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Sample records for two-choice discrimination task

  1. The Diffusion Decision Model: Theory and Data for Two-Choice Decision Tasks

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    Ratcliff, Roger; McKoon, Gail

    2008-01-01

    The diffusion decision model allows detailed explanations of behavior in two-choice discrimination tasks. In this article, the model is reviewed to show how it translates behavioral data—accuracy, mean response times, and response time distributions—into components of cognitive processing. Three experiments are used to illustrate experimental manipulations of three components: stimulus difficulty affects the quality of information on which a decision is based; instructions emphasizing either ...

  2. Task-irrelevant emotion facilitates face discrimination learning.

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    Lorenzino, Martina; Caudek, Corrado

    2015-03-01

    We understand poorly how the ability to discriminate faces from one another is shaped by visual experience. The purpose of the present study is to determine whether face discrimination learning can be facilitated by facial emotions. To answer this question, we used a task-irrelevant perceptual learning paradigm because it closely mimics the learning processes that, in daily life, occur without a conscious intention to learn and without an attentional focus on specific facial features. We measured face discrimination thresholds before and after training. During the training phase (4 days), participants performed a contrast discrimination task on face images. They were not informed that we introduced (task-irrelevant) subtle variations in the face images from trial to trial. For the Identity group, the task-irrelevant features were variations along a morphing continuum of facial identity. For the Emotion group, the task-irrelevant features were variations along an emotional expression morphing continuum. The Control group did not undergo contrast discrimination learning and only performed the pre-training and post-training tests, with the same temporal gap between them as the other two groups. Results indicate that face discrimination improved, but only for the Emotion group. Participants in the Emotion group, moreover, showed face discrimination improvements also for stimulus variations along the facial identity dimension, even if these (task-irrelevant) stimulus features had not been presented during training. The present results highlight the importance of emotions for face discrimination learning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Subcortical plasticity following perceptual learning in a pitch discrimination task

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    Carcagno, Samuele; Plack, Christopher J.

    2011-01-01

    Practice can lead to dramatic improvements in the discrimination of auditory stimuli. In this study, we investigated changes of the frequency-following response (FFR), a subcortical component of the auditory evoked potentials, after a period of pitch discrimination training. Twenty-seven adult listeners were trained for 10 h on a pitch discrimination task using one of three different complex tone stimuli. One had a static pitch contour, one had a rising pitch contour, and one had a falling pi...

  4. Modulation of radial blood flow during Braille character discrimination task.

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    Murata, Jun; Matsukawa, K; Komine, H; Tsuchimochi, H

    2012-03-01

    Human hands are excellent in performing sensory and motor function. We have hypothesized that blood flow of the hand is dynamically regulated by sympathetic outflow during concentrated finger perception. To identify this hypothesis, we measured radial blood flow (RBF), radial vascular conductance (RVC), heart rate (HR), and arterial blood pressure (AP) during Braille reading performed under the blind condition in nine healthy subjects. The subjects were instructed to read a flat plate with raised letters (Braille reading) for 30 s by the forefinger, and to touch a blank plate as control for the Braille discrimination procedure. HR and AP slightly increased during Braille reading but remained unchanged during the touching of the blank plate. RBF and RVC were reduced during the Braille character discrimination task (decreased by -46% and -49%, respectively). Furthermore, the changes in RBF and RVC were much greater during the Braille character discrimination task than during the touching of the blank plate (decreased by -20% and -20%, respectively). These results have suggested that the distribution of blood flow to the hand is modulated via sympathetic nerve activity during concentrated finger perception.

  5. Subcortical plasticity following perceptual learning in a pitch discrimination task.

    Science.gov (United States)

    Carcagno, Samuele; Plack, Christopher J

    2011-02-01

    Practice can lead to dramatic improvements in the discrimination of auditory stimuli. In this study, we investigated changes of the frequency-following response (FFR), a subcortical component of the auditory evoked potentials, after a period of pitch discrimination training. Twenty-seven adult listeners were trained for 10 h on a pitch discrimination task using one of three different complex tone stimuli. One had a static pitch contour, one had a rising pitch contour, and one had a falling pitch contour. Behavioral measures of pitch discrimination and FFRs for all the stimuli were measured before and after the training phase for these participants, as well as for an untrained control group (n = 12). Trained participants showed significant improvements in pitch discrimination compared to the control group for all three trained stimuli. These improvements were partly specific for stimuli with the same pitch modulation (dynamic vs. static) and with the same pitch trajectory (rising vs. falling) as the trained stimulus. Also, the robustness of FFR neural phase locking to the sound envelope increased significantly more in trained participants compared to the control group for the static and rising contour, but not for the falling contour. Changes in FFR strength were partly specific for stimuli with the same pitch modulation (dynamic vs. static) of the trained stimulus. Changes in FFR strength, however, were not specific for stimuli with the same pitch trajectory (rising vs. falling) as the trained stimulus. These findings indicate that even relatively low-level processes in the mature auditory system are subject to experience-related change.

  6. Different levels of food restriction reveal genotype-specific differences in learning a visual discrimination task.

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    Kalina Makowiecki

    Full Text Available In behavioural experiments, motivation to learn can be achieved using food rewards as positive reinforcement in food-restricted animals. Previous studies reduce animal weights to 80-90% of free-feeding body weight as the criterion for food restriction. However, effects of different degrees of food restriction on task performance have not been assessed. We compared learning task performance in mice food-restricted to 80 or 90% body weight (BW. We used adult wildtype (WT; C57Bl/6j and knockout (ephrin-A2⁻/⁻ mice, previously shown to have a reverse learning deficit. Mice were trained in a two-choice visual discrimination task with food reward as positive reinforcement. When mice reached criterion for one visual stimulus (80% correct in three consecutive 10 trial sets they began the reverse learning phase, where the rewarded stimulus was switched to the previously incorrect stimulus. For the initial learning and reverse phase of the task, mice at 90%BW took almost twice as many trials to reach criterion as mice at 80%BW. Furthermore, WT 80 and 90%BW groups significantly differed in percentage correct responses and learning strategy in the reverse learning phase, whereas no differences between weight restriction groups were observed in ephrin-A2⁻/⁻ mice. Most importantly, genotype-specific differences in reverse learning strategy were only detected in the 80%BW groups. Our results indicate that increased food restriction not only results in better performance and a shorter training period, but may also be necessary for revealing behavioural differences between experimental groups. This has important ethical and animal welfare implications when deciding extent of diet restriction in behavioural studies.

  7. Aging Effect on Audiovisual Integrative Processing in Spatial Discrimination Task

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    Zhi Zou

    2017-11-01

    Full Text Available Multisensory integration is an essential process that people employ daily, from conversing in social gatherings to navigating the nearby environment. The aim of this study was to investigate the impact of aging on modulating multisensory integrative processes using event-related potential (ERP, and the validity of the study was improved by including “noise” in the contrast conditions. Older and younger participants were involved in perceiving visual and/or auditory stimuli that contained spatial information. The participants responded by indicating the spatial direction (far vs. near and left vs. right conveyed in the stimuli using different wrist movements. electroencephalograms (EEGs were captured in each task trial, along with the accuracy and reaction time of the participants’ motor responses. Older participants showed a greater extent of behavioral improvements in the multisensory (as opposed to unisensory condition compared to their younger counterparts. Older participants were found to have fronto-centrally distributed super-additive P2, which was not the case for the younger participants. The P2 amplitude difference between the multisensory condition and the sum of the unisensory conditions was found to correlate significantly with performance on spatial discrimination. The results indicated that the age-related effect modulated the integrative process in the perceptual and feedback stages, particularly the evaluation of auditory stimuli. Audiovisual (AV integration may also serve a functional role during spatial-discrimination processes to compensate for the compromised attention function caused by aging.

  8. Action recognition and movement direction discrimination tasks are associated with different adaptation patterns

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    Stephan eDe La Rosa

    2016-02-01

    Full Text Available The ability to discriminate between different actions is essential for action recognition and social interaction. Surprisingly previous research has often probed action recognition mechanisms with tasks that did not require participants to discriminate between actions, e.g. left-right direction discrimination tasks. It is not known to what degree visual processes in direction discrimination tasks are also involved in the discrimination of actions, e.g. when telling apart a handshake from a high-five. Here, we examined whether action discrimination is influenced by movement direction and whether direction discrimination depends on the type of action. We used an action adaptation paradigm to target action and direction discrimination specific visual processes. In separate conditions participants visually adapted to forward and backward moving handshake and high-five actions. Participants subsequently either categorized the action or the movement direction of an ambiguous action. The results showed that direction discrimination adaptation effects were modulated by the type of action but action discrimination adaptation effects were unaffected by movement direction. These results suggest that action discrimination and direction categorization rely on partly different visual information. We propose that action discrimination tasks should be considered for the exploration of visual action recognition mechanisms.

  9. Speech Discrimination in Preschool Children: A Comparison of Two Tasks.

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    Menary, Susan; And Others

    1982-01-01

    Eleven four-year-old children were tested for discrimination of the following word pairs: rope/robe, seat/seed, pick/pig, ice/eyes, and mouse/mouth. All word pairs were found to be discriminable, but performance on seat/seed and mouse/mouth was inferior to that of the other word pairs. (Author)

  10. Activations of human auditory cortex to phonemic and nonphonemic vowels during discrimination and memory tasks.

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    Harinen, Kirsi; Rinne, Teemu

    2013-08-15

    We used fMRI to investigate activations within human auditory cortex (AC) to vowels during vowel discrimination, vowel (categorical n-back) memory, and visual tasks. Based on our previous studies, we hypothesized that the vowel discrimination task would be associated with increased activations in the anterior superior temporal gyrus (STG), while the vowel memory task would enhance activations in the posterior STG and inferior parietal lobule (IPL). In particular, we tested the hypothesis that activations in the IPL during vowel memory tasks are associated with categorical processing. Namely, activations due to categorical processing should be higher during tasks performed on nonphonemic (hard to categorize) than on phonemic (easy to categorize) vowels. As expected, we found distinct activation patterns during vowel discrimination and vowel memory tasks. Further, these task-dependent activations were different during tasks performed on phonemic or nonphonemic vowels. However, activations in the IPL associated with the vowel memory task were not stronger during nonphonemic than phonemic vowel blocks. Together these results demonstrate that activations in human AC to vowels depend on both the requirements of the behavioral task and the phonemic status of the vowels. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Investigating the time course of tactile reflexive attention using a non-spatial discrimination task.

