Keil, Jacqueline M.; Laske, Mary Therese; Stewart, Jennifer

2011-01-01

This research investigates the relationships among bullying behavior, mother's and father's work hours, and early adolescents' perceptions of whether they spend sufficient time with their parents. In cross-sectional models, we find maternal work hours are modestly associated with increases in bullying behavior. However, in more rigorous change…

The real-time link between person perception and action: brain potential evidence for dynamic continuity.

Science.gov (United States)

Freeman, Jonathan B; Ambady, Nalini; Midgley, Katherine J; Holcomb, Phillip J

2011-01-01

Using event-related potentials, we investigated how the brain extracts information from another's face and translates it into relevant action in real time. In Study 1, participants made between-hand sex categorizations of sex-typical and sex-atypical faces. Sex-atypical faces evoked negativity between 250 and 550 ms (N300/N400 effects), reflecting the integration of accumulating sex-category knowledge into a coherent sex-category interpretation. Additionally, the lateralized readiness potential revealed that the motor cortex began preparing for a correct hand response while social category knowledge was still gradually evolving in parallel. In Study 2, participants made between-hand eye-color categorizations as part of go/no-go trials that were contingent on a target's sex. On no-go trials, although the hand did not actually move, information about eye color partially prepared the motor cortex to move the hand before perception of sex had finalized. Together, these findings demonstrate the dynamic continuity between person perception and action, such that ongoing results from face processing are immediately and continuously cascaded into the motor system over time. The preparation of action begins based on tentative perceptions of another's face before perceivers have finished interpreting what they just saw. © 2010 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business

Losing track of time through delayed body representations.

Science.gov (United States)

Fritz, Thomas H; Steixner, Agnes; Boettger, Joachim; Villringer, Arno

2015-01-01

The ability to keep track of time is perceived as crucial in most human societies. However, to lose track of time may also serve an important social role, associated with recreational purpose. To this end a number of social technologies are employed, some of which may relate to a manipulation of time perception through a modulation of body representation. Here, we investigated an influence of real-time or delayed videos of own-body representations on time perception in an experimental setup with virtual mirrors. Seventy participants were asked to either stay in the installation until they thought that a defined time (90 s) had passed, or they were encouraged to stay in the installation as long as they wanted and after exiting were asked to estimate the duration of their stay. Results show that a modulation of body representation by time-delayed representations of the mirror-video displays influenced time perception. Furthermore, these time-delayed conditions were associated with a greater sense of arousal and intoxication. We suggest that feeding in references to the immediate past into working memory could be the underlying mental mechanism mediating the observed modulation of time perception. We argue that such an influence on time perception would probably not only be achieved visually, but might also work with acoustic references to the immediate past (e.g., with music).

Losing track of time through delayed body representations

Directory of Open Access Journals (Sweden)

Thomas Hans Fritz

2015-04-01

Full Text Available The ability to keep track of time is perceived as crucial in most human societies. However, to lose track of time may also serve an important social role, associated with recreational purpose. To this end a number of social technologies are employed, some of which may relate to a manipulation of time perception through a modulation of body representation. Here we investigated an influence of real-time or delayed videos of own-body representations on time perception in an experimental setup with virtual mirrors. Seventy participants were asked to either stay in the installation until they thought that a defined time (90 s had passed, or they were encouraged to stay in the installation as long as they wanted and after exiting were asked to estimate the duration of their stay. Results show that a modulation of body representation by time-delayed representations of the mirror-video displays influenced time perception. Furthermore, these time-delayed conditions were associated with a greater sense of arousal and intoxication. We suggest that feeding in references to the immediate past into working memory could be the underlying mental mechanism mediating the observed modulation of time perception. We argue that such an influence on time perception would probably not only be achieved visually, but might also work with acoustic references to the immediate past (e.g., with music.

Neural mechanisms underlying melodic perception and memory for pitch.

Science.gov (United States)

Zatorre, R J; Evans, A C; Meyer, E

1994-04-01

The neural correlates of music perception were studied by measuring cerebral blood flow (CBF) changes with positron emission tomography (PET). Twelve volunteers were scanned using the bolus water method under four separate conditions: (1) listening to a sequence of noise bursts, (2) listening to unfamiliar tonal melodies, (3) comparing the pitch of the first two notes of the same set of melodies, and (4) comparing the pitch of the first and last notes of the melodies. The latter two conditions were designed to investigate short-term pitch retention under low or high memory load, respectively. Subtraction of the obtained PET images, superimposed on matched MRI scans, provides anatomical localization of CBF changes associated with specific cognitive functions. Listening to melodies, relative to acoustically matched noise sequences, resulted in CBF increases in the right superior temporal and right occipital cortices. Pitch judgments of the first two notes of each melody, relative to passive listening to the same stimuli, resulted in right frontal-lobe activation. Analysis of the high memory load condition relative to passive listening revealed the participation of a number of cortical and subcortical regions, notably in the right frontal and right temporal lobes, as well as in parietal and insular cortex. Both pitch judgment conditions also revealed CBF decreases within the left primary auditory cortex. We conclude that specialized neural systems in the right superior temporal cortex participate in perceptual analysis of melodies; pitch comparisons are effected via a neural network that includes right prefrontal cortex, but active retention of pitch involves the interaction of right temporal and frontal cortices.

How is time perspective related to perceptions of self and of interpersonal relationships?

Science.gov (United States)

Akirmak, Umit

2014-12-17

Previous research has revealed a positive association between balanced time perspective (BTP) and subjective well-being (Boniwell & Zimbardo, 2004), however mechanisms underlying BTP are yet to be determined. The goal of the present study was to examine the contributions of personality and quality of interpersonal relationships in the development of BTP. Additionally, the correlations between these measures and time perspective dimensions were evaluated as an attempt to provide further psychometric properties of the Zimbardo Time Perspective Inventory (ZTPI) in a Turkish sample. 178 undergraduates filled out a survey that included the ZTPI and measures that assessed personality characteristics, and quality of parent, peer, and adult relationships. Results showed that deviation from BTP was positively associated with romantic anxiety (r = .41, p < .001), romantic avoidance (r = .33, p < .001), and neuroticism (r = .49, p < .001) but negatively associated with self-esteem (r = -.50, p < .001) and security of the mother (r = -.38, p < .001), father (r = -.37, p < .001) and peer (r = -.27, p < .001) attachment. When personality and attachment measures were employed in a regression analysis, father attachment, romantic anxiety, self-esteem, and neuroticism were found to be significant predictors of the deviation from BTP scores (adjusted R 2 = .39, f 2 = .75). Finally, the inter-correlations of the ZTPI dimensions and their correlations with the personality and attachment measures provided additional support for the validity and reliability of the Turkish version of the ZTPI. These findings imply that positive perceptions of self and of interpersonal relationships are crucial in the development of BTP.

The clocks and the perception of time in the 18th century society

Science.gov (United States)

Cardinal, Catherine

The ownership of clocks and watches became widespread in 18th century society, particularly amongst the wealthy classes. They liked the decorative appearance, practical advantages, and social prestige which those objects conferred. The use of 'mechanized' time in the towns supplanted the age old reliance on time as dictated by nature and the Church. New temporal reference points gave the day its rhythm. Data from that era (correspondence, memoirs, newspapers, engravings, and paintings) make it possible to catch a glimpse of the influence of clocks on the perception of time. From the beginning of the 'mechanized time' era, efforts to improve the accuracy and the technical performance of mechanisms were made. The importance of such a precise time measurement in every day life is considered.

The color red distorts time perception for men, but not for women.

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Shibasaki, Masahiro; Masataka, Nobuo

2014-07-31

We investigated the effect of the color red on time perception using a temporal bisection task with human adults. The results showed that the perceived duration of a red screen was longer than was that of a blue screen. However, the results reflected sex differences; men, but not women, overestimated the duration of the red screen. Additionally, the reaction times to a red screen were faster than those to a blue screen, and we found a significant correlation between reaction time and the tendency to overestimate the duration of a red screen. Participants who reacted quickly to a red screen overestimated its duration. These results are discussed within the context of recent studies indicating that the color red exerts certain special psychological effects on human behavior.

simEye: computer-based simulation of visual perception under various eye defects using Zernike polynomials

OpenAIRE

Fink, Wolfgang; Micol, Daniel

2006-01-01

We describe a computer eye model that allows for aspheric surfaces and a three-dimensional computer-based ray-tracing technique to simulate optical properties of the human eye and visual perception under various eye defects. Eye surfaces, such as the cornea, eye lens, and retina, are modeled or approximated by a set of Zernike polynomials that are fitted to input data for the respective surfaces. A ray-tracing procedure propagates light rays using Snell’s law of refraction from an input objec...

Sensitivity and bias in decision-making under risk: evaluating the perception of reward, its probability and value.

Directory of Open Access Journals (Sweden)

Madeleine E Sharp

Full Text Available BACKGROUND: There are few clinical tools that assess decision-making under risk. Tests that characterize sensitivity and bias in decisions between prospects varying in magnitude and probability of gain may provide insights in conditions with anomalous reward-related behaviour. OBJECTIVE: We designed a simple test of how subjects integrate information about the magnitude and the probability of reward, which can determine discriminative thresholds and choice bias in decisions under risk. DESIGN/METHODS: Twenty subjects were required to choose between two explicitly described prospects, one with higher probability but lower magnitude of reward than the other, with the difference in expected value between the two prospects varying from 3 to 23%. RESULTS: Subjects showed a mean threshold sensitivity of 43% difference in expected value. Regarding choice bias, there was a 'risk premium' of 38%, indicating a tendency to choose higher probability over higher reward. An analysis using prospect theory showed that this risk premium is the predicted outcome of hypothesized non-linearities in the subjective perception of reward value and probability. CONCLUSIONS: This simple test provides a robust measure of discriminative value thresholds and biases in decisions under risk. Prospect theory can also make predictions about decisions when subjective perception of reward or probability is anomalous, as may occur in populations with dopaminergic or striatal dysfunction, such as Parkinson's disease and schizophrenia.

Sensitivity and Bias in Decision-Making under Risk: Evaluating the Perception of Reward, Its Probability and Value

Science.gov (United States)

Sharp, Madeleine E.; Viswanathan, Jayalakshmi; Lanyon, Linda J.; Barton, Jason J. S.

2012-01-01

Background There are few clinical tools that assess decision-making under risk. Tests that characterize sensitivity and bias in decisions between prospects varying in magnitude and probability of gain may provide insights in conditions with anomalous reward-related behaviour. Objective We designed a simple test of how subjects integrate information about the magnitude and the probability of reward, which can determine discriminative thresholds and choice bias in decisions under risk. Design/Methods Twenty subjects were required to choose between two explicitly described prospects, one with higher probability but lower magnitude of reward than the other, with the difference in expected value between the two prospects varying from 3 to 23%. Results Subjects showed a mean threshold sensitivity of 43% difference in expected value. Regarding choice bias, there was a ‘risk premium’ of 38%, indicating a tendency to choose higher probability over higher reward. An analysis using prospect theory showed that this risk premium is the predicted outcome of hypothesized non-linearities in the subjective perception of reward value and probability. Conclusions This simple test provides a robust measure of discriminative value thresholds and biases in decisions under risk. Prospect theory can also make predictions about decisions when subjective perception of reward or probability is anomalous, as may occur in populations with dopaminergic or striatal dysfunction, such as Parkinson's disease and schizophrenia. PMID:22493669

Integration time for the perception of depth from motion parallax.

Science.gov (United States)

Nawrot, Mark; Stroyan, Keith

2012-04-15

The perception of depth from relative motion is believed to be a slow process that "builds-up" over a period of observation. However, in the case of motion parallax, the potential accuracy of the depth estimate suffers as the observer translates during the viewing period. Our recent quantitative model for the perception of depth from motion parallax proposes that relative object depth (d) can be determined from retinal image motion (dθ/dt), pursuit eye movement (dα/dt), and fixation distance (f) by the formula: d/f≈dθ/dα. Given the model's dynamics, it is important to know the integration time required by the visual system to recover dα and dθ, and then estimate d. Knowing the minimum integration time reveals the incumbent error in this process. A depth-phase discrimination task was used to determine the time necessary to perceive depth-sign from motion parallax. Observers remained stationary and viewed a briefly translating random-dot motion parallax stimulus. Stimulus duration varied between trials. Fixation on the translating stimulus was monitored and enforced with an eye-tracker. The study found that relative depth discrimination can be performed with presentations as brief as 16.6 ms, with only two stimulus frames providing both retinal image motion and the stimulus window motion for pursuit (mean range=16.6-33.2 ms). This was found for conditions in which, prior to stimulus presentation, the eye was engaged in ongoing pursuit or the eye was stationary. A large high-contrast masking stimulus disrupted depth-discrimination for stimulus presentations less than 70-75 ms in both pursuit and stationary conditions. This interval might be linked to ocular-following response eye-movement latencies. We conclude that neural mechanisms serving depth from motion parallax generate a depth estimate much more quickly than previously believed. We propose that additional sluggishness might be due to the visual system's attempt to determine the maximum dθ/dα ratio

Neural mechanisms underlying temporal modulation of visual perception

NARCIS (Netherlands)

Jong, M.C. de

2015-01-01

However confident we feel about the way we perceive the visual world around us, there is not a one-to-one relation between visual stimulation and visual perception. Our eyes register reflections of the visual environment and our brain has the difficult task of constructing ‘reality’ from this

Wave Functions for Time-Dependent Dirac Equation under GUP

Science.gov (United States)

Zhang, Meng-Yao; Long, Chao-Yun; Long, Zheng-Wen

2018-04-01

In this work, the time-dependent Dirac equation is investigated under generalized uncertainty principle (GUP) framework. It is possible to construct the exact solutions of Dirac equation when the time-dependent potentials satisfied the proper conditions. In (1+1) dimensions, the analytical wave functions of the Dirac equation under GUP have been obtained for the two kinds time-dependent potentials. Supported by the National Natural Science Foundation of China under Grant No. 11565009

Public perceptions of energy system risks: some policy implications

International Nuclear Information System (INIS)

Thomas, K.; Otway, H.J.

1980-01-01

The subject is discussed under the headings: introduction; perceptions, beliefs and attitudes; the survey of public perceptions and attitudes towards energy systems; attitudes towards the five energy systems (nuclear, coal, oil, solar and hydro); perceptions of energy systems - the underlying dimensions of belief (economic benefits; environmental risk; psychological and physical risk; indirect risk; technology development); differential analysis of the perceptions of those pro and con nuclear energy; summary of perceptions of energy systems - relevance to the Austrian dilemma; policy implications. (U.K.)

Embodied cognition and the perception-action link

Science.gov (United States)

Bridgeman, Bruce; Tseng, Philip

2011-03-01

Perception is interpreted as a set of capabilities that facilitate two functions necessary for survival; learning about the environment and controlling real-time behavioral interactions with it. Perceptual capabilities evolve in the context of an organism and its environment, adapted to an organism's ecological niche. The relation between embodied perception and action can be studied in the context of the only muscles that serve only to enable perception - the eye muscles. The only eye movements under cognitive control are saccades, the rapid jumps of binocular fixation from one target to another. The world is perceived as stable while the retinal image, and the corresponding projections inside the brain, are displaced with each saccade. This space constancy forms the stable platform for all other visual functions and requires an explanation that involves visual short-term memory. This memory, and the change detection that it makes possible, is enhanced when there is a physical interaction between the observer and the visual stimulus. Perception is something you do, not something that happens to you.

A Desire for Growth: Online Full-Time Faculty's Perceptions of Evaluation Processes

Directory of Open Access Journals (Sweden)

Meredith DeCosta

2015-07-01

Full Text Available Post-secondary educational institutions use various means to evaluate the teaching performance of faculty members. There are benefits to effective faculty evaluation, including advancing the scholarship of teaching and learning, as well as improving the functionality and innovation of courses, curriculum, departments, and ultimately the broader community (Boyer, 1990; Glassick, Huber, & Maeroff, 1997. While there is a body of research related to the evaluation of faculty in traditional settings, there have been fewer studies examining online faculty members’ perceptions of evaluation processes. Further, due to the growth of online education, the existing evaluation scales, including those used in traditional settings, have been questioned (Berk, 2013; Hathorn & Hathorn, 2010; Rothman, Romeo, Brennan, & Mitchell, 2011. This qualitative study examines one university’s online full-time faculty and their perceptions of the tools and processes used to evaluate their teaching. Through a systematic content analysis of survey data, findings indicate that online faculty members have a desire to grow as instructors, infrequently focusing on modality or job expectations as a means for growth. Participants expressed an interest in holistic, descriptive evaluation feedback by a range of stakeholders, particularly those with content knowledge. Study findings have implications for administrators and other stakeholders related to online full-time faculty, including the processes and documents through which they are evaluated.

A Desire for Growth: Online Full-Time Faculty's Perceptions of Evaluation Processes

Directory of Open Access Journals (Sweden)

Meredith DeCosta

2016-07-01

Full Text Available College and universities evaluate the teaching performance of faculty members in a variety of ways. Benefits to effective faculty evaluation include advancing the scholarship of teaching and learning, as well as improving the functionality and innovation of courses, curriculum, departments, and ultimately the broader community (Boyer, 1990; Glassick, Huber, & Maeroff, 1997. While there is ample research related to the evaluation of faculty in traditional settings, there have been fewer studies examining online faculty members’ perceptions of evaluation processes. Further, due to the growth of online education, the existing evaluation scales, including those used in traditional settings, have been called into question (Berk, 2013; Hathorn & Hathorn, 2010; Rothman, Romeo, Brennan, & Mitchell, 2011. This qualitative study examines one university’s online full-time faculty and their perceptions of the tools and processes used to evaluate their teaching. Through a systematic qualitative content analysis of survey data, findings indicate that online faculty members have a desire to grow as instructors, focusing little on modality or task-oriented expectations as a means for growth. Participants expressed an interest in holistic, descriptive evaluation feedback by a range of stakeholders, particularly those with content knowledge. Study findings have implications for administrators and other stakeholders related to online full-time faculty, including the processes and documents through which they are evaluated.

Time perception and reproduction in young adults with attention deficit hyperactivity disorder.

Science.gov (United States)

Barkley, R A; Murphy, K R; Bush, T

2001-07-01

Adults with attention deficit hyperactivity disorder (ADHD; n = 104) were compared with a control group (n = 64) on time estimation and reproduction tasks. Results were unaffected by ADHD subtype or gender. The ADHD group provided larger time estimations than the control group, particularly at long intervals. This became nonsignificant after controlling for IQ. The ADHD group made shorter reproductions than did the control group (15- and 60-s intervals) and greater reproduction errors (12-, 45-, 60-s durations). These differences remained after controlling for IQ and comorbid oppositional defiant disorder, depression, and anxiety. Only the level of anxiety contributed to errors (at 12-s duration) beyond the level of ADHD. Results extended findings on time perception in ADHD children to adults and ruled out comorbidity as the basis of the errors.

Attention switching during scene perception: how goals influence the time course of eye movements across advertisements.

Science.gov (United States)

Wedel, Michel; Pieters, Rik; Liechty, John

2008-06-01

Eye movements across advertisements express a temporal pattern of bursts of respectively relatively short and long saccades, and this pattern is systematically influenced by activated scene perception goals. This was revealed by a continuous-time hidden Markov model applied to eye movements of 220 participants exposed to 17 ads under a free-viewing condition, and a scene-learning goal (ad memorization), a scene-evaluation goal (ad appreciation), a target-learning goal (product learning), or a target-evaluation goal (product evaluation). The model reflects how attention switches between two states--local and global--expressed in saccades of shorter and longer amplitude on a spatial grid with 48 cells overlaid on the ads. During the 5- to 6-s duration of self-controlled exposure to ads in the magazine context, attention predominantly started in the local state and ended in the global state, and rapidly switched about 5 times between states. The duration of the local attention state was much longer than the duration of the global state. Goals affected the frequency of switching between attention states and the duration of the local, but not of the global, state. (c) 2008 APA, all rights reserved

Children's Perceptions of Moral Themes in Television Drama.

Science.gov (United States)

Christenson, Peter G.

To determine children's perceptions of underlying morals or messages in television drama, a study was conducted in which four early prime time situation comedies were selected for viewing by 15 children per program in kindergarten/first grade, 15 children per program in third/fourth grade, and 8 children per program at the sixth grade level. The…

Perceptions of trust in physician-managers.

Science.gov (United States)

Cregård, Anna; Eriksson, Nomie

2015-01-01

The purpose of this paper is to explore the dual role of physician-managers through an examination of perceptions of trust and distrust in physician-managers. The healthcare sector needs physicians to lead. Physicians in part-time managerial positions who continue their medical practice are called part-time physician-managers. This paper explores this dual role through an examination of perceptions of trust and distrust in physician-managers. The study takes a qualitative research approach in which interviews and focus group discussions with physician-managers and nurse-managers provide the empirical data. An analytical model, with the three elements of ability, benevolence and integrity, was used in the analysis of trust and distrust in physician-managers. The respondents (physician-managers and nurse-managers) perceived both an increase and a decrease in physicians' trust in the physician-managers. Because elements of distrust were more numerous and more severe than elements of trust, the physician-managers received negative perceptions of their role. This paper's findings are based on perceptions of perceptions. The physicians were not interviewed on their trust and distrust of physician-managers. The healthcare sector must pay attention to the diverse expectations of the physician-manager role that is based on both managerial and medical logics. Hospital management should provide proper support to physician-managers in their dual role to ensure their willingness to continue to assume managerial responsibilities. The paper takes an original approach in its research into the dual role of physician-managers who work under two conflicting logics: the medical logic and the managerial logic. The focus on perceived trust and distrust in physician-managers is a new perspective on this complicated role.

The Interface Theory of Perception.

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Hoffman, Donald D; Singh, Manish; Prakash, Chetan

2015-12-01

Perception is a product of evolution. Our perceptual systems, like our limbs and livers, have been shaped by natural selection. The effects of selection on perception can be studied using evolutionary games and genetic algorithms. To this end, we define and classify perceptual strategies and allow them to compete in evolutionary games in a variety of worlds with a variety of fitness functions. We find that veridical perceptions--strategies tuned to the true structure of the world--are routinely dominated by nonveridical strategies tuned to fitness. Veridical perceptions escape extinction only if fitness varies monotonically with truth. Thus, a perceptual strategy favored by selection is best thought of not as a window on truth but as akin to a windows interface of a PC. Just as the color and shape of an icon for a text file do not entail that the text file itself has a color or shape, so also our perceptions of space-time and objects do not entail (by the Invention of Space-Time Theorem) that objective reality has the structure of space-time and objects. An interface serves to guide useful actions, not to resemble truth. Indeed, an interface hides the truth; for someone editing a paper or photo, seeing transistors and firmware is an irrelevant hindrance. For the perceptions of H. sapiens, space-time is the desktop and physical objects are the icons. Our perceptions of space-time and objects have been shaped by natural selection to hide the truth and guide adaptive behaviors. Perception is an adaptive interface.

Rate-distortion theory and human perception.

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Sims, Chris R

2016-07-01

The fundamental goal of perception is to aid in the achievement of behavioral objectives. This requires extracting and communicating useful information from noisy and uncertain sensory signals. At the same time, given the complexity of sensory information and the limitations of biological information processing, it is necessary that some information must be lost or discarded in the act of perception. Under these circumstances, what constitutes an 'optimal' perceptual system? This paper describes the mathematical framework of rate-distortion theory as the optimal solution to the problem of minimizing the costs of perceptual error subject to strong constraints on the ability to communicate or transmit information. Rate-distortion theory offers a general and principled theoretical framework for developing computational-level models of human perception (Marr, 1982). Models developed in this framework are capable of producing quantitatively precise explanations for human perceptual performance, while yielding new insights regarding the nature and goals of perception. This paper demonstrates the application of rate-distortion theory to two benchmark domains where capacity limits are especially salient in human perception: discrete categorization of stimuli (also known as absolute identification) and visual working memory. A software package written for the R statistical programming language is described that aids in the development of models based on rate-distortion theory. Copyright © 2016 The Author. Published by Elsevier B.V. All rights reserved.

Deficits in Interval Timing Measured by the Dual-Task Paradigm among Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

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Hwang, Shoou-Lian; Gau, Susan Shur-Fen; Hsu, Wen-Yau; Wu, Yu-Yu

2010-01-01

Background: The underlying mechanism of time perception deficit in long time intervals in attention-deficit/hyperactivity disorder (ADHD) is still unclear. This study used the time reproduction dual task to explore the role of the attentional resource in time perception deficits among children and adolescents with ADHD. Methods: Participants…

“History is not linear … it zigzags”: The Perception of Time in Magris' novel Blindly

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Irena Prosenc Šegula

2012-12-01

Full Text Available In his novel Blindly Claudio Magris develops a complex perception of time. This perception is intertwined with reflections on history, identity and the status of the narrative voice. History, which “is not linear” but “zigzags” is presented as a continuously repetitive phenomenon, while temporal time is impossible to measure. The status of the autodiegetic narrator becomes highly problematic as the narrative voice assumes identities belonging to various historical periods ranging from the late 18th to the 20th centuries. The novel focuses on repressive historical periods which deform the protagonists' identities, thereby conveying an image of history as a blind and violent force. Fragmentation, one of the basic narrative techniques in the novel, concerns time sequences as well as the protagonists' identities and the narrative voice itself. As the protagonists' lives can only be narrated as fragments, there are frequent passages between different time periods. These merge into extratemporality, which is associated with eternal suffering stemming from the repetitive, oppressive nature of history. The historical events depicted in the novel are interpreted through the extratemporal dimension of the Argonaut myth.

Bistable Perception in Normal Aging: Perceptual Reversibility and its Relation to Cognition

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Díaz-Santos, Mirella; Mauro, Samantha; Cao, Bo; Yazdanbakhsh, Arash; Neargarder, Sandy; Cronin-Golomb, Alice

2017-01-01

The effects of age on the ability to resolve perceptual ambiguity are unknown, though it depends on fronto-parietal attentional networks known to change with age. We presented the bistable Necker cube to 24 middle-aged and older adults (OA; 56–78 years) and 20 younger adults (YA; 18–24 years) under passive-viewing and volitional control conditions: Hold one cube percept and Switch between cube percepts. During passive viewing, OA had longer dominance durations (time spent on each percept) than YA. In the Hold condition, OA were less able than YA to increase dominance durations. In the Switch condition, OA and YA did not differ in performance. Dominance durations in either condition correlated with performance on tests of executive function mediated by the frontal lobes. Eye movements (fixation deviations) did not differ between groups. These results suggest that OA’s reduced ability to hold a percept may arise from reduced selective attention. The lack of correlation of performance between Hold and executive-function measures suggests at least a partial segregation of underlying mechanisms. PMID:27116194

Privacy under construction : A developmental perspective on privacy perception

NARCIS (Netherlands)

Steijn, W.M.P.; Vedder, A.H.

2015-01-01

We present a developmental perspective regarding the difference in perceptions toward privacy between young and old. Here, we introduce the notion of privacy conceptions, that is, the specific ideas that individuals have regarding what privacy actually is. The differences in privacy concerns often

On the relation between texture perception and fundamental mechanical parameters for liquids and time dependent solids

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Vliet, van T.

2002-01-01

Abstract Aspects of the relationship between texture perception in the mouth and fundamental mechanical parameters for liquids and time dependent solids are discussed. The emphasis is on the physical side of the relation. The importance is stressed of the incorporation of a thorough knowledge of

The neural bases underlying social risk perception in purchase decisions.

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Yokoyama, Ryoichi; Nozawa, Takayuki; Sugiura, Motoaki; Yomogida, Yukihito; Takeuchi, Hikaru; Akimoto, Yoritaka; Shibuya, Satoru; Kawashima, Ryuta

2014-05-01

Social considerations significantly influence daily purchase decisions, and the perception of social risk (i.e., the anticipated disapproval of others) is crucial in dissuading consumers from making purchases. However, the neural basis for consumers' perception of social risk remains undiscovered, and this novel study clarifies the relevant neural processes. A total of 26 volunteers were scanned while they evaluated purchase intention of products (purchase intention task) and their anticipation of others' disapproval for possessing a product (social risk task), using functional magnetic resonance imaging (fMRI). The fMRI data from the purchase intention task was used to identify the brain region associated with perception of social risk during purchase decision making by using subjective social risk ratings for a parametric modulation analysis. Furthermore, we aimed to explore if there was a difference between participants' purchase decisions and their explicit evaluations of social risk, with reference to the neural activity associated with social risk perception. For this, subjective social risk ratings were used for a parametric modulation analysis on fMRI data from the social risk task. Analysis of the purchase intention task revealed a significant positive correlation between ratings of social risk and activity in the anterior insula, an area of the brain that is known as part of the emotion-related network. Analysis of the social risk task revealed a significant positive correlation between ratings of social risk and activity in the temporal parietal junction and the medial prefrontal cortex, which are known as theory-of-mind regions. Our results suggest that the anterior insula processes consumers' social risk implicitly to prompt consumers not to buy socially unacceptable products, whereas ToM-related regions process such risk explicitly in considering the anticipated disapproval of others. These findings may prove helpful in understanding the mental

Effect of drivers' age and push button locations on visual time off road, steering wheel deviation and safety perception.

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Dukic, T; Hanson, L; Falkmer, T

2006-01-15

The study examined the effects of manual control locations on two groups of randomly selected young and old drivers in relation to visual time off road, steering wheel deviation and safety perception. Measures of visual time off road, steering wheel deviations and safety perception were performed with young and old drivers during real traffic. The results showed an effect of both driver's age and button location on the dependent variables. Older drivers spent longer visual time off road when pushing the buttons and had larger steering wheel deviations. Moreover, the greater the eccentricity between the normal line of sight and the button locations, the longer the visual time off road and the larger the steering wheel deviations. No interaction effect between button location and age was found with regard to visual time off road. Button location had an effect on perceived safety: the further away from the normal line of sight the lower the rating.

ADHD symptoms and benefit from extended time testing accommodations.