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    Miles, Eleanor; Poliakoff, Ellen; Brown, Richard J

    2008-06-01

    Peripheral cues are thought to facilitate responses to stimuli presented at the same location because they lead to exogenous attention shifts. Facilitation has been observed in numerous studies of visual and auditory attention, but there have been only four demonstrations of tactile facilitation, all in studies with potential confounds. Three studies used a spatial (finger versus thumb) discrimination task, where the cue could have provided a spatial framework that might have assisted the discrimination of subsequent targets presented on the same side as the cue. The final study circumvented this problem by using a non-spatial discrimination; however, the cues were informative and interspersed with visual cues which may have affected the attentional effects observed. In the current study, therefore, we used a non-spatial tactile frequency discrimination task following a non-informative tactile white noise cue. When the target was presented 150 ms after the cue, we observed faster discrimination responses to targets presented on the same side compared to the opposite side as the cue; by 1000 ms, responses were significantly faster to targets presented on the opposite side to the cue. Thus, we demonstrated that tactile attentional facilitation can be observed in a non-spatial discrimination task, under unimodal conditions and with entirely non-predictive cues. Furthermore, we provide the first demonstration of significant tactile facilitation and tactile inhibition of return within a single experiment.

  12. A novel perceptual discrimination training task: Reducing fear overgeneralization in the context of fear learning.

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    Ginat-Frolich, Rivkah; Klein, Zohar; Katz, Omer; Shechner, Tomer

    2017-06-01

    Generalization is an adaptive learning mechanism, but it can be maladaptive when it occurs in excess. A novel perceptual discrimination training task was therefore designed to moderate fear overgeneralization. We hypothesized that improvement in basic perceptual discrimination would translate into lower fear overgeneralization in affective cues. Seventy adults completed a fear-conditioning task prior to being allocated into training or placebo groups. Predesignated geometric shape pairs were constructed for the training task. A target shape from each pair was presented. Thereafter, participants in the training group were shown both shapes and asked to identify the image that differed from the target. Placebo task participants only indicated the location of each shape on the screen. All participants then viewed new geometric pairs and indicated whether they were identical or different. Finally, participants completed a fear generalization test consisting of perceptual morphs ranging from the CS + to the CS-. Fear-conditioning was observed through physiological and behavioural measures. Furthermore, the training group performed better than the placebo group on the assessment task and exhibited decreased fear generalization in response to threat/safety cues. The findings offer evidence for the effectiveness of the novel discrimination training task, setting the stage for future research with clinical populations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Voluntary Exercise Improves Performance of a Discrimination Task through Effects on the Striatal Dopamine System

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    Eddy, Meghan C.; Stansfield, Katherine J.; Green, John T.

    2014-01-01

    We have previously demonstrated that voluntary exercise facilitates discrimination learning in a modified T-maze. There is evidence implicating the dorsolateral striatum (DLS) as the substrate for this task. The present experiments examined whether changes in DLS dopamine receptors might underlie the exercise-associated facilitation. Infusing a…

  14. The influence of short-term memory on standard discrimination and cued identification olfactory tasks.

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    Zucco, Gesualdo M; Hummel, Thomas; Tomaiuolo, Francesco; Stevenson, Richard J

    2014-01-30

    Amongst the techniques to assess olfactory functions, discrimination and cued identification are those most prone to the influence of odour short-term memory (STM). Discrimination task requires participants to detect the odd one out of three presented odourants. As re-smelling is not permitted, an un-intended STM load may generate, even though the task purports to assess discrimination ability. Analogously, cued identification task requires participants to smell an odour, and then select a label from three or four alternatives. As the interval between smelling and reading each label increases this too imposes a STM load, even though the task aims to measure identification ability. We tested whether modifying task design to reduce STM load improve performance on these tests. We examined five age-groups of participants (Adolescents, Young adults, Middle-aged, Elderly, very Elderly), some of whom should be more prone to the effects of STM load than others, on standard and modified tests of discrimination and identification. We found that using a technique to reduce STM load improved performance, especially for the very Elderly and Adolescent groups. Sources of error are now prevented. Findings indicate that STM load can adversely affect performance in groups vulnerable from memory impairment (i.e., very Elderly) and in those who may still be acquiring memory-based representations of familiar odours (i.e., Adolescents). It may be that adults in general would be even more sensitive to the effects of olfactory STM load reduction, if the odour-related task was more difficult. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Discriminating talent-identified junior Australian football players using a video decision-making task.

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    Woods, Carl T; Raynor, Annette J; Bruce, Lyndell; McDonald, Zane

    2016-01-01

    This study examined if a video decision-making task could discriminate talent-identified junior Australian football players from their non-talent-identified counterparts. Participants were recruited from the 2013 under 18 (U18) West Australian Football League competition and classified into two groups: talent-identified (State U18 Academy representatives; n = 25; 17.8 ± 0.5 years) and non-talent-identified (non-State U18 Academy selection; n = 25; 17.3 ± 0.6 years). Participants completed a video decision-making task consisting of 26 clips sourced from the Australian Football League game-day footage, recording responses on a sheet provided. A score of "1" was given for correct and "0" for incorrect responses, with the participants total score used as the criterion value. One-way analysis of variance tested the main effect of "status" on the task criterion, whilst a bootstrapped receiver operating characteristic (ROC) curve assessed the discriminant ability of the task. An area under the curve (AUC) of 1 (100%) represented perfect discrimination. Between-group differences were evident (P talent-identified and non-talent-identified participants, respectively. Future research should investigate the mechanisms leading to the superior decision-making observed in the talent-identified group.

  16. Valence of facial cues influences sheep learning in a visual discrimination task

    OpenAIRE

    Bellegarde, Lucille; Erhard, Hans; Weiss, A.; Boissy, Alain; Haskell, M.J.

    2017-01-01

    Sheep are one of the most studied farm species in terms of their ability to process information from faces, but little is known about their face-based emotion recognition abilities. We investigated (a) whether sheep could use images of sheep faces taken in situation of varying valence as cues in a simultaneous discrimination task and (b) whether the valence of the situation affects their learning performance. To accomplish this, we photographed faces of sheep in three situations inducing emot...

  17. Valence of Facial Cues Influences Sheep Learning in a Visual Discrimination Task

    OpenAIRE

    Lucille G. A. Bellegarde; Lucille G. A. Bellegarde; Lucille G. A. Bellegarde; Hans W. Erhard; Alexander Weiss; Alain Boissy; Marie J. Haskell

    2017-01-01

    Sheep are one of the most studied farm species in terms of their ability to process information from faces, but little is known about their face-based emotion recognition abilities. We investigated (a) whether sheep could use images of sheep faces taken in situation of varying valence as cues in a simultaneous discrimination task and (b) whether the valence of the situation affects their learning performance. To accomplish this, we photographed faces of sheep in three situations inducing emot...

  18. A Report on Applying EEGnet to Discriminate Human State Effects on Task Performance

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    2018-01-01

    indicate that EEGNet could discriminate sleep history of a user. This could be used in future adaptive technologies to detect user fatigue and likely...is unlimited. 1. Introduction As the amount of battlefield technology continues to increase, Soldiers are faced with a daunting task of trying to...integrate diverse information across numerous devices. The growing information burden across devices has spawned a strong in- terest in “smart technology

  19. Brain activity during auditory and visual phonological, spatial and simple discrimination tasks.

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    Salo, Emma; Rinne, Teemu; Salonen, Oili; Alho, Kimmo

    2013-02-16

    We used functional magnetic resonance imaging to measure human brain activity during tasks demanding selective attention to auditory or visual stimuli delivered in concurrent streams. Auditory stimuli were syllables spoken by different voices and occurring in central or peripheral space. Visual stimuli were centrally or more peripherally presented letters in darker or lighter fonts. The participants performed a phonological, spatial or "simple" (speaker-gender or font-shade) discrimination task in either modality. Within each modality, we expected a clear distinction between brain activations related to nonspatial and spatial processing, as reported in previous studies. However, within each modality, different tasks activated largely overlapping areas in modality-specific (auditory and visual) cortices, as well as in the parietal and frontal brain regions. These overlaps may be due to effects of attention common for all three tasks within each modality or interaction of processing task-relevant features and varying task-irrelevant features in the attended-modality stimuli. Nevertheless, brain activations caused by auditory and visual phonological tasks overlapped in the left mid-lateral prefrontal cortex, while those caused by the auditory and visual spatial tasks overlapped in the inferior parietal cortex. These overlapping activations reveal areas of multimodal phonological and spatial processing. There was also some evidence for intermodal attention-related interaction. Most importantly, activity in the superior temporal sulcus elicited by unattended speech sounds was attenuated during the visual phonological task in comparison with the other visual tasks. This effect might be related to suppression of processing irrelevant speech presumably distracting the phonological task involving the letters. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. The neural network involved in a bimanual tactile-tactile matching discrimination task: a functional imaging study at 3 T

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    Habas, Christophe; Cabanis, Emmanuel A. [UPMC Paris 6, Service de NeuroImagerie, Hopital des Quinze-Vingts, Paris (France)

    2007-08-15

    The cerebral and cerebellar network involved in a bimanual object recognition was studied in blood oxygenation dependent level functional magnetic resonance imaging (fMRI). Nine healthy right-handed volunteers were scanned (1) while performing bilateral finger movements (nondiscrimination motor task), and (2) while performing a bimanual tactile-tactile matching discrimination task using small chess pieces (tactile discrimination task). Extensive activations were specifically observed in the parietal (SII, superior lateral lobule), insular, prefrontal, cingulate and neocerebellar cortices (HVIII), with a left predominance in motor areas, during the tactile discrimination task in contrast to the findings during the nondiscrimination motor task. Bimanual tactile-tactile matching discrimination recruits multiple sensorimotor and associative cerebral and neocerebellar networks (including the cerebellar second homunculus, HVIII), comparable to the neural circuits involved in unimanual tactile object recognition. (orig.)

  1. Eye Contact and Fear of Being Laughed at in a Gaze Discrimination Task

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    Jorge Torres-Marín

    2017-11-01

    Full Text Available Current approaches conceptualize gelotophobia as a personality trait characterized by a disproportionate fear of being laughed at by others. Consistently with this perspective, gelotophobes are also described as neurotic and introverted and as having a paranoid tendency to anticipate derision and mockery situations. Although research on gelotophobia has significantly progressed over the past two decades, no evidence exists concerning the potential effects of gelotophobia in reaction to eye contact. Previous research has pointed to difficulties in discriminating gaze direction as the basis of possible misinterpretations of others’ intentions or mental states. The aim of the present research was to examine whether gelotophobia predisposition modulates the effects of eye contact (i.e., gaze discrimination when processing faces portraying several emotional expressions. In two different experiments, participants performed an experimental gaze discrimination task in which they responded, as quickly and accurately as possible, to the eyes’ directions on faces displaying either a happy, angry, fear, neutral, or sad emotional expression. In particular, we expected trait-gelotophobia to modulate the eye contact effect, showing specific group differences in the happiness condition. The results of Study 1 (N = 40 indicated that gelotophobes made more errors than non-gelotophobes did in the gaze discrimination task. In contrast to our initial hypothesis, the happiness expression did not have any special role in the observed differences between individuals with high vs. low trait-gelotophobia. In Study 2 (N = 40, we replicated the pattern of data concerning gaze discrimination ability, even after controlling for individuals’ scores on social anxiety. Furthermore, in our second experiment, we found that gelotophobes did not exhibit any problem with identifying others’ emotions, or a general incorrect attribution of affective features, such as valence

  2. Valence of Facial Cues Influences Sheep Learning in a Visual Discrimination Task

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    Lucille G. A. Bellegarde

    2017-11-01

    Full Text Available Sheep are one of the most studied farm species in terms of their ability to process information from faces, but little is known about their face-based emotion recognition abilities. We investigated (a whether sheep could use images of sheep faces taken in situation of varying valence as cues in a simultaneous discrimination task and (b whether the valence of the situation affects their learning performance. To accomplish this, we photographed faces of sheep in three situations inducing emotional states of neutral (ruminating in the home pen or negative valence (social isolation or aggressive interaction. Sheep (n = 35 first had to learn a discrimination task with colored cards. Animals that reached the learning criterion (n = 16 were then presented with pairs of images of the face of a single individual taken in the neutral situation and in one of the negative situations. Finally, sheep had to generalize what they had learned to new pairs of images of faces taken in the same situation, but of a different conspecific. All sheep that learned the discrimination task with colored cards reached the learning criterion with images of faces. Sheep that had to associate a negative image with a food reward learned faster than sheep that had to associate a neutral image with a reward. With the exception of sheep from the aggression-rewarded group, sheep generalized this discrimination to images of faces of different individuals. Our results suggest that sheep can perceive the emotional valence displayed on faces of conspecifics and that this valence affects learning processes.

  3. Songbirds and humans apply different strategies in a sound sequence discrimination task

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    Yoshimasa eSeki

    2013-07-01

    Full Text Available The abilities of animals and humans to extract rules from sound sequences have previously been compared using observation of spontaneous responses and conditioning techniques. However, the results were inconsistently interpreted across studies possibly due to methodological and/or species differences. Therefore, we examined the strategies for discrimination of sound sequences in Bengalese finches and humans using the same protocol. Birds were trained on a GO/NOGO task to discriminate between two categories of sound stimulus generated based on an AAB or ABB rule. The sound elements used were taken from a variety of male (M and female (F calls, such that the sequences could be represented as MMF and MFF. In test sessions, FFM and FMM sequences, which were never presented in the training sessions but conformed to the rule, were presented as probe stimuli. The results suggested two discriminative strategies were being applied: 1 memorizing sound patterns of either GO or NOGO stimuli and generating the appropriate responses for only those sounds; and 2 using the repeated element as a cue. There was no evidence that the birds successfully extracted the abstract rule (i.e. AAB and ABB; MMF-GO subjects did not produce a GO response for FFM and vice versa. Next we examined whether those strategies were also applicable for human participants on the same task. The results and questionnaires revealed that participants extracted the abstract rule, and most of them employed it to discriminate the sequences. This strategy was never observed in bird subjects, although some participants used strategies similar to the birds when responding to the probe stimuli. Our results showed that the human participants applied the abstract rule in the task even without instruction but Bengalese finches did not, thereby reconfirming that humans have to extract abstract rules from sound sequences that is distinct from non-human animals.

  4. Songbirds and humans apply different strategies in a sound sequence discrimination task.

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    Seki, Yoshimasa; Suzuki, Kenta; Osawa, Ayumi M; Okanoya, Kazuo

    2013-01-01

    The abilities of animals and humans to extract rules from sound sequences have previously been compared using observation of spontaneous responses and conditioning techniques. However, the results were inconsistently interpreted across studies possibly due to methodological and/or species differences. Therefore, we examined the strategies for discrimination of sound sequences in Bengalese finches and humans using the same protocol. Birds were trained on a GO/NOGO task to discriminate between two categories of sound stimulus generated based on an "AAB" or "ABB" rule. The sound elements used were taken from a variety of male (M) and female (F) calls, such that the sequences could be represented as MMF and MFF. In test sessions, FFM and FMM sequences, which were never presented in the training sessions but conformed to the rule, were presented as probe stimuli. The results suggested two discriminative strategies were being applied: (1) memorizing sound patterns of either GO or NOGO stimuli and generating the appropriate responses for only those sounds; and (2) using the repeated element as a cue. There was no evidence that the birds successfully extracted the abstract rule (i.e., AAB and ABB); MMF-GO subjects did not produce a GO response for FFM and vice versa. Next we examined whether those strategies were also applicable for human participants on the same task. The results and questionnaires revealed that participants extracted the abstract rule, and most of them employed it to discriminate the sequences. This strategy was never observed in bird subjects, although some participants used strategies similar to the birds when responding to the probe stimuli. Our results showed that the human participants applied the abstract rule in the task even without instruction but Bengalese finches did not, thereby reconfirming that humans have to extract abstract rules from sound sequences that is distinct from non-human animals.

  5. Priming in implicit memory tasks: prior study causes enhanced discriminability, not only bias.

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    Zeelenberg, René; Wagenmakers, Eric-Jan M; Raaijmakers, Jeroen G W

    2002-03-01

    R. Ratcliff and G. McKoon (1995, 1996, 1997; R. Ratcliff, D. Allbritton, & G. McKoon, 1997) have argued that repetition priming effects are solely due to bias. They showed that prior study of the target resulted in a benefit in a later implicit memory task. However, prior study of a stimulus similar to the target resulted in a cost. The present study, using a 2-alternative forced-choice procedure, investigated the effect of prior study in an unbiased condition: Both alternatives were studied prior to their presentation in an implicit memory task. Contrary to a pure bias interpretation of priming, consistent evidence was obtained in 3 implicit memory tasks (word fragment completion, auditory word identification, and picture identification) that performance was better when both alternatives were studied than when neither alternative was studied. These results show that prior study results in enhanced discriminability, not only bias.

  6. Discrimination task reveals differences in neural bases of tinnitus and hearing impairment.

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    Fatima T Husain

    Full Text Available We investigated auditory perception and cognitive processing in individuals with chronic tinnitus or hearing loss using functional magnetic resonance imaging (fMRI. Our participants belonged to one of three groups: bilateral hearing loss and tinnitus (TIN, bilateral hearing loss without tinnitus (HL, and normal hearing without tinnitus (NH. We employed pure tones and frequency-modulated sweeps as stimuli in two tasks: passive listening and active discrimination. All subjects had normal hearing through 2 kHz and all stimuli were low-pass filtered at 2 kHz so that all participants could hear them equally well. Performance was similar among all three groups for the discrimination task. In all participants, a distributed set of brain regions including the primary and non-primary auditory cortices showed greater response for both tasks compared to rest. Comparing the groups directly, we found decreased activation in the parietal and frontal lobes in the participants with tinnitus compared to the HL group and decreased response in the frontal lobes relative to the NH group. Additionally, the HL subjects exhibited increased response in the anterior cingulate relative to the NH group. Our results suggest that a differential engagement of a putative auditory attention and short-term memory network, comprising regions in the frontal, parietal and temporal cortices and the anterior cingulate, may represent a key difference in the neural bases of chronic tinnitus accompanied by hearing loss relative to hearing loss alone.

  7. Face adaptation does not improve performance on search or discrimination tasks.

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    Ng, Minna; Boynton, Geoffrey M; Fine, Ione

    2008-01-04

    The face adaptation effect, as described by M. A. Webster and O. H. MacLin (1999), is a robust perceptual shift in the appearance of faces after a brief adaptation period. For example, prolonged exposure to Asian faces causes a Eurasian face to appear distinctly Caucasian. This adaptation effect has been documented for general configural effects, as well as for the facial properties of gender, ethnicity, expression, and identity. We began by replicating the finding that adaptation to ethnicity, gender, and a combination of both features induces selective shifts in category appearance. We then investigated whether this adaptation has perceptual consequences beyond a shift in the perceived category boundary by measuring the effects of adaptation on RSVP, spatial search, and discrimination tasks. Adaptation had no discernable effect on performance for any of these tasks.