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Lovett, Benjamin J; Leja, Ashley M

2015-02-01

To investigate the relationship between ADHD symptoms, executive functioning problems, and benefit from extended time testing accommodations. College students completed a battery of measures assessing processing speed and reading fluency, reading comprehension (under two different time limits), symptoms of ADHD, executive functioning deficits, and perceptions of need for extended time. Students reporting more symptoms of ADHD and executive functioning deficits actually benefited less from extended time, and students' perceptions of their timing needs did not predict benefit. Students with more ADHD symptoms are less likely to use extended time effectively, possibly because of their associated executive functioning problems. These results suggest there may be little justification for examining a student's ADHD symptoms when making extended time accommodation decisions. © 2013 SAGE Publications.

Perception of neighborhood safety and screen time in adolescents from Curitiba, Brazil.

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Prado, Crisley Vanessa; Rech, Cassiano Ricardo; Hino, Adriano Akira Ferreira; Reis, Rodrigo Siqueira

2017-01-01

To analyze the association between perceptions of neighborhood safety (PNS) and screen time among adolescents and to assess the moderating effects of sex, age and socioeconomic status. A cross-sectional study with school survey was conducted in Curitiba, Brazil. First, six schools (three public and three private) were intentionally selected. Next, one class within each educational level (from the sixth year of elementary school to the third year of high school) was randomly selected. PNS was assessed using a NEWS-Y scale, and daily screen time was defined as the time spent watching TV/videos/DVDs, playing video games and using the Internet. Multinomial logistic regression models were used to test the association between PNS and screen time, adjusting for the confounding variables. The sample included 776 adolescents (boys and girls), aged between 11 and 18 years old. Perceived crime was associated with time playing video games among older teenagers (p < 0.05). Pedestrian and traffic safety was inversely associated with time playing video games among adolescents with high socioeconomic status (p < 0.05). The association between PNS and screen time is complex among adolescents and varies according to sociodemographic variables and the screen time outcome (TV/videos/DVDs, video games and the Internet).

Effect of saliva on physical food properties in fat texture perception.

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Kupirovič, Urška Pivk; Elmadfa, Ibrahim; Juillerat, Marcel-Alexandre; Raspor, Peter

2017-04-13

Sensory properties of food drive our food choices and it is generally accepted that lipids greatly contribute to the sensory properties of many foods and consequently to eating pleasure. Many studies have investigated the mechanisms of the fat perception. Unfortunately they used a variety of methods and products, thereby making generalization very difficult. The mechanism of fat perception in oral cavity is combined of several processes. Lipid composition and its properties strongly influence food structure. During consumption food is exposed to a range of in-mouth processing steps. Oral sensation of fat texture changes with time, from a first bite to chewing, while mixing with saliva, up to swallowing and even after swallowing. The present work reviews many aspects of fat texture perception from physical chemistry to physiology. Understanding the underlying mechanisms of in-mouth lipid processing would provide new concepts to produce low-fat food products with full-fat perception.

A novel approach to assess temporal sensory perception of muscle foods: application of a time-intensity technique to diverse Iberian meat products.

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Lorido, Laura; Estévez, Mario; Ventanas, Sonia

2014-01-01

Although dynamic sensory techniques such as time-intensity (TI) have been applied to certain meat products, existing knowledge regarding the temporal sensory perception of muscle foods is still limited. The objective of the present study was to apply TI to the flavour and texture perception of three different Iberian meat products: liver pâté, dry-cured sausages ("salchichon") and dry-cured loin. Moreover, the advantages of using dynamic versus static sensory techniques were explored by subjecting the same products to a quantitative descriptive analysis (QDA). TI was a suitable technique to assess the impact of composition and structure of the three meat products on flavour and texture perception from a dynamic perspective. TI parameters extracted from the TI-curves and related to temporal perception enabled the detection of clear differences in sensory temporal perception between the meat products and provided additional insight on sensory perception compared to the conventional static sensory technique (QDA). © 2013.

Real-time multiple human perception with color-depth cameras on a mobile robot.

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Zhang, Hao; Reardon, Christopher; Parker, Lynne E

2013-10-01

The ability to perceive humans is an essential requirement for safe and efficient human-robot interaction. In real-world applications, the need for a robot to interact in real time with multiple humans in a dynamic, 3-D environment presents a significant challenge. The recent availability of commercial color-depth cameras allow for the creation of a system that makes use of the depth dimension, thus enabling a robot to observe its environment and perceive in the 3-D space. Here we present a system for 3-D multiple human perception in real time from a moving robot equipped with a color-depth camera and a consumer-grade computer. Our approach reduces computation time to achieve real-time performance through a unique combination of new ideas and established techniques. We remove the ground and ceiling planes from the 3-D point cloud input to separate candidate point clusters. We introduce the novel information concept, depth of interest, which we use to identify candidates for detection, and that avoids the computationally expensive scanning-window methods of other approaches. We utilize a cascade of detectors to distinguish humans from objects, in which we make intelligent reuse of intermediary features in successive detectors to improve computation. Because of the high computational cost of some methods, we represent our candidate tracking algorithm with a decision directed acyclic graph, which allows us to use the most computationally intense techniques only where necessary. We detail the successful implementation of our novel approach on a mobile robot and examine its performance in scenarios with real-world challenges, including occlusion, robot motion, nonupright humans, humans leaving and reentering the field of view (i.e., the reidentification challenge), human-object and human-human interaction. We conclude with the observation that the incorporation of the depth information, together with the use of modern techniques in new ways, we are able to create an

Fixation times in evolutionary games under weak selection

International Nuclear Information System (INIS)

Altrock, Philipp M; Traulsen, Arne

2009-01-01

In evolutionary game dynamics, reproductive success increases with the performance in an evolutionary game. If strategy A performs better than strategy B, strategy A will spread in the population. Under stochastic dynamics, a single mutant will sooner or later take over the entire population or go extinct. We analyze the mean exit times (or average fixation times) associated with this process. We show analytically that these times depend on the payoff matrix of the game in an amazingly simple way under weak selection, i.e. strong stochasticity: the payoff difference Δπ is a linear function of the number of A individuals i, Δπ=u i+v. The unconditional mean exit time depends only on the constant term v. Given that a single A mutant takes over the population, the corresponding conditional mean exit time depends only on the density dependent term u. We demonstrate this finding for two commonly applied microscopic evolutionary processes.

Memory, not just perception, plays an important role in terrestrial mammalian migration.

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Bracis, Chloe; Mueller, Thomas

2017-05-31

One of the key questions regarding the underlying mechanisms of mammalian land migrations is how animals select where to go. Most studies assume perception of resources as the navigational mechanism. The possible role of memory that would allow forecasting conditions at distant locations and times based on information about environmental conditions from previous years has been little studied. We study migrating zebra in Botswana using an individual-based simulation model, where perceptually guided individuals use currently sensed resources at different perceptual ranges, while memory-guided individuals use long-term averages of past resources to forecast future conditions. We compare simulated individuals guided by perception or memory on resource landscapes of remotely sensed vegetation data to trajectories of GPS-tagged zebras. Our results show that memory provides a clear signal that best directs migrants to their destination compared to perception at even the largest perceptual ranges. Zebras modelled with memory arrived two to four times, or up to 100 km, closer to the migration destination than those using perception. We suggest that memory in addition to perception is important for directing ungulate migration. Furthermore, our findings are important for the conservation of migratory mammals, as memory informing direction suggests migration routes could be relatively inflexible. © 2017 The Author(s).

Tourist Perceptions On Supporting Infrastructure Facilities And Climate-Based Visiting Time Of Ngebel Lake, Ponorogo

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Ardhila Ayu Prasetyowati

2014-04-01

Full Text Available This study aims to analyze the tourists’ perception about the importance and satisfaction on the product of fisheries tourism, and to assess the visiting time of tourist based on climate conditions. The research was conducted in May to June 2013 in Ngebel Lake, Ponorogo. We used descriptive quantitative approach, with 45 respondents. Data collected from interview, questionnaire and observation. Analytical methods were used to determine the perception of tourists on the satisfaction and interest in fisheries tourism products, i.e. Importance Performance Analysis (IPA. We also used Tourism Climate Index (TCI to determine the visiting time of tourist. The results show the value of satisfaction and tourist interest is low, therefore the improvement of several aspects become important. It is encompasses: a the existence of parking area; b the condition of Ngebel Lake; c planning and management system, the condition of the local community; and d activities of fish course restaurant and fish farming system of floating net cages. TCI value indicates ideal conditions for tourists traveled in Ngebel Lake is in November (convenience index value of 106, in December (97 and in April (94. This appropriate time to visit Ngebel Lake is expected to create a good impression for the tourists and enjoy the various fisheries activities in Ngebel Lake. Keywords: Importance Performance Analysis, Ngebel Lake, Tourist Climate Index

Changes in Student Perceptions and Study Strategies Over Time in a Veterinary Clinical Pathology Course Using Case-Based Instruction.

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Fernandez, Nicole J; Wagg, Catherine R; Warren, Amy L

2018-06-13

Veterinary students are challenged to develop new, nonlinear ways of thinking as they learn diagnostic reasoning skills. To support this process, we use real-life cases in our clinical pathology course. Changes in student perceptions regarding the use of cases and changes in study strategies over time have not been previously investigated or compared to student grades. Students participated in three voluntary online surveys that included 4-point Likert scale questions and open-ended questions on the helpfulness of cases for learning and study strategies used during the course. We used Friedman tests to detect any differences in perceptions over time; McNemar's test and "Wilcoxon signed-rank tests were used to detect any differences in study strategies over time. Fisher's exact tests'were used to examine the association between the Likert scale responses and grades in quartiles. Before beginning the course, 29% of students responded that cases were very helpful to their learning, with similar "responses for helpfulness in applying course material and grasping important concepts. There was a significant trend of increasing positivity over the duration of the course, with 74% responding that cases were very helpful at the end of the course. The most-reported study strategy was working individually on cases before the midterm (74% of students), and the most helpful study strategy was attending class regularly (88% reported it as very "helpful). Study strategies did not change significantly over time. Overall, perceptions and study strategies did not vary significantly with grades.

The influence of culture: holistic versus analytic perception.

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Nisbett, Richard E; Miyamoto, Yuri

2005-10-01

There is recent evidence that perceptual processes are influenced by culture. Westerners tend to engage in context-independent and analytic perceptual processes by focusing on a salient object independently of its context, whereas Asians tend to engage in context-dependent and holistic perceptual processes by attending to the relationship between the object and the context in which the object is located. Recent research has explored mechanisms underlying such cultural differences, which indicate that participating in different social practices leads to both chronic as well as temporary shifts in perception. These findings establish a dynamic relationship between the cultural context and perceptual processes. We suggest that perception can no longer be regarded as consisting of processes that are universal across all people at all times.

Acute physical exercise under hypoxia improves sleep, mood and reaction time.

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de Aquino-Lemos, Valdir; Santos, Ronaldo Vagner T; Antunes, Hanna Karen Moreira; Lira, Fabio S; Luz Bittar, Irene G; Caris, Aline V; Tufik, Sergio; de Mello, Marco Tulio

2016-02-01

This study aimed to assess the effect of two sessions of acute physical exercise at 50% VO2peak performed under hypoxia (equivalent to an altitude of 4500 m for 28 h) on sleep, mood and reaction time. Forty healthy men were randomized into 4 groups: Normoxia (NG) (n = 10); Hypoxia (HG) (n = 10); Exercise under Normoxia (ENG) (n = 10); and Exercise under Hypoxia (EHG) (n = 10). All mood and reaction time assessments were performed 40 min after awakening. Sleep was reassessed on the first day at 14 h after the initiation of hypoxia; mood and reaction time were measured 28 h later. Two sessions of acute physical exercise at 50% VO2peak were performed for 60 min on the first and second days after 3 and 27 h, respectively, after starting to hypoxia. Improved sleep efficiency, stage N3 and REM sleep and reduced wake after sleep onset were observed under hypoxia after acute physical exercise. Tension, anger, depressed mood, vigor and reaction time scores improved after exercise under hypoxia. We conclude that hypoxia impairs sleep, reaction time and mood. Acute physical exercise at 50% VO2peak under hypoxia improves sleep efficiency, reversing the aspects that had been adversely affected under hypoxia, possibly contributing to improved mood and reaction time.

Perceiving groups: The people perception of diversity and hierarchy.

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Phillips, L Taylor; Slepian, Michael L; Hughes, Brent L

2018-05-01

The visual perception of individuals has received considerable attention (visual person perception), but little social psychological work has examined the processes underlying the visual perception of groups of people (visual people perception). Ensemble-coding is a visual mechanism that automatically extracts summary statistics (e.g., average size) of lower-level sets of stimuli (e.g., geometric figures), and also extends to the visual perception of groups of faces. Here, we consider whether ensemble-coding supports people perception, allowing individuals to form rapid, accurate impressions about groups of people. Across nine studies, we demonstrate that people visually extract high-level properties (e.g., diversity, hierarchy) that are unique to social groups, as opposed to individual persons. Observers rapidly and accurately perceived group diversity and hierarchy, or variance across race, gender, and dominance (Studies 1-3). Further, results persist when observers are given very short display times, backward pattern masks, color- and contrast-controlled stimuli, and absolute versus relative response options (Studies 4a-7b), suggesting robust effects supported specifically by ensemble-coding mechanisms. Together, we show that humans can rapidly and accurately perceive not only individual persons, but also emergent social information unique to groups of people. These people perception findings demonstrate the importance of visual processes for enabling people to perceive social groups and behave effectively in group-based social interactions. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Leadership emergence over time in short-lived groups: Integrating expectations states theory with temporal person-perception and self-serving bias.

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Kalish, Yuval; Luria, Gil

2016-10-01

Research into leadership emergence typically focuses on the attributes of the emergent leader. By considering also the attributes of perceivers and the passage of time, we develop a more complete theory of leadership emergence in short-lived groups. Using expectation states theory as an overarching theoretical framework, and integrating it with the surface- and deep-level diversity literature and with theories of self-serving biases, we examine the predictors of leadership emergence in short timeframes. We conduct a field study in a military assessment boot camp (a pilot study, n = 60; and a main study, n = 89). We use cross-sectional and longitudinal exponential random graph models to analyze data on participants' abilities and on their perceptions of who, in their respective groups, were "leaders." We find that the criteria by which people perceive leadership in others change over time, from easily noticeable attributes to covert leadership-relevant attributes, and that people also rely on leadership-relevant attributes that they possess at high levels to inform their perceptions of leadership in others. The integration of expectation states theory, attribute salience over time and theories of self-serving bias is needed for a full understanding of leadership emergence in groups, because perceivers' own abilities are instrumental in shaping their perceptions of emergent leadership over time. Theoretical and practical implications are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Criterion-free measurement of motion transparency perception at different speeds

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Rocchi, Francesca; Ledgeway, Timothy; Webb, Ben S.

2018-01-01

Transparency perception often occurs when objects within the visual scene partially occlude each other or move at the same time, at different velocities across the same spatial region. Although transparent motion perception has been extensively studied, we still do not understand how the distribution of velocities within a visual scene contribute to transparent perception. Here we use a novel psychophysical procedure to characterize the distribution of velocities in a scene that give rise to transparent motion perception. To prevent participants from adopting a subjective decision criterion when discriminating transparent motion, we used an “odd-one-out,” three-alternative forced-choice procedure. Two intervals contained the standard—a random-dot-kinematogram with dot speeds or directions sampled from a uniform distribution. The other interval contained the comparison—speeds or directions sampled from a distribution with the same range as the standard, but with a notch of different widths removed. Our results suggest that transparent motion perception is driven primarily by relatively slow speeds, and does not emerge when only very fast speeds are present within a visual scene. Transparent perception of moving surfaces is modulated by stimulus-based characteristics, such as the separation between the means of the overlapping distributions or the range of speeds presented within an image. Our work illustrates the utility of using objective, forced-choice methods to reveal the mechanisms underlying motion transparency perception. PMID:29614154

“Patient-Time,” “Doctor-Time,” and “Institution-Time”: Perceptions and Definitions of Time Among Doctors Who Become Patients

Science.gov (United States)

Klitzman, Robert

2010-01-01

Objective To examine views and experiences of conflicts concerning time in healthcare, from the perspective of physicians who have become patients. Methods We conducted two in-depth semi-structured two-hour interviews concerning experiences of being health care workers, and becoming a patient, with each of 50 doctors who had serious illnesses. Results These doctor-patients often came to realize as they had not before how patients experience time differently, and how “patient-time,” “doctor-time,” and “institution-time” exist and can conflict. Differences arose in both long and short term, regarding historical time (prior eras/decades in medicine), prognosis (months/years), scheduling delays (days/weeks), daily medical events and tasks (hours), and periods in waiting rooms (minutes/hours). Definitions of periods of time (e.g., “fast,” “slow,” “plenty,” and “soon”) also varied widely, and could clash. Professional socialization had heretofore impeded awareness of these differences. Physicians tried to address these conflicts in several ways (e.g., trying to provide test results promptly), though full resolution remained difficult. Conclusions Doctors who became patients often now realized how physicians and patients differ in subjective experiences of time. Medical education and research have not adequately considered these issues, which can affect patient satisfaction, doctor-patient relationships and communication, and care. Practice Implications Physicians need to be more sensitive to how their definitions, perceptions, and experiences concerning time can differ from those of patients. PMID:17125956

Radiological risk perception in Spain

International Nuclear Information System (INIS)

Martinez-Arias, R.; Prades, A.; Meza, R.; Sola, R.

1997-01-01

How does society perceive radiation risks?. Is there any logic underlying those perceptions?.The article describes the results of a cross-cultural survey on radiological risk perception applied to a representative sample of the Spanish population. This study has been carried out in the framework of a research project subsidized by the European Union and the CSN. (Author) 16 refs

Perception of Nonverbal Communication Influenced by Culture

Institute of Scientific and Technical Information of China (English)

张蒙蒙

2013-01-01

The concept of perception influenced by culture is pretty important in the study of intercultural communication. The perceptions of language and nonverbal language formed under various cultures intimate with each other during communication. This paper aims to explore the relationship between perception and culture in nonverbal communication through the study of eye language and body odor, and promote the communication among people of different culture as well.

A reinterpretation of transparency perception in terms of gamut relativity.

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Vladusich, Tony

2013-03-01

Classical approaches to transparency perception assume that transparency constitutes a perceptual dimension corresponding to the physical dimension of transmittance. Here I present an alternative theory, termed gamut relativity, that naturally explains key aspects of transparency perception. Rather than being computed as values along a perceptual dimension corresponding to transmittance, gamut relativity postulates that transparency is built directly into the fabric of the visual system's representation of surface color. The theory, originally developed to explain properties of brightness and lightness perception, proposes how the relativity of the achromatic color gamut in a perceptual blackness-whiteness space underlies the representation of foreground and background surface layers. Whereas brightness and lightness perception were previously reanalyzed in terms of the relativity of the achromatic color gamut with respect to illumination level, transparency perception is here reinterpreted in terms of relativity with respect to physical transmittance. The relativity of the achromatic color gamut thus emerges as a fundamental computational principle underlying surface perception. A duality theorem relates the definition of transparency provided in gamut relativity with the classical definition underlying the physical blending models of computer graphics.

Rapid and acute effects of estrogen on time perception in male and female rats

Directory of Open Access Journals (Sweden)

Kristen ePleil

2011-10-01

Full Text Available Sex differences in the rapid and acute effects of estrodiol on time perception were investigated in adult male and female Sprague-Dawley rats. Because estrodiol has been shown to increase striatal dopamine release, it may be able to modify time perception and timed performance by increasing the speed of an internal clock in a manner similar to indirect dopamine agonists such as amphetamine and cocaine. Two groups of females (neonatally estradiol-treated/adult ovariectomized and neonatally oil-treated/adult ovariectomized and 2 groups of males (neonatally castrated and adult castrated were trained in a 2 s vs. 8 s duration bisection procedure and tested using intermediate signal durations. After obtaining oil-injected baseline psychometric functions over several days, rats were administered 5μg of estradiol for 4 days and behaviorally evaluated 30 min following each injection. This oil-estradiol administration cycle was subsequently repeated 3 times following the re-establishment of baseline training. Results revealed significant sex differences in the initial baseline functions that were not modifiable by organizational hormones, with males’ duration bisection functions shifted horizontally to the left of females’. Upon the first administration of estradiol, females, but not males, showed a significant, transient leftward shift in their bisection functions, indicative of an increase in clock speed. After extensive retraining in the duration bisection procedure, rats that were exposed to gonadal hormones during the first week of life showed a significant rightward shift in their bisection functions on the fourth day of estradiol administration during each cycle, suggesting a decrease in clock speed. Taken together, our results support the view that there are multiple mechanisms of estrogens’ action in the striatum that modulate dopaminergic activity and are differentially organized by gonadal steroids during early brain development.

Hysteresis in audiovisual synchrony perception.

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Jean-Rémy Martin

Full Text Available The effect of stimulation history on the perception of a current event can yield two opposite effects, namely: adaptation or hysteresis. The perception of the current event thus goes in the opposite or in the same direction as prior stimulation, respectively. In audiovisual (AV synchrony perception, adaptation effects have primarily been reported. Here, we tested if perceptual hysteresis could also be observed over adaptation in AV timing perception by varying different experimental conditions. Participants were asked to judge the synchrony of the last (test stimulus of an AV sequence with either constant or gradually changing AV intervals (constant and dynamic condition, respectively. The onset timing of the test stimulus could be cued or not (prospective vs. retrospective condition, respectively. We observed hysteretic effects for AV synchrony judgments in the retrospective condition that were independent of the constant or dynamic nature of the adapted stimuli; these effects disappeared in the prospective condition. The present findings suggest that knowing when to estimate a stimulus property has a crucial impact on perceptual simultaneity judgments. Our results extend beyond AV timing perception, and have strong implications regarding the comparative study of hysteresis and adaptation phenomena.

Visual motion perception predicts driving hazard perception ability.

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Lacherez, Philippe; Au, Sandra; Wood, Joanne M

2014-02-01

To examine the basis of previous findings of an association between indices of driving safety and visual motion sensitivity and to examine whether this association could be explained by low-level changes in visual function. A total of 36 visually normal participants (aged 19-80 years) completed a battery of standard vision tests including visual acuity, contrast sensitivity and automated visual fields and two tests of motion perception including sensitivity for movement of a drifting Gabor stimulus and sensitivity for displacement in a random dot kinematogram (Dmin ). Participants also completed a hazard perception test (HPT), which measured participants' response times to hazards embedded in video recordings of real-world driving, which has been shown to be linked to crash risk. Dmin for the random dot stimulus ranged from -0.88 to -0.12 log minutes of arc, and the minimum drift rate for the Gabor stimulus ranged from 0.01 to 0.35 cycles per second. Both measures of motion sensitivity significantly predicted response times on the HPT. In addition, while the relationship involving the HPT and motion sensitivity for the random dot kinematogram was partially explained by the other visual function measures, the relationship with sensitivity for detection of the drifting Gabor stimulus remained significant even after controlling for these variables. These findings suggest that motion perception plays an important role in the visual perception of driving-relevant hazards independent of other areas of visual function and should be further explored as a predictive test of driving safety. Future research should explore the causes of reduced motion perception to develop better interventions to improve road safety. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

Neural mechanisms underlying sound-induced visual motion perception: An fMRI study.

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Hidaka, Souta; Higuchi, Satomi; Teramoto, Wataru; Sugita, Yoichi

2017-07-01

Studies of crossmodal interactions in motion perception have reported activation in several brain areas, including those related to motion processing and/or sensory association, in response to multimodal (e.g., visual and auditory) stimuli that were both in motion. Recent studies have demonstrated that sounds can trigger illusory visual apparent motion to static visual stimuli (sound-induced visual motion: SIVM): A visual stimulus blinking at a fixed location is perceived to be moving laterally when an alternating left-right sound is also present. Here, we investigated brain activity related to the perception of SIVM using a 7T functional magnetic resonance imaging technique. Specifically, we focused on the patterns of neural activities in SIVM and visually induced visual apparent motion (VIVM). We observed shared activations in the middle occipital area (V5/hMT), which is thought to be involved in visual motion processing, for SIVM and VIVM. Moreover, as compared to VIVM, SIVM resulted in greater activation in the superior temporal area and dominant functional connectivity between the V5/hMT area and the areas related to auditory and crossmodal motion processing. These findings indicate that similar but partially different neural mechanisms could be involved in auditory-induced and visually-induced motion perception, and neural signals in auditory, visual, and, crossmodal motion processing areas closely and directly interact in the perception of SIVM. Copyright © 2017 Elsevier B.V. All rights reserved.

Under Pressure: Job Security, Resource Allocation, and Productivity in Schools under No Child Left Behind

OpenAIRE

Randall Reback; Jonah Rockoff; Heather L. Schwartz

2014-01-01

We conduct the first nationwide study of incentives under the No Child Left Behind (NCLB) Act, which requires states to punish schools failing to meet target passing rates on students' standardized exams. States' idiosyncratic policies created variation in the risk of failure among very similar schools in different states, which we use to identify effects of accountability pressure. We find NCLB lowers teachers' perceptions of job security, shifts time towards specialist teachers in high-stak...

Enhancing sequential time perception and storytelling ability of deaf and hard of hearing children.

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Ingber, Sara; Eden, Sigal

2011-01-01

A 3-month intervention was conducted to enhance the sequential time perception and storytelling ability of young children with hearing loss. The children were trained to arrange pictorial episodes of temporal scripts and tell the stories they created. Participants (N = 34, aged 4-7 years) were divided into 2 groups based on whether their spoken-language gap was more or less than 1 year compared to age norms. They completed A. Kaufman and N. Kaufman's (1983) picture series subtest and Guralnik's (1982) storytelling test at pretest and posttest. Measures demonstrated significant improvement in sequential time and storytelling achievement postintervention. Three of the examined demographic variables revealed correlations: Participants with genetic etiology showed greater improvement in time sequencing and storytelling than participants with unknown etiology; early onset of treatment correlated with better achievement in time sequencing; cochlear implant users showed greater storytelling improvement than hearing aid users.

Can patients with asthma feel inhaler therapy working right away? Two clinical trials testing the effect of timing of assessment on patient perception.

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Leidy, Nancy Kline; Gutierrez, Benjamin; Lampl, Kathy; Uryniak, Tom; O'Brien, Christopher D

2009-12-01

Feeling a maintenance therapy work right away may provide positive reinforcement and may offer one way to improve adherence in patients with asthma. Precise measurement is required to accurately compare the presence of this effect across clinical trial treatment groups. Two randomized, controlled studies tested whether timing of assessment (daily vs weekly, study 1; and predose vs postdose, study 2) influenced patients' reports of whether they can feel a medication working right away (perception), and their satisfaction with this perception (satisfaction). These 2-week US-based multicenter double-blind, parallel-group studies included patients > or = 18 years of age with mild to moderate persistent asthma. In each, patients were randomized to one of two drugs with different onset profiles: budesonide/formoterol pressurized metered-dose inhaler (pMDI) 80/4.5 microg x 2 inhalations (160/9 microg) twice daily or budesonide pMDI 80 microg x 2 inhalations (160 microg) twice daily. Patients were further randomized to complete previously validated perception and satisfaction questions in a cross-over fashion, either daily and weekly (N = 123) or predose and postdose (N = 134). Patient surveys also assessed perceptions of the onset of effect of medication and their value of these perceptions. No significant differences were observed in patients' reports of perception, either daily versus weekly or predose versus postdose. A statistically significant difference in satisfaction was found in study 1 only, favoring weekly recall (p away (136 of 157 patients) identified positive airway sensations. Most patients reported that feeling their medication work right away is reassuring and would help them manage their asthma. Assessment timing has no effect on patient response to the perception of feeling a medication working right away. Differences found in satisfaction levels reported with weekly versus daily recall were consistent across treatment groups, indicating that no bias

Environment perception and leisure-time physical activity in Portuguese high school students

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Rita Pereira

2018-06-01

Full Text Available This study aims to analyze the association between perceived environmental factors and leisure-time physical activity (PA among adolescents of both genders. Data were collected in autumn of 2011 from 866 adolescents (412 girls and 454 boys 12- to 18-years-old, from four Portuguese cities. Perception of environmental factors was assessed by Assessing Levels of Physical Activity and Fitness (ALPHA questionnaire (Spittaels et al., 2010, IJBNPA. PA was assessed by a questionnaire that evaluated PA during leisure-time and participants were assigned into the following categories: sedentary; low active; moderate active; and very active. Boys presented higher levels of structured PA, frequency and intensity of PA, and level of sport competition than girls (p<0.001. Distance to local facilities (p=0.001 for girls; p<0.001 for boys and home environment (p=0.004 for girls; p=0.015 for boys were negatively associated with PA. Total, cycling and walking infrastructures (p<0.001, as well as cycling and walking network (p=0.049 and connectivity (p=0.034 showed a positive association with PA in boys. Analysis of variance showed significant differences between girls' PA regarding aesthetics (p=0.013, study environment (p=0.023, home environment (p=0.014 and whether it is pleasant or not (p=0.023. Differences between boys' PA were observed for distance to local facilities (p=0.003, total, cycling and walking infrastructures (p<0.001 and home environment (p=0.002. This study results support that some environmental factors are associated with adolescents' PA levels, with relevant differences between genders. Therefore, these gender differences must be taken into account, in order to increase levels of PA in Portuguese youth, especially in girls. Keywords: Environment perception, Physical activity, Adolescents, ALPHA questionnaire

Under Construction: Undergraduates' Perceptions of Their Music Teacher Role-Identities

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Draves, Tami J.