  8. Multi-task linear programming discriminant analysis for the identification of progressive MCI individuals.

    Directory of Open Access Journals (Sweden)

    Guan Yu

    Full Text Available Accurately identifying mild cognitive impairment (MCI individuals who will progress to Alzheimer's disease (AD is very important for making early interventions. Many classification methods focus on integrating multiple imaging modalities such as magnetic resonance imaging (MRI and fluorodeoxyglucose positron emission tomography (FDG-PET. However, the main challenge for MCI classification using multiple imaging modalities is the existence of a lot of missing data in many subjects. For example, in the Alzheimer's Disease Neuroimaging Initiative (ADNI study, almost half of the subjects do not have PET images. In this paper, we propose a new and flexible binary classification method, namely Multi-task Linear Programming Discriminant (MLPD analysis, for the incomplete multi-source feature learning. Specifically, we decompose the classification problem into different classification tasks, i.e., one for each combination of available data sources. To solve all different classification tasks jointly, our proposed MLPD method links them together by constraining them to achieve the similar estimated mean difference between the two classes (under classification for those shared features. Compared with the state-of-the-art incomplete Multi-Source Feature (iMSF learning method, instead of constraining different classification tasks to choose a common feature subset for those shared features, MLPD can flexibly and adaptively choose different feature subsets for different classification tasks. Furthermore, our proposed MLPD method can be efficiently implemented by linear programming. To validate our MLPD method, we perform experiments on the ADNI baseline dataset with the incomplete MRI and PET images from 167 progressive MCI (pMCI subjects and 226 stable MCI (sMCI subjects. We further compared our method with the iMSF method (using incomplete MRI and PET images and also the single-task classification method (using only MRI or only subjects with both MRI and

  9. Multi-task linear programming discriminant analysis for the identification of progressive MCI individuals.

    Science.gov (United States)

    Yu, Guan; Liu, Yufeng; Thung, Kim-Han; Shen, Dinggang

    2014-01-01

    Accurately identifying mild cognitive impairment (MCI) individuals who will progress to Alzheimer's disease (AD) is very important for making early interventions. Many classification methods focus on integrating multiple imaging modalities such as magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (FDG-PET). However, the main challenge for MCI classification using multiple imaging modalities is the existence of a lot of missing data in many subjects. For example, in the Alzheimer's Disease Neuroimaging Initiative (ADNI) study, almost half of the subjects do not have PET images. In this paper, we propose a new and flexible binary classification method, namely Multi-task Linear Programming Discriminant (MLPD) analysis, for the incomplete multi-source feature learning. Specifically, we decompose the classification problem into different classification tasks, i.e., one for each combination of available data sources. To solve all different classification tasks jointly, our proposed MLPD method links them together by constraining them to achieve the similar estimated mean difference between the two classes (under classification) for those shared features. Compared with the state-of-the-art incomplete Multi-Source Feature (iMSF) learning method, instead of constraining different classification tasks to choose a common feature subset for those shared features, MLPD can flexibly and adaptively choose different feature subsets for different classification tasks. Furthermore, our proposed MLPD method can be efficiently implemented by linear programming. To validate our MLPD method, we perform experiments on the ADNI baseline dataset with the incomplete MRI and PET images from 167 progressive MCI (pMCI) subjects and 226 stable MCI (sMCI) subjects. We further compared our method with the iMSF method (using incomplete MRI and PET images) and also the single-task classification method (using only MRI or only subjects with both MRI and PET images

  10. The time-course of activation in the dorsal and ventral visual streams during landmark cueing and perceptual discrimination tasks.

    Science.gov (United States)

    Lambert, Anthony J; Wootton, Adrienne

    2017-08-01

    Different patterns of high density EEG activity were elicited by the same peripheral stimuli, in the context of Landmark Cueing and Perceptual Discrimination tasks. The C1 component of the visual event-related potential (ERP) at parietal - occipital electrode sites was larger in the Landmark Cueing task, and source localisation suggested greater activation in the superior parietal lobule (SPL) in this task, compared to the Perceptual Discrimination task, indicating stronger early recruitment of the dorsal visual stream. In the Perceptual Discrimination task, source localisation suggested widespread activation of the inferior temporal gyrus (ITG) and fusiform gyrus (FFG), structures associated with the ventral visual stream, during the early phase of the P1 ERP component. Moreover, during a later epoch (171-270ms after stimulus onset) increased temporal-occipital negativity, and stronger recruitment of ITG and FFG were observed in the Perceptual Discrimination task. These findings illuminate the contrasting functions of the dorsal and ventral visual streams, to support rapid shifts of attention in response to contextual landmarks, and conscious discrimination, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Isolating Discriminant Neural Activity in the Presence of Eye Movements and Concurrent Task Demands

    Directory of Open Access Journals (Sweden)

    Jon Touryan

    2017-07-01

    Full Text Available A growing number of studies use the combination of eye-tracking and electroencephalographic (EEG measures to explore the neural processes that underlie visual perception. In these studies, fixation-related potentials (FRPs are commonly used to quantify early and late stages of visual processing that follow the onset of each fixation. However, FRPs reflect a mixture of bottom-up (sensory-driven and top-down (goal-directed processes, in addition to eye movement artifacts and unrelated neural activity. At present there is little consensus on how to separate this evoked response into its constituent elements. In this study we sought to isolate the neural sources of target detection in the presence of eye movements and over a range of concurrent task demands. Here, participants were asked to identify visual targets (Ts amongst a grid of distractor stimuli (Ls, while simultaneously performing an auditory N-back task. To identify the discriminant activity, we used independent components analysis (ICA for the separation of EEG into neural and non-neural sources. We then further separated the neural sources, using a modified measure-projection approach, into six regions of interest (ROIs: occipital, fusiform, temporal, parietal, cingulate, and frontal cortices. Using activity from these ROIs, we identified target from non-target fixations in all participants at a level similar to other state-of-the-art classification techniques. Importantly, we isolated the time course and spectral features of this discriminant activity in each ROI. In addition, we were able to quantify the effect of cognitive load on both fixation-locked potential and classification performance across regions. Together, our results show the utility of a measure-projection approach for separating task-relevant neural activity into meaningful ROIs within more complex contexts that include eye movements.

  12. COMMUNICATION: On variability and use of rat primary motor cortex responses in behavioral task discrimination

    Science.gov (United States)

    Jensen, Winnie; Rousche, Patrick J.

    2006-03-01

    The success of a cortical motor neuroprosthetic system will rely on the system's ability to effectively execute complex motor tasks in a changing environment. Invasive, intra-cortical electrodes have been successfully used to predict joint movement and grip force of a robotic arm/hand with a non-human primate (Chapin J K, Moxon K A, Markowitz R S and Nicolelis M A L 1999 Real-time control of a robotic arm using simultaneously recorded neurons in the motor cortex Nat. Neurosci. 2 664-70). It is well known that cortical encoding occurs with a high degree of cortical plasticity and depends on both the functional and behavioral context. Questions on the expected robustness of future motor prosthesis systems therefore still remain. The objective of the present work was to study the effect of minor changes in functional movement strategies on the M1 encoding. We compared the M1 encoding in freely moving, non-constrained animals that performed two similar behavioral tasks with the same end-goal, and investigated if these behavioral tasks could be discriminated based on the M1 recordings. The rats depressed a response paddle either with a set of restrictive bars ('WB') or without the bars ('WOB') placed in front of the paddle. The WB task required changes in the motor strategy to complete the paddle press and resulted in highly stereotyped movements, whereas in the WOB task the movement strategy was not restricted. Neural population activity was recorded from 16-channel micro-wire arrays and data up to 200 ms before a paddle hit were analyzed off-line. The analysis showed a significant neural firing difference between the two similar WB and WOB tasks, and using principal component analysis it was possible to distinguish between the two tasks with a best classification at 76.6%. While the results are dependent upon a small, randomly sampled neural population, they indicate that information about similar behavioral tasks may be extracted from M1 based on relatively few

  13. Perirhinal Cortex Resolves Feature Ambiguity in Configural Object Recognition and Perceptual Oddity Tasks

    Science.gov (United States)

    Bartko, Susan J.; Winters, Boyer D.; Cowell, Rosemary A.; Saksida, Lisa M.; Bussey, Timothy J.

    2007-01-01

    The perirhinal cortex (PRh) has a well-established role in object recognition memory. More recent studies suggest that PRh is also important for two-choice visual discrimination tasks. Specifically, it has been suggested that PRh contains conjunctive representations that help resolve feature ambiguity, which occurs when a task cannot easily be…

  14. Intelligence and P3 Components of the Event-Related Potential Elicited during an Auditory Discrimination Task with Masking

    Science.gov (United States)

    De Pascalis, V.; Varriale, V.; Matteoli, A.

    2008-01-01

    The relationship between fluid intelligence (indexed by scores on Raven Progressive Matrices) and auditory discrimination ability was examined by recording event-related potentials from 48 women during the performance of an auditory oddball task with backward masking. High ability (HA) subjects exhibited shorter response times, greater response…

  15. Fixation to features and neural processing of facial expressions in a gender discrimination task.

    Science.gov (United States)

    Neath, Karly N; Itier, Roxane J

    2015-10-01

    Early face encoding, as reflected by the N170 ERP component, is sensitive to fixation to the eyes. Whether this sensitivity varies with facial expressions of emotion and can also be seen on other ERP components such as P1 and EPN, was investigated. Using eye-tracking to manipulate fixation on facial features, we found the N170 to be the only eye-sensitive component and this was true for fearful, happy and neutral faces. A different effect of fixation to features was seen for the earlier P1 that likely reflected general sensitivity to face position. An early effect of emotion (∼120 ms) for happy faces was seen at occipital sites and was sustained until ∼350 ms post-stimulus. For fearful faces, an early effect was seen around 80 ms followed by a later effect appearing at ∼150 ms until ∼300 ms at lateral posterior sites. Results suggests that in this emotion-irrelevant gender discrimination task, processing of fearful and happy expressions occurred early and largely independently of the eye-sensitivity indexed by the N170. Processing of the two emotions involved different underlying brain networks active at different times. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. The anterior thalamus is critical for overcoming interference in a context-dependent odor discrimination task.

    Science.gov (United States)

    Law, L Matthew; Smith, David M

    2012-10-01

    The anterior thalamus (AT) is anatomically interconnected with the hippocampus and other structures known to be involved in memory, and the AT is involved in many of the same learning and memory functions as the hippocampus. For example, like the hippocampus, the AT is involved in spatial cognition and episodic memory. The hippocampus also has a well-documented role in contextual memory processes, but it is not known whether the AT is similarly involved in contextual memory. In the present study, we assessed the role of the AT in contextual memory processes by temporarily inactivating the AT and training rats on a recently developed context-based olfactory list learning task, which was designed to assess the use of contextual information to resolve interference. Rats were trained on one list of odor discrimination problems, followed by training on a second list in either the same context or a different context. In order to induce interference, some of the odors appeared on both lists with their predictive value reversed. Control rats that learned the two lists in different contexts performed significantly better than rats that learned the two lists in the same context. However, AT lesions completely abolished this contextual learning advantage, a result that is very similar to the effects of hippocampal inactivation. These findings demonstrate that the AT, like the hippocampus, is involved in contextual memory and suggest that the hippocampus and AT are part of a functional circuit involved in contextual memory. PsycINFO Database Record (c) 2012 APA, all rights reserved.

  17. Effects of zolpidem on sedation, anxiety, and memory in the plus-maze discriminative avoidance task.

    Science.gov (United States)

    Zanin, Karina A; Patti, Camilla L; Sanday, Leandro; Fernandes-Santos, Luciano; Oliveira, Larissa C; Poyares, Dalva; Tufik, Sergio; Frussa-Filho, Roberto

    2013-04-01

    Zolpidem (Zolp), a hypnotic drug prescribed to treat insomnia, may have negative effects on memory, but reports are inconsistent. We examined the effects of acute doses of Zolp (2, 5, or 10 mg/kg, i.p.) on memory formation (learning, consolidation, and retrieval) using the plus-maze discriminative avoidance task. Mice were acutely treated with Zolp 30 min before training or testing. In addition, the effects of Zolp and midazolam (Mid; a classic benzodiazepine) on consolidation at different time points were examined. The possible role of state dependency was investigated using combined pre-training and pre-test treatments. Zolp produced a dose-dependent sedative effect, without modifying anxiety-like behavior. The pre-training administration of 5 or 10 mg/kg resulted in retention deficits. When administered immediately after training or before testing, memory was preserved. Zolp post-training administration (2 or 3 h) impaired subsequent memory. There was no participation of state dependency phenomenon in the amnestic effects of Zolp. Similar to Zolp, Mid impaired memory consolidation when administered 1 h after training. Amnestic effects occurred when Zolp was administered either before or 2-3 h after training. These memory deficits are not related to state dependency. Moreover, Zolp did not impair memory retrieval. Notably, the memory-impairing effects of Zolp are similar to those of Mid, with the exception of the time point at which the drug can modify consolidation. Finally, the memory effects were unrelated to sedation or anxiolysis.

  18. Methamphetamine functions as a positive and negative drug feature in a Pavlovian appetitive discrimination task.

    Science.gov (United States)

    Reichel, Carmela M; Wilkinson, Jamie L; Bevins, Rick A

    2007-12-01

    This research determined the ability of methamphetamine to serve as a positive or negative feature, and assessed the ability of bupropion, cocaine, and naloxone to substitute for the methamphetamine features. Rats received methamphetamine (0.5 mg/kg, intraperitoneally) or saline 15 min before a conditioning session. For the feature positive (FP) group, offset of 15-s cue lights was followed by access to sucrose on methamphetamine sessions; sucrose was withheld during saline sessions. For the feature negative (FN) group, the light offset was followed by sucrose on saline sessions; sucrose was withheld during methamphetamine sessions. During acquisition, the FP group had higher responding on methamphetamine sessions than on saline sessions. For the FN group, responding was higher on saline sessions than on methamphetamine sessions. Conditioned responding was sensitive to methamphetamine dose. For the FP group, bupropion and cocaine fully and partially substituted for methamphetamine, respectively. In contrast, both drugs fully substituted for methamphetamine in the FN group. Naloxone did not substitute in either set of rats. FP-trained rats were more sensitive to the locomotor stimulating effects of the test drugs than FN-trained rats. This research demonstrates that the pharmacological effects of methamphetamine function as a FP or FN in this Pavlovian discrimination task and that training history can affect conditioned responding and locomotor effects evoked by a drug.

  19. Roles of Approval Motivation and Generalized Expectancy for Reinforcement in Children's Conceptual Discrimination Learning

    Science.gov (United States)

    Nyce, Peggy A.; And Others

    1977-01-01

    Forty-four third graders were given a two-choice conceptual discrimination learning task. The two major factors were (1) four treatment groups varying at the extremes on two personality measures, approval motivation and locus of control and (2) sex. (MS)

  20. Food's visually perceived fat content affects discrimination speed in an orthogonal spatial task.

    Science.gov (United States)

    Harrar, Vanessa; Toepel, Ulrike; Murray, Micah M; Spence, Charles

    2011-10-01

    Choosing what to eat is a complex activity for humans. Determining a food's pleasantness requires us to combine information about what is available at a given time with knowledge of the food's palatability, texture, fat content, and other nutritional information. It has been suggested that humans may have an implicit knowledge of a food's fat content based on its appearance; Toepel et al. (Neuroimage 44:967-974, 2009) reported visual-evoked potential modulations after participants viewed images of high-energy, high-fat food (HF), as compared to viewing low-fat food (LF). In the present study, we investigated whether there are any immediate behavioural consequences of these modulations for human performance. HF, LF, or non-food (NF) images were used to exogenously direct participants' attention to either the left or the right. Next, participants made speeded elevation discrimination responses (up vs. down) to visual targets presented either above or below the midline (and at one of three stimulus onset asynchronies: 150, 300, or 450 ms). Participants responded significantly more rapidly following the presentation of a HF image than following the presentation of either LF or NF images, despite the fact that the identity of the images was entirely task-irrelevant. Similar results were found when comparing response speeds following images of high-carbohydrate (HC) food items to low-carbohydrate (LC) food items. These results support the view that people rapidly process (i.e. within a few hundred milliseconds) the fat/carbohydrate/energy value or, perhaps more generally, the pleasantness of food. Potentially as a result of HF/HC food items being more pleasant and thus having a higher incentive value, it seems as though seeing these foods results in a response readiness, or an overall alerting effect, in the human brain.

  1. Temporal discrimination thresholds in adult-onset primary torsion dystonia: an analysis by task type and by dystonia phenotype.

    LENUS (Irish Health Repository)

    Bradley, D

    2012-01-01

    Adult-onset primary torsion dystonia (AOPTD) is an autosomal dominant disorder with markedly reduced penetrance. Sensory abnormalities are present in AOPTD and also in unaffected relatives, possibly indicating non-manifesting gene carriage (acting as an endophenotype). The temporal discrimination threshold (TDT) is the shortest time interval at which two stimuli are detected to be asynchronous. We aimed to compare the sensitivity and specificity of three different TDT tasks (visual, tactile and mixed\\/visual-tactile). We also aimed to examine the sensitivity of TDTs in different AOPTD phenotypes. To examine tasks, we tested TDT in 41 patients and 51 controls using visual (2 lights), tactile (non-painful electrical stimulation) and mixed (1 light, 1 electrical) stimuli. To investigate phenotypes, we examined 71 AOPTD patients (37 cervical dystonia, 14 writer\\'s cramp, 9 blepharospasm, 11 spasmodic dysphonia) and 8 musician\\'s dystonia patients. The upper limit of normal was defined as control mean +2.5 SD. In dystonia patients, the visual task detected abnormalities in 35\\/41 (85%), the tactile task in 35\\/41 (85%) and the mixed task in 26\\/41 (63%); the mixed task was less sensitive than the other two (p = 0.04). Specificity was 100% for the visual and tactile tasks. Abnormal TDTs were found in 36 of 37 (97.3%) cervical dystonia, 12 of 14 (85.7%) writer\\'s cramp, 8 of 9 (88.8%) blepharospasm, 10 of 11 (90.1%) spasmodic dysphonia patients and 5 of 8 (62.5%) musicians. The visual and tactile tasks were found to be more sensitive than the mixed task. Temporal discrimination threshold results were comparable across common adult-onset primary torsion dystonia phenotypes, with lower sensitivity in the musicians.

  2. Comparison of model and human observer performance for detection and discrimination tasks using dual-energy x-ray images

    International Nuclear Information System (INIS)

    Richard, Samuel; Siewerdsen, Jeffrey H.

    2008-01-01

    Model observer performance, computed theoretically using cascaded systems analysis (CSA), was compared to the performance of human observers in detection and discrimination tasks. Dual-energy (DE) imaging provided a wide range of acquisition and decomposition parameters for which observer performance could be predicted and measured. This work combined previously derived observer models (e.g., Fisher-Hotelling and non-prewhitening) with CSA modeling of the DE image noise-equivalent quanta (NEQ) and imaging task (e.g., sphere detection, shape discrimination, and texture discrimination) to yield theoretical predictions of detectability index (d ' ) and area under the receiver operating characteristic (A Z ). Theoretical predictions were compared to human observer performance assessed using 9-alternative forced-choice tests to yield measurement of A Z as a function of DE image acquisition parameters (viz., allocation of dose between the low- and high-energy images) and decomposition technique [viz., three DE image decomposition algorithms: standard log subtraction (SLS), simple-smoothing of the high-energy image (SSH), and anti-correlated noise reduction (ACNR)]. Results showed good agreement between theory and measurements over a broad range of imaging conditions. The incorporation of an eye filter and internal noise in the observer models demonstrated improved correspondence with human observer performance. Optimal acquisition and decomposition parameters were shown to depend on the imaging task; for example, ACNR and SSH yielded the greatest performance in the detection of soft-tissue and bony lesions, respectively. This study provides encouraging evidence that Fourier-based modeling of NEQ computed via CSA and imaging task provides a good approximation to human observer performance for simple imaging tasks, helping to bridge the gap between Fourier metrics of detector performance (e.g., NEQ) and human observer performance.