2014-01-01

The purpose of this research was to explore how participants perceived themselves as preservice music teachers. Bouij's (1998) salient role-identities in music education served as an a priori theoretical framework. By investigating participants' perceptions of role-identity, some of the socialization processes that contributed to identity…

Determinant factors of residential consumption and perception of energy conservation: Time-series analysis by large-scale questionnaire in Suita, Japan

International Nuclear Information System (INIS)

Hara, Keishiro; Uwasu, Michinori; Kishita, Yusuke; Takeda, Hiroyuki

2015-01-01

In this study, we examined determinant factors associated with the residential consumption and perception of savings of electricity and city gas; this was based on data collected from a large-scale questionnaire sent to households in Suita, Osaka Prefecture, Japan, in two different years: 2009 and 2013. We applied an ordered logit model to determine the overall trend of the determinant factors, and then we performed a more detailed analysis in order to understand the reasons why the determinant factors changed between the two periods. Results from the ordered logit model reveal that electricity and gas consumption was primarily determined by such factors as household income, number of family members, the number of home appliances, and the perceptions of energy savings; there was not much difference between the two years, although in 2013, household income did not affect the perception of energy savings. Detailed analysis demonstrated that households with high energy consumption and those with moderate consumption are becoming polarized and that there was a growing gap between consumption behavior and the perception of conservation. The implications derived from the analyses provide an essential insight into the design of a municipal policy to induce lifestyle changes for an energy-saving society. - Highlights: • Questionnaire was conducted to households in two years for time-series analysis. • We analyzed residential energy consumption and perception of savings in households. • Determinant factors for consumption and perception of savings were identified. • Households being wasteful of energy are also found willing to cut consumption. • Policy intervention could affect consumption pattern and perception of savings.

Art Perception in the Museum: How We Spend Time and Space in Art Exhibitions

Directory of Open Access Journals (Sweden)

Claus-Christian Carbon

2017-02-01

Full Text Available Aesthetics research aiming at understanding art experience is an emerging field; however, most research is conducted in labs without access to real artworks, without the social context of a museum and without the presence of other persons. The present article replicates and complements key findings of art perception in museum contexts. When observing museum visitors (N = 225; 126 female, M(age = 43.3 years while perceiving a series of six Gerhard Richter paintings of various sizes (0.26–3.20 sq. m in a temporary art exhibition in January and February 2015 showing 28 paintings in total, we revealed patterns compatible to previous research. The mean time taken in viewing artworks was much longer than was mostly realized in lab contexts, here 32.9 s (Mdn = 25.4 s. We were also able to replicate visitors spending more time on viewing artworks when attending in groups of people. Additionally, we uncovered a close positive relationship (r2 = .929 between canvas size and viewing distance, ranging on average between 1.49 and 2.12 m (M = 1.72 m. We also found that more than half of the visitors returned to paintings, especially those people who had not previously paid too much attention at the initial viewing. After adding the times of returning viewers, each picture was viewed longer than had been estimated in previous research (M = 50.5 s, Mdn = 43.0 s. Results are discussed in the context of current art perception theories, focusing on the need for the ecologically valid testing of artworks in aesthetics research.

Periodic capacity management under a lead-time performance constraint

NARCIS (Netherlands)

Büyükkaramikli, N.C.; Bertrand, J.W.M.; Ooijen, van H.P.G.

2013-01-01

In this paper, we study a production system that operates under a lead-time performance constraint which guarantees the completion of an order before a pre-determined lead-time with a certain probability. The demand arrival times and the service requirements for the orders are random. To reduce the

Probing interval timing with scalp-recorded electroencephalography (EEG).

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Ng, Kwun Kei; Penney, Trevor B

2014-01-01

Humans, and other animals, are able to easily learn the durations of events and the temporal relationships among them in spite of the absence of a dedicated sensory organ for time. This chapter summarizes the investigation of timing and time perception using scalp-recorded electroencephalography (EEG), a non-invasive technique that measures brain electrical potentials on a millisecond time scale. Over the past several decades, much has been learned about interval timing through the examination of the characteristic features of averaged EEG signals (i.e., event-related potentials, ERPs) elicited in timing paradigms. For example, the mismatch negativity (MMN) and omission potential (OP) have been used to study implicit and explicit timing, respectively, the P300 has been used to investigate temporal memory updating, and the contingent negative variation (CNV) has been used as an index of temporal decision making. In sum, EEG measures provide biomarkers of temporal processing that allow researchers to probe the cognitive and neural substrates underlying time perception.

The Effects of Textisms on Learning, Study Time, and Instructional Perceptions in an Online Artificial Intelligence Instructional Module

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Beasley, Robert; Bryant, Nathan L.; Dodson, Phillip T.; Entwistle, Kevin C.

2013-01-01

The purpose of this study was to investigate the effects of textisms (i.e., abbreviated spellings, acronyms, and other shorthand notations) on learning, study time, and instructional perceptions in an online artificial intelligence instructional module. The independent variable in this investigation was experimental condition. For the control…

Public risk perception of food additives and food scares. The case in Suzhou, China.

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Wu, Linhai; Zhong, Yingqi; Shan, Lijie; Qin, Wei

2013-11-01

This study examined the factors affecting public risk perception of food additive safety and possible resulting food scares using a survey conducted in Suzhou, Jiangsu Province, China. The model was proposed based on literature relating to the role of risk perception and information perception of public purchase intention under food scares. Structural equation modeling (SEM) was used for data analysis. The results showed that attitude towards behavior, subjective norm and information perception exerted moderate to high effect on food scares, and the effects were also mediated by risk perceptions of additive safety. Significant covariance was observed between attitudes toward behavior, subjective norm and information perception. Establishing an effective mechanism of food safety risk communication, releasing information of government supervision on food safety in a timely manner, curbing misleading media reports on public food safety risk, and enhancing public knowledge of the food additives are key to the development and implementation of food safety risk management policies by the Chinese government. Copyright © 2013 Elsevier Ltd. All rights reserved.

Perception and eye movements in simulated traffic situations.

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Luoma, J

1984-01-01

In an experiment to simulate the perception task of a driver, subjects were shown uninterrupted series of colour slides of different kinds of highway scenes. The dependent variables were eye fixations, fixation times and conscious perceptions for the part of the traffic signs and roadside advertisements. Perceptions were achieved mostly as a result of fixation, but partly also by using peripheral vision. On the other hand fixation did not always cause perception. The lengthening of fixation time increased the number of correct perceptions. When the traffic sign and the roadside advertisement were in the same slide, the advertisement disturbed the perception of the sign, but in the daylight conditions this effect was not noticed as an alteration of the fixation of the sign, but as prevention of further information processing. The disturbing influence of the advertisement was increased by its bad information ergonomics which caused a long fixation time.

Prosodic Perception Problems in Spanish Dyslexia

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Cuetos, Fernando; Martínez-García, Cristina; Suárez-Coalla, Paz

2018-01-01

The aim of this study was to investigate the prosody abilities on top of phonological and visual abilities in children with dyslexia in Spanish that can be considered a syllable-timed language. The performances on prosodic tasks (prosodic perception, rise-time perception), phonological tasks (phonological awareness, rapid naming, verbal working…

Students' Perceptions of Business Ethics: Using Cheating as a Surrogate for Business Situations

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Smyth, Lynnette S.; Davis, James R.; Kroncke, Charles O.

2009-01-01

Today's college students are entering the workplace at a time when ethical issues are under greater scrutiny. Thus, the authors examined students' perceptions of varying ethical situations, sampling 786 college students at 3 institutions (1 public, 1 Baptist affiliated, 1 Catholic affiliated). The authors used an anonymous survey and statistically…

Perceived Physician-informed Weight Status Predicts Accurate Weight Self-Perception and Weight Self-Regulation in Low-income, African American Women.

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Harris, Charlie L; Strayhorn, Gregory; Moore, Sandra; Goldman, Brian; Martin, Michelle Y

2016-01-01

Obese African American women under-appraise their body mass index (BMI) classification and report fewer weight loss attempts than women who accurately appraise their weight status. This cross-sectional study examined whether physician-informed weight status could predict weight self-perception and weight self-regulation strategies in obese women. A convenience sample of 118 low-income women completed a survey assessing demographic characteristics, comorbidities, weight self-perception, and weight self-regulation strategies. BMI was calculated during nurse triage. Binary logistic regression models were performed to test hypotheses. The odds of obese accurate appraisers having been informed about their weight status were six times greater than those of under-appraisers. The odds of those using an "approach" self-regulation strategy having been physician-informed were four times greater compared with those using an "avoidance" strategy. Physicians are uniquely positioned to influence accurate weight self-perception and adaptive weight self-regulation strategies in underserved women, reducing their risk for obesity-related morbidity.

Clear signals or mixed messages: inter-individual emotion congruency modulates brain activity underlying affective body perception

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de Gelder, B.

2016-01-01

The neural basis of emotion perception has mostly been investigated with single face or body stimuli. However, in daily life one may also encounter affective expressions by groups, e.g. an angry mob or an exhilarated concert crowd. In what way is brain activity modulated when several individuals express similar rather than different emotions? We investigated this question using an experimental design in which we presented two stimuli simultaneously, with same or different emotional expressions. We hypothesized that, in the case of two same-emotion stimuli, brain activity would be enhanced, while in the case of two different emotions, one emotion would interfere with the effect of the other. The results showed that the simultaneous perception of different affective body expressions leads to a deactivation of the amygdala and a reduction of cortical activity. It was revealed that the processing of fearful bodies, compared with different-emotion bodies, relied more strongly on saliency and action triggering regions in inferior parietal lobe and insula, while happy bodies drove the occipito-temporal cortex more strongly. We showed that this design could be used to uncover important differences between brain networks underlying fearful and happy emotions. The enhancement of brain activity for unambiguous affective signals expressed by several people simultaneously supports adaptive behaviour in critical situations. PMID:27025242

Congenital Amusia in linguistic and non-linguistic pitch perception - What behavior and reaction times reveal

NARCIS (Netherlands)

Pfeifer, J.; Hamann, S.; Exter, M.; Campbell, N.; Gibbon, D.; Hirst, D.

2014-01-01

Congenital Amusia is a developmental disorder that has a negative influence on pitch perception. While it used to be described as a disorder of musical pitch perception, recent studies indicate that congenital amusics also show deficits in linguistic pitch perception. This study investigates the

Is Part-Time Child Care Surrogate Parenting? Parents' Perceptions.

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Rana, Avis

The purpose of this survey and report is to gain information about parental planning for child-rearing when the mother is employed. This study is intended to explore mothers' perceptions of possible delegation of some basic child-rearing functions during the mothers' absence for employment. Comparison of the child care arrangements which the…

HIV-Positive Patients' Perceptions of Antiretroviral Therapy Adherence in Relation to Subjective Time: Imprinting, Domino Effects, and Future Shadowing.

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Lessard, David; Toupin, Isabelle; Engler, Kim; Lènàrt, Andràs; Lebouché, Bertrand

2018-01-01

Antiretroviral treatment adherence barriers are major concerns in HIV care. They are multiple and change over time. Considering temporality in patients' perceptions of adherence barriers could improve adherence management. We explored how temporality manifests itself in patients' perceptions of adherence barriers. We conducted 2 semi-structured focus groups on adherence barriers with 12 adults with HIV which were analyzed with grounded theory. A third focus group served to validate the results obtained. Three temporal categories were manifest in HIV-positive patients' perceptions of barriers: (1) imprinting (events with lasting impacts on patients), (2) domino effects (chain of life events), and (3) future shadowing (apprehension about long-term adherence). An overarching theme, weathering (gradual erosion of abilities to adhere), traversed these categories. These temporalities explain how similar barriers may be perceived differently by patients. They could be useful to providers for adapting their interventions and improving understanding of patients' subjective experience of adherence.

Art Perception in the Museum: How We Spend Time and Space in Art Exhibitions.

Science.gov (United States)

Carbon, Claus-Christian

2017-01-01

Aesthetics research aiming at understanding art experience is an emerging field; however, most research is conducted in labs without access to real artworks, without the social context of a museum and without the presence of other persons. The present article replicates and complements key findings of art perception in museum contexts. When observing museum visitors ( N  = 225; 126 female, M (age) = 43.3 years) while perceiving a series of six Gerhard Richter paintings of various sizes (0.26-3.20 sq. m) in a temporary art exhibition in January and February 2015 showing 28 paintings in total, we revealed patterns compatible to previous research. The mean time taken in viewing artworks was much longer than was mostly realized in lab contexts, here 32.9 s ( Mdn  = 25.4 s). We were also able to replicate visitors spending more time on viewing artworks when attending in groups of people. Additionally, we uncovered a close positive relationship ( r 2  = .929) between canvas size and viewing distance, ranging on average between 1.49 and 2.12 m ( M  = 1.72 m). We also found that more than half of the visitors returned to paintings, especially those people who had not previously paid too much attention at the initial viewing. After adding the times of returning viewers, each picture was viewed longer than had been estimated in previous research ( M  = 50.5 s, Mdn  = 43.0 s). Results are discussed in the context of current art perception theories, focusing on the need for the ecologically valid testing of artworks in aesthetics research.

Time perception and illness acceptance among remitting-relapsing multiple sclerosis patients under treatment.

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Król, Joanna; Szcześniak, Małgorzata; Koziarska, Dorota; Rzepa, Teresa

2015-01-01

The aim of the study was to determine temporal orientation in patients diagnosed with RR-MS as compared with that of healthy individuals; to analyse self-evaluated acceptance levels in terms of physical and psychological condition and self-reliance; an attempt to identify factors of illness acceptance in patients with RR-MS including temporal perspective. Acceptance of Illness Scale (AIS, adapted into Polish by Z. Juczyński), Zimbardo Time Perspective Inventory (ZTPI, adapted into Polish by M. Mażewski), and original interview aimed to assess socio-demographic data and self-evaluated physical as well as psychological condition and self-reliance of patients with MS (referred to the neurological testing according to the EDSS). Patients with RR-MS focus on fatalistic and hedonistic present more than healthy individuals. They also tend to reflect on their negative past experience. Acceptance of illness correlated positively with subjective assessment of physical and psychological condition as well as self-reliance, and negatively with objective disability score (measured with the use of EDSS) and a factor considering time of disease duration. Avoiding contemplation of negative past and concentrating on hedonistic future constitute significant predictors of illness acceptance. These results may be of importance in terms of holistic approach to treatment of RR-MS patients. In the initial stage of the disease progression, patients might benefit from psychological support due to change in temporal orientation.

Vision under mesopic and scotopic illumination

Directory of Open Access Journals (Sweden)

Andrew J Zele

2015-01-01

Full Text Available Evidence has accumulated that rod activation under mesopic and scotopic light levels alters visual perception and performance. Here we review the most recent developments in the measurement of rod and cone contributions to mesopic color perception and temporal processing, with a focus on data measured using the four-primary photostimulator method that independently controls rod and cone excitations. We discuss the findings in the context of rod inputs to the three primary retinogeniculate pathways to understand rod contributions to mesopic vision. Additionally, we present evidence that hue perception is possible under scotopic, pure rod-mediated conditions that involves cortical mechanisms.

The influence of attention toward facial expressions on size perception.

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Choi, Jeong-Won; Kim, Kiho; Lee, Jang-Han

2016-01-01

According to the New Look theory, size perception is affected by emotional factors. Although previous studies have attempted to explain the effects of both emotion and motivation on size perception, they have failed to identify the underlying mechanisms. This study aimed to investigate the underlying mechanisms of size perception by applying attention toward facial expressions using the Ebbinghaus illusion as a measurement tool. The participants, female university students, were asked to judge the size of a target stimulus relative to the size of facial expressions (i.e., happy, angry, and neutral) surrounding the target. The results revealed that the participants perceived angry and neutral faces to be larger than happy faces. This finding indicates that individuals pay closer attention to neutral and angry faces than happy ones. These results suggest that the mechanisms underlying size perception involve cognitive processes that focus attention toward relevant stimuli and block out irrelevant stimuli.

Neural Basis of Disgust Perception in Racial Prejudice

NARCIS (Netherlands)

Liu, Yunzhe; Lin, Wanjun; Xu, Pengfei; Zhang, Dandan; Luo, Yuejia

2015-01-01

Worldwide racial prejudice is originated from in-group/out-group discrimination. This prejudice can bias face perception at the very beginning of social interaction. However, little is known about the neurocognitive mechanism underlying the influence of racial prejudice on facial emotion perception.

Risk perception influences athletic pacing strategy.

Science.gov (United States)

Micklewright, Dominic; Parry, David; Robinson, Tracy; Deacon, Greg; Renfree, Andrew; St Clair Gibson, Alan; Matthews, William J

2015-05-01

The objective of this study is to examine risk taking and risk perception associations with perceived exertion, pacing, and performance in athletes. Two experiments were conducted in which risk perception was assessed using the domain-specific risk taking (DOSPERT) scale in 20 novice cyclists (experiment 1) and 32 experienced ultramarathon runners (experiment 2). In experiment 1, participants predicted their pace and then performed a 5-km maximum effort cycling time trial on a calibrated Kingcycle mounted bicycle. Split times and perceived exertion were recorded every kilometer. In experiment 2, each participant predicted their split times before running a 100-km ultramarathon. Split times and perceived exertion were recorded at seven checkpoints. In both experiments, higher and lower risk perception groups were created using median split of DOSPERT scores. In experiment 1, pace during the first kilometer was faster among lower risk perceivers compared with higher risk perceivers (t(18) = 2.0, P = 0.03) and faster among higher risk takers compared with lower risk takers (t(18) = 2.2, P = 0.02). Actual pace was slower than predicted pace during the first kilometer in both the higher risk perceivers (t(9) = -4.2, P = 0.001) and lower risk perceivers (t(9) = -1.8, P = 0.049). In experiment 2, pace during the first 36 km was faster among lower risk perceivers compared with higher risk perceivers (t(16) = 2.0, P = 0.03). Irrespective of risk perception group, actual pace was slower than predicted pace during the first 18 km (t(16) = 8.9, P risk perception groups. Initial pace is associated with an individual's perception of risk, with low perceptions of risk being associated with a faster starting pace. Large differences between predicted and actual pace suggest that the performance template lacks accuracy, perhaps indicating greater reliance on momentary pacing decisions rather than preplanned strategy.

Interbrains cooperation: Hyperscanning and self-perception in joint actions.

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Balconi, Michela; Vanutelli, Maria Elide

2017-08-01

The aim of the present study was to investigate the neural bases of cooperative behaviors and social self-perception underlying the execution of joint actions by using a hyperscanning brain paradigm with functional near-infrared spectroscopy (fNIRS). We firstly found that an artificial positive feedback on the cognitive performance was able to affect the self-perception of social position and hierarchy (higher social ranking) for the dyad, as well as the cognitive performance (decreased error rate, ER, and response times, RTs). In addition, the shared cognitive strategy was concurrently improved within the dyad after this social reinforcing. Secondly, fNIRS measures revealed an increased brain activity in the postfeedback condition for the dyad. Moreover, an interbrain similarity was found for the dyads during the task, with higher coherent prefrontal cortex (PFC) activity for the interagents in the postfeedback condition. Finally, a significant prefrontal brain lateralization effect was revealed, with the left hemisphere being more engaged during the postfeedback condition. To summarize, the self-perception, the cognitive performance, and the shared brain activity were all reinforced by the social feedback within the dyad.

Nurses' perceptions of conflict as constructive or destructive.

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Kim, Wonsun Sunny; Nicotera, Anne M; McNulty, Julie

2015-09-01

The aim of this study was to examine nurses' perceptions of constructive and destructive conflicts and their management among nurses. Conflict among nurses is common and has been associated with lack of collaboration, lack of communication and disruptive behaviour, with the potential to have negative impact teamwork. However, unlike the broader social science literature, positive views of conflict are scarce in the nursing literature. Given the various functions of conflict and the high stakes of ineffective conflict management in nursing, it is necessary to examine how nurses understand both sides of conflict: constructive and destructive. A qualitative descriptive design. Data were collected from 34 full time nurses as part of a conflict skills training course offered over 6 months beginning in October 2009. Each participant was asked to write a weekly journal about conflicts in his/her work place. Data yielded 163 entries (82 classified as constructive and 81 as destructive). Results showed that quality patient care and cooperative communication contributed to the perception that conflict is constructive in nature. The central underlying themes in nurses' perceptions of destructive conflict were time constraints, role conflict and power differences that are not managed through communication. This article helps to identify nursing perceptions of constructive and destructive conflict and to understand complexities nurses face during their interactions with other nurses, physicians and patients. The insight that constructive views are related to constructive processes provides an excellent opportunity for an educational intervention, so that we can educate nurses to analyse problems and learn how to manage conflict with effective collaborative processes. © 2015 John Wiley & Sons Ltd.

Unmanned Ground Vehicle Perception Using Thermal Infrared Cameras

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Rankin, Arturo; Huertas, Andres; Matthies, Larry; Bajracharya, Max; Assad, Christopher; Brennan, Shane; Bellutta, Paolo; Sherwin, Gary W.

2011-01-01

The ability to perform off-road autonomous navigation at any time of day or night is a requirement for some unmanned ground vehicle (UGV) programs. Because there are times when it is desirable for military UGVs to operate without emitting strong, detectable electromagnetic signals, a passive only terrain perception mode of operation is also often a requirement. Thermal infrared (TIR) cameras can be used to provide day and night passive terrain perception. TIR cameras have a detector sensitive to either mid-wave infrared (MWIR) radiation (3-5?m) or long-wave infrared (LWIR) radiation (8-12?m). With the recent emergence of high-quality uncooled LWIR cameras, TIR cameras have become viable passive perception options for some UGV programs. The Jet Propulsion Laboratory (JPL) has used a stereo pair of TIR cameras under several UGV programs to perform stereo ranging, terrain mapping, tree-trunk detection, pedestrian detection, negative obstacle detection, and water detection based on object reflections. In addition, we have evaluated stereo range data at a variety of UGV speeds, evaluated dual-band TIR classification of soil, vegetation, and rock terrain types, analyzed 24 hour water and 12 hour mud TIR imagery, and analyzed TIR imagery for hazard detection through smoke. Since TIR cameras do not currently provide the resolution available from megapixel color cameras, a UGV's daytime safe speed is often reduced when using TIR instead of color cameras. In this paper, we summarize the UGV terrain perception work JPL has performed with TIR cameras over the last decade and describe a calibration target developed by General Dynamics Robotic Systems (GDRS) for TIR cameras and other sensors.

Illness perceptions or recurrence risk perceptions: What comes first? A longitudinal cross-lagged examination among cardiac patients.

Science.gov (United States)

Peleg, Shira; Drori, Erga; Banai, Shmuel; Finkelstein, Ariel; Shiloh, Shoshana

2016-05-01

Previous research suggested that illness perceptions provide the basis for illness risk perceptions through an inductive reasoning process. This study aimed to assess the direction of relationships between illness and recurrence risk perceptions over time, among cardiac patients. A longitudinal study was conducted among 138 patients undergoing coronary angioplasty. Self-report questionnaires measured perceived recurrence risk and illness perceptions one day and one month after catheterisation. Cross-lagged Panel Model Analyses revealed that higher perceptions of timeline, consequences and emotional representations of illness at hospitalisation were associated with higher recurrence risk perceptions one month later. Perceived personal control was the only illness perception with bi-directional associations: higher perceived personal control at hospitalisation was associated with higher recurrence risk perceptions one month later; and higher recurrence risk perceptions at hospitalisation was associated with lower personal control one month later. The findings suggest that the associations between recurrence risk and illness perceptions can only partly be explained by inductive reasoning. Halo effects and defensive processes are suggested as complementary explanations for the observed associations between risk and illness perceptions.

New Communication Technologies, Local Journalism and the Perception of Locality

Directory of Open Access Journals (Sweden)

Ali ÖZCAN

2016-12-01

Full Text Available Studies on local journalism as an important element of participatory democracy generally focus on the history of the local press, the financial insufficiencies of local newspapers as well as technical/ technological incompetency that occurs as a result of these factors. This research analyzes local newspapers with a new scientific point of view by focusing on the perception of locality as a mental projection of geographical constraint. Perspectives regarding the transformations on perceptions of locality as a result of the disappearance of time and space constraints due to new communication technologies, and the opportunities that new communication environments offer to local newspapers will be provided. Moreover, the ways in which local newspapers reflect on locality with their printed versions under time and space constraints will be analyzed. The research scope of the study has been limited to 15 newspapers in Konya. Structured interviews and content analysis methods were used for data collection and analysis.

Influence of Customer Quality Perception on the Effectiveness of Commercial Stimuli for Electronic Products.

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Garrido-Morgado, Álvaro; González-Benito, Óscar; Martos-Partal, Mercedes

2016-01-01

Creating and maintaining customer loyalty are strategic requirements for modern business. In the current competitive context, product quality, and brand experience are crucial in building and maintaining customer loyalty. Consumer loyalty, which may be classified into cognitive loyalty and affective loyalty, is related to customers' quality perception. Cue utilization theory distinguishes two dimensions for perceived quality, extrinsic quality-linked to the brand-and intrinsic quality-related with internal product characteristics. We propose that (i) cognitive loyalty is more influenced by intrinsic product quality whereas extrinsic product quality (brand name) is more salient for affective loyalty and, (ii) different commercial stimuli have a differential effectiveness on intrinsic and extrinsic perceived quality. In fact, in this study, we analyze how perceived quality dimensions may influence the effectiveness of two different commercial stimuli: displays and advertising flyers. While displays work within the point of sale under time-constrained conditions where consumers are more likely to use heuristics to simplify their decisions, advertising flyers work outside of the point of sale under low time-constrained conditions, and therefore favor a more reasoned purchase decision where systematic processing will be more likely. We analyze the role of quality perception in determining the effectiveness of both these commercial stimuli for selling products that induce high purchase involvement and perceived risk. The empirical analysis focuses on computer products sold by one of Europe's largest computer retailers and it combines scanner, observational, and survey data. The results show that both dimensions of quality perceptions moderate the influence of displays and advertising flyers on sales, but their impact is different on each commercial stimuli. Extrinsic quality perception increases to a greater extent the effect of displays due to the use of a brand name

Spontaneous default mode network phase-locking moderates performance perceptions under stereotype threat.

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Forbes, Chad E; Leitner, Jordan B; Duran-Jordan, Kelly; Magerman, Adam B; Schmader, Toni; Allen, John J B

2015-07-01

This study assessed whether individual differences in self-oriented neural processing were associated with performance perceptions of minority students under stereotype threat. Resting electroencephalographic activity recorded in white and minority participants was used to predict later estimates of task errors and self-doubt on a presumed measure of intelligence. We assessed spontaneous phase-locking between dipole sources in left lateral parietal cortex (LPC), precuneus/posterior cingulate cortex (P/PCC), and medial prefrontal cortex (MPFC); three regions of the default mode network (DMN) that are integral for self-oriented processing. Results revealed that minorities with greater LPC-P/PCC phase-locking in the theta band reported more accurate error estimations. All individuals experienced less self-doubt to the extent they exhibited greater LPC-MPFC phase-locking in the alpha band but this effect was driven by minorities. Minorities also reported more self-doubt to the extent they overestimated errors. Findings reveal novel neural moderators of stereotype threat effects on subjective experience. Spontaneous synchronization between DMN regions may play a role in anticipatory coping mechanisms that buffer individuals from stereotype threat. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Reliability-Based Marginal Cost Pricing Problem Case with Both Demand Uncertainty and Travelers’ Perception Errors

Directory of Open Access Journals (Sweden)

Shaopeng Zhong

2013-01-01

Full Text Available Focusing on the first-best marginal cost pricing (MCP in a stochastic network with both travel demand uncertainty and stochastic perception errors within the travelers’ route choice decision processes, this paper develops a perceived risk-based stochastic network marginal cost pricing (PRSN-MCP model. Numerical examples based on an integrated method combining the moment analysis approach, the fitting distribution method, and the reliability measures are also provided to demonstrate the importance and properties of the proposed model. The main finding is that ignoring the effect of travel time reliability and travelers’ perception errors may significantly reduce the performance of the first-best MCP tolls, especially under high travelers’ confidence and network congestion levels. The analysis result could also enhance our understanding of (1 the effect of stochastic perception error (SPE on the perceived travel time distribution and the components of road toll; (2 the effect of road toll on the actual travel time distribution and its reliability measures; (3 the effect of road toll on the total network travel time distribution and its statistics; and (4 the effect of travel demand level and the value of reliability (VoR level on the components of road toll.

Clear signals or mixed messages: inter-individual emotion congruency modulates brain activity underlying affective body perception.

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de Borst, A W; de Gelder, B

2016-08-01

The neural basis of emotion perception has mostly been investigated with single face or body stimuli. However, in daily life one may also encounter affective expressions by groups, e.g. an angry mob or an exhilarated concert crowd. In what way is brain activity modulated when several individuals express similar rather than different emotions? We investigated this question using an experimental design in which we presented two stimuli simultaneously, with same or different emotional expressions. We hypothesized that, in the case of two same-emotion stimuli, brain activity would be enhanced, while in the case of two different emotions, one emotion would interfere with the effect of the other. The results showed that the simultaneous perception of different affective body expressions leads to a deactivation of the amygdala and a reduction of cortical activity. It was revealed that the processing of fearful bodies, compared with different-emotion bodies, relied more strongly on saliency and action triggering regions in inferior parietal lobe and insula, while happy bodies drove the occipito-temporal cortex more strongly. We showed that this design could be used to uncover important differences between brain networks underlying fearful and happy emotions. The enhancement of brain activity for unambiguous affective signals expressed by several people simultaneously supports adaptive behaviour in critical situations. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

On the modeling of epidemics under the influence of risk perception

NARCIS (Netherlands)

De Lillo, S.; Fioriti, G.; Prioriello, M.L.

2017-01-01

An epidemic spreading model is presented in the framework of the kinetic theory of active particles. The model is characterized by the influence of risk perception which can reduce the diffusion of infection. The evolution of the system is modeled through nonlinear interactions, whose output is

Toward time-based design: Creating an applied time evaluation checklist for urban design research

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Amir Shakibamanesh

2017-09-01

Full Text Available The perception of a 3D space, in which movement takes place, is subjectively based on experience. The pedestrians’ perception of subjective duration is one of the related issues that receive little attention in urban design literature. Pedestrians often misperceive the required time to pass a certain distance. A wide range of factors affects one׳s perception of time in urban environments. These factors include individual factors (e.g., gender, age, and psychological state, social and cultural contexts, purpose and motivation for being in the space, and knowledge of the given area. This study aims to create an applied checklist that can be used by urban designers in analyzing the effects of individual experience on subjective duration. This checklist will enable urban designers to perform a phenomenological assessment of time perception and compare this perception in different urban spaces, thereby improving pedestrians’ experiences of time through a purposeful design. A combination of exploratory and descriptive analytical research is used as methodology due to the complexity of time perception.