  3. Time and Number Discrimination in a Bisection Task with a Sequence of Stimuli: A Developmental Approach.

    Science.gov (United States)

    Droit-Volet, Sylvie; Clement, Angelique; Fayol, Michel

    2003-01-01

    This study tested 5- and 8-year-olds and adults in a bisection task with a sequence of stimuli in which time and number co-varied. Findings indicated that the number of stimuli interfered with 5-year-olds' performance on the temporal bisection task. Number interference decreased both with age and counting strategy. In the numerical bisection task,…

  4. Sleep deprivation effects on object discrimination task in zebrafish (Danio rerio).

    Science.gov (United States)

    Pinheiro-da-Silva, Jaquelinne; Silva, Priscila Fernandes; Nogueira, Marcelo Borges; Luchiari, Ana Carolina

    2017-03-01

    The zebrafish is an ideal vertebrate model for neurobehavioral studies with translational relevance to humans. Many aspects of sleep have been studied, but we still do not understand how and why sleep deprivation alters behavioral and physiological processes. A number of hypotheses suggest its role in memory consolidation. In this respect, the aim of this study was to analyze the effects of sleep deprivation on memory in zebrafish (Danio rerio), using an object discrimination paradigm. Four treatments were tested: control, partial sleep deprivation, total sleep deprivation by light pulses, and total sleep deprivation by extended light. The control group explored the new object more than the known object, indicating clear discrimination. The partially sleep-deprived group explored the new object more than the other object in the discrimination phase, suggesting a certain degree of discriminative performance. By contrast, both total sleep deprivation groups equally explored all objects, regardless of their novelty. It seems that only one night of sleep deprivation is enough to affect discriminative response in zebrafish, indicating its negative impact on cognitive processes. We suggest that this study could be a useful screening tool for cognitive dysfunction and a better understanding of the effect of sleep-wake cycles on cognition.

  5. Eye movements discriminate fatigue due to chronotypical factors and time spent on task--a double dissociation.

    Directory of Open Access Journals (Sweden)

    Dario Cazzoli

    Full Text Available Systematic differences in circadian rhythmicity are thought to be a substantial factor determining inter-individual differences in fatigue and cognitive performance. The synchronicity effect (when time of testing coincides with the respective circadian peak period seems to play an important role. Eye movements have been shown to be a reliable indicator of fatigue due to sleep deprivation or time spent on cognitive tasks. However, eye movements have not been used so far to investigate the circadian synchronicity effect and the resulting differences in fatigue. The aim of the present study was to assess how different oculomotor parameters in a free visual exploration task are influenced by: a fatigue due to chronotypical factors (being a 'morning type' or an 'evening type'; b fatigue due to the time spent on task. Eighteen healthy participants performed a free visual exploration task of naturalistic pictures while their eye movements were recorded. The task was performed twice, once at their optimal and once at their non-optimal time of the day. Moreover, participants rated their subjective fatigue. The non-optimal time of the day triggered a significant and stable increase in the mean visual fixation duration during the free visual exploration task for both chronotypes. The increase in the mean visual fixation duration correlated with the difference in subjectively perceived fatigue at optimal and non-optimal times of the day. Conversely, the mean saccadic speed significantly and progressively decreased throughout the duration of the task, but was not influenced by the optimal or non-optimal time of the day for both chronotypes. The results suggest that different oculomotor parameters are discriminative for fatigue due to different sources. A decrease in saccadic speed seems to reflect fatigue due to time spent on task, whereas an increase in mean fixation duration a lack of synchronicity between chronotype and time of the day.

  6. A discrimination task used as a novel method of testing decision-making behavior following traumatic brain injury.

    Science.gov (United States)

    Martens, Kris M; Vonder Haar, Cole; Hutsell, Blake A; Hoane, Michael R

    2012-10-10

    Traumatic brain injury (TBI) results in a multitude of deficits following injury. Some of the most pervasive in humans are the changes that affect frontally-mediated cognitive functioning, such as decision making. The assessment of decision-making behavior in rodents has been extensively tested in the field of the experimental analysis of behavior. However, due to the narrow therapeutic window following TBI, time-intensive operant paradigms are rarely incorporated into the battery of tests traditionally used, the majority of which assess motor and sensory functioning. The cognitive measures that are used are frequently limited to memory and do not account for changes in decision-making behavior. The purpose of the present study was to develop a simplified discrimination task that can assess deficits in decision-making behavior in rodents. For the task, rats were required to dig in cocoa-scented sand (versus unscented sand) for a reinforcer. Rats were given 12 sessions per day until a criterion level of 80% accuracy for 3 days straight was reached. Once the criterion was achieved, cortical contusion injuries were induced (frontal, parietal, or sham). Following a recovery period, the rats were re-tested on cocoa versus unscented sand. Upon reaching criterion, a reversal discrimination was evaluated in which the reinforcer was placed in unscented sand. Finally, a novel scent discrimination (basil versus coffee with basil reinforced), and a reversal (coffee) were evaluated. The results indicated that the Dig task is a simple experimental preparation that can be used to assess deficits in decision-making behavior following TBI.

  7. The location discrimination reversal task in mice is sensitive to deficits in performance caused by aging, pharmacological and other challenges.

    Science.gov (United States)

    Graf, Radka; Longo, Jami L; Hughes, Zoë A

    2018-06-01

    Deficits in hippocampal-mediated pattern separation are one aspect of cognitive function affected in schizophrenia (SZ) or Alzheimer's disease (AD). To develop novel therapies, it is beneficial to explore this specific aspect of cognition preclinically. The location discrimination reversal (LDR) task is a hippocampal-dependent operant paradigm that evaluates spatial learning and cognitive flexibility using touchscreens. Here we assessed baseline performance as well as multimodal disease-relevant manipulations in mice. Mice were trained to discriminate between the locations of two images where the degree of separation impacted performance. Administration of putative pro-cognitive agents was unable to improve performance at narrow separation. Furthermore, a range of disease-relevant manipulations were characterized to assess whether performance could be impaired and restored. Pertinent to the cholinergic loss in AD, scopolamine (0.1 mg/kg) produced a disruption in LDR, which was attenuated by donepezil (1 mg/kg). Consistent with NMDA hypofunction in cognitive impairment associated with SZ, MK-801 (0.1 mg/kg) also disrupted performance; however, this deficit was not modified by rolipram. Microdeletion of genes associated with SZ (22q11) resulted in impaired performance, which was restored by rolipram (0.032 mg/kg). Since aging and inflammation affect cognition and are risk factors for AD, these aspects were also evaluated. Aged mice were slower to acquire the task than young mice and did not reach the same level of performance. A systemic inflammatory challenge (lipopolysaccharide (LPS), 1 mg/kg) produced prolonged (7 days) deficits in the LDR task. These data suggest that LDR task is a valuable platform for evaluating disease-relevant deficits in pattern separation and offers potential for identifying novel therapies.

  8. A possible structural correlate of learning performance on a colour discrimination task in the brain of the bumblebee

    Science.gov (United States)

    Li, Li; MaBouDi, HaDi; Egertová, Michaela; Elphick, Maurice R.

    2017-01-01

    Synaptic plasticity is considered to be a basis for learning and memory. However, the relationship between synaptic arrangements and individual differences in learning and memory is poorly understood. Here, we explored how the density of microglomeruli (synaptic complexes) within specific regions of the bumblebee (Bombus terrestris) brain relates to both visual learning and inter-individual differences in learning and memory performance on a visual discrimination task. Using whole-brain immunolabelling, we measured the density of microglomeruli in the collar region (visual association areas) of the mushroom bodies of the bumblebee brain. We found that bumblebees which made fewer errors during training in a visual discrimination task had higher microglomerular density. Similarly, bumblebees that had better retention of the learned colour-reward associations two days after training had higher microglomerular density. Further experiments indicated experience-dependent changes in neural circuitry: learning a colour-reward contingency with 10 colours (but not two colours) does result, and exposure to many different colours may result, in changes to microglomerular density in the collar region of the mushroom bodies. These results reveal the varying roles that visual experience, visual learning and foraging activity have on neural structure. Although our study does not provide a causal link between microglomerular density and performance, the observed positive correlations provide new insights for future studies into how neural structure may relate to inter-individual differences in learning and memory. PMID:28978727

  9. A possible structural correlate of learning performance on a colour discrimination task in the brain of the bumblebee.

    Science.gov (United States)

    Li, Li; MaBouDi, HaDi; Egertová, Michaela; Elphick, Maurice R; Chittka, Lars; Perry, Clint J

    2017-10-11

    Synaptic plasticity is considered to be a basis for learning and memory. However, the relationship between synaptic arrangements and individual differences in learning and memory is poorly understood. Here, we explored how the density of microglomeruli (synaptic complexes) within specific regions of the bumblebee ( Bombus terrestris ) brain relates to both visual learning and inter-individual differences in learning and memory performance on a visual discrimination task. Using whole-brain immunolabelling, we measured the density of microglomeruli in the collar region (visual association areas) of the mushroom bodies of the bumblebee brain. We found that bumblebees which made fewer errors during training in a visual discrimination task had higher microglomerular density. Similarly, bumblebees that had better retention of the learned colour-reward associations two days after training had higher microglomerular density. Further experiments indicated experience-dependent changes in neural circuitry: learning a colour-reward contingency with 10 colours (but not two colours) does result, and exposure to many different colours may result, in changes to microglomerular density in the collar region of the mushroom bodies. These results reveal the varying roles that visual experience, visual learning and foraging activity have on neural structure. Although our study does not provide a causal link between microglomerular density and performance, the observed positive correlations provide new insights for future studies into how neural structure may relate to inter-individual differences in learning and memory. © 2017 The Authors.

  10. Single-trial effective brain connectivity patterns enhance discriminability of mental imagery tasks

    Science.gov (United States)

    Rathee, Dheeraj; Cecotti, Hubert; Prasad, Girijesh

    2017-10-01

    Objective. The majority of the current approaches of connectivity based brain-computer interface (BCI) systems focus on distinguishing between different motor imagery (MI) tasks. Brain regions associated with MI are anatomically close to each other, hence these BCI systems suffer from low performances. Our objective is to introduce single-trial connectivity feature based BCI system for cognition imagery (CI) based tasks wherein the associated brain regions are located relatively far away as compared to those for MI. Approach. We implemented time-domain partial Granger causality (PGC) for the estimation of the connectivity features in a BCI setting. The proposed hypothesis has been verified with two publically available datasets involving MI and CI tasks. Main results. The results support the conclusion that connectivity based features can provide a better performance than a classical signal processing framework based on bandpass features coupled with spatial filtering for CI tasks, including word generation, subtraction, and spatial navigation. These results show for the first time that connectivity features can provide a reliable performance for imagery-based BCI system. Significance. We show that single-trial connectivity features for mixed imagery tasks (i.e. combination of CI and MI) can outperform the features obtained by current state-of-the-art method and hence can be successfully applied for BCI applications.

  11. PROBABILISTIC PROGRAMMING FOR ADVANCED MACHINE LEARNING (PPAML) DISCRIMINATIVE LEARNING FOR GENERATIVE TASKS (DILIGENT)

    Science.gov (United States)

    2017-11-29

    follows, to see the performance of the SVM Standard algorithm: python mamiStd.py --nJobs 2 --trainSize 80 where nJobs tell the computer to use ...follows: python mamiLupi.py --nJobs 2 --trainSize 80 where nJobs tell the computer to use 2 processors and trainSize tells it to run the...in the course of DARPA PPAML program. 2 INTRODUCTION As explained in Introduction , the focus of our project is to enable the use of discriminative

  12. Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects.

    Science.gov (United States)

    Trott, C M; Ouyang, J; El Fakhri, G

    2010-11-21

    Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest (99m)Tc-sestamibi/(123)I-BMIPP imaging protocol in place of the commonly used sequential rest/stress (99m)Tc-sestamibi protocol. The theoretical precision with which the severity of a cardiac defect and the transmural extent of infarct can be measured is computed for simultaneous and sequential SPECT imaging, and their performance is compared for discriminating (1) degrees of defect severity and (2) sub-endocardial from transmural defects. We consider cardiac infarcts for which reduced perfusion and metabolism are observed. From an information perspective, simultaneous imaging is found to yield comparable or improved performance compared with sequential imaging for discriminating both severity of defect and transmural extent of infarct, for three defects of differing location and size.

  13. Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects

    International Nuclear Information System (INIS)

    Trott, C M; Ouyang, J; El Fakhri, G

    2010-01-01

    Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest 99m Tc-sestamibi/ 123 I-BMIPP imaging protocol in place of the commonly used sequential rest/stress 99m Tc-sestamibi protocol. The theoretical precision with which the severity of a cardiac defect and the transmural extent of infarct can be measured is computed for simultaneous and sequential SPECT imaging, and their performance is compared for discriminating (1) degrees of defect severity and (2) sub-endocardial from transmural defects. We consider cardiac infarcts for which reduced perfusion and metabolism are observed. From an information perspective, simultaneous imaging is found to yield comparable or improved performance compared with sequential imaging for discriminating both severity of defect and transmural extent of infarct, for three defects of differing location and size.

  14. Performance of Pugs, German Shepherds, and Greyhounds (Canis lupus familiaris) on an odor-discrimination task.

    Science.gov (United States)

    Hall, Nathaniel J; Glenn, Kelsey; Smith, David W; Wynne, Clive D L

    2015-08-01

    Public opinion and the scientific literature alike reflect a widespread assumption that there are differences in behavior between dog breeds. Direct empirical behavioral assessments of such differences, however, are rare and have produced mixed results. One area where breed differences are often assumed is olfaction, where German Shepherds, hounds, and Labradors are commonly used for odor-detection work, whereas toy breeds and brachycephalic dogs, such as Pugs, are not. Choice of breed for scent detection work, however, may be driven more by historical choices than data. In this article we directly assessed the ability of German Shepherds, Pugs, and Greyhounds to acquire a simple olfactory discrimination, and their ability to maintain performance when the target odorant was diluted. Our results show that contrary to expectations, Pugs significantly outperformed the German Shepherds in acquiring the odor discrimination and maintaining performance when the odorant concentration was decreased. Nine of 10 Greyhounds did not complete acquisition training because they failed a motivation criterion. These results indicate that Pugs outperformed German Shepherds in the dimensions of olfaction assessed. Greyhounds showed a general failure to participate. Overall, our results highlight the importance of direct behavioral measurement of assumed behavioral breed differences. (c) 2015 APA, all rights reserved).

  15. Response competition and response inhibition during different choice-discrimination tasks: evidence from ERP measured inside MRI scanner.

    Science.gov (United States)

    Gonzalez-Rosa, Javier J; Inuggi, Alberto; Blasi, Valeria; Cursi, Marco; Annovazzi, Pietro; Comi, Giancarlo; Falini, Andrea; Leocani, Letizia

    2013-07-01

    We investigated the neural correlates underlying response inhibition and conflict detection processes using ERPs and source localization analyses simultaneously acquired during fMRI scanning. ERPs were elicited by a simple reaction time task (SRT), a Go/NoGo task, and a Stroop-like task (CST). The cognitive conflict was thus manipulated in order to probe the degree to which information processing is shared across cognitive systems. We proposed to dissociate inhibition and interference conflict effects on brain activity by using identical Stroop-like congruent/incongruent stimuli in all three task contexts and while varying the response required. NoGo-incongruent trials showed a larger N2 and enhanced activations of rostral anterior cingulate cortex (ACC) and pre-supplementary motor area, whereas Go-congruent trials showed a larger P3 and increased parietal activations. Congruent and incongruent conditions of the CST task also elicited similar N2, P3 and late negativity (LN) ERPs, though CST-incongruent trials revealed a larger LN and enhanced prefrontal and ACC activations. Considering the stimulus probability and experimental manipulation of our study, current findings suggest that NoGo N2 and frontal NoGo P3 appear to be more associated to response inhibition rather than a specific conflict monitoring, whereas occipito-parietal P3 of Go and CST conditions may be more linked to a planned response competition between the prepared and required response. LN, however, appears to be related to higher level conflict monitoring associated with response choice-discrimination but not when the presence of cognitive conflict is associated with response inhibition. Copyright © 2013. Published by Elsevier B.V.

  16. P2-13: Location word Cues' Effect on Location Discrimination Task: Cross-Modal Study

    Directory of Open Access Journals (Sweden)

    Satoko Ohtsuka

    2012-10-01

    Full Text Available As is well known, participants are slower and make more errors in responding to the display color of an incongruent color word than a congruent one. This traditional stroop effect is often accounted for with relatively automatic and dominant word processing. Although the word dominance account has been widely supported, it is not clear in what extent of perceptual tasks it is valid. Here we aimed to examine whether the word dominance effect is observed in location stroop tasks and in audio-visual situations. The participants were required to press a key according to the location of visual (Experiment 1 and audio (Experiment 2 targets, left or right, as soon as possible. A cue of written (Experiments 1a and 2a or spoken (Experiments 1b and 2b location words, “left” or “right”, was presented on the left or right side of the fixation with cue lead times (CLT of 200 ms and 1200 ms. Reaction time from target presentation to key press was recorded as a dependent variable. The results were that the location validity effect was marked in within-modality but less so in cross-modality trials. The word validity effect was strong in within- but not in cross-modality trials. The CLT gave some effect of inhibition of return. So the word dominance could be less effective in location tasks and in cross-modal situations. The spatial correspondence seems to overcome the word effect.

  17. The effects of visual discriminability and rotation angle on 30-month-olds’ search performance in spatial rotation tasks

    Directory of Open Access Journals (Sweden)

    Mirjam Ebersbach

    2016-10-01

    Full Text Available Tracking objects that are hidden and then moved is a crucial ability related to object permanence, which develops across several stages in early childhood. In spatial rotation tasks, children observe a target object that is hidden in one of two or more containers before the containers are rotated around a fixed axis. Usually, 30-month-olds fail to find the hidden object after it was rotated by 180°. We examined whether visual discriminability of the containers improves 30-month-olds’ success in this task and whether children perform better after 90° than after 180° rotations. Two potential hiding containers with same or different colors were placed on a board that was rotated by 90° or 180° in a within-subjects design. Children (N = 29 performed above chance level in all four conditions. Their overall success in finding the object did not improve by differently colored containers. However, different colors prevented children from showing an inhibition bias in 90° rotations, that is, choosing the empty container more often when it was located close to them than when it was farther away: This bias emerged in the same colors condition but not in the different colors condition. Results are discussed in view of particular challenges that might facilitate or deteriorate spatial rotation tasks for young children.

  18. The Effects of Visual Discriminability and Rotation Angle on 30-Month-Olds' Search Performance in Spatial Rotation Tasks.

    Science.gov (United States)

    Ebersbach, Mirjam; Nawroth, Christian

    2016-01-01

    Tracking objects that are hidden and then moved is a crucial ability related to object permanence, which develops across several stages in early childhood. In spatial rotation tasks, children observe a target object that is hidden in one of two or more containers before the containers are rotated around a fixed axis. Usually, 30-month-olds fail to find the hidden object after it was rotated by 180°. We examined whether visual discriminability of the containers improves 30-month-olds' success in this task and whether children perform better after 90° than after 180° rotations. Two potential hiding containers with same or different colors were placed on a board that was rotated by 90° or 180° in a within-subjects design. Children ( N = 29) performed above chance level in all four conditions. Their overall success in finding the object did not improve by differently colored containers. However, different colors prevented children from showing an inhibition bias in 90° rotations, that is, choosing the empty container more often when it was located close to them than when it was farther away: This bias emerged in the same colors condition but not in the different colors condition. Results are discussed in view of particular challenges that might facilitate or deteriorate spatial rotation tasks for young children.

  19. Social cognition and African American men: The roles of perceived discrimination and experimenter race on task performance.