Effects of Production Training and Perception Training on Lexical Tone Perception--Are the Effects Domain General or Domain Specific?

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Lu, Shuang

2013-01-01

The relationship between speech perception and production has been debated for a long time. The Motor Theory of speech perception (Liberman et al., 1989) claims that perceiving speech is identifying the intended articulatory gestures rather than perceiving the sound patterns. It seems to suggest that speech production precedes speech perception,…

How far from Just-in-time are Portuguese firms? A survey of its progress and perception.

OpenAIRE

Maria Rosário Moreira; Rui Alves

2006-01-01

As competition increases, Just-in-Time (JIT) manufacturing becomes an important issue in Portuguese industry. After a brief review of its history, elements, advantages and limitations, this paper presents the results of a postal questionnaire survey about JIT system sent to a sample of manufacturing firms in Portugal, with the aim of determining the degree of development, perception and status of JIT production in Portuguese industries. The findings suggest that the surveyed firms have a basi...

Collective Activity of Many Bistable Assemblies Reproduces Characteristic Dynamics of Multistable Perception.

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Cao, Robin; Pastukhov, Alexander; Mattia, Maurizio; Braun, Jochen

2016-06-29

The timing of perceptual decisions depends on both deterministic and stochastic factors, as the gradual accumulation of sensory evidence (deterministic) is contaminated by sensory and/or internal noise (stochastic). When human observers view multistable visual displays, successive episodes of stochastic accumulation culminate in repeated reversals of visual appearance. Treating reversal timing as a "first-passage time" problem, we ask how the observed timing densities constrain the underlying stochastic accumulation. Importantly, mean reversal times (i.e., deterministic factors) differ enormously between displays/observers/stimulation levels, whereas the variance and skewness of reversal times (i.e., stochastic factors) keep characteristic proportions of the mean. What sort of stochastic process could reproduce this highly consistent "scaling property?" Here we show that the collective activity of a finite population of bistable units (i.e., a generalized Ehrenfest process) quantitatively reproduces all aspects of the scaling property of multistable phenomena, in contrast to other processes under consideration (Poisson, Wiener, or Ornstein-Uhlenbeck process). The postulated units express the spontaneous dynamics of attractor assemblies transitioning between distinct activity states. Plausible candidates are cortical columns, or clusters of columns, as they are preferentially connected and spontaneously explore a restricted repertoire of activity states. Our findings suggests that perceptual representations are granular, probabilistic, and operate far from equilibrium, thereby offering a suitable substrate for statistical inference. Spontaneous reversals of high-level perception, so-called multistable perception, conform to highly consistent and characteristic statistics, constraining plausible neural representations. We show that the observed perceptual dynamics would be reproduced quantitatively by a finite population of distinct neural assemblies, each with

Understanding human perception by human-made illusions.

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Carbon, Claus-Christian

2014-01-01

IT MAY BE FUN TO PERCEIVE ILLUSIONS, BUT THE UNDERSTANDING OF HOW THEY WORK IS EVEN MORE STIMULATING AND SUSTAINABLE: They can tell us where the limits and capacity of our perceptual apparatus are found-they can specify how the constraints of perception are set. Furthermore, they let us analyze the cognitive sub-processes underlying our perception. Illusions in a scientific context are not mainly created to reveal the failures of our perception or the dysfunctions of our apparatus, but instead point to the specific power of human perception. The main task of human perception is to amplify and strengthen sensory inputs to be able to perceive, orientate and act very quickly, specifically and efficiently. The present paper strengthens this line of argument, strongly put forth by perceptual pioneer Richard L. Gregory (e.g., Gregory, 2009), by discussing specific visual illusions and how they can help us to understand the magic of perception.

On disturbed time continuity in schizophrenia: an elementary impairment in visual perception?

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Anne eGiersch

2013-05-01

Full Text Available Schizophrenia is associated with a series of visual perception impairments, which might impact on the patients’ every day life and be related to clinical symptoms. However, the heterogeneity of the visual disorders make it a challenge to understand both the mechanisms and the consequences of these impairments, i.e. the way patients experience the outer world. Based on earlier psychiatry literature, we argue that issues regarding time might shed a new light on the disorders observed in patients with schizophrenia. We will briefly review the mechanisms involved in the sense of time continuity and clinical evidence that they are impaired in patients with schizophrenia. We will then summarize a recent experimental approach regarding the coding of time-event structure in time, namely the ability to discriminate between simultaneous and asynchronous events. The use of an original method of analysis allowed us to distinguish between explicit and implicit judgements of synchrony. We showed that for SOAs below 20 ms neither patients nor controls fuse events in time. On the contrary subjects distinguish events at an implicit level even when judging them as synchronous. In addition, the implicit responses of patients and controls differ qualitatively. It is as if controls always put more weight on the last occurred event, whereas patients have a difficulty to follow events in time at an implicit level. In patients, there is a clear dissociation between results at short and large asynchronies, that suggest selective mechanisms for the implicit coding of time-event structure. These results might explain the disruption of the sense of time continuity in patients. We argue that this line of research might also help us to better understand the mechanisms of the visual impairments in patients and how they see their environment.

Gender Stereotyping and Female Pupils' Perception of Studying ...

African Journals Online (AJOL)

Gender Stereotyping and Female Pupils' Perception of Studying Advanced Level Sciences: A Survey of One Province in Zimbabwe. C Pinias, VS Matswetu. Abstract. In spite of advances in the field of science and technology, females are still under-represented in the sciences. The study sought to explore the perceptions of ...

Context-Dependent Neural Modulations in the Perception of Duration.

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Murai, Yuki; Yotsumoto, Yuko

2016-01-01

Recent neuroimaging studies have revealed that distinct brain networks are recruited in the perception of sub- and supra-second timescales, whereas psychophysical studies have suggested that there are common or continuous mechanisms for perceiving these two durations. The present study aimed to elucidate the neural implementation of such continuity by examining the neural correlates of peri-second timing. We measured neural activity during a duration reproduction task using functional magnetic resonance imaging. Our results replicate the findings of previous studies in showing that separate neural networks are recruited for sub-versus supra-second time perception: motor systems including the motor cortex and the supplementary motor area for sub-second perception, and the frontal, parietal, and auditory cortical areas for supra-second perception. We further found that the peri-second perception activated both the sub- and supra-second networks, and that the timing system that processed duration perception in previous trials was more involved in subsequent peri-second processing. These results indicate that the sub- and supra-second timing systems overlap at around 1 s, and cooperate to optimally encode duration based on the hysteresis of previous trials.

Role of Cerebellum in Motion Perception and Vestibulo-ocular Reflex—Similarities and Disparities

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Shaikh, Aasef G.; Palla, Antonella; Marti, Sarah; Olasagasti, Itsaso; Optican, Lance M.; Zee, David S.; Straumann, Dominik

2012-01-01

Vestibular velocity storage enhances the efficacy of the angular vestibulo-ocular reflex (VOR) during relatively low-frequency head rotations. This function is modulated by GABA-mediated inhibitory cerebellar projections. Velocity storage also exists in perceptual pathway and has similar functional principles as VOR. However, it is not known whether the neural substrate for perception and VOR overlap. We propose two possibilities. First, there is the same velocity storage for both VOR and perception; second, there are nonoverlapping neural networks: one might be involved in perception and the other for the VOR. We investigated these possibilities by measuring VOR and perceptual responses in healthy human subjects during whole-body, constant-velocity rotation steps about all three dimensions (yaw, pitch, and roll) before and after 10 mg of 4-aminopyridine (4-AP). 4-AP, a selective blocker of inward rectifier potassium conductance, can lead to increased synchronization and precision of Purkinje neuron discharge and possibly enhance the GABAergic action. Hence 4-AP could reduce the decay time constant of the perceived angular velocity and VOR. We found that 4-AP reduced the decay time constant, but the amount of reduction in the two processes, perception and VOR, was not the same, suggesting the possibility of nonoverlapping or partially overlapping neural substrates for VOR and perception. We also noted that, unlike the VOR, the perceived angular velocity gradually built up and plateau prior to decay. Hence, the perception pathway may have additional mechanism that changes the dynamics of perceived angular velocity beyond the velocity storage. 4-AP had no effects on the duration of build-up of perceived angular velocity, suggesting that the higher order processing of perception, beyond the velocity storage, might not occur under the influence of mechanism that could be influenced by 4-AP. PMID:22777507

Physical activity and sedentary time: male perceptions in a university work environment.

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George, Emma S; Kolt, Gregory S; Rosenkranz, Richard R; Guagliano, Justin M

2014-03-01

Promoting physical activity and reducing sedentary time in males can be challenging, and interventions tailored specifically for males are limited. Understanding male perceptions of physical activity and sedentary behavior is important to inform development of relevant interventions, especially for males working in an office setting. As part of a larger intervention study to increase physical activity and reduce sedentary time, male university employees aged 35 to 64 years were invited to partake in focus groups to discuss benefits, motivators, and barriers related to physical activity and sedentary time. Five semistructured focus group sessions, ranging from 50 to 70 minutes in duration, were conducted on two campuses at an Australian university. A total of 15 participants (9 academic/faculty staff and 6 professional staff), with a mean (± SD) age of 46.1 (±8.0) years took part in the study. Health and family were commonly discussed motivators for physical activity, whereas time constraints and work commitments were major barriers to physical activity participation. Sedentary time was a perceived "by-product" of participants' university employment, as a substantial proportion of their days were spent sitting, primarily at a computer. Participants believed that physical activity should be recognized as a legitimate activity at work, embedded within the university culture and endorsed using a top-down approach. It is important to encourage breaks in sedentary time and recognize physical activity as a legitimate health-promoting activity that is supported and encouraged during working hours. These findings can be used as a platform from which to develop targeted strategies to promote physical activity in male university employees.

Reject analysis: A comparison of radiographer and radiologist perceptions of image quality

International Nuclear Information System (INIS)

Mount, J.

2016-01-01

This study explores the potential differences in perceptions of image quality between radiographers and radiologists in a large UK hospital and the subsequent impact this has on image rejection. Image rejection, while sometimes necessary, often leads to an increased radiation dose to the patient due to the need to repeat. Moreover, this translates into increased waiting times, departmental costs, and lower patient satisfaction. Adopting a mixed methods approach, this paper first seeks to quantify the differences in radiographer and radiologist perceptions and second establish the underlying causes of such differences through a quantitative and qualitative investigation respectively. Using a standardized psychometric scale of a GP lateral knee, the study reveals significant differences in the perceptions of quality and rejection rates between radiographers and radiologists driven by a conflict in the evaluation criteria used. The study has significant implications for improving departmental performance and proposes a potential solution for reducing reject rates and image repeats. - Highlights: • Significant differences are found to exist in perceptions of image quality. • Differences in perceptions of image quality directly influence reject rates. • Radiographers judge images on technical criteria. • Radiologists judge images on diagnostic criteria. • Results suggest better communication could reduce reject rates.

Roles of Time Hazard in Perceptual Decision Making under High Time Pressure

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Minju Kim

2011-05-01

Full Text Available The drift diffusion model (DDM has been successful in capturing the joint dynamics of accuracy and latency data in various perceptual decision making tasks. We evaluated how well the DDM describes dynamics of perceptual decision when subjects were under a varying degree of time pressure. We collected choice and latency responses from human subjects, who discriminated the size of a thin ring stimulus with a varying degree of uncertainty. The degree of time pressure was manipulated both by giving subjects an explicit instruction of different time limits across sessions (0.7 ∼ 1.2 s and by providing feedback to responses that were made later than those time limits. When fitted to the data of choice and latency, the three major variants of the DDM (with static bounds & gain, with time-varying bounds, and with time-varying gain showed a systematic pattern of latency-dependent prediction errors. Here we propose a new variant of the DDM, which adopts a ‘boundary for time hazard’ on the time axis in addition to the choice boundary on the choice-evidence axis in decision space. Our model did not exhibit the biased pattern of errors and was superior than the other models in goodness of fit to the data.

Making sense of perceptions of risk of diseases and vaccinations: a qualitative study combining models of health beliefs, decision-making and risk perception

OpenAIRE

Bond Lyndal; Nolan Terry

2011-01-01

Abstract Background Maintaining high levels of childhood vaccinations is important for public health. Success requires better understanding of parents' perceptions of diseases and consequent decisions about vaccinations, however few studies have considered this from the theoretical perspectives of risk perception and decision-making under uncertainty. The aim of this study was to examine the utility of subjective risk perception and decision-making theories to provide a better understanding o...

Perception of Product Risks

NARCIS (Netherlands)

Fischer, A.R.H.

2017-01-01

This chapter provides several explanations for consumer risk perception. For frequently repeated behavior that is seemingly under their own control, consumers tend to be overly optimistic. This occurs in spite of the general tendency of consumers to be risk averse. Specific dimensions of different

The impact of systemic cortical alterations on perception

Science.gov (United States)

Zhang, Zheng

2011-12-01

Perception is the process of transmitting and interpreting sensory information, and the primary somatosensory (SI) area in the human cortex is the main sensory receptive area for the sensation of touch. The elaborate neuroanatomical connectivity that subserves the neuronal communication between adjacent and near-adjacent regions within sensory cortex has been widely recognized to be essential to normal sensory function. As a result, systemic cortical alterations that impact the cortical regional interaction, as associated with many neurological disorders, are expected to have significant impact on sensory perception. Recently, our research group has developed a novel sensory diagnostic system that employs quantitative sensory testing methods and is able to non-invasively assess central nervous system healthy status. The intent of this study is to utilize quantitative sensory testing methods that were designed to generate discriminable perception to objectively and quantitatively assess the impacts of different conditions on human sensory information processing capacity. The correlation between human perceptions with observations from animal research enables a better understanding of the underlying neurophysiology of human perception. Additional findings on different subject populations provide valuable insight of the underlying mechanisms for the development and maintenance of different neurological diseases. During the course of the study, several protocols were designed and utilized. And this set of sensory-based perceptual metrics was employed to study the effects of different conditions (non-noxious thermal stimulation, chronic pain stage, and normal aging) on sensory perception. It was found that these conditions result in significant deviations of the subjects' tactile information processing capacities from normal values. Although the observed shift of sensory detection sensitivity could be a result of enhanced peripheral activity, the changes in the effects

Revisiting diversity: cultural variation reveals the constructed nature of emotion perception.

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Gendron, Maria

2017-10-01

The extent of cultural variation in emotion perception has long been assumed to be bounded by underlying universality. A growing body of research reveals, however, that evidence of universality in emotion perception is method-bound. Without the assumption of underlying universality, new lines of inquiry become relevant. Accumulating evidence suggests that cultures vary in what cues are relevant to perceptions of emotion. Further, cultural groups vary in their spontaneous inferences; mental state inference does not appear to be the only, or even most routine, mode of perception across cultures. Finally, setting universality assumptions aside requires innovation in the theory and measurement of culture. Recent studies reveal the promise of refinements in psychological approaches to culture. Together, the available evidence is consistent with a view of emotion perceptions as actively constructed by perceivers to fit the social and physical constraints of their cultural worlds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Perceptions of acceptable conducts by university students.

Science.gov (United States)

Marques, Dora Nazaré; Macedo, António Filipe

2016-01-01

To determine perceptions of acceptable conducts amongst under and postgraduate optometry students and to compare them with students from other disciplines. Students (under/postgraduate) of optometry (n=156) and other courses (n=54) from University of Minho participated in a voluntary online questionnaire about perception of conducts, classifying as acceptable or unacceptable 15 academic or professional scenarios. 210 questionnaires were analyzed. Differences in perceptions were found between optometry under and postgraduates in scenario 5, Chi-square(2,156)=4.3, p=0.038, and scenario 7, Chi-square(2,156)=7.0, p=0.008 (both with cheating more acceptable for postgrads). Differences between under and postgraduates from other courses were found in scenario 9 (taking supplies from classroom more acceptable for undergrads), Chi-square(1,54)=5.0, p=0.025, and scenario 14 (forging a signature more acceptable for postgrads), Chi-square(1,54)=3.9, p=0.046. Differences between optometry and other courses undergraduates were observed in scenario 2 (plagiarism more acceptable for optometry undergrads), Chi-square(1,154)=8.3, p=0.004 and scenario 9 (taking supplies from classroom more acceptable for other undergrads), chi-square(1,54)=7.8, p=0.005. Differences between optometry and other courses postgraduates were observed in scenario 7, Chi-square(1,56)=5.8, p=0.016, scenario 10 (both with cheating more acceptable for optometry postgrads), chi-square(1,54)=8.1, p=0.004 and scenario 14 (forging a signature more acceptable for other postgrads), Chi-square(1,54)=6.1, p=0.026. Academic misconducts were mainly considered more acceptable than professional misconducts. Our results show that perceptions of acceptable conducts amongst optometry students are not very different from other students, and, against our initial prediction, do not show a general change in misconduct perception when students become more mature. Universities should pay more attention to this problem and take

College Students' Perceptions of Depressed Mood: Exploring Accuracy and Associations.

Science.gov (United States)

Geisner, Irene M; Kirk, Jennifer L; Mittmann, Angela J; Kilmer, Jason R; Larimer, Mary E

2015-10-01

College is a time of high risk for depressed mood. Theories about depression (i.e. Cognitive Theory and Depressive Realism theory) are well researched, but suggest different venues of understanding the cognitive underpinnings of mood. In addition, much research is available about normative perceptions around substance use and how those perceptions relate to behaviors. However, there are no studies examining normative perceptions around depressed mood nor how these perceptions may relate to students' own well-being. Undergraduates (N=1577) ages 18-24 responded to an online survey as part of a larger study on drinking and depressed mood. The survey assessed symptoms of depression and feelings of sadness, depression and suicidal ideation experienced in the past 2 weeks, as well as students' perceptions of the prevalence of these feelings among other students. Rates of sadness and depression reported in the sample were relatively high; whereas rates of reported suicidal ideation were low. Most students under-estimated the prevalence of sadness and depression experienced by other students; a finding that was especially true for male students. Conversely, most students over-estimated the prevalence of suicidal ideation. Students who reported experiencing a given feeling in the past two weeks perceived greater rates of the feeling among other students. Depression symptoms were associated with both greater perceived prevalence of sadness, depression and suicidal ideation, as well as correct and over-estimates of the prevalence of sadness and depression. Implications for future directions in prevention and interventions efforts are discussed.

Interference Control Modulations Over Conscious Perception

Directory of Open Access Journals (Sweden)

Itsaso Colás

2017-05-01

Full Text Available The relation between attention and consciousness has been a controversial topic over the last decade. Although there seems to be an agreement on their distinction at the functional level, no consensus has been reached about attentional processes being or not necessary for conscious perception. Previous studies have explored the relation of alerting and orienting systems of attention and conscious perception, but the impact of the anterior executive attention system on conscious access remains unexplored. In the present study, we investigated the behavioral interaction between executive attention and conscious perception, testing control mechanisms both at stimulus-level representation and after error commission. We presented a classical Stroop task, manipulating the proportion of congruent and incongruent trials, and analyzed the effect of reactive and proactive control on the conscious perception of near-threshold stimuli. Reactive control elicited under high proportion congruent conditions influenced participants’ decision criterion, whereas proactive control elicited under low proportion congruent conditions was ineffective in modulating conscious perception. In addition, error commission affected both perceptual sensitivity to detect near-threshold information and response criterion. These results suggest that reactivation of task goals through reactive control strategies in conflict situations impacts decision stages of conscious processing, whereas interference control elicited by error commission impacts both perceptual sensitivity and decision stages of conscious processing. We discuss the implications of our results for the gateway hypothesis about attention and consciousness, as they showed that interference control (both at stimulus-level representation and after error commission can modulate the conscious access of near-threshold stimuli.

5 CFR 330.504 - Special restrictions after appointment under Part-time Direct Hire Program.

Science.gov (United States)

2010-01-01

... under Part-time Direct Hire Program. 330.504 Section 330.504 Administrative Personnel OFFICE OF... To Protect Competitive Principles § 330.504 Special restrictions after appointment under Part-time Direct Hire Program. (a) A person hired under the Part-time Direct Hire Program may not be changed to...

Effects of different sleep deprivation protocols on sleep perception in healthy volunteers.

Science.gov (United States)

Goulart, Leonardo I; Pinto, Luciano R; Perlis, Michael L; Martins, Raquel; Caboclo, Luis Otavio; Tufik, Sergio; Andersen, Monica L

2014-10-01

To investigate whether different protocols of sleep deprivation modify sleep perception. The effects of total sleep deprivation (TD) and selective rapid eye movement (REM) sleep deprivation (RD) on sleep perception were analyzed in normal volunteers. Thirty-one healthy males with normal sleep were randomized to one of three conditions: (i) normal uninterrupted sleep; (ii) four nights of RD; or (iii) two nights of TD. Morning perception of total sleep time was evaluated for each condition. Sleep perception was estimated using total sleep time (in hours) as perceived by the volunteer divided by the total sleep time (in hours) measured by polysomnography (PSG). The final value of this calculation was defined as the perception index (PI). There were no significant differences among the three groups of volunteers in the total sleep time measured by PSG or in the perception of total sleep time at baseline condition. Volunteers submitted to RD exhibited lower sleep PI scores as compared with controls during the sleep deprivation period (P sleep deprivation reduced the ability of healthy young volunteers to perceive their total sleep time when compared with time measured by PSG. The data reinforce the influence of sleep deprivation on sleep perception. Copyright © 2014 Elsevier B.V. All rights reserved.

Individual differences in the perception of melodic contours and pitch-accent timing in speech: Support for domain-generality of pitch processing.

Science.gov (United States)

Morrill, Tuuli H; McAuley, J Devin; Dilley, Laura C; Hambrick, David Z

2015-08-01

Do the same mechanisms underlie processing of music and language? Recent investigations of this question have yielded inconsistent results. Likely factors contributing to discrepant findings are use of small samples and failure to control for individual differences in cognitive ability. We investigated the relationship between music and speech prosody processing, while controlling for cognitive ability. Participants (n = 179) completed a battery of cognitive ability tests, the Montreal Battery of Evaluation of Amusia (MBEA) to assess music perception, and a prosody test of pitch peak timing discrimination (early, as in insight vs. late, incite). Structural equation modeling revealed that only music perception was a significant predictor of prosody test performance. Music perception accounted for 34.5% of variance on prosody test performance; cognitive abilities and music training added only about 8%. These results indicate musical pitch and temporal processing are highly predictive of pitch discrimination in speech processing, even after controlling for other possible predictors of this aspect of language processing. (c) 2015 APA, all rights reserved).

Wildlife disease and risk perception.

Science.gov (United States)

Hanisch-Kirkbride, Shauna L; Riley, Shawn J; Gore, Meredith L

2013-10-01

Risk perception has an important influence on wildlife management and is particularly relevant to issues that present health risks, such as those associated with wildlife disease management. Knowledge of risk perceptions is useful to wildlife health professionals in developing communication messages that enhance public understanding of wildlife disease risks and that aim to increase public support for disease management. To promote knowledge of public understanding of disease risks in the context of wildlife disease management, we used a self-administered questionnaire mailed to a stratified random sample (n = 901) across the continental United States to accomplish three objectives: 1) assess zoonotic disease risk perceptions; 2) identify sociodemographic and social psychologic factors underlying these risk perceptions; and 3) examine the relationship between risk perception and agreement with wildlife disease management practices. Diseases we assessed in the surveys were rabies, plague, and West Nile virus. Risk perception, as measured by an index consisting of severity, susceptibility, and dread, was greatest for rabies and West Nile virus disease (x = 2.62 and 2.59, respectively, on a scale of 1 to 4 and least for plague (x = 2.39). The four most important variables associated with disease risk perception were gender, education, prior exposure to the disease, and concern for health effects. We found that stronger risk perception was associated with greater agreement with wildlife disease management. We found particular concern for the vulnerability of wildlife to zoonotic disease and for protection of wildlife health, indicating that stakeholders may be receptive to messages emphasizing the potential harm to wildlife from disease and to messages promoting One Health (i.e., those that emphasize the interdependence of human, domestic animal, wildlife, and ecosystem health).

Decision making under time pressure, modeled in a prospect theory framework.

Science.gov (United States)

Young, Diana L; Goodie, Adam S; Hall, Daniel B; Wu, Eric

2012-07-01

The current research examines the effects of time pressure on decision behavior based on a prospect theory framework. In Experiments 1 and 2, participants estimated certainty equivalents for binary gains-only bets in the presence or absence of time pressure. In Experiment 3, participants assessed comparable bets that were framed as losses. Data were modeled to establish psychological mechanisms underlying decision behavior. In Experiments 1 and 2, time pressure led to increased risk attractiveness, but no significant differences emerged in either probability discriminability or outcome utility. In Experiment 3, time pressure reduced probability discriminability, which was coupled with severe risk-seeking behavior for both conditions in the domain of losses. No significant effects of control over outcomes were observed. Results provide qualified support for theories that suggest increased risk-seeking for gains under time pressure.

Music, emotion, and time perception: the influence of subjective emotional valence and arousal?

Science.gov (United States)

Droit-Volet, Sylvie; Ramos, Danilo; Bueno, José L. O.; Bigand, Emmanuel

2013-01-01

The present study used a temporal bisection task with short (2 s) stimulus durations to investigate the effect on time estimation of several musical parameters associated with emotional changes in affective valence and arousal. In order to manipulate the positive and negative valence of music, Experiments 1 and 2 contrasted the effect of musical structure with pieces played normally and backwards, which were judged to be pleasant and unpleasant, respectively. This effect of valence was combined with a subjective arousal effect by changing the tempo of the musical pieces (fast vs. slow) (Experiment 1) or their instrumentation (orchestral vs. piano pieces). The musical pieces were indeed judged more arousing with a fast than with a slow tempo and with an orchestral than with a piano timbre. In Experiment 3, affective valence was also tested by contrasting the effect of tonal (pleasant) vs. atonal (unpleasant) versions of the same musical pieces. The results showed that the effect of tempo in music, associated with a subjective arousal effect, was the major factor that produced time distortions with time being judged longer for fast than for slow tempi. When the tempo was held constant, no significant effect of timbre on the time judgment was found although the orchestral music was judged to be more arousing than the piano music. Nevertheless, emotional valence did modulate the tempo effect on time perception, the pleasant music being judged shorter than the unpleasant music. PMID:23882233

Music, Emotion and Time Perception: The influence of subjective emotional valence and arousal?

Directory of Open Access Journals (Sweden)

SYLVIE eDROIT-VOLET

2013-07-01

Full Text Available The present study used a temporal bisection task with short (< 2 s and long (> 2 s stimulus durations to investigate the effect on time estimation of several musical parameters associated with emotional changes in affective valence and arousal. In order to manipulate the positive and negative valence of music, Experiments 1 and 2 contrasted the effect of musical structure with pieces played normally and backwards, which were judged to be pleasant and unpleasant, respectively. This effect of valence was combined with a subjective arousal effect by changing the tempo of the musical pieces (fast vs. slow (Experiment 1 or their instrumentation (orchestral vs. piano pieces. The musical pieces were indeed judged more arousing with a fast than with a slow tempo and with an orchestral than with a piano timbre. In Experiment 3, affective valence was also tested by contrasting the effect of tonal (pleasant versus atonal (unpleasant versions of the same musical pieces. The results showed that the effect of tempo in music, associated with a subjective arousal effect, was the major factor that produced time distortions with time being judged longer for fast than for slow tempi. When the tempo was held constant, no significant effect of timbre on the time judgment was found although the orchestral music was judged to be more arousing than the piano music. Nevertheless, emotional valence did modulate the tempo effect on time perception, the pleasant music being judged shorter than the unpleasant music.

Music, emotion, and time perception: the influence of subjective emotional valence and arousal?

Science.gov (United States)

Droit-Volet, Sylvie; Ramos, Danilo; Bueno, José L O; Bigand, Emmanuel

2013-01-01

The present study used a temporal bisection task with short (2 s) stimulus durations to investigate the effect on time estimation of several musical parameters associated with emotional changes in affective valence and arousal. In order to manipulate the positive and negative valence of music, Experiments 1 and 2 contrasted the effect of musical structure with pieces played normally and backwards, which were judged to be pleasant and unpleasant, respectively. This effect of valence was combined with a subjective arousal effect by changing the tempo of the musical pieces (fast vs. slow) (Experiment 1) or their instrumentation (orchestral vs. piano pieces). The musical pieces were indeed judged more arousing with a fast than with a slow tempo and with an orchestral than with a piano timbre. In Experiment 3, affective valence was also tested by contrasting the effect of tonal (pleasant) vs. atonal (unpleasant) versions of the same musical pieces. The results showed that the effect of tempo in music, associated with a subjective arousal effect, was the major factor that produced time distortions with time being judged longer for fast than for slow tempi. When the tempo was held constant, no significant effect of timbre on the time judgment was found although the orchestral music was judged to be more arousing than the piano music. Nevertheless, emotional valence did modulate the tempo effect on time perception, the pleasant music being judged shorter than the unpleasant music.

Attention increases the temporal precision of conscious perception: verifying the Neural-ST Model.

Directory of Open Access Journals (Sweden)

Srivas Chennu

2009-11-01

Full Text Available What role does attention play in ensuring the temporal precision of visual perception? Behavioural studies have investigated feature selection and binding in time using fleeting sequences of stimuli in the Rapid Serial Visual Presentation (RSVP paradigm, and found that temporal accuracy is reduced when attentional control is diminished. To reduce the efficacy of attentional deployment, these studies have employed the Attentional Blink (AB phenomenon. In this article, we use electroencephalography (EEG to directly investigate the temporal dynamics of conscious perception. Specifically, employing a combination of experimental analysis and neural network modelling, we test the hypothesis that the availability of attention reduces temporal jitter in the latency between a target's visual onset and its consolidation into working memory. We perform time-frequency analysis on data from an AB study to compare the EEG trials underlying the P3 ERPs (Event-related Potential evoked by targets seen outside vs. inside the AB time window. We find visual differences in phase-sorted ERPimages and statistical differences in the variance of the P3 phase distributions. These results argue for increased variation in the latency of conscious perception during the AB. This experimental analysis is complemented by a theoretical exploration of temporal attention and target processing. Using activation traces from the Neural-ST(2 model, we generate virtual ERPs and virtual ERPimages. These are compared to their human counterparts to propose an explanation of how target consolidation in the context of the AB influences the temporal variability of selective attention. The AB provides us with a suitable phenomenon with which to investigate the interplay between attention and perception. The combination of experimental and theoretical elucidation in this article contributes to converging evidence for the notion that the AB reflects a reduction in the temporal acuity of

Visual perception system and method for a humanoid robot

Science.gov (United States)

Wells, James W. (Inventor); Mc Kay, Neil David (Inventor); Chelian, Suhas E. (Inventor); Linn, Douglas Martin (Inventor); Wampler, II, Charles W. (Inventor); Bridgwater, Lyndon (Inventor)

2012-01-01

A robotic system includes a humanoid robot with robotic joints each moveable using an actuator(s), and a distributed controller for controlling the movement of each of the robotic joints. The controller includes a visual perception module (VPM) for visually identifying and tracking an object in the field of view of the robot under threshold lighting conditions. The VPM includes optical devices for collecting an image of the object, a positional extraction device, and a host machine having an algorithm for processing the image and positional information. The algorithm visually identifies and tracks the object, and automatically adapts an exposure time of the optical devices to prevent feature data loss of the image under the threshold lighting conditions. A method of identifying and tracking the object includes collecting the image, extracting positional information of the object, and automatically adapting the exposure time to thereby prevent feature data loss of the image.

Human perception of indoor environment generated by chilled ceiling combined with mixing ventilation or localised chilled beam under cooling mode

DEFF Research Database (Denmark)

Bolashikov, Zhecho Dimitrov; Nygaard, Linette; Uth, Simon C.

2014-01-01

Experiments with 24 subjects were performed to study and compare the human perception of the indoor environment under summer conditions generated by a chilled ceiling combined with overhead mixing ventilation and localised chilled beam. The experiments were performed in an experimental chamber (4....../s and 16 0C. The localised chilled beam was installed over the workstation placed by the simulated window. During the experiment the subjects were delegated control over the primary flow rate supplied by the localised chilled beam. The whole exposure lasted 2 hours with 30 min of acclimatisation before...

Understanding how biodiversity unfolds through time under neutral theory.

Science.gov (United States)

Missa, Olivier; Dytham, Calvin; Morlon, Hélène

2016-04-05

Theoretical predictions for biodiversity patterns are typically derived under the assumption that ecological systems have reached a dynamic equilibrium. Yet, there is increasing evidence that various aspects of ecological systems, including (but not limited to) species richness, are not at equilibrium. Here, we use simulations to analyse how biodiversity patterns unfold through time. In particular, we focus on the relative time required for various biodiversity patterns (macroecological or phylogenetic) to reach equilibrium. We simulate spatially explicit metacommunities according to the Neutral Theory of Biodiversity (NTB) under three modes of speciation, which differ in how evenly a parent species is split between its two daughter species. We find that species richness stabilizes first, followed by species area relationships (SAR) and finally species abundance distributions (SAD). The difference in timing of equilibrium between these different macroecological patterns is the largest when the split of individuals between sibling species at speciation is the most uneven. Phylogenetic patterns of biodiversity take even longer to stabilize (tens to hundreds of times longer than species richness) so that equilibrium predictions from neutral theory for these patterns are unlikely to be relevant. Our results suggest that it may be unwise to assume that biodiversity patterns are at equilibrium and provide a first step in studying how these patterns unfold through time. © 2016 The Author(s).

How does cognitive load influence speech perception? An encoding hypothesis.

Science.gov (United States)

Mitterer, Holger; Mattys, Sven L

2017-01-01

Two experiments investigated the conditions under which cognitive load exerts an effect on the acuity of speech perception. These experiments extend earlier research by using a different speech perception task (four-interval oddity task) and by implementing cognitive load through a task often thought to be modular, namely, face processing. In the cognitive-load conditions, participants were required to remember two faces presented before the speech stimuli. In Experiment 1, performance in the speech-perception task under cognitive load was not impaired in comparison to a no-load baseline condition. In Experiment 2, we modified the load condition minimally such that it required encoding of the two faces simultaneously with the speech stimuli. As a reference condition, we also used a visual search task that in earlier experiments had led to poorer speech perception. Both concurrent tasks led to decrements in the speech task. The results suggest that speech perception is affected even by loads thought to be processed modularly, and that, critically, encoding in working memory might be the locus of interference.

On the modeling of epidemics under the influence of risk perception

Science.gov (United States)

de Lillo, S.; Fioriti, G.; Prioriello, M. L.

An epidemic spreading model is presented in the framework of the kinetic theory of active particles. The model is characterized by the influence of risk perception which can reduce the diffusion of infection. The evolution of the system is modeled through nonlinear interactions, whose output is described by stochastic games. The results of numerical simulations are discussed for different initial conditions.

Do Corruption Measures Have a Perception Problem

DEFF Research Database (Denmark)

Charron, Nicholas

2016-01-01

How well do corruption perception measures reflect actual levels of public sector corruption? Leading cross-national corruption perception measures have come under much theoretical and empirical scrutiny in recent years, with serious implications for the validity and reliability of the data...... in this ever growing sub-field. Critics argue that perceptions – in particular those of outside experts – do not reflect actual corruption in that they are far too ‘noisy’ or simply biased by external factors such as economic performance. Moreover, a number of recent empirical studies, focused on developing...... areas, have put forth evidence that outside expert assessments of corruption correspond little, if at all, with the experiences and views of actual citizens, and that such a lack of correspondence demonstrates pessimism for existing perception measures. This study offers a systematic analysis...

Inferior Frontal Gyrus Activation Underlies the Perception of Emotions, While Precuneus Activation Underlies the Feeling of Emotions during Music Listening

Science.gov (United States)

Tabei, Ken-ichi

2015-01-01

While music triggers many physiological and psychological reactions, the underlying neural basis of perceived and experienced emotions during music listening remains poorly understood. Therefore, using functional magnetic resonance imaging (fMRI), I conducted a comparative study of the different brain areas involved in perceiving and feeling emotions during music listening. I measured fMRI signals while participants assessed the emotional expression of music (perceived emotion) and their emotional responses to music (felt emotion). I found that cortical areas including the prefrontal, auditory, cingulate, and posterior parietal cortices were consistently activated by the perceived and felt emotional tasks. Moreover, activity in the inferior frontal gyrus increased more during the perceived emotion task than during a passive listening task. In addition, the precuneus showed greater activity during the felt emotion task than during a passive listening task. The findings reveal that the bilateral inferior frontal gyri and the precuneus are important areas for the perception of the emotional content of music as well as for the emotional response evoked in the listener. Furthermore, I propose that the precuneus, a brain region associated with self-representation, might be involved in assessing emotional responses. PMID:26504353

Inferior Frontal Gyrus Activation Underlies the Perception of Emotions, While Precuneus Activation Underlies the Feeling of Emotions during Music Listening.

Science.gov (United States)

Tabei, Ken-ichi

2015-01-01

While music triggers many physiological and psychological reactions, the underlying neural basis of perceived and experienced emotions during music listening remains poorly understood. Therefore, using functional magnetic resonance imaging (fMRI), I conducted a comparative study of the different brain areas involved in perceiving and feeling emotions during music listening. I measured fMRI signals while participants assessed the emotional expression of music (perceived emotion) and their emotional responses to music (felt emotion). I found that cortical areas including the prefrontal, auditory, cingulate, and posterior parietal cortices were consistently activated by the perceived and felt emotional tasks. Moreover, activity in the inferior frontal gyrus increased more during the perceived emotion task than during a passive listening task. In addition, the precuneus showed greater activity during the felt emotion task than during a passive listening task. The findings reveal that the bilateral inferior frontal gyri and the precuneus are important areas for the perception of the emotional content of music as well as for the emotional response evoked in the listener. Furthermore, I propose that the precuneus, a brain region associated with self-representation, might be involved in assessing emotional responses.

The role of sleep in aesthetic perception and empathy: A mediation analysis.

Science.gov (United States)

Peretti, Sara; Tempesta, Daniela; Socci, Valentina; Pino, Maria C; Mazza, Monica; Valenti, Marco; De Gennaro, Luigi; Di Dio, Cinzia; Marchetti, Antonella; Ferrara, Michele

2018-02-06

The ability to experience aesthetics plays a fundamental role in human social interactions, as well as the capacity to feel empathy. Some studies have shown that beauty perception shares part of the neural network underlying emotional and empathic abilities, which are also known to affect sleep quality and duration. In this study, we evaluated for the first time the effects of sleep on the relation between aesthetic perception and empathic abilities in healthy subjects using a mediation analysis approach. One-hundred and twenty-six subjects participated in this study. One-hundred and one subjects slept at home (Sleep Group). The remaining 25 subjects were tested as controls after 1 night of sleep deprivation to assess the effects of lack of sleep on aesthetic perception and empathy (Sleep-Deprived Group). All participants underwent one testing session in which they performed a battery of empathy tests and an aesthetic perception task (Golden Beauty). The results showed that sleep duration mediates the relationship between empathy and aesthetic perception in the sleep group. The mediation effect of sleep was more evident on the emotional empathy measures. Conversely, in the sleep deprivation group the lack of correlations among empathy, aesthetic perception and sleep variables did not allow to perform the mediation analysis. These results suggest that adequate sleep duration may play a significant role in improving cognitive and emotional empathic abilities as well as the capability to give accurate aesthetic judgements. © 2018 European Sleep Research Society.

Monolayer phosphorene under time-dependent magnetic field

Science.gov (United States)

Nascimento, J. P. G.; Aguiar, V.; Guedes, I.

2018-02-01

We obtain the exact wave function of a monolayer phosphorene under a low-intensity time-dependent magnetic field using the dynamical invariant method. We calculate the quantum-mechanical energy expectation value and the transition probability for a constant and an oscillatory magnetic field. For the former we observe that the Landau level energy varies linearly with the quantum numbers n and m and the magnetic field intensity B0. No transition takes place. For the latter, we observe that the energy oscillates in time, increasing linearly with the Landau level n and m and nonlinearly with the magnetic field. The (k , l) →(n , m) transitions take place only for l = m. We investigate the (0,0) →(n , 0) and (1 , l) and (2 , l) probability transitions.

Adolescent Perceptions of Underage Drinkers in TV Beer Ads.

Science.gov (United States)

Slater, Michael D.; And Others

1996-01-01

Tests adolescents' perception of characters' ages in four television beer advertisements and examines correlational relationships between such age judgments and alcohol use. Some 39.4% of participants reported that the youngest character was under 21. Perceptions were positively related to amount of alcohol use among junior high school students,…

Bayesian Model Selection under Time Constraints

Science.gov (United States)

Hoege, M.; Nowak, W.; Illman, W. A.

2017-12-01

Bayesian model selection (BMS) provides a consistent framework for rating and comparing models in multi-model inference. In cases where models of vastly different complexity compete with each other, we also face vastly different computational runtimes of such models. For instance, time series of a quantity of interest can be simulated by an autoregressive process model that takes even less than a second for one run, or by a partial differential equations-based model with runtimes up to several hours or even days. The classical BMS is based on a quantity called Bayesian model evidence (BME). It determines the model weights in the selection process and resembles a trade-off between bias of a model and its complexity. However, in practice, the runtime of models is another weight relevant factor for model selection. Hence, we believe that it should be included, leading to an overall trade-off problem between bias, variance and computing effort. We approach this triple trade-off from the viewpoint of our ability to generate realizations of the models under a given computational budget. One way to obtain BME values is through sampling-based integration techniques. We argue with the fact that more expensive models can be sampled much less under time constraints than faster models (in straight proportion to their runtime). The computed evidence in favor of a more expensive model is statistically less significant than the evidence computed in favor of a faster model, since sampling-based strategies are always subject to statistical sampling error. We present a straightforward way to include this misbalance into the model weights that are the basis for model selection. Our approach follows directly from the idea of insufficient significance. It is based on a computationally cheap bootstrapping error estimate of model evidence and is easy to implement. The approach is illustrated in a small synthetic modeling study.

Influence of Customer Quality Perception on the Effectiveness of Commercial Stimuli for Electronic Products

Science.gov (United States)

Garrido-Morgado, Álvaro; González-Benito, Óscar; Martos-Partal, Mercedes

2016-01-01

Creating and maintaining customer loyalty are strategic requirements for modern business. In the current competitive context, product quality, and brand experience are crucial in building and maintaining customer loyalty. Consumer loyalty, which may be classified into cognitive loyalty and affective loyalty, is related to customers' quality perception. Cue utilization theory distinguishes two dimensions for perceived quality, extrinsic quality—linked to the brand—and intrinsic quality—related with internal product characteristics. We propose that (i) cognitive loyalty is more influenced by intrinsic product quality whereas extrinsic product quality (brand name) is more salient for affective loyalty and, (ii) different commercial stimuli have a differential effectiveness on intrinsic and extrinsic perceived quality. In fact, in this study, we analyze how perceived quality dimensions may influence the effectiveness of two different commercial stimuli: displays and advertising flyers. While displays work within the point of sale under time-constrained conditions where consumers are more likely to use heuristics to simplify their decisions, advertising flyers work outside of the point of sale under low time-constrained conditions, and therefore favor a more reasoned purchase decision where systematic processing will be more likely. We analyze the role of quality perception in determining the effectiveness of both these commercial stimuli for selling products that induce high purchase involvement and perceived risk. The empirical analysis focuses on computer products sold by one of Europe's largest computer retailers and it combines scanner, observational, and survey data. The results show that both dimensions of quality perceptions moderate the influence of displays and advertising flyers on sales, but their impact is different on each commercial stimuli. Extrinsic quality perception increases to a greater extent the effect of displays due to the use of a brand

Influence of customer quality perception on the effectiveness of commercial stimuli for electronic products

Directory of Open Access Journals (Sweden)

Álvaro eGarrido-Morgado

2016-03-01

Full Text Available Creating and maintaining customer loyalty are strategic requirements for modern business. In the current competitive context, product quality and brand experience are crucial in building and maintaining customer loyalty. Consumer loyalty, which may be classified into cognitive loyalty and affective loyalty, is related to customers’ quality perception. Cue utilization theory distinguishes two dimensions for perceived quality, extrinsic quality –linked to the brand– and intrinsic quality –related with internal product characteristics. We propose that (i cognitive loyalty is more influenced by intrinsic product quality whereas extrinsic product quality (brand name is more salient for affective loyalty and, (ii different commercial stimuli have a differential effectiveness on intrinsic and extrinsic perceived quality. In fact, in this study, we analyze how perceived quality dimensions may influence the effectiveness of two different commercial stimuli: displays and advertising flyers. While displays work within the point of sale under time-constrained conditions where consumers are more likely to use heuristics to simplify their decisions, advertising flyers work outside of the point of sale under low time-constrained conditions, and therefore favor a more reasoned purchase decision where systematic processing will be more likely. We analyze the role of quality perception in determining the effectiveness of both these commercial stimuli for selling products that induce high purchase involvement and perceived risk. The empirical analysis focuses on computer products sold by one of Europe’s largest computer retailers and it combines scanner, observational, and survey data. The results show that both dimensions of quality perceptions moderate the influence of displays and advertising flyers on sales, but their impact is different on each commercial stimuli. Extrinsic quality perception increases to a greater extent the effect of displays due

Decision making under time pressure, modeled in a prospect theory framework

Science.gov (United States)

Young, Diana L.; Goodie, Adam S.; Hall, Daniel B.; Wu, Eric

2012-01-01

The current research examines the effects of time pressure on decision behavior based on a prospect theory framework. In Experiments 1 and 2, participants estimated certainty equivalents for binary gains-only bets in the presence or absence of time pressure. In Experiment 3, participants assessed comparable bets that were framed as losses. Data were modeled to establish psychological mechanisms underlying decision behavior. In Experiments 1 and 2, time pressure led to increased risk attractiveness, but no significant differences emerged in either probability discriminability or outcome utility. In Experiment 3, time pressure reduced probability discriminability, which was coupled with severe risk-seeking behavior for both conditions in the domain of losses. No significant effects of control over outcomes were observed. Results provide qualified support for theories that suggest increased risk-seeking for gains under time pressure. PMID:22711977

On robust forecasting of autoregressive time series under censoring

OpenAIRE

Kharin, Y.; Badziahin, I.

2009-01-01

Problems of robust statistical forecasting are considered for autoregressive time series observed under distortions generated by interval censoring. Three types of robust forecasting statistics are developed; meansquare risk is evaluated for the developed forecasting statistics. Numerical results are given.

Rapid encoding and perception of novel odors in the rat.

Directory of Open Access Journals (Sweden)

Daniel W Wesson

2008-04-01

Full Text Available To gain insight into which parameters of neural activity are important in shaping the perception of odors, we combined a behavioral measure of odor perception with optical imaging of odor representations at the level of receptor neuron input to the rat olfactory bulb. Instead of the typical test of an animal's ability to discriminate two familiar odorants by exhibiting an operant response, we used a spontaneously expressed response to a novel odorant-exploratory sniffing-as a measure of odor perception. This assay allowed us to measure the speed with which rats perform spontaneous odor discriminations. With this paradigm, rats discriminated and began responding to a novel odorant in as little as 140 ms. This time is comparable to that measured in earlier studies using operant behavioral readouts after extensive training. In a subset of these trials, we simultaneously imaged receptor neuron input to the dorsal olfactory bulb with near-millisecond temporal resolution as the animal sampled and then responded to the novel odorant. The imaging data revealed that the bulk of the discrimination time can be attributed to the peripheral events underlying odorant detection: receptor input arrives at the olfactory bulb 100-150 ms after inhalation begins, leaving only 50-100 ms for central processing and response initiation. In most trials, odor discrimination had occurred even before the initial barrage of receptor neuron firing had ceased and before spatial maps of activity across glomeruli had fully developed. These results suggest a coding strategy in which the earliest-activated glomeruli play a major role in the initial perception of odor quality, and place constraints on coding and processing schemes based on simple changes in spike rate.

Farmers' perceptions of goat kid mortality under communal farming in Eastern Cape, South Africa.

Science.gov (United States)

Slayi, Mhlangabezi; Maphosa, Viola; Fayemi, Olutope Peter; Mapfumo, Lizwell

2014-10-01

Rearing of goats under communal farming conditions is characterised by high kid mortality and low weaning percentages. A survey was conducted to determine farmers' perceptions on the causes of kid mortality during summer under the communal farming system in Nkonkobe Local Municipality in the Eastern Cape, South Africa. This was done by administering questionnaires to a total of 162 respondents in 14 villages around Nkonkobe Local Municipality. The study showed that majority of farmers (75 %) keep flock sizes of less than 10 goats and kids, and this indicates that goat production in Nkonkobe Local Municipality is suppressed. According to the farmers, diseases (89 %), endo-parasites (72 %) and ecto-parasites (68 %) were perceived as the major causes of kid mortality. Other causes reported include starvation (15 %), extreme weather conditions (28 %), abortion (7 %), theft (35 %), diarrhoea (43 %), accidents (10 %) and wounds (9 %). The low number of goats could be attributed to high mortalities. It was also found that all causes reported by farmers played a role in high kid mortality in Nkonkobe Local Municipality. However, the causes which require more emphasis to formulate extension support were tick-borne diseases and parasites. This study provided baseline information on possible causes of kid mortalities in Nkonkobe Local Municipality. There is, however, a need to conduct further studies to determine actual causes of high kid mortalities so as to develop preventive strategies that would minimize kid mortality for good economic returns.

Reentrant processing in intuitive perception.

Directory of Open Access Journals (Sweden)

Phan Luu

Full Text Available The process of perception requires not only the brain's receipt of sensory data but also the meaningful organization of that data in relation to the perceptual experience held in memory. Although it typically results in a conscious percept, the process of perception is not fully conscious. Research on the neural substrates of human visual perception has suggested that regions of limbic cortex, including the medial orbital frontal cortex (mOFC, may contribute to intuitive judgments about perceptual events, such as guessing whether an object might be present in a briefly presented fragmented drawing. Examining dense array measures of cortical electrical activity during a modified Waterloo Gestalt Closure Task, results show, as expected, that activity in medial orbital frontal electrical responses (about 250 ms was associated with intuitive judgments. Activity in the right temporal-parietal-occipital (TPO region was found to predict mOFC (approximately 150 ms activity and, in turn, was subsequently influenced by the mOFC at a later time (approximately 300 ms. The initial perception of gist or meaning of a visual stimulus in limbic networks may thus yield reentrant input to the visual areas to influence continued development of the percept. Before perception is completed, the initial representation of gist may support intuitive judgments about the ongoing perceptual process.

Towards best-case response times of real-time tasks under fixed-priority scheduling with deferred preemption

NARCIS (Netherlands)

Bril, R.J.; Verhaegh, W.F.J.; Puaut, I.

2005-01-01

In this paper, we present lower bounds for best-case response times of periodic tasks under fixed-priority scheduling with deferred preemption (FPDS) and arbitrary phasing. Our analysis is based on a dedicated conjecture for a ¿-optimal instant, and uses the notion of best-case occupied time. We

Surface color perception under two illuminants: the second illuminant reduces color constancy

Science.gov (United States)

Yang, Joong Nam; Shevell, Steven K.

2003-01-01

This study investigates color perception in a scene with two different illuminants. The two illuminants, in opposite corners, simultaneously shine on a (simulated) scene with an opaque dividing wall, which controls how much of the scene is illuminated by each source. In the first experiment, the height of the dividing wall was varied. This changed the amount of each illuminant reaching objects on the opposite side of the wall. Results showed that the degree of color constancy decreased when a region on one side of the wall had cues to both illuminants, suggesting that cues from the second illuminant are detrimental to color constancy. In a later experiment, color constancy was found to improve when the specular highlight cues from the second illuminant were altered to be consistent with the first illuminant. This corroborates the influence of specular highlights in surface color perception, and suggests that the reduced color constancy in the first experiment is due to the inconsistent, though physically correct, cues from the two illuminants.

A Longitudinal Study on Newcomers' Perception of Organisational Culture

Science.gov (United States)

Turker, Duygu; Altuntas, Ceren

2015-01-01

Purpose: The purpose of this paper is to analyse how newcomers' perceptions of organisational culture can change over time. The study tries to address whether initial working experience changes newcomers' perceptions about the ideal organisational culture, and whether these perceptions converge with those of their supervisors.…

The perception of hazards

International Nuclear Information System (INIS)

Fritzsche, A.F.

1986-01-01

The fourth chapter deals with the profusion of factors determining the differing assessment of hazards by our society. Subjective factors influencing risk perception comprise, among others, general knowledge and recognition of a hazard; the degree of voluntariness when taking the risk and its influencibility; the problem of large scale accidents; immediate and delayed results. Next to the objective and the subjective risks, the individual and the social or collective risks are assessed differently. The author dicusses in detail recent investigations into and study methods for the determination of risk perception, while eliminating systematic trends from subjective perception since common assessments are shared by whole groups of individuals time and again which allow a better understanding of today's handling of hazards. (HSCH) [de

Perception bias in route choice

NARCIS (Netherlands)

Vreeswijk, Jacob Dirk; Thomas, Tom; van Berkum, Eric C.; van Arem, Bart

2014-01-01

Travel time is probably one of the most studied attributes in route choice. Recently, perception of travel time received more attention as several studies have shown its importance in explaining route choice behavior. In particular, travel time estimates by travelers appear to be biased against

Perceptions of Pediatric Nephrologists regarding Timing of Dialysis Initiation in Children in Canada

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Jeremy A. Saban

2016-07-01

Full Text Available Background: Significant practice variation exists in Canada with respect to timing of dialysis initiation in children. In the absence of evidence to guide practice, physicians' perceptions may significantly influence decision-making. Objective: The objectives of this study are to (1 evaluate Canadian pediatric nephrologists' perceptions regarding dialysis initiation in children with chronic kidney disease (CKD and (2 determine the factors guiding practice that may contribute to practice variation across Canada. Design: This study was a cross-sectional online survey. Setting: This study was done in academic pediatric nephrology centers in Canada. Participants: The participants of this study are pediatric nephrologists. Measurements and methods: An anonymous web-based survey was administered to pediatric nephrologists in Canada to evaluate perspectives and practice patterns regarding timing of dialysis initiation. We also explored the importance of estimated glomerular filtration rate (eGFR vs. symptoms and the role of patient and provider factors influencing decisions. Results: Thirty-five nephrologists (59 % completed the survey. Most respondents care for advanced CKD patients in a multidisciplinary clinic (86 % and no centers have a formal policy on timing of dialysis initiation. Seventy-five percent of centers follow 30 patients. Discussions about dialysis initiation are generally informal (75 % and the decision to start is made by the nephrologist (37 % or a team (57 %. Fifty percent agreed GFR was important when deciding when to initiate dialysis, 41 % were neutral, and 9 % disagreed. Variability exists in the threshold that nephrologists considered early (vs. late dialysis initiation: >20 (21 %, >15 (38 %, >12 (26 %, and >10 ml/min/1.73 m 2 (12 %. Practitioners however typically start dialysis in asymptomatic patients at eGFRs of 7–9 (9 %, 10–11 (41 %, 12–14 (38 %, and 15–19 (6 % ml/min/1.73 m 2 . Patient factors important in the

GABA shapes the dynamics of bistable perception.

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van Loon, Anouk M; Knapen, Tomas; Scholte, H Steven; St John-Saaltink, Elexa; Donner, Tobias H; Lamme, Victor A F

2013-05-06

Sometimes, perception fluctuates spontaneously between two distinct interpretations of a constant sensory input. These bistable perceptual phenomena provide a unique window into the neural mechanisms that create the contents of conscious perception. Models of bistable perception posit that mutual inhibition between stimulus-selective neural populations in visual cortex plays a key role in these spontaneous perceptual fluctuations. However, a direct link between neural inhibition and bistable perception has not yet been established experimentally. Here, we link perceptual dynamics in three distinct bistable visual illusions (binocular rivalry, motion-induced blindness, and structure from motion) to measurements of gamma-aminobutyric acid (GABA) concentrations in human visual cortex (as measured with magnetic resonance spectroscopy) and to pharmacological stimulation of the GABAA receptor by means of lorazepam. As predicted by a model of neural interactions underlying bistability, both higher GABA concentrations in visual cortex and lorazepam administration induced slower perceptual dynamics, as reflected in a reduced number of perceptual switches and a lengthening of percept durations. Thus, we show that GABA, the main inhibitory neurotransmitter, shapes the dynamics of bistable perception. These results pave the way for future studies into the competitive neural interactions across the visual cortical hierarchy that elicit conscious perception. Copyright © 2013 Elsevier Ltd. All rights reserved.

Continuous Time Portfolio Selection under Conditional Capital at Risk

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Gordana Dmitrasinovic-Vidovic

2010-01-01

Full Text Available Portfolio optimization with respect to different risk measures is of interest to both practitioners and academics. For there to be a well-defined optimal portfolio, it is important that the risk measure be coherent and quasiconvex with respect to the proportion invested in risky assets. In this paper we investigate one such measure—conditional capital at risk—and find the optimal strategies under this measure, in the Black-Scholes continuous time setting, with time dependent coefficients.

Crash probability estimation via quantifying driver hazard perception.

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Li, Yang; Zheng, Yang; Wang, Jianqiang; Kodaka, Kenji; Li, Keqiang

2018-07-01

Crash probability estimation is an important method to predict the potential reduction of crash probability contributed by forward collision avoidance technologies (FCATs). In this study, we propose a practical approach to estimate crash probability, which combines a field operational test and numerical simulations of a typical rear-end crash model. To consider driver hazard perception characteristics, we define a novel hazard perception measure, called as driver risk response time, by considering both time-to-collision (TTC) and driver braking response to impending collision risk in a near-crash scenario. Also, we establish a driving database under mixed Chinese traffic conditions based on a CMBS (Collision Mitigation Braking Systems)-equipped vehicle. Applying the crash probability estimation in this database, we estimate the potential decrease in crash probability owing to use of CMBS. A comparison of the results with CMBS on and off shows a 13.7% reduction of crash probability in a typical rear-end near-crash scenario with a one-second delay of driver's braking response. These results indicate that CMBS is positive in collision prevention, especially in the case of inattentive drivers or ole drivers. The proposed crash probability estimation offers a practical way for evaluating the safety benefits in the design and testing of FCATs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neural networks for perception human and machine perception

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Wechsler, Harry

1991-01-01

Neural Networks for Perception, Volume 1: Human and Machine Perception focuses on models for understanding human perception in terms of distributed computation and examples of PDP models for machine perception. This book addresses both theoretical and practical issues related to the feasibility of both explaining human perception and implementing machine perception in terms of neural network models. The book is organized into two parts. The first part focuses on human perception. Topics on network model ofobject recognition in human vision, the self-organization of functional architecture in t

College Students’ Perceptions of Depressed Mood: Exploring Accuracy and Associations

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Geisner, Irene M.; Kirk, Jennifer L.; Mittmann, Angela J.; Kilmer, Jason R.; Larimer, Mary E.

2015-01-01

College is a time of high risk for depressed mood. Theories about depression (i.e. Cognitive Theory and Depressive Realism theory) are well researched, but suggest different venues of understanding the cognitive underpinnings of mood. In addition, much research is available about normative perceptions around substance use and how those perceptions relate to behaviors. However, there are no studies examining normative perceptions around depressed mood nor how these perceptions may relate to students’ own well-being. Undergraduates (N=1577) ages 18–24 responded to an online survey as part of a larger study on drinking and depressed mood. The survey assessed symptoms of depression and feelings of sadness, depression and suicidal ideation experienced in the past 2 weeks, as well as students’ perceptions of the prevalence of these feelings among other students. Rates of sadness and depression reported in the sample were relatively high; whereas rates of reported suicidal ideation were low. Most students under-estimated the prevalence of sadness and depression experienced by other students; a finding that was especially true for male students. Conversely, most students over-estimated the prevalence of suicidal ideation. Students who reported experiencing a given feeling in the past two weeks perceived greater rates of the feeling among other students. Depression symptoms were associated with both greater perceived prevalence of sadness, depression and suicidal ideation, as well as correct and over-estimates of the prevalence of sadness and depression. Implications for future directions in prevention and interventions efforts are discussed. PMID:26500389

Adaptive and Selective Time Averaging of Auditory Scenes

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McWalter, Richard Ian; McDermott, Josh H.

2018-01-01

longer than previously reported integration times in the auditory system. Integration also showed signs of being restricted to sound elements attributed to a common source. The results suggest an integration process that depends on stimulus characteristics, integrating over longer extents when......To overcome variability, estimate scene characteristics, and compress sensory input, perceptual systems pool data into statistical summaries. Despite growing evidence for statistical representations in perception, the underlying mechanisms remain poorly understood. One example...... it benefits statistical estimation of variable signals and selectively integrating stimulus components likely to have a common cause in the world. Our methodology could be naturally extended to examine statistical representations of other types of sensory signals. Sound texture perception is thought...

Sensory perception: lessons from synesthesia: using synesthesia to inform the understanding of sensory perception.

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Harvey, Joshua Paul

2013-06-01

Synesthesia, the conscious, idiosyncratic, repeatable, and involuntary sensation of one sensory modality in response to another, is a condition that has puzzled both researchers and philosophers for centuries. Much time has been spent proving the condition's existence as well as investigating its etiology, but what can be learned from synesthesia remains a poorly discussed topic. Here, synaesthesia is presented as a possible answer rather than a question to the current gaps in our understanding of sensory perception. By first appreciating the similarities between normal sensory perception and synesthesia, one can use what is known about synaesthesia, from behavioral and imaging studies, to inform our understanding of "normal" sensory perception. In particular, in considering synesthesia, one can better understand how and where the different sensory modalities interact in the brain, how different sensory modalities can interact without confusion - the binding problem - as well as how sensory perception develops.

Consumer Food Safety Risk Attitudes and Perceptions Over Time: The Case of BSE Crisis

OpenAIRE

Kalogeras, Nikos; Pennings, Joost M.E.; van Ittersum, Koert

2008-01-01

Recent research has shown that by decoupling the risk response behaviour of consumers into the separate components of risk perception and risk attitude, a more robust conceptualization and prediction of consumers’ reactions to food safety issues is possible. Furthermore, it has been argued that the influence of risk attitudes and risk perceptions on consumer risk behaviour for contaminated food products can be used to formulate effective agricultural policies and strategies in case of a food ...

Patient perceptions regarding physician reimbursements, wait times, and out-of-pocket payments for anterior cruciate ligament reconstruction in Ontario.

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Memon, Muzammil; Ginsberg, Lydia; de Sa, Darren; Nashed, Andrew; Simunovic, Nicole; Phillips, Mark; Denkers, Matthew; Ogilvie, Rick; Peterson, Devin; Ayeni, Olufemi R

2017-12-01

Currently, there is a lack of knowledge regarding patient perceptions surrounding physician reimbursements, appropriate wait times, and out-of-pocket payment options for anterior cruciate ligament reconstruction (ACLR). Our objective was to determine the current state of these perceptions in an Ontario setting. A survey was developed and pretested to address patient perceptions about physician reimbursements, appropriate wait times, and out-of-pocket payment options for ACLR using a focus group of experts and by reviewing prior surveys. The survey was administered to patients in a waiting room setting. Two hundred and fifty completed surveys were obtained (79.9% response rate). Participants responded that an appropriate physician reimbursement for ACLR was $1000.00 and that the Ontario Health Insurance Plan (OHIP) reimbursed physicians $700.00 for ACLR. Seventy-four percent of participants responded that the OHIP reimbursement of $615.20 for the procedure was either lower or much lower than what they considered to be an appropriate reimbursement for ACLR. Over 90% of participants responded that an ACLR should occur within 90 days of injury. Thirty-five percent of participants were willing to pay $750.00 out-of-pocket to have an ACLR done sooner, while 16.4% of participants were willing to pay $2500.00 out-of-pocket to travel outside of Canada for expedited surgery. This survey study demonstrates that patients' estimates of both appropriate and actual physician reimbursements were greater than the current reimbursement for ACLR. Further, the majority of individuals report that the surgical fee for ACLR is lower than what they consider to be an appropriate amount of compensation for the procedure. Additionally, nearly all respondents believe that a ruptured ACL should be reconstructed within 90 days of injury. Consequently, a number of patients are willing to pay out-of-pocket for expedited surgery either in Canada or abroad. However, patients' preferences for

[Physician and autonomy: on time perception and job satisfaction].

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Huisman, Frank G

2015-01-01

Is it true that haste is sneaking into medicine? In this article, it is argued that it mainly concerns the perception of being rushed, which is caused by a loss of autonomy of the modern physician. In the fifties, physicians were busy as well, but because they enjoyed a greater degree of autonomy compared to their contemporary colleagues, they did not experience this in a negative way. Due to increased bureaucracy and the introduction of market dynamics, the medical profession has lost autonomy, which in turn led to a loss of job satisfaction.

Does Attorney Advertising Influence Patient Perceptions of Pelvic Mesh?

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Tippett, Elizabeth; King, Jesse; Lucent, Vincent; Ephraim, Sonya; Murphy, Miles; Taff, Eileen

2018-01-01

To measure the relative influence of attorney advertising on patient perceptions of pelvic mesh compared with a history of surgery and a first urology visit. A 52-item survey was administered to 170 female patients in 2 urology offices between 2014 and 2016. Multiple survey items were combined to form scales for benefit and risk perceptions of pelvic mesh, perceptions of the advertising, attitudes toward pelvic mesh, and knowledge of pelvic mesh and underlying medical conditions. Data were analyzed using hierarchical linear regression models. Exposure to attorney advertising was quite high; 88% reported seeing a mesh-related attorney advertisement in the last 6 months. Over half of patients reported seeing attorney advertisements more than once per week. A history of prior mesh implant surgery was the strongest predictor of benefit and risk perceptions of pelvic mesh. Exposure to attorney advertising was associated with higher risk perceptions but did not significantly affect perceptions of benefits. Past urologist visits increased perceptions of benefits but had no effect on risk perceptions. Attorney advertising appears to have some influence on risk perceptions, but personal experience and discussions with a urogynecologist or urologist also influence patient perceptions. Implications, limitations, and future research are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Patients' perception of DED and its relation with time to diagnosis and quality of life: an international and multilingual survey.

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Labetoulle, Marc; Rolando, Maurizio; Baudouin, Christophe; van Setten, Gysbert

2017-08-01

To improve understanding of patients' experience and perception of dry eye disease (DED) and its impact on quality of life (QoL). This survey was observational, non-interventional and cross-sectional. The survey was conducted online on 706 patients with DED from five European countries (France, Germany, Italy, Spain and the UK). All patients met the following inclusion criteria: 40 years or older with DED diagnosed by a healthcare professional (HCP), not wearing contact lenses and using tear substitutes daily for at least 6 months. The survey (performed in the five native languages) included 9 screening questions (inclusion criteria) and 26 complementary questions about patients' demography, disease history, DED diagnosis, use of relief treatments, perceptions of DED condition and its impact on QoL. Overall, 218 of 706 (31%) patients perceived DED as a 'disease' or even a 'handicap', and 468 of 706 (66%) as a 'discomfort'. High impact of DED on patients' QoL was associated with negative perception, delay in diagnosis, visits to more than one HCP before diagnosis and high frequency of treatment use. This survey also provided us with a list of language-specific keywords that patients used most frequently to spontaneously describe their condition. Findings showed that negative perception of DED, delayed diagnosis and high frequency of treatment use were inter-related, and that all have a negative impact on patients' QoL. The generated language-specific keywords used to describe DED could serve as the basis for a comprehensive QoL questionnaire to be used in clinical settings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Computer Breakdown as a Stress Factor during Task Completion under Time Pressure: Identifying Gender Differences Based on Skin Conductance

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René Riedl

2013-01-01

Full Text Available In today’s society, as computers, the Internet, and mobile phones pervade almost every corner of life, the impact of Information and Communication Technologies (ICT on humans is dramatic. The use of ICT, however, may also have a negative side. Human interaction with technology may lead to notable stress perceptions, a phenomenon referred to as technostress. An investigation of the literature reveals that computer users’ gender has largely been ignored in technostress research, treating users as “gender-neutral.” To close this significant research gap, we conducted a laboratory experiment in which we investigated users’ physiological reaction to the malfunctioning of technology. Based on theories which explain that men, in contrast to women, are more sensitive to “achievement stress,” we predicted that male users would exhibit higher levels of stress than women in cases of system breakdown during the execution of a human-computer interaction task under time pressure, if compared to a breakdown situation without time pressure. Using skin conductance as a stress indicator, the hypothesis was confirmed. Thus, this study shows that user gender is crucial to better understanding the influence of stress factors such as computer malfunctions on physiological stress reactions.

Risk perception and decision processes underlying informed consent to research participation.

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Reynolds, William W; Nelson, Robert M

2007-11-01

According to the rational choice model, informed consent should consist of a systematic, step-by-step evaluation of all information pertinent to the treatment or research participation decision. Research shows that people frequently deviate from this normative model, however, employing decision-making shortcuts, or heuristics. In this paper we report findings from a qualitative study of 32 adolescents and (their) 31 parents who were recruited from two Northeastern US hospitals and asked to consider the risks of and make hypothetical decisions about research participation. The purpose of this study was to increase our understanding of how diabetic and at-risk adolescents (i.e., those who are obese and/or have a family history of diabetes) and their parents perceive risks and make decisions about research participation. Using data collected from adolescents and parents, we identify heuristic decision processes in which participant perceptions of risk magnitude, which are formed quickly and intuitively and appear to be based on affective responses to information, are far more prominent and central to the participation decision than are perceptions of probability. We discuss participants' use of decision-making heuristics in the context of recent research on affect and decision processes, and we consider the implications of these findings for researchers.

General practitioners' perceptions of the effectiveness of medical interventions: an exploration of underlying constructs

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Marteau Theresa M

2010-02-01

Full Text Available Abstract Background Many interventions shown to be effective through clinical trials are not readily implemented in clinical practice. Unfortunately, little is known regarding how clinicians construct their perceptions of the effectiveness of medical interventions. This study aims to explore general practitioners' perceptions of the nature of 'effectiveness'. Methods The design was qualitative in nature using the repertory grid technique to elicit the constructs underlying the perceived effectiveness of a range of medical interventions. Eight medical interventions were used as stimuli (diclophenac to reduce acute pain, cognitive behaviour therapy to treat depression, weight loss surgery to achieve weight loss, diet and exercise to prevent type 2 diabetes, statins to prevent heart disease, stopping smoking to prevent heart disease, nicotine replacement therapy to stop smoking, and stop smoking groups to stop smoking. The setting involved face-to-face interviews followed by questionnaires in London Primary Care Trusts. Participants included a random sample of 13 general practitioners. Results Analysis of the ratings showed that the constructs clustered around two dimensions: low patient effort versus high patient effort (dimension one, and small impact versus large impact (dimension two. Dimension one represented constructs such as 'success requires little motivation', 'not a lifestyle intervention', and 'health-care professional led intervention'. Dimension two represented constructs such as 'weak and/or minimal evidence of effectiveness', 'small treatment effect for users', 'a small proportion of users will benefit' and 'not cost-effective'. Constructs within each dimension were closely related. Conclusions General practitioners judged the effectiveness of medical interventions by considering two broad dimensions: the extent to which interventions involve patient effort, and the size of their impact. The latter is informed by trial evidence, but

Reliable Rescue Routing Optimization for Urban Emergency Logistics under Travel Time Uncertainty

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Qiuping Li

2018-02-01

Full Text Available The reliability of rescue routes is critical for urban emergency logistics during disasters. However, studies on reliable rescue routing under stochastic networks are still rare. This paper proposes a multiobjective rescue routing model for urban emergency logistics under travel time reliability. A hybrid metaheuristic integrating ant colony optimization (ACO and tabu search (TS was designed to solve the model. An experiment optimizing rescue routing plans under a real urban storm event, was carried out to validate the proposed model. The experimental results showed how our approach can improve rescue efficiency with high travel time reliability.

Increased timing variability in schizophrenia and bipolar disorder.

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Amanda R Bolbecker

Full Text Available Theoretical and empirical evidence suggests that impaired time perception and the neural circuitry underlying internal timing mechanisms may contribute to severe psychiatric disorders, including psychotic and mood disorders. The degree to which alterations in temporal perceptions reflect deficits that exist across psychosis-related phenotypes and the extent to which mood symptoms contribute to these deficits is currently unknown. In addition, compared to schizophrenia, where timing deficits have been more extensively investigated, sub-second timing has been studied relatively infrequently in bipolar disorder. The present study compared sub-second duration estimates of schizophrenia (SZ, schizoaffective disorder (SA, non-psychotic bipolar disorder (BDNP, bipolar disorder with psychotic features (BDP, and healthy non-psychiatric controls (HC on a well-established time perception task using sub-second durations. Participants included 66 SZ, 37 BDNP, 34 BDP, 31 SA, and 73 HC who participated in a temporal bisection task that required temporal judgements about auditory durations ranging from 300 to 600 milliseconds. Timing variability was significantly higher in SZ, BDP, and BDNP groups compared to healthy controls. The bisection point did not differ across groups. These findings suggest that both psychotic and mood symptoms may be associated with disruptions in internal timing mechanisms. Yet unexpected findings emerged. Specifically, the BDNP group had significantly increased variability compared to controls, but the SA group did not. In addition, these deficits appeared to exist independent of current symptom status. The absence of between group differences in bisection point suggests that increased variability in the SZ and bipolar disorder groups are due to alterations in perceptual timing in the sub-second range, possibly mediated by the cerebellum, rather than cognitive deficits.

Modeling the Time Course of Feature Perception and Feature Information Retrieval

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Kent, Christopher; Lamberts, Koen

2006-01-01

Three experiments investigated whether retrieval of information about different dimensions of a visual object varies as a function of the perceptual properties of those dimensions. The experiments involved two perception-based matching tasks and two retrieval-based matching tasks. A signal-to-respond methodology was used in all tasks. A stochastic…

Does visual attention drive the dynamics of bistable perception?

Science.gov (United States)

Dieter, Kevin C; Brascamp, Jan; Tadin, Duje; Blake, Randolph

2016-10-01

How does attention interact with incoming sensory information to determine what we perceive? One domain in which this question has received serious consideration is that of bistable perception: a captivating class of phenomena that involves fluctuating visual experience in the face of physically unchanging sensory input. Here, some investigations have yielded support for the idea that attention alone determines what is seen, while others have implicated entirely attention-independent processes in driving alternations during bistable perception. We review the body of literature addressing this divide and conclude that in fact both sides are correct-depending on the form of bistable perception being considered. Converging evidence suggests that visual attention is required for alternations in the type of bistable perception called binocular rivalry, while alternations during other types of bistable perception appear to continue without requiring attention. We discuss some implications of this differential effect of attention for our understanding of the mechanisms underlying bistable perception, and examine how these mechanisms operate during our everyday visual experiences.

Patterns and perceptions of physical activity and sedentary time in male transport drivers working in regional Australia.

Science.gov (United States)

Wong, Jason Y L; Gilson, Nicholas D; Bush, Robert A; Brown, Wendy J

2014-08-01

To objectively measure physical activity (PA) patterns and sedentary time, and explore perceptions of workplace PA opportunities in regional male transport workers. A multi-method study involving 28 drivers (52.4±9.69 years) working at a bus company in South-East Queensland, Australia. PA was measured using accelerometers (n=23) to determine the proportion of time spent in sedentary (organisational barriers (shift work and irregular driving routines), tended to preclude some drivers from engaging with these opportunities. Findings contest the notion that a sedentary occupation such as driving necessitates an inactive work environment. This research informs ongoing intervention efforts to target inactive drivers who are struggling to take advantage of existing workplace-related PA opportunities. © 2014 Public Health Association of Australia.

Age Differences in Emotion Perception: The Effects of the Social Environment

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Murry, Matthew W. E.; Isaacowitz, Derek M.

2017-01-01

Older adults tend to have lower emotion-perception accuracy compared to younger adults. Previous studies have centered on individual characteristics, including cognitive decline and positive attentional preferences, as possible mechanisms underlying these age differences in emotion perception; however, thus far, no perceiver-focused factor has…

A PDP model of the simultaneous perception of multiple objects

Science.gov (United States)

Henderson, Cynthia M.; McClelland, James L.

2011-06-01

Illusory conjunctions in normal and simultanagnosic subjects are two instances where the visual features of multiple objects are incorrectly 'bound' together. A connectionist model explores how multiple objects could be perceived correctly in normal subjects given sufficient time, but could give rise to illusory conjunctions with damage or time pressure. In this model, perception of two objects benefits from lateral connections between hidden layers modelling aspects of the ventral and dorsal visual pathways. As with simultanagnosia, simulations of dorsal lesions impair multi-object recognition. In contrast, a large ventral lesion has minimal effect on dorsal functioning, akin to dissociations between simple object manipulation (retained in visual form agnosia and semantic dementia) and object discrimination (impaired in these disorders) [Hodges, J.R., Bozeat, S., Lambon Ralph, M.A., Patterson, K., and Spatt, J. (2000), 'The Role of Conceptual Knowledge: Evidence from Semantic Dementia', Brain, 123, 1913-1925; Milner, A.D., and Goodale, M.A. (2006), The Visual Brain in Action (2nd ed.), New York: Oxford]. It is hoped that the functioning of this model might suggest potential processes underlying dorsal and ventral contributions to the correct perception of multiple objects.

Maternal immune activation in rats produces temporal perception impairments in adult offspring analogous to those observed in schizophrenia.

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Ashley R Deane

Full Text Available The neurophysiology underlying temporal perception significantly overlaps with areas of dysfunction identified in schizophrenia. Patients commonly exhibit distorted temporal perception, which likely contributes to functional impairments. Thus, study of temporal perception in animal models of the disease may help to understand both cognitive and neurobiological factors involved in functional impairments in patients. As maternal immune activation (MIA has been shown to be a significant etiological risk factor in development of schizophrenia and other developmental psychiatric diseases, we tested interval timing in a rat model of MIA that has previously been shown to recapitulate several behavioural and neurophysiological impairments observed in the disease. Rats were tested on a temporal-bisection task, in which temporal duration stimuli were categorized as either "short" or "long" by responding to a corresponding lever. Data from this task were modeled to provide estimates of accuracy and sensitivity of temporal perception. Parameter estimates derived from the model fitting showed that MIA rats significantly overestimated the passage of time compared to controls. These results indicate that the MIA rat paradigm recapitulates timing distortions that are phenotypical of schizophrenia. These findings lend further support to the epidemiological validity of this MIA rat model, supporting its relevance for future research into the role of maternal immune activation in producing neurobiological and behavioural impairments in schizophrenia.

Drug addiction: self-perception of oral health

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Eduardo Luiz Da-ré

2015-12-01

Full Text Available Objective: To report the self-perception of substance-abusing individuals who were in a recovery process regarding sociodemographic conditions and general and oral health. Methods: Descriptive cross-sectional study conducted in a recovery center for drug addiction in Alfenas, Minas Gerais, Brazil, in 2015, with 39 men aged over 18 years old. Data were collected using a semi-structured questionnaire that addressed: socioeconomic status, selfperception of general and oral health, access to dental care, relationship with the dentist, and other issues. In order to assess the self-perception of oral health, the variable was dichotomized into “satisfactory” and “unsatisfactory”, which refer to what the individual acknowledges as a good or poor condition of oral health, using Fisher’s exact test with 5% significance level. Results: Most frequent diseases were depression, 35.90% (n=14, insomnia, 35.9%, (n=14 and recurring headache (23.1%; n=9; however, 61.50% (n=24 of the participants reported not getting sick easily, which contrasts with their self-perception. Regarding oral health, only 30.50% (n=12 of the participants reported brushing their teeth three times a day; 53.80% (n=21 had dentinal hypersensitivity; 41.00% (n=16 had dry mouth and bad breath; 30.80% (n=12 claimed to have bruxism and reported having one or more loose teeth; 28.20% (n=11 reported clenching the teeth in an exaggerated way, and 33.30% (n=13 reported feeling tooth pain. Conclusion: The self-perception of individuals – under 30 years old, single, white or mulattos – regarding their general health was contradictory, as they rated it as good but have reported depression, insomnia and weight loss; additionally, oral health was considered poor with unsatisfactory conditions, which highlights the harmful effects of substance abuse.

Effect of Epidural Block under General Anesthesia on Pulse Transit Time

International Nuclear Information System (INIS)

Choi, Byeong Cheol; Kim, Seong Min; Jung, Dong Keun; Kim, Gi Ryon; Lee, He Jeong; Jeon, Gye Rock

2005-01-01

Epidural block under general anesthesia has been widely used to control postoperative pain. In this anesthetic state many hemodynamic parameters are changed. Moreover pulse transit time is influenced by this memodynamic change. PPT change in the finger and the toe due to relaxation of arterial wall muscle after general anesthesia and epidural block under general anesthesia. This study, in the both general anesthesia and epidural block under general anesthesia, ΔPTT of the toe and of the finger are measured. In addition, ΔPTT(toe-finger) of the epidural block under general anesthesia and of the general anesthesia were compared

Action preparation modulates sensory perception in unseen personal space: An electrophysiological investigation.

Science.gov (United States)

Job, Xavier E; de Fockert, Jan W; van Velzen, José

2016-08-01

Behavioural and electrophysiological evidence has demonstrated that preparation of goal-directed actions modulates sensory perception at the goal location before the action is executed. However, previous studies have focused on sensory perception in areas of peripersonal space. The present study investigated visual and tactile sensory processing at the goal location of upcoming movements towards the body, much of which is not visible, as well as visible peripersonal space. A motor task cued participants to prepare a reaching movement towards goals either in peripersonal space in front of them or personal space on the upper chest. In order to assess modulations of sensory perception during movement preparation, event-related potentials (ERPs) were recorded in response to task-irrelevant visual and tactile probe stimuli delivered randomly at one of the goal locations of the movements. In line with previous neurophysiological findings, movement preparation modulated visual processing at the goal of a movement in peripersonal space. Movement preparation also modulated somatosensory processing at the movement goal in personal space. The findings demonstrate that tactile perception in personal space is subject to similar top-down sensory modulation by motor preparation as observed for visual stimuli presented in peripersonal space. These findings show for the first time that the principles and mechanisms underlying adaptive modulation of sensory processing in the context of action extend to tactile perception in unseen personal space. Copyright © 2016 Elsevier Ltd. All rights reserved.

12 CFR 516.10 - How does OTS compute time periods under this part?

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false How does OTS compute time periods under this part? 516.10 Section 516.10 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY APPLICATION PROCESSING PROCEDURES § 516.10 How does OTS compute time periods under this part? In computing...

Time pressure and attention allocation effect on upper limb motion steadiness.

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Liu, Sicong; Eklund, Robert C; Tenenbaum, Gershon

2015-01-01

Following ironic process theory (IPT), the authors aimed at investigating how attentional allocation affects participants' upper limb motion steadiness under low and high levels of mental load. A secondary purpose was to examine the validity of skin conductance level in measuring perception of pressure. The study consisted of 1 within-participant factor (i.e., phase: baseline, test) and 4 between-participant factors (i.e., gender: male, female; mental load: fake time constraints, no time constraints; attention: positive, suppressive; order: baseline → → → test, test → → baseline). Eighty college students (40 men and 40 women, Mage = 20.20 years, SD(age) = 1.52 years) participated in the study. Gender-stratified random assignment was employed in a 2 × 2 × 2 × 2 × 2 mixed experimental design. The findings generally support IPT but its predictions on motor performance under mental load may not be entirely accurate. Unlike men, women's performance was not susceptible to manipulations of mental load and attention allocation. The validity of skin conductance readings as an index of pressure perception was called into question.

Risk factor for phlebitis: a questionnaire study of nurses' perception.

Science.gov (United States)

Milutinović, Dragana; Simin, Dragana; Zec, Davor

2015-01-01

to assess nurses' perceptions of risk factors for the development of phlebitis, with a special focus on the perception of phlebitic potentials of some infusion medications and solutions. a cross-sectional questionnaire study, which included a sample of 102 nurses. Nurses recognized some factors that may reduce the incidence of phlebitis; however, more than half of the nurses were unaware that the material and diameter of the cannula can affect the incidence rate of phlebitis. Furthermore,underlying disease and high pH of medications or solutions were identified as potential risk factors, whereas low pH and low osmolality were not. Nurses identified Vancomycin and Benzylpenicillin antibiotics with the strongest phlebitic potential. Among other medications and intravenous fluids, Aminophylline, Amiodaronehydrochloride and Potassium chloride 7.4% were identified as potentially causing phlebitis. predisposing factors for phlebitis relating to patients and administered therapy were identified by nurses, while some cannula related risk factors, in particular its physicochemical properties and the time for cannula replacement, were not fully perceived.

Teaching Time Investment: Does Online Really Take More Time than Face-to-Face?

Science.gov (United States)

Van de Vord, Rebecca; Pogue, Korolyn

2012-01-01

Enrollments in online programs are growing, increasing demand for online courses. The perception that teaching online takes more time than teaching face-to-face creates concerns related to faculty workload. To date, the research on teaching time does not provide a clear answer as to the accuracy of this perception. This study was designed to…

Elevated arousal levels enhance contrast perception.

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Kim, Dongho; Lokey, Savannah; Ling, Sam

2017-02-01

Our state of arousal fluctuates from moment to moment-fluctuations that can have profound impacts on behavior. Arousal has been proposed to play a powerful, widespread role in the brain, influencing processes as far ranging as perception, memory, learning, and decision making. Although arousal clearly plays a critical role in modulating behavior, the mechanisms underlying this modulation remain poorly understood. To address this knowledge gap, we examined the modulatory role of arousal on one of the cornerstones of visual perception: contrast perception. Using a reward-driven paradigm to manipulate arousal state, we discovered that elevated arousal state substantially enhances visual sensitivity, incurring a multiplicative modulation of contrast response. Contrast defines vision, determining whether objects appear visible or invisible to us, and these results indicate that one of the consequences of decreased arousal state is an impaired ability to visually process our environment.

Linking performance decline to choking: players' perceptions in basketball.

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Fryer, Ashley Marie; Tenenbaum, Gershon; Chow, Graig M

2018-02-01

This study was aimed at examining how basketball players view unexpected performance errors in basketball, and under what conditions they perceive them as choking. Fifty-three basketball players were randomly assigned into 2 groups (game half) to evaluate the linkage between performance decline and choking as a function of game-time, score gap and game half. Within each group, players viewed 8 scenario clips, which featured a different player conducting an error, and subsequently rated the extent of performance decline, the instance of choking and the salience of various performance attributions regarding the error. The analysis revealed that choking was most salient in the 2nd half of the game, but an error was perceived as choking more saliently in the beginning of the 2nd half. This trend was also shown for players' perception of performance decline. Players' ratings of the attributions assigned to errors, however, revealed that during the end of the 2nd half, time pressure and lack of concentration were the causes of errors. Overall, the results provide evidence towards a conceptual framework linking performance decline to the perception of choking, and that errors conducted by players are perceived as choking when there is not a salient reason to suggest its occurrence.

Perceptions of control in adults with epilepsy.

Science.gov (United States)

Gehlert, S

1994-01-01

That psychosocial problems are extant in epilepsy is evidenced by a suicide rate among epileptic persons five times that of the general population and an unemployment rate estimated to be more than twice that of the population as a whole. External perceptions of control secondary to repeated episodes of seizure activity that generalize to the social sphere have been implicated as causes of these problems. The hypothesis that individuals who continue to have seizures become more and more external in perceptions of control was tested by a survey mailed to a sample of individuals with epilepsy in a metropolitan area of the Midwest. Dependent variables were, scores on instruments measuring locus of control and attributional style. The independent variable was a measure of seizure control based on present age, age at onset, and length of time since last seizure. Gender, socioeconomic status, and certain parenting characteristics were included as control variables, as they are also known to affect perceptions of control. Analysis by multiple regression techniques supported the study's hypothesis when perceptions of control was conceptualized as learned helplessness for bad, but not for good, events. The hypothesis was not confirmed when perceptions of control was conceptualized as either general or health locus of control.

Neural Mechanisms of Interference Control and Time Discrimination in Attention-Deficit/Hyperactivity Disorder

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Vloet, Timo D.; Gilsbach, Susanne; Neufang, Susanne; Fink, Gereon R.; Herpertz-Dahlmann, Beate; Konrad, Kerstin

2010-01-01

Objective: Both executive functions and time perception are typically impaired in subjects with attention-deficit/hyperactivity disorder (ADHD). However, the exact neural mechanisms underlying these deficits remain to be investigated. Method: Fourteen subjects with ADHD and 14 age- and IQ-matched controls (aged 9 through 15 years) were assessed…

Controlled interaction: strategies for using virtual reality to study perception.

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Durgin, Frank H; Li, Zhi

2010-05-01

Immersive virtual reality systems employing head-mounted displays offer great promise for the investigation of perception and action, but there are well-documented limitations to most virtual reality systems. In the present article, we suggest strategies for studying perception/action interactions that try to depend on both scale-invariant metrics (such as power function exponents) and careful consideration of the requirements of the interactions under investigation. New data concerning the effect of pincushion distortion on the perception of surface orientation are presented, as well as data documenting the perception of dynamic distortions associated with head movements with uncorrected optics. A review of several successful uses of virtual reality to study the interaction of perception and action emphasizes scale-free analysis strategies that can achieve theoretical goals while minimizing assumptions about the accuracy of virtual simulations.

Cortical hierarchies perform Bayesian causal inference in multisensory perception.

Directory of Open Access Journals (Sweden)

Tim Rohe

2015-02-01

Full Text Available To form a veridical percept of the environment, the brain needs to integrate sensory signals from a common source but segregate those from independent sources. Thus, perception inherently relies on solving the "causal inference problem." Behaviorally, humans solve this problem optimally as predicted by Bayesian Causal Inference; yet, the underlying neural mechanisms are unexplored. Combining psychophysics, Bayesian modeling, functional magnetic resonance imaging (fMRI, and multivariate decoding in an audiovisual spatial localization task, we demonstrate that Bayesian Causal Inference is performed by a hierarchy of multisensory processes in the human brain. At the bottom of the hierarchy, in auditory and visual areas, location is represented on the basis that the two signals are generated by independent sources (= segregation. At the next stage, in posterior intraparietal sulcus, location is estimated under the assumption that the two signals are from a common source (= forced fusion. Only at the top of the hierarchy, in anterior intraparietal sulcus, the uncertainty about the causal structure of the world is taken into account and sensory signals are combined as predicted by Bayesian Causal Inference. Characterizing the computational operations of signal interactions reveals the hierarchical nature of multisensory perception in human neocortex. It unravels how the brain accomplishes Bayesian Causal Inference, a statistical computation fundamental for perception and cognition. Our results demonstrate how the brain combines information in the face of uncertainty about the underlying causal structure of the world.

Complexity, specificity, and the timescales of developing expectations in visual perception

OpenAIRE

Gekas, Nikos

2015-01-01

Perception is strongly influenced by our expectations, especially under situations of uncertainty. A growing body of work suggests that perception is akin to Bayesian Inference in which expectations can be viewed as ‘prior’ beliefs that are combined via Bayes’ rule with sensory evidence to form the ‘posterior’ beliefs. In this thesis, I aim to answer open questions regarding the nature of expectations in perception, and, in particular, what the limits of complexity and specific...

Intergroup conflict management strategies as related to perceptions of dual identity and separate groups.

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Bizman, Aharon; Yinon, Yoel

2004-04-01

The authors examined the relations between (a) the perceptions of dual identity and separate groups and (b) intergroup conflict management strategies, in two contexts: the conflict between the secular and religious sectors in Israel and the allocation of resources among organizational subunits. In both contexts, contention (i.e., forcing one's will on the other party) was associated with the perception of separate groups. Only in the organizational context, avoidance (i.e., doing nothing or discontinuing participation in the conflict) was associated with the perception of dual identity. Problem solving (i.e., finding a solution that is acceptable to both parties) was related to the perception of dual identity in the secular-religious context. In the organizational context, this relation appeared only under a low perception of separate groups. Yielding (i.e., satisfying the other party's needs at the expense of one's own) was related to the perception of dual identity in the organizational context. In the secular-religious context, this relation appeared only under a high perception of separate groups. The authors discussed the varying pattern of the associations between (a) the perceptions of dual identity and separate groups and (b) the conflict management strategies in the two contexts in terms of the Dual Concern Model and the perceived feasibility of the strategies.

Aspects of two-level systems under external time-dependent fields

Energy Technology Data Exchange (ETDEWEB)

Bagrov, V.G.; Wreszinski, W.F. [Tomsk State University and Tomsk Institute of High Current Electronics (Russian Federation); Barata, J.C.A.; Gitman D.M. [Universidade de Sao Paulo, Instituto de Fisica (Brazil)]. E-mails: jbarata@fma.if.usp.br; gitman@fma.if.usp.br

2001-12-14

The dynamics of two-level systems in time-dependent backgrounds is under consideration. We present some new exact solutions in special backgrounds decaying in time. On the other hand, following ideas of Feynman et al, we discuss in detail the possibility of reducing the quantum dynamics to a classical Hamiltonian system. This, in particular, opens the possibility of directly applying powerful methods of classical mechanics (e.g. KAM methods) to study the quantum system. Following such an approach, we draw conclusions of relevance for 'quantum chaos' when the external background is periodic or quasi-periodic in time. (author)

The role of temporal structure in the investigation of sensory memory, auditory scene analysis, and speech perception: a healthy-aging perspective.

Science.gov (United States)

Rimmele, Johanna Maria; Sussman, Elyse; Poeppel, David

2015-02-01

Listening situations with multiple talkers or background noise are common in everyday communication and are particularly demanding for older adults. Here we review current research on auditory perception in aging individuals in order to gain insights into the challenges of listening under noisy conditions. Informationally rich temporal structure in auditory signals--over a range of time scales from milliseconds to seconds--renders temporal processing central to perception in the auditory domain. We discuss the role of temporal structure in auditory processing, in particular from a perspective relevant for hearing in background noise, and focusing on sensory memory, auditory scene analysis, and speech perception. Interestingly, these auditory processes, usually studied in an independent manner, show considerable overlap of processing time scales, even though each has its own 'privileged' temporal regimes. By integrating perspectives on temporal structure processing in these three areas of investigation, we aim to highlight similarities typically not recognized. Copyright © 2014 Elsevier B.V. All rights reserved.

Neurophysiological influence of musical training on speech perception.

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Shahin, Antoine J

2011-01-01

Does musical training affect our perception of speech? For example, does learning to play a musical instrument modify the neural circuitry for auditory processing in a way that improves one's ability to perceive speech more clearly in noisy environments? If so, can speech perception in individuals with hearing loss (HL), who struggle in noisy situations, benefit from musical training? While music and speech exhibit some specialization in neural processing, there is evidence suggesting that skills acquired through musical training for specific acoustical processes may transfer to, and thereby improve, speech perception. The neurophysiological mechanisms underlying the influence of musical training on speech processing and the extent of this influence remains a rich area to be explored. A prerequisite for such transfer is the facilitation of greater neurophysiological overlap between speech and music processing following musical training. This review first establishes a neurophysiological link between musical training and speech perception, and subsequently provides further hypotheses on the neurophysiological implications of musical training on speech perception in adverse acoustical environments and in individuals with HL.

Gender and Socioeconomic Status in Relation to Weight Perception and Weight Control Behavior in Korean Adults

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Hee-Kyung Joh

2013-02-01

Full Text Available Aim: In Korea, obesity is more prevalent among men and lower socioeconomic groups. To explain this obesity disparity, we compared weight perception and weight control behavior across gender and socioeconomic status (SES. Methods: We analyzed data from 16,260 participants aged 20 years or older in a nationally representative cross-sectional survey. SES indicators included education and income levels. Weight under-perception was defined when participants considered themselves lighter than their measured BMI status. Either no active or inappropriate weight control (i.e., trying to gain weight in obese individuals was considered to be unhealthy patterns. Multivariate prevalence ratios were calculated using log-binomial regressions. Results: Men had a higher prevalence of weight under-perception (24.5 vs. 11.9% and unhealthy patterns of weight control behavior (57 vs. 40% than women. Low education level was associated with weight under-perception (ptrend = 0.022 in men, ptrend trend trend = 0.047 in men, ptrend Conclusion: Weight perception and weight control behavior significantly varied by gender and SES. Public actions should be directed toward improving perception and behavior of high-risk populations.

Perception of low dose radiation risks among radiation researchers in Korea.

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Seong, Ki Moon; Kwon, TaeWoo; Seo, Songwon; Lee, Dalnim; Park, Sunhoo; Jin, Young Woo; Lee, Seung-Sook

2017-01-01

Expert's risk evaluation of radiation exposure strongly influences the public's risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts' radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual's opinions have often exacerbated the public's confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years' research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects perception of radiation exposure.

Perception of low dose radiation risks among radiation researchers in Korea

Science.gov (United States)

Seo, Songwon; Lee, Dalnim; Park, Sunhoo; Jin, Young Woo; Lee, Seung-Sook

2017-01-01

Expert’s risk evaluation of radiation exposure strongly influences the public’s risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts’ radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual’s opinions have often exacerbated the public’s confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years’ research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at risk perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects risk perception of radiation exposure. PMID:28166286

Category Selectivity of Human Visual Cortex in Perception of Rubin Face–Vase Illusion

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Xiaogang Wang

2017-09-01

Full Text Available When viewing the Rubin face–vase illusion, our conscious perception spontaneously alternates between the face and the vase; this illusion has been widely used to explore bistable perception. Previous functional magnetic resonance imaging (fMRI studies have studied the neural mechanisms underlying bistable perception through univariate and multivariate pattern analyses; however, no studies have investigated the issue of category selectivity. Here, we used fMRI to investigate the neural mechanisms underlying the Rubin face–vase illusion by introducing univariate amplitude and multivariate pattern analyses. The results from the amplitude analysis suggested that the activity in the fusiform face area was likely related to the subjective face perception. Furthermore, the pattern analysis results showed that the early visual cortex (EVC and the face-selective cortex could discriminate the activity patterns of the face and vase perceptions. However, further analysis of the activity patterns showed that only the face-selective cortex contains the face information. These findings indicated that although the EVC and face-selective cortex activities could discriminate the visual information, only the activity and activity pattern in the face-selective areas contained the category information of face perception in the Rubin face–vase illusion.

Dedicated clock/timing-circuit theories of time perception and timed performance.

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van Rijn, Hedderik; Gu, Bon-Mi; Meck, Warren H

2014-01-01

Scalar Timing Theory (an information-processing version of Scalar Expectancy Theory) and its evolution into the neurobiologically plausible Striatal Beat-Frequency (SBF) theory of interval timing are reviewed. These pacemaker/accumulator or oscillation/coincidence detection models are then integrated with the Adaptive Control of Thought-Rational (ACT-R) cognitive architecture as dedicated timing modules that are able to make use of the memory and decision-making mechanisms contained in ACT-R. The different predictions made by the incorporation of these timing modules into ACT-R are discussed as well as the potential limitations. Novel implementations of the original SBF model that allow it to be incorporated into ACT-R in a more fundamental fashion than the earlier simulations of Scalar Timing Theory are also considered in conjunction with the proposed properties and neural correlates of the "internal clock".

Numerical solution of continuous-time DSGE models under Poisson uncertainty

DEFF Research Database (Denmark)

Posch, Olaf; Trimborn, Timo

We propose a simple and powerful method for determining the transition process in continuous-time DSGE models under Poisson uncertainty numerically. The idea is to transform the system of stochastic differential equations into a system of functional differential equations of the retarded type. We...... classes of models. We illustrate the algorithm simulating both the stochastic neoclassical growth model and the Lucas model under Poisson uncertainty which is motivated by the Barro-Rietz rare disaster hypothesis. We find that, even for non-linear policy functions, the maximum (absolute) error is very...

Enhancing Motion-In-Depth Perception of Random-Dot Stereograms.

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Zhang, Di; Nourrit, Vincent; De Bougrenet de la Tocnaye, Jean-Louis

2018-07-01

Random-dot stereograms have been widely used to explore the neural mechanisms underlying binocular vision. Although they are a powerful tool to stimulate motion-in-depth (MID) perception, published results report some difficulties in the capacity to perceive MID generated by random-dot stereograms. The purpose of this study was to investigate whether the performance of MID perception could be improved using an appropriate stimulus design. Sixteen inexperienced observers participated in the experiment. A training session was carried out to improve the accuracy of MID detection before the experiment. Four aspects of stimulus design were investigated: presence of a static reference, background texture, relative disparity, and stimulus contrast. Participants' performance in MID direction discrimination was recorded and compared to evaluate whether varying these factors helped MID perception. Results showed that only the presence of background texture had a significant effect on MID direction perception. This study provides suggestions for the design of 3D stimuli in order to facilitate MID perception.

Secondary school students' perceptions of working life skills in science-related careers

Science.gov (United States)

Salonen, Anssi; Hartikainen-Ahia, Anu; Hense, Jonathan; Scheersoi, Annette; Keinonen, Tuula

2017-07-01

School students demonstrate a lack of interest in choosing science studies and science-related careers. To better understand the underlying reasons, this study aims to examine secondary school students' perceptions of working life skills and how these perceptions relate to the skills of the twenty-first century. The participants in this study were 144 Finnish 7th graders (aged 13-14 years). Using a questionnaire and qualitative content analysis, we examined their perceptions of working life skills in 'careers in science' and 'careers with science'. Results reveal that although students have a great deal of knowledge about working life skills, it is often just stereotyped. Sector-specific knowledge and skills were highlighted in particular but skills related to society, organisation, time and higher order thinking, were often omitted. Results also indicate that students do not associate 'careers in science' with creativity, innovation, collaboration or technology and ICT skills. Conversely, according to the students, these careers demand more sector-specific knowledge and responsibility than 'careers with science'. We conclude that students need more wide-ranging information about scientific careers and the competencies demanded; such information can be acquired by e.g. interacting with professionals and their real working life problems.

Motor-sensory confluence in tactile perception.

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Saig, Avraham; Gordon, Goren; Assa, Eldad; Arieli, Amos; Ahissar, Ehud

2012-10-03

Perception involves motor control of sensory organs. However, the dynamics underlying emergence of perception from motor-sensory interactions are not yet known. Two extreme possibilities are as follows: (1) motor and sensory signals interact within an open-loop scheme in which motor signals determine sensory sampling but are not affected by sensory processing and (2) motor and sensory signals are affected by each other within a closed-loop scheme. We studied the scheme of motor-sensory interactions in humans using a novel object localization task that enabled monitoring the relevant overt motor and sensory variables. We found that motor variables were dynamically controlled within each perceptual trial, such that they gradually converged to steady values. Training on this task resulted in improvement in perceptual acuity, which was achieved solely by changes in motor variables, without any change in the acuity of sensory readout. The within-trial dynamics is captured by a hierarchical closed-loop model in which lower loops actively maintain constant sensory coding, and higher loops maintain constant sensory update flow. These findings demonstrate interchangeability of motor and sensory variables in perception, motor convergence during perception, and a consistent hierarchical closed-loop perceptual model.

Perception and the temporal properties of speech

Science.gov (United States)

Gordon, Peter C.

1991-11-01

Four experiments addressing the role of attention in phonetic perception are reported. The first experiment shows that the relative importance of two cues to the voicing distinction changes when subjects must perform an arithmetic distractor task at the same time as identifying a speech stimulus. The voice onset time cue loses phonetic significance when subjects are distracted, while the F0 onset frequency cue does not. The second experiment shows a similar pattern for two cues to the distinction between the vowels /i/ (as in 'beat') and /I/ (as in 'bit'). Together these experiments indicate that careful attention to speech perception is necessary for strong acoustic cues to achieve their full phonetic impact, while weaker acoustic cues achieve their full phonetic impact without close attention. Experiment 3 shows that this pattern is obtained when the distractor task places little demand on verbal short term memory. Experiment 4 provides a large data set for testing formal models of the role of attention in speech perception. Attention is shown to influence the signal to noise ratio in phonetic encoding. This principle is instantiated in a network model in which the role of attention is to reduce noise in the phonetic encoding of acoustic cues. Implications of this work for understanding speech perception and general theories of the role of attention in perception are discussed.

Neurocognitive Mechanisms of Prejudice Formation: The Role of Time-Dependent Memory Consolidation.

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Enge, Luke R; Lupo, Amber K; Zárate, Michael A

2015-07-01

Prejudice is generally thought to derive from learned, emotion-laden experiences. The mechanisms underlying the formation of prejudice over time, however, remain unknown. In the present research, we proposed and tested hypotheses regarding prejudice formation derived from research on memory consolidation and social perception. We hypothesized that time-dependent memory consolidation would produce better implicit memory for negative out-group information and positive in-group information, compared with negative in-group information and positive out-group information. Fifty undergraduates learned positive and negative information about racial in-group (Latino) and out-group (African American) targets. Participants returned after both a short time delay (2-6 hr after the learning session) and a long time delay (48 hr after the learning session) to complete a lexical decision task. Results demonstrated that participants responded to information consistent with an in-group bias faster after a long time delay than after a short time delay. Our findings have important implications for the study of social perception and memory consolidation. © The Author(s) 2015.

Understanding person perception.

Science.gov (United States)

Young, Andrew W; Bruce, Vicki

2011-11-01

Bruce and Young's (1986) theoretical framework was actually a synthesis of ideas contributed by several people. Some of its insights have stood the test of time - especially the importance of using converging evidence from as wide a range of methods of enquiry as possible, and an emphasis on understanding the demands that are made by particular face perception tasks. But there were also areas where Bruce and Young failed to obey their own edicts (emotion recognition), and some topics they simply omitted (gaze perception). We discuss these, and then look at how the field has been transformed by computing developments, finishing with a few thoughts about where things may go over the next few (25?) years. ©2011 The British Psychological Society.

Time-dependent theory of double ionization of helium under XUV radiation

International Nuclear Information System (INIS)

Nikolopoulos, L A A; Lambropoulos, P

2007-01-01

We present non-perturbative time-dependent calculations of single and double ionization of helium, under XUV radiation of photon energy ranging from 40 to 45 eV, through the direct propagation of the time-dependent Schroedinger equation. The time-dependent wavefunction of the atom under the field is expanded in terms of correlated multichannel states normalized with incoming-wave boundary conditions. In addition to presenting a new non-perturbative approach to the three-body problem, in a fully correlated scheme, capable of providing in the same calculation photoelectron energy and angularly resolved spectra, as well as cross sections through the lowest non-vanishing order transition amplitude, we also present a detailed comparison of the values of certain key quantities that have been obtained through a variety of other methods. The degree of agreement we find, while lending credence to the approach and its versatility, also highlights the remaining open questions in this novel context of double ionization

Effects of coloured lighting on the perception of interior spaces.

Science.gov (United States)

Odabaşioğlu, Seden; Olguntürk, Nіlgün

2015-02-01

Use of coloured lighting in interior spaces has become prevalent in recent years. Considerable importance is ascribed to coloured lighting in interior and lighting design. The effects of colour on the perception of interior spaces have been studied as surface colour; but here, the effects of three different types of chromatic light were investigated. The lighting differed in colour (red, green and white) and perceptions of interior space were assessed. 97 participants (59 women, 38 men; M age = 21.4 yr.) evaluated the experiment room on a questionnaire assessing eight evaluative factors: Pleasantness, Arousal, Aesthetics, Usefulness, Comfort, Spaciousness, Colour, and Lighting quality. Perceptions of the room differed by colour of lighting for some of the evaluative factors, but there was no sex difference in perceptions. Interior spaces may be perceived as equally pleasant under white, green and red lighting. Under white lighting a space is perceived as more useful, spacious, clear, and luminous. Green lighting would make the same effect. Green and white lighting were perceived equally comfortable in an interior space. Chromatic coloured lighting was perceived to be more aesthetic than white lighting. The results support previous findings for some evaluative factors, but differed for others.

Perception of Child Weight and Feeding Styles in Parents of Chinese-American Preschoolers.

Science.gov (United States)

Chang, Lucy Y; Mendelsohn, Alan L; Fierman, Arthur H; Au, Loretta Y; Messito, Mary Jo

2017-04-01

Parent perception of weight and feeding styles are associated with obesity in other racial groups but have not been explored in-depth in Chinese-American preschoolers. Cross-sectional survey of 253 Chinese-American parents with preschoolers was performed in a community clinic. Regression analysis was used to assess relationships between parental perception of weight and feeding styles. Parent under-perception of weight was common but more likely in boys than girls (χ 2  = 4.91, p = 0.03). Pressuring was also greater in boys [adjusted mean difference (95% CI) 0.24 (0.004, 0.49)]. In girls, pressuring was lower for children perceived as overweight [adjusted mean difference in CFQ scores -0.75 (-1.27, -0.23)]; in boys, pressuring was high regardless of perceived child weight. Weight perceptions and feeding styles related to childhood obesity in other groups were identified in Chinese-American families. Parent under-perception of child weight and pressure to eat were more common in boys. These factors should be addressed in Chinese-American preschooler obesity prevention programs.

Absolute continuity under time shift of trajectories and related stochastic calculus

CERN Document Server

Löbus, Jörg-Uwe

2017-01-01

The text is concerned with a class of two-sided stochastic processes of the form X=W+A. Here W is a two-sided Brownian motion with random initial data at time zero and A\\equiv A(W) is a function of W. Elements of the related stochastic calculus are introduced. In particular, the calculus is adjusted to the case when A is a jump process. Absolute continuity of (X,P) under time shift of trajectories is investigated. For example under various conditions on the initial density with respect to the Lebesgue measure, m, and on A with A_0=0 we verify \\frac{P(dX_{\\cdot -t})}{P(dX_\\cdot)}=\\frac{m(X_{-t})}{m(X_0)}\\cdot \\prod_i\\left|\

Novelty enhances visual perception.

Directory of Open Access Journals (Sweden)

Judith Schomaker

Full Text Available The effects of novelty on low-level visual perception were investigated in two experiments using a two-alternative forced-choice tilt detection task. A target, consisting of a Gabor patch, was preceded by a cue that was either a novel or a familiar fractal image. Participants had to indicate whether the Gabor stimulus was vertically oriented or slightly tilted. In the first experiment tilt angle was manipulated; in the second contrast of the Gabor patch was varied. In the first, we found that sensitivity was enhanced after a novel compared to a familiar cue, and in the second we found sensitivity to be enhanced for novel cues in later experimental blocks when participants became more and more familiarized with the familiar cue. These effects were not caused by a shift in the response criterion. This shows for the first time that novel stimuli affect low-level characteristics of perception. We suggest that novelty can elicit a transient attentional response, thereby enhancing perception.

Novelty enhances visual perception.

Science.gov (United States)

Schomaker, Judith; Meeter, Martijn

2012-01-01

The effects of novelty on low-level visual perception were investigated in two experiments using a two-alternative forced-choice tilt detection task. A target, consisting of a Gabor patch, was preceded by a cue that was either a novel or a familiar fractal image. Participants had to indicate whether the Gabor stimulus was vertically oriented or slightly tilted. In the first experiment tilt angle was manipulated; in the second contrast of the Gabor patch was varied. In the first, we found that sensitivity was enhanced after a novel compared to a familiar cue, and in the second we found sensitivity to be enhanced for novel cues in later experimental blocks when participants became more and more familiarized with the familiar cue. These effects were not caused by a shift in the response criterion. This shows for the first time that novel stimuli affect low-level characteristics of perception. We suggest that novelty can elicit a transient attentional response, thereby enhancing perception.

Real-Time Eye Detection and Tracking under Various Light Conditions

Directory of Open Access Journals (Sweden)

Feng Jiao

2007-10-01

Full Text Available This paper describes a real-time online prototype automobile and truck driver-fatigue monitor. It uses remotely located charge-coupled-device cameras equipped with active infrared illuminators to acquire video images of the driver. Various visual cues that typically characterize the level of alertness of a person are extracted in real time and systematically combined to infer the fatigue level of the driver. The visual cues employed characterize eyelid movement, gaze movement, head movement, and facial expression. A probabilistic model is developed to model human fatigue and to predict fatigue based on the visual cues obtained. The simultaneous use of multiple visual cues and their systematic combination yields a much more robust and accurate fatigue characterization than using a single visual cue. This system was validated under real-life fatigue conditions with human subjects of different ethnic backgrounds, genders, and ages; with/without glasses; and under different illumination conditions. It was found to be reasonably robust, reliable, and accurate in fatigue characterization.

Computation of reactor control rod drop time under accident conditions

International Nuclear Information System (INIS)

Dou Yikang; Yao Weida; Yang Renan; Jiang Nanyan

1998-01-01

The computational method of reactor control rod drop time under accident conditions lies mainly in establishing forced vibration equations for the components under action of outside forces on control rod driven line and motion equation for the control rod moving in vertical direction. The above two kinds of equations are connected by considering the impact effects between control rod and its outside components. Finite difference method is adopted to make discretization of the vibration equations and Wilson-θ method is applied to deal with the time history problem. The non-linearity caused by impact is iteratively treated with modified Newton method. Some experimental results are used to validate the validity and reliability of the computational method. Theoretical and experimental testing problems show that the computer program based on the computational method is applicable and reliable. The program can act as an effective tool of design by analysis and safety analysis for the relevant components

Contact high: Mania proneness and positive perception of emotional touches.

Science.gov (United States)

Piff, Paul K; Purcell, Amanda; Gruber, June; Hertenstein, Matthew J; Keltner, Dacher

2012-01-01

How do extreme degrees of positive emotion-such as those characteristic of mania-influence emotion perception? The present study investigated how mania proneness, assessed using the Hypomanic Personality Scale, influences the perception of emotion via touch. Using a validated dyadic interaction paradigm for communicating emotion through touch (Hertenstein, Keltner, App, Bulleit, & Jaskolka, 2006), participants (N=53) received eight different touches to their forearm from a stranger and then identified the emotion via forced-choice methodology. Mania proneness predicted increased overall accuracy in touch perception, particularly for positive emotion touches, as well as the over-attribution of positive and under-attribution of negative emotions across all touches. These findings highlight the effects of positive emotion extremes on the perception of emotion in social interactions.

[Cleavage time for a hydrogen bond under a load].

Science.gov (United States)

Bespalov, S V; Tolpygo, K B

1993-01-01

Statistics of the hydrogen bond formation and break in a bundle of actin and myosin filaments realizing the attractive force in the sarcomere of a muscle is studied. Purely mechanical problem of the attractive-force formation and motion of myosin heads and action globules under their action is supplemented by accounting for the irreversible processes: 1. Thermal de-excitation of the latter in the chain of hydrogen bond during the elementary act of the ATP energy use resulting in fixing the extended actin filament. 2. Break of the hydrogen bonds, realizing this fixing, due to thermal fluctuations for the time tau. The average life-time turns out to be the order of time necessary for the movement of z-membrane sarcomere for the value of action filament extension delta 1, which is necessary for the process of muscle contraction to be continued.

Impact of knowledge and misconceptions on benefit and risk perception of CCS.

Science.gov (United States)

Wallquist, Lasse; Visschers, Vivianne H M; Siegrist, Michael

2010-09-01

Carbon Dioxide Capture and Storage (CCS) is assumed to be one of the key technologies in the mitigation of climate change. Public acceptance may have a strong impact on the progress of this technology. Benefit perception and risk perception are known to be important determinants of public acceptance of CCS. In this study, the prevalence and effect of cognitive concepts underlying laypeople's risk perception and benefit perception of CCS were examined in a representative survey (N=654) in Switzerland. Results confirm findings from previous qualitative studies and show a quantification of a variety of widespread intuitive concepts that laypeople hold about storage mechanisms as well as about leakage and socioeconomic issues, which all appeared to influence risk perception and benefit perception. The perception of an overpressurized reservoir and concerns about diffuse impacts furthermore amplified risk perception. Appropriate images about storage mechanisms and climate change awareness were increasing the perception of benefits. Knowledge about CO2 seemed to lower both perceived benefits and perceived risks. Implications for risk communication and management are discussed.

Perception of Upright: Multisensory Convergence and the Role of Temporo-Parietal Cortex

Directory of Open Access Journals (Sweden)

Amir Kheradmand

2017-10-01

Full Text Available We inherently maintain a stable perception of the world despite frequent changes in the head, eye, and body positions. Such “orientation constancy” is a prerequisite for coherent spatial perception and sensorimotor planning. As a multimodal sensory reference, perception of upright represents neural processes that subserve orientation constancy through integration of sensory information encoding the eye, head, and body positions. Although perception of upright is distinct from perception of body orientation, they share similar neural substrates within the cerebral cortical networks involved in perception of spatial orientation. These cortical networks, mainly within the temporo-parietal junction, are crucial for multisensory processing and integration that generate sensory reference frames for coherent perception of self-position and extrapersonal space transformations. In this review, we focus on these neural mechanisms and discuss (i neurobehavioral aspects of orientation constancy, (ii sensory models that address the neurophysiology underlying perception of upright, and (iii the current evidence for the role of cerebral cortex in perception of upright and orientation constancy, including findings from the neurological disorders that affect cortical function.

Audiovisual perception in amblyopia: A review and synthesis.

Science.gov (United States)

Richards, Michael D; Goltz, Herbert C; Wong, Agnes M F

2018-05-17

Amblyopia is a common developmental sensory disorder that has been extensively and systematically investigated as a unisensory visual impairment. However, its effects are increasingly recognized to extend beyond vision to the multisensory domain. Indeed, amblyopia is associated with altered cross-modal interactions in audiovisual temporal perception, audiovisual spatial perception, and audiovisual speech perception. Furthermore, although the visual impairment in amblyopia is typically unilateral, the multisensory abnormalities tend to persist even when viewing with both eyes. Knowledge of the extent and mechanisms of the audiovisual impairments in amblyopia, however, remains in its infancy. This work aims to review our current understanding of audiovisual processing and integration deficits in amblyopia, and considers the possible mechanisms underlying these abnormalities. Copyright © 2018. Published by Elsevier Ltd.

Scalar Aharonov–Bohm Phase in Ramsey Atom Interferometry under Time-Varying Potential

Directory of Open Access Journals (Sweden)

Atsuo Morinaga

2016-08-01

Full Text Available In a Ramsey atom interferometer excited by two electromagnetic fields, if atoms are under a time-varying scalar potential during the interrogation time, the phase of the Ramsey fringes shifts owing to the scalar Aharonov–Bohm effect. The phase shift was precisely examined using a Ramsey atom interferometer with a two-photon Raman transition under the second-order Zeeman potential, and a formula for the phase shift was derived. Using the derived formula, the frequency shift due to the scalar Aharonov–Bohm effect in the frequency standards utilizing the Ramsey atom interferometer was discussed.

The origin and nature of categorical perception of colour: Evidence from event-related brain potentials.

OpenAIRE

Clifford, Alexandra.

2009-01-01

Categorical perception (CP) of colour is demonstrated by faster or more accurate discrimination of colours that cross a category boundary, compared to equivalently spaced colours from the same colour category. Despite a plethora of behavioural research exploring the origin and nature of colour CP, the processes involved in the effect are still unresolved. This thesis investigates the time course and underlying mechanisms of colour CP by using the Event-Related Potential (ERP) technique. This ...

Speech perception benefits of internet versus conventional telephony for hearing-impaired individuals.

Science.gov (United States)

Mantokoudis, Georgios; Dubach, Patrick; Pfiffner, Flurin; Kompis, Martin; Caversaccio, Marco; Senn, Pascal

2012-07-16

Telephone communication is a challenge for many hearing-impaired individuals. One important technical reason for this difficulty is the restricted frequency range (0.3-3.4 kHz) of conventional landline telephones. Internet telephony (voice over Internet protocol [VoIP]) is transmitted with a larger frequency range (0.1-8 kHz) and therefore includes more frequencies relevant to speech perception. According to a recently published, laboratory-based study, the theoretical advantage of ideal VoIP conditions over conventional telephone quality has translated into improved speech perception by hearing-impaired individuals. However, the speech perception benefits of nonideal VoIP network conditions, which may occur in daily life, have not been explored. VoIP use cannot be recommended to hearing-impaired individuals before its potential under more realistic conditions has been examined. To compare realistic VoIP network conditions, under which digital data packets may be lost, with ideal conventional telephone quality with respect to their impact on speech perception by hearing-impaired individuals. We assessed speech perception using standardized test material presented under simulated VoIP conditions with increasing digital data packet loss (from 0% to 20%) and compared with simulated ideal conventional telephone quality. We monaurally tested 10 adult users of cochlear implants, 10 adult users of hearing aids, and 10 normal-hearing adults in the free sound field, both in quiet and with background noise. Across all participant groups, mean speech perception scores using VoIP with 0%, 5%, and 10% packet loss were 15.2% (range 0%-53%), 10.6% (4%-46%), and 8.8% (7%-33%) higher, respectively, than with ideal conventional telephone quality. Speech perception did not differ between VoIP with 20% packet loss and conventional telephone quality. The maximum benefits were observed under ideal VoIP conditions without packet loss and were 36% (P = .001) for cochlear implant users, 18

Left insular cortex and left SFG underlie prismatic adaptation effects on time perception: evidence from fMRI.

Science.gov (United States)

Magnani, Barbara; Frassinetti, Francesca; Ditye, Thomas; Oliveri, Massimiliano; Costantini, Marcello; Walsh, Vincent

2014-05-15

Prismatic adaptation (PA) has been shown to affect left-to-right spatial representations of temporal durations. A leftward aftereffect usually distorts time representation toward an underestimation, while rightward aftereffect usually results in an overestimation of temporal durations. Here, we used functional magnetic resonance imaging (fMRI) to study the neural mechanisms that underlie PA effects on time perception. Additionally, we investigated whether the effect of PA on time is transient or stable and, in the case of stability, which cortical areas are responsible of its maintenance. Functional brain images were acquired while participants (n=17) performed a time reproduction task and a control-task before, immediately after and 30 min after PA inducing a leftward aftereffect, administered outside the scanner. The leftward aftereffect induced an underestimation of time intervals that lasted for at least 30 min. The left anterior insula and the left superior frontal gyrus showed increased functional activation immediately after versus before PA in the time versus the control-task, suggesting these brain areas to be involved in the executive spatial manipulation of the representation of time. The left middle frontal gyrus showed an increase of activation after 30 min with respect to before PA. This suggests that this brain region may play a key role in the maintenance of the PA effect over time. Copyright © 2014. Published by Elsevier Inc.

Dedicated clock/timing-circuit theories of time perception and timed performance

NARCIS (Netherlands)

van Rijn, Hedderik; Gu, Bon-Mi; Meck, Warren H

2014-01-01

Scalar Timing Theory (an information-processing version of Scalar Expectancy Theory) and its evolution into the neurobiologically plausible Striatal Beat-Frequency (SBF) theory of interval timing are reviewed. These pacemaker/accumulator or oscillation/coincidence detection models are then

Community knowledge and perceptions on the management of non-malarial fevers under reduced malaria burden and implications on the current malaria treatment policy in Morogoro, Tanzania

Directory of Open Access Journals (Sweden)

Donath Samuel Tarimo

2016-02-01

Full Text Available Objective: To investigate community knowledge and perceptions on the management of nonmalarial fevers under reduced malaria burden and the implications on the uptake of artmetherlumefantrine (ALu for malaria treatment. Methods: A cross sectional survey was carried out in Morogoro Municipality in March 2015 to examine community knowledge and perceptions on the management of fever among underfives and effectiveness of ALu for malaria treatment. Household members were interviewed on knowledge of common childhood illnesses, recognition of fever symptom, and illnesses that present with fever; under-fives with a history of fever and malaria test and use of antimalarials in the last two weeks. Notion of whether every fever is due to malaria and the perceived effectiveness of ALu for malaria treatment was also assessed. Results: Fever was reported in 1 146 (69.2% under-fives, with malaria being the commonest illness (81.8% which was highly associated with fever (92.1%; other conditions associated with fever were respiratory (60.0% and gastroenteric (47.8% conditions. Malaria test was positive in 257/1 140 (22.5% under-fives; however 23.2% received ALu. The large majority (84.6% had the notion that not all fevers are due to malaria. About two thirds (63.4% believed that ALu has reduced fever episodes; however only about a half (54.6% rated ALu as being very effective. More than two thirds (70.4% of the respondents would prefer to continue using ALu as a 1st line drug. Conclusions: Fever is still a major health problem recognized to be associated with not only malaria. There is a need for continuous public education that ALu is still effective.

Holistic face perception is modulated by experience-dependent perceptual grouping.

Science.gov (United States)

Curby, Kim M; Entenman, Robert J; Fleming, Justin T

2016-07-01

What role do general-purpose, experience-sensitive perceptual mechanisms play in producing characteristic features of face perception? We previously demonstrated that different-colored, misaligned framing backgrounds, designed to disrupt perceptual grouping of face parts appearing upon them, disrupt holistic face perception. In the current experiments, a similar part-judgment task with composite faces was performed: face parts appeared in either misaligned, different-colored rectangles or aligned, same-colored rectangles. To investigate whether experience can shape impacts of perceptual grouping on holistic face perception, a pre-task fostered the perception of either (a) the misaligned, differently colored rectangle frames as parts of a single, multicolored polygon or (b) the aligned, same-colored rectangle frames as a single square shape. Faces appearing in the misaligned, differently colored rectangles were processed more holistically by those in the polygon-, compared with the square-, pre-task group. Holistic effects for faces appearing in aligned, same-colored rectangles showed the opposite pattern. Experiment 2, which included a pre-task condition fostering the perception of the aligned, same-colored frames as pairs of independent rectangles, provided converging evidence that experience can modulate impacts of perceptual grouping on holistic face perception. These results are surprising given the proposed impenetrability of holistic face perception and provide insights into the elusive mechanisms underlying holistic perception.

Alpha Power Predicts Persistence of Bistable Perception

NARCIS (Netherlands)

Piantoni, Giovanni; Romeijn, Nico; Gomez-Herrero, German; Van Der Werf, Ysbrand D; Van Someren, Eus J W

2017-01-01

Perception is strongly affected by the intrinsic state of the brain, which controls the propensity to either maintain a particular perceptual interpretation or switch to another. To understand the mechanisms underlying the spontaneous drive of the brain to explore alternative interpretations of

[Perception of asymmetry smile: Attempt to evaluation through Photoshop].

Science.gov (United States)

Diakite, C; Diep, D; Labbe, D

2016-04-01

In the labial palliative surgery of facial paralysis, it can persist asymmetry smile. Evaluate the impact of an augmentation or reduction of the commissural course on the perception of a smile anomaly, and determine from which asymmetry threshold, the smile is estimated unsightly. We took a picture of two people with a smile not forced; including one with a "cuspid smile", and the another one with a "Mona Lisa" smile. The pictures obtained were modified by the Photoshop software, to simulate an asymmetry labial smile. The changes were related to the move of the left labial commissure, the left nasolabial furrow, and the left cheek using under-correction and overcorrection, every 4 mm. Three pictures with under-correction and four pictures with over-correction were obtained. These smiles were shown to three groups of five people, which included doctors in smile specialties, doctors in other specialties, and non-doctors. Participants were then asked to indicate on which of the pictures, the smile seemed abnormal. Between -8 mm under-correction, and +8 mm over-correction, the asymmetry of the commissural course does not hinder the perception of smile. In the labial palliative surgery of facial paralysis, in the case of persistent asymmetry, there is a tolerance in the perception of "normality" of smile concerning the amplitude of the commissural course going up to 8 mm of asymmetric with under-correction or over-correction. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Neural basis of disgust perception in racial prejudice.

Science.gov (United States)

Liu, Yunzhe; Lin, Wanjun; Xu, Pengfei; Zhang, Dandan; Luo, Yuejia

2015-12-01

Worldwide racial prejudice is originated from in-group/out-group discrimination. This prejudice can bias face perception at the very beginning of social interaction. However, little is known about the neurocognitive mechanism underlying the influence of racial prejudice on facial emotion perception. Here, we examined the neural basis of disgust perception in racial prejudice using a passive viewing task and functional magnetic resonance imaging. We found that compared with the disgusted faces of in-groups, the disgusted faces of out-groups result in increased amygdala and insular engagement, positive coupling of the insula with amygdala-based emotional system, and negative coupling of the insula with anterior cingulate cortex (ACC)-based regulatory system. Furthermore, machine-learning algorithms revealed that the level of implicit racial prejudice could be predicted by functional couplings of the insula with both the amygdala and the ACC, which suggests that the insula is largely involved in racially biased disgust perception through two distinct neural circuits. In addition, individual difference in disgust sensitivity was found to be predictive of implicit racial prejudice. Taken together, our results suggest a crucial role of insula-centered circuits for disgust perception in racial prejudice. © 2015 Wiley Periodicals, Inc.

Location-Dependent Query Processing Under Soft Real-Time Constraints

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Zoubir Mammeri

2009-01-01

Full Text Available In recent years, mobile devices and applications achieved an increasing development. In database field, this development required methods to consider new query types like location-dependent queries (i.e. the query results depend on the query issuer location. Although several researches addressed problems related to location-dependent query processing, a few works considered timing requirements that may be associated with queries (i.e., the query results must be delivered to mobile clients on time. The main objective of this paper is to propose a solution for location-dependent query processing under soft real-time constraints. Hence, we propose methods to take into account client location-dependency and to maximize the percentage of queries respecting their deadlines. We validate our proposal by implementing a prototype based on Oracle DBMS. Performance evaluation results show that the proposed solution optimizes the percentage of queries meeting their deadlines and the communication cost.

Farmers\\' Perception Of Improved And Local Cassava Cultivars In ...

African Journals Online (AJOL)

Quantity of the byproduct of cassava, taste of byproduct, maturity time and disease resistance significantly contributed to farmers' perception of the cassava cultivars. Apart from good agronomic characteristics of disease resistance and early maturity, farmers' perception of cultivars is also tied to food value issues, field ...

Embodied perception: A proposal to reconcile affordance and spatial perception

NARCIS (Netherlands)

Canal Bruland, R.; van der Kamp, J.

2015-01-01

Proffitt's embodied approach to perception is deeply indebted to Gibson's ecological approach to visual perception, in particular the idea that the primary objects of perception are affordances or what the environment offers for action. Yet, rather than directly addressing affordance perception,

Do cortical gamma oscillations promote or suppress perception? An under-asked question with an over-assumed answer

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William eSedley

2013-09-01

Full Text Available Cortical gamma oscillations occur alongside perceptual processes, and in proportion to perceptual salience. They have a number of properties that make them ideal candidates to explain perception, including incorporating synchronised discharges of neural assemblies, and their emergence over a fast timescale consistent with that of perception. These observations have led to widespread assumptions that gamma oscillations’ role is to cause or facilitate conscious perception (i.e. a ‘positive’ role. While the majority of the human literature on gamma oscillations is consistent with this interpretation, many or most of these studies could equally be interpreted as showing a suppressive or inhibitory (i.e. ‘negative’ role. For example, presenting a stimulus and recording a response of increased gamma oscillations would only suggest a role for gamma oscillations in the representation of that stimulus, and would not specify what that role were. For instance, if gamma oscillations were inhibitory, then they would become selectively activated in response to the stimulus they acted to inhibit.In this review, we consider two classes of gamma oscillations: broadband and narrowband, which have very different properties (and likely roles. We first discuss studies on gamma oscillations that are non-discriminatory, with respect to the role of gamma oscillations, followed by studies that specifically support specifically a positive or negative role. These include work on perception in healthy individuals, and in the pathological contexts of phantom perception and epilepsy. Reference is based as much as possible on magnetoencephalography (MEG and electroencephalography (EEG studies, but we also consider evidence from invasive recordings in humans and other animals. Attempts are made to reconcile findings within a common framework. We conclude with a summary of the pertinent questions that remain unanswered, and suggest how future studies might address

Secondary School Students' Perceptions of Working Life Skills in Science-Related Careers

Science.gov (United States)

Salonen, Anssi; Hartikainen-Ahia, Anu; Hense, Jonathan; Scheersoi, Annette; Keinonen, Tuula

2017-01-01

School students demonstrate a lack of interest in choosing science studies and science-related careers. To better understand the underlying reasons, this study aims to examine secondary school students' perceptions of working life skills and how these perceptions relate to the skills of the twenty-first century. The participants in this study were…

Risk factor for phlebitis: a questionnaire study of nurses' perception

Directory of Open Access Journals (Sweden)

Dragana Milutinović

2015-08-01

Full Text Available AbstractObjectives: to assess nurses' perceptions of risk factors for the development of phlebitis, with a special focus on the perception of phlebitic potentials of some infusion medications and solutions.Method: a cross-sectional questionnaire study, which included a sample of 102 nurses.Results: Nurses recognized some factors that may reduce the incidence of phlebitis; however, more than half of the nurses were unaware that the material and diameter of the cannula can affect the incidence rate of phlebitis. Furthermore,underlying disease and high pH of medications or solutions were identified as potential risk factors, whereas low pH and low osmolality were not. Nurses identified Vancomycin and Benzylpenicillin antibiotics with the strongest phlebitic potential. Among other medications and intravenous fluids, Aminophylline, Amiodaronehydrochloride and Potassium chloride 7.4% were identified as potentially causing phlebitis.Conclusion: predisposing factors for phlebitis relating to patients and administered therapy were identified by nurses, while some cannula related risk factors, in particular its physicochemical properties and the time for cannula replacement, were not fully perceived.

Embodied Perception: A Proposal to Reconcile Affordance and Spatial Perception

OpenAIRE

Ca?al-Bruland, Rouwen; van der Kamp, John

2015-01-01

Proffitt's embodied approach to perception is deeply indebted to Gibson's ecological approach to visual perception, in particular the idea that the primary objects of perception are affordances or what the environment offers for action. Yet, rather than directly addressing affordance perception, most of the empirical work evaluating Proffitt's approach focuses on the perception of spatial properties of the environment. We propose that theoretical and empirical efforts should be directed towar...

One-dimensional radionuclide transport under time-varying conditions

International Nuclear Information System (INIS)

Gelbard, F.; Olague, N.E.; Longsine, D.E.

1990-01-01

This paper discusses new analytical and numerical solutions presented for one-dimensional radionuclide transport under time-varying fluid-flow conditions including radioactive decay. The analytical solution assumes that all radionuclides have identical retardation factors, and is limited to instantaneous releases. The numerical solution does not have these limitations, but is tested against the limiting case given for the analytical solution. Reasonable agreement between the two solutions was found. Examples are given for the transport of a three-member radionuclide chain transported over distances and flow rates comparable to those reported for Yucca Mountain, the proposed disposal site for high-level nuclear waste

Correlated individual differences suggest a common mechanism underlying metacognition in visual perception and visual short-term memory.

Science.gov (United States)

Samaha, Jason; Postle, Bradley R

2017-11-29

Adaptive behaviour depends on the ability to introspect accurately about one's own performance. Whether this metacognitive ability is supported by the same mechanisms across different tasks is unclear. We investigated the relationship between metacognition of visual perception and metacognition of visual short-term memory (VSTM). Experiments 1 and 2 required subjects to estimate the perceived or remembered orientation of a grating stimulus and rate their confidence. We observed strong positive correlations between individual differences in metacognitive accuracy between the two tasks. This relationship was not accounted for by individual differences in task performance or average confidence, and was present across two different metrics of metacognition and in both experiments. A model-based analysis of data from a third experiment showed that a cross-domain correlation only emerged when both tasks shared the same task-relevant stimulus feature. That is, metacognition for perception and VSTM were correlated when both tasks required orientation judgements, but not when the perceptual task was switched to require contrast judgements. In contrast with previous results comparing perception and long-term memory, which have largely provided evidence for domain-specific metacognitive processes, the current findings suggest that metacognition of visual perception and VSTM is supported by a domain-general metacognitive architecture, but only when both domains share the same task-relevant stimulus feature. © 2017 The Author(s).

Evaluation of an Efficient Approach for Target Tracking from Acoustic Imagery for the Perception System of an Autonomous Underwater Vehicle

Directory of Open Access Journals (Sweden)

Sebastián A. Villar

2014-02-01

Full Text Available This article describes the core algorithms of the perception system to be included within an autonomous underwater vehicle (AUV. This perception system is based on the acoustic data acquired from side scan sonar (SSS. These data should be processed in an efficient time, so that the perception system is able to detect and recognize a predefined target. This detection and recognition outcome is therefore an important piece of knowledge for the AUVs dynamic mission planner (DMP. Effectively, the DMP should propose different trajectories, navigation depths and other parameters that will change the robot's behaviour according to the perception system output. Hence, the time in which to make a decision is critical in order to assure safe robot operation and to acquire good quality data; consequently, the efficiency of the on-line image processing from acoustic data is a key issue. Current techniques for acoustic data processing are time and computationally intensive. Hence, it was decided to process data coming from a SSS using a technique that is used for radars, due to its efficiency and its amenability to on-line processing. The engineering problem to solve in this case was underwater pipeline tracking for routine inspections in the off-shore industry. Then, an automatic oil pipeline detection system was developed borrowing techniques from the processing of radar measurements. The radar technique is known as Cell Average – Constant False Alarm Rate (CA – CFAR. With a slight variation of the algorithms underlying this radar technique, which consisted of the previous accumulation of partial sums, a great improvement in computing time and effort was achieved. Finally, a comparison with previous approaches over images acquired with a SSS from a vessel in the Salvador de Bahia bay in Brazil showed the feasibility of using this on-board technique for AUV perception.

Cross-cultural differences in risk perceptions of disasters.

Science.gov (United States)

Gierlach, Elaine; Belsher, Bradley E; Beutler, Larry E

2010-10-01

Public risk perceptions of mass disasters carry considerable influences, both psychologically and economically, despite their oft-times imprecise nature. Prior research has identified the presence of an optimistic bias that affects risk perception, but there is a dearth of literature examining how these perceptions differ among cultures-particularly with regard to mass disasters. The present study explores differences among Japanese, Argentinean, and North American mental health workers in their rates of the optimistic bias in risk perceptions as contrasted between natural disasters and terrorist events. The results indicate a significant difference among cultures in levels of perceived risk that do not correspond to actual exposure rates. Japanese groups had the highest risk perceptions for both types of hazards and North Americans and Argentineans had the lowest risk perceptions for terrorism. Additionally, participants across all cultures rated risk to self as lower than risk to others (optimistic bias) across all disaster types. These findings suggest that cultural factors may have a greater influence on risk perception than social exposure, and that the belief that one is more immune to disasters compared to others may be a cross-cultural phenomenon. © 2010 Society for Risk Analysis.

Exploring women's beliefs and perceptions about healthy eating blogs: a qualitative study.

Science.gov (United States)

Bissonnette-Maheux, Véronique; Provencher, Veronique; Lapointe, Annie; Dugrenier, Marilyn; Dumas, Audrée-Anne; Pluye, Pierre; Straus, Sharon; Gagnon, Marie-Pierre; Desroches, Sophie

2015-04-08

information, and allowed interaction with a dietitian. Disadvantages included increased time spent on the Internet and guilt if recommendations were not followed. Important people who would approve were family, colleagues, and friends. Important people who could disapprove were family and doctors. Main facilitators were visually attractive blogs, receiving an email notification about new posts, and finding new information on the blog. Main barriers were too much text, advertising on the blog, and lack of time. The women in this study valued the credibility of healthy eating blogs written by dietitians and the contact with dietitians they provided. Identifying salient beliefs underlying women's perceptions of using such blogs provides an empirically supported basis for the design of knowledge translation interventions to help prevent chronic diseases.

Chinese University EFL Teachers' Perceptions of Plagiarism

Science.gov (United States)

Lei, Jun; Hu, Guangwei

2015-01-01

Although Chinese university students' perceptions of plagiarism have been extensively investigated, those of their teachers have been surprisingly under-researched. This study sought to address this gap by investigating 112 Chinese university English teachers' knowledge of and attitudes towards plagiarism. While 57 participating teachers had…

Workplace Incivility and Bullying in the Library: Perception or Reality?

Science.gov (United States)

Freedman, Shin; Vreven, Dawn

2016-01-01

Recent media reports have increased awareness of workplace incivility and bullying. However, the literature regarding workplace incivility and bullying in academic libraries is under reported and under researched. This study examines the current state of librarians' perceptions on workplace incivility and bullying and evaluates the effects of…

Investigations on response time of magnetorheological elastomer under compression mode

Science.gov (United States)

Zhu, Mi; Yu, Miao; Qi, Song; Fu, Jie

2018-05-01

For efficient fast control of vibration system with magnetorheological elastomer (MRE)-based smart device, the response time of MRE material is the key parameter which directly affects the control performance of the vibration system. For a step coil current excitation, this paper proposed a Maxwell behavior model with time constant λ to describe the normal force response of MRE, and the response time of MRE was extracted through the separation of coil response time. Besides, the transient responses of MRE under compression mode were experimentally investigated, and the effects of (i) applied current, (ii) particle distribution and (iii) compressive strain on the response time of MRE were addressed. The results revealed that the three factors can affect the response characteristic of MRE quite significantly. Besides the intrinsic importance for contributing to the response evaluation and effective design of MRE device, this study may conduce to the optimal design of controller for MRE control system.

“They Like Me, They Like Me Not”: Popularity and Adolescents’ Perceptions of Acceptance Predicting Social Functioning Over Time

Science.gov (United States)

McElhaney, Kathleen B.; Antonishak, Jill; Allen, Joseph P.

2011-01-01

This study examined the dual roles of adolescents’ perceptions of social acceptance and sociometric popularity in predicting relative changes over time in adolescents’ social functioning. Observational, self-report, and peer report data were obtained from 164 adolescents who were interviewed at age 13 years and then again at age 14 years, as well as their same-sex close friends. Adolescents who felt positively about their own social standing fared well over time, regardless of their level of sociometric popularity. Further, low popularity was particularly problematic for adolescents who failed to see themselves as fitting in. Results suggest that during adolescence, when it becomes increasingly possible for teens to choose their own social niches, it is possible to be socially successful without being broadly popular. PMID:18489423

The development of visual speech perception in Mandarin Chinese-speaking children.

Science.gov (United States)

Chen, Liang; Lei, Jianghua

2017-01-01

The present study aimed to investigate the development of visual speech perception in Chinese-speaking children. Children aged 7, 13 and 16 were asked to visually identify both consonant and vowel sounds in Chinese as quickly and accurately as possible. Results revealed (1) an increase in accuracy of visual speech perception between ages 7 and 13 after which the accuracy rate either stagnates or drops; and (2) a U-shaped development pattern in speed of perception with peak performance in 13-year olds. Results also showed that across all age groups, the overall levels of accuracy rose, whereas the response times fell for simplex finals, complex finals and initials. These findings suggest that (1) visual speech perception in Chinese is a developmental process that is acquired over time and is still fine-tuned well into late adolescence; (2) factors other than cross-linguistic differences in phonological complexity and degrees of reliance on visual information are involved in development of visual speech perception.

The effects of music on time perception and performance of a driving game.

Science.gov (United States)

Cassidy, G G; Macdonald, R A R

2010-12-01

There is an established and growing body of evidence highlighting that music can influence behavior across a range of diverse domains (Miell, MacDonald, & Hargreaves 2005). One area of interest is the monitoring of "internal timing mechanisms", with features such as tempo, liking, perceived affective nature and everyday listening contexts implicated as important (North & Hargreaves, 2008). The current study addresses these issues by comparing the effects of self-selected and experimenter-selected music (fast and slow) on actual and perceived performance of a driving game activity. Seventy participants completed three laps of a driving game in seven sound conditions: (1) silence; (2) car sounds; (3) car sounds with self-selected music, and car sounds with experimenter-selected music; (4) high-arousal (70 bpm); (5) high-arousal (130 bpm); (6) low-arousal (70 bpm); and (7) low-arousal (130 bpm) music. Six performance measures (time, accuracy, speed, and retrospective perception of these), and four experience measures (perceived distraction, liking, appropriateness and enjoyment) were taken. Exposure to self-selected music resulted in overestimation of elapsed time and inaccuracy, while benefiting accuracy and experience. In contrast, exposure to experimenter-selected music resulted in poorest performance and experience. Increasing the tempo of experimenter-selected music resulted in faster performance and increased inaccuracy for high-arousal music, but did not impact experience. It is suggested that personal meaning and subjective associations connected to self-selected music promoted increased engagement with the activity, overriding detrimental effects attributed to unfamiliar, less liked and less appropriate experimenter-selected music. © 2010 The Authors. Scandinavian Journal of Psychology © 2010 The Scandinavian Psychological Associations.

Pitch perception prior to cortical maturation

Science.gov (United States)

Lau, Bonnie K.

Pitch perception plays an important role in many complex auditory tasks including speech perception, music perception, and sound source segregation. Because of the protracted and extensive development of the human auditory cortex, pitch perception might be expected to mature, at least over the first few months of life. This dissertation investigates complex pitch perception in 3-month-olds, 7-month-olds and adults -- time points when the organization of the auditory pathway is distinctly different. Using an observer-based psychophysical procedure, a series of four studies were conducted to determine whether infants (1) discriminate the pitch of harmonic complex tones, (2) discriminate the pitch of unresolved harmonics, (3) discriminate the pitch of missing fundamental melodies, and (4) have comparable sensitivity to pitch and spectral changes as adult listeners. The stimuli used in these studies were harmonic complex tones, with energy missing at the fundamental frequency. Infants at both three and seven months of age discriminated the pitch of missing fundamental complexes composed of resolved and unresolved harmonics as well as missing fundamental melodies, demonstrating perception of complex pitch by three months of age. More surprisingly, infants in both age groups had lower pitch and spectral discrimination thresholds than adult listeners. Furthermore, no differences in performance on any of the tasks presented were observed between infants at three and seven months of age. These results suggest that subcortical processing is not only sufficient to support pitch perception prior to cortical maturation, but provides adult-like sensitivity to pitch by three months.

A study on the validity of a computer-based game to assess cognitive processes, reward mechanisms, and time perception in children aged 4-8 years

NARCIS (Netherlands)

Peijnenborgh, J.C.A.W.; Hurks, P.M.; Aldenkamp, A.P.; van der Spek, E.D.; Rauterberg, G.W.M.; Vles, J.S.H.; Hendriksen, J.G.M.

2016-01-01

BACKGROUND: A computer-based game, named Timo's Adventure, was developed to assess specific cognitive functions (eg, attention, planning, and working memory), time perception, and reward mechanisms in young school-aged children. The game consists of 6 mini-games embedded in a story line and includes

Vibration amplitude rule study for rotor under large time scale

International Nuclear Information System (INIS)

Yang Xuan; Zuo Jianli; Duan Changcheng

2014-01-01

The rotor is an important part of the rotating machinery; its vibration performance is one of the important factors affecting the service life. This paper presents both theoretical analyses and experimental demonstrations of the vibration rule of the rotor under large time scales. The rule can be used for the service life estimation of the rotor. (authors)

Green Point residents' perceptions of the 2010 FIFA World Cup: A ...

African Journals Online (AJOL)

Green Point residents' perceptions of the 2010 FIFA World Cup: A post-event ... positive perceptions and attitudes towards South Africa's hosting of the event. ... longitudinal studies are recommended to gauge perceptual changes over time.

Commonalities between perception and cognition

Directory of Open Access Journals (Sweden)

Michela C. Tacca

2011-11-01

Full Text Available Perception and cognition are highly interrelated. Given the influence that these systems exert on one another, it is important to explain how perceptual representations and cognitive representations interact. In this paper, I analyze the similarities between visual perceptual representations and cognitive representations in terms of their structural properties and content. Specifically, I argue that the spatial structure underlying visual object representation displays systematicity—a property that is considered to be characteristic of propositional cognitive representations. To this end, I propose a logical characterization of visual feature binding as described by Treisman’s Feature Integration Theory and argue that systematicity is not only a property of language-like representations, but also of spatially organized visual representations. Furthermore, I argue that if systematicity is taken to be a criterion to distinguish between conceptual and nonconceptual representations, then visual representations, that display systematicity, might count as an early type of conceptual representations. Showing these analogies between visual perception and cognition is an important step towards understanding the interface between the two systems. The ideas here presented might also set the stage for new empirical studies that directly compare binding (and other relational operations in visual perception and higher cognition.

Perceptions regarding strategic and structural entry barriers

NARCIS (Netherlands)

Lutz, C.H.M.; Kemp, R.G.M.; Dijkstra, S.G.

2010-01-01

This article uses factor analysis to identify the underlying dimensions of strategic and structural entry barriers. We find that, in the perception of firms, both types of barriers are important and that the effectiveness of strategic barriers depends on attributes of the market structure. Based on