    Science.gov (United States)

    Nagendra, Arundati; Twery, Benjamin L; Neblett, Enrique W; Mustafic, Hasan; Jones, Tevin S; Gatewood, D'Angelo; Penn, David L

    2018-01-01

    The Social Cognition Psychometric Evaluation (SCOPE) study consists of a battery of eight tasks selected to measure social-cognitive deficits in individuals with schizophrenia. The battery is currently in a multisite validation process. While the SCOPE study collects basic demographic data, more nuanced race-related factors might artificially inflate cross-cultural differences in social cognition. As an initial step, we investigated whether race, independent of mental illness status, affects performance on the SCOPE battery. Thus, we examined the effects of perceived discrimination and experimenter race on the performance of 51 non-clinical African American men on the SCOPE battery. Results revealed that these factors impacted social cognitive task performance. Specifically, participants performed better on a skills-based task factor in the presence of Black experimenters, and frequency of perceived racism predicted increased perception of hostility in negative interpersonal situations with accidental causes. Thus, race-related factors are important to identify and explore in the measurement of social cognition in African Americans. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The Effects of Visual Discriminability and Rotation Angle on 30-Month-Olds’ Search Performance in Spatial Rotation Tasks

    Science.gov (United States)

    Ebersbach, Mirjam; Nawroth, Christian

    2016-01-01

    Tracking objects that are hidden and then moved is a crucial ability related to object permanence, which develops across several stages in early childhood. In spatial rotation tasks, children observe a target object that is hidden in one of two or more containers before the containers are rotated around a fixed axis. Usually, 30-month-olds fail to find the hidden object after it was rotated by 180°. We examined whether visual discriminability of the containers improves 30-month-olds’ success in this task and whether children perform better after 90° than after 180° rotations. Two potential hiding containers with same or different colors were placed on a board that was rotated by 90° or 180° in a within-subjects design. Children (N = 29) performed above chance level in all four conditions. Their overall success in finding the object did not improve by differently colored containers. However, different colors prevented children from showing an inhibition bias in 90° rotations, that is, choosing the empty container more often when it was located close to them than when it was farther away: This bias emerged in the same colors condition but not in the different colors condition. Results are discussed in view of particular challenges that might facilitate or deteriorate spatial rotation tasks for young children. PMID:27812346

  1. Context effects in a temporal discrimination task" further tests of the Scalar Expectancy Theory and Learning-to-Time models.

    Science.gov (United States)

    Arantes, Joana; Machado, Armando

    2008-07-01

    Pigeons were trained on two temporal bisection tasks, which alternated every two sessions. In the first task, they learned to choose a red key after a 1-s signal and a green key after a 4-s signal; in the second task, they learned to choose a blue key after a 4-s signal and a yellow key after a 16-s signal. Then the pigeons were exposed to a series of test trials in order to contrast two timing models, Learning-to-Time (LeT) and Scalar Expectancy Theory (SET). The models made substantially different predictions particularly for the test trials in which the sample duration ranged from 1 s to 16 s and the choice keys were Green and Blue, the keys associated with the same 4-s samples: LeT predicted that preference for Green should increase with sample duration, a context effect, but SET predicted that preference for Green should not vary with sample duration. The results were consistent with LeT. The present study adds to the literature the finding that the context effect occurs even when the two basic discriminations are never combined in the same session.

  2. Attenuated audiovisual integration in middle-aged adults in a discrimination task.

    Science.gov (United States)

    Yang, Weiping; Ren, Yanna

    2018-02-01

    Numerous studies have focused on the diversity of audiovisual integration between younger and older adults. However, consecutive trends in audiovisual integration throughout life are still unclear. In the present study, to clarify audiovisual integration characteristics in middle-aged adults, we instructed younger and middle-aged adults to conduct an auditory/visual stimuli discrimination experiment. Randomized streams of unimodal auditory (A), unimodal visual (V) or audiovisual stimuli were presented on the left or right hemispace of the central fixation point, and subjects were instructed to respond to the target stimuli rapidly and accurately. Our results demonstrated that the responses of middle-aged adults to all unimodal and bimodal stimuli were significantly slower than those of younger adults (p Audiovisual integration was markedly delayed (onset time 360 ms) and weaker (peak 3.97%) in middle-aged adults than in younger adults (onset time 260 ms, peak 11.86%). The results suggested that audiovisual integration was attenuated in middle-aged adults and further confirmed age-related decline in information processing.

  3. Adults with dyslexia demonstrate large effects of crowding and detrimental effects of distractors in a visual tilt discrimination task.

    Directory of Open Access Journals (Sweden)

    Rizan Cassim

    Full Text Available Previous research has shown that adults with dyslexia (AwD are disproportionately impacted by close spacing of stimuli and increased numbers of distractors in a visual search task compared to controls [1]. Using an orientation discrimination task, the present study extended these findings to show that even in conditions where target search was not required: (i AwD had detrimental effects of both crowding and increased numbers of distractors; (ii AwD had more pronounced difficulty with distractor exclusion in the left visual field and (iii measures of crowding and distractor exclusion correlated significantly with literacy measures. Furthermore, such difficulties were not accounted for by the presence of covarying symptoms of ADHD in the participant groups. These findings provide further evidence to suggest that the ability to exclude distracting stimuli likely contributes to the reported visual attention difficulties in AwD and to the aetiology of literacy difficulties. The pattern of results is consistent with weaker and asymmetric attention in AwD.

  4. Trial-dependent psychometric functions accounting for perceptual learning in 2-AFC discrimination tasks.

    Science.gov (United States)

    Kattner, Florian; Cochrane, Aaron; Green, C Shawn

    2017-09-01

    The majority of theoretical models of learning consider learning to be a continuous function of experience. However, most perceptual learning studies use thresholds estimated by fitting psychometric functions to independent blocks, sometimes then fitting a parametric function to these block-wise estimated thresholds. Critically, such approaches tend to violate the basic principle that learning is continuous through time (e.g., by aggregating trials into large "blocks" for analysis that each assume stationarity, then fitting learning functions to these aggregated blocks). To address this discrepancy between base theory and analysis practice, here we instead propose fitting a parametric function to thresholds from each individual trial. In particular, we implemented a dynamic psychometric function whose parameters were allowed to change continuously with each trial, thus parameterizing nonstationarity. We fit the resulting continuous time parametric model to data from two different perceptual learning tasks. In nearly every case, the quality of the fits derived from the continuous time parametric model outperformed the fits derived from a nonparametric approach wherein separate psychometric functions were fit to blocks of trials. Because such a continuous trial-dependent model of perceptual learning also offers a number of additional advantages (e.g., the ability to extrapolate beyond the observed data; the ability to estimate performance on individual critical trials), we suggest that this technique would be a useful addition to each psychophysicist's analysis toolkit.

  5. Functional magnetic resonance imaging of visual object construction and shape discrimination : relations among task, hemispheric lateralization, and gender.

    Science.gov (United States)

    Georgopoulos, A P; Whang, K; Georgopoulos, M A; Tagaris, G A; Amirikian, B; Richter, W; Kim, S G; Uğurbil, K

    2001-01-01

    , the FIT distribution was, overall, more anterior and inferior than that of the SAME task. A detailed analysis of the counts and spatial distributions of activated pixels was carried out for 15 brain areas (all in the cerebral cortex) in which a consistent activation (in > or = 3 subjects) was observed (n = 323 activated pixels). We found the following. Except for the inferior temporal gyrus, which was activated exclusively in the FIT task, all other areas showed activation in both tasks but to different extents. Based on the extent of activation, areas fell within two distinct groups (FIT or SAME) depending on which pixel count (i.e., FIT or SAME) was greater. The FIT group consisted of the following areas, in decreasing FIT/SAME order (brackets indicate ties): GTi, GTs, GC, GFi, GFd, [GTm, GF], GO. The SAME group consisted of the following areas, in decreasing SAME/FIT order : GOi, LPs, Sca, GPrC, GPoC, [GFs, GFm]. These results indicate that there are distributed, graded, and partially overlapping patterns of activation during performance of the two tasks. We attribute these overlapping patterns of activation to the engagement of partially shared processes. Activated pixels clustered to three types of clusters : FIT-only (111 pixels), SAME-only (97 pixels), and FIT + SAME (115 pixels). Pixels contained in FIT-only and SAME-only clusters were distributed approximately equally between the left and right hemispheres, whereas pixels in the SAME + FIT clusters were located mostly in the left hemisphere. With respect to gender, the left-right distribution of activated pixels was very similar in women and men for the SAME-only and FIT + SAME clusters but differed for the FIT-only case in which there was a prominent left side preponderance for women, in contrast to a right side preponderance for men. We conclude that (a) cortical mechanisms common for processing visual object construction and discrimination involve mostly the left hemisphere, (b) cortical mechanisms

  6. Fos Protein Expression in Olfactory-Related Brain Areas after Learning and after Reactivation of a Slowly Acquired Olfactory Discrimination Task in the Rat

    Science.gov (United States)

    Roullet, Florence; Lienard, Fabienne; Datiche, Frederique; Cattarelli, Martine

    2005-01-01

    Fos protein immunodetection was used to investigate the neuronal activation elicited in some olfactory-related areas after either learning of an olfactory discrimination task or its reactivation 10 d later. Trained rats (T) progressively acquired the association between one odor of a pair and water-reward in a four-arm maze. Two groups of…

  7. Estimation of Symptom Severity Scores for Patients with Schizophrenia Using ERP Source Activations during a Facial Affect Discrimination Task.

    Science.gov (United States)

    Kim, Do-Won; Lee, Seung-Hwan; Shim, Miseon; Im, Chang-Hwan

    2017-01-01

    Precise diagnosis of psychiatric diseases and a comprehensive assessment of a patient's symptom severity are important in order to establish a successful treatment strategy for each patient. Although great efforts have been devoted to searching for diagnostic biomarkers of schizophrenia over the past several decades, no study has yet investigated how accurately these biomarkers are able to estimate an individual patient's symptom severity. In this study, we applied electrophysiological biomarkers obtained from electroencephalography (EEG) analyses to an estimation of symptom severity scores of patients with schizophrenia. EEG signals were recorded from 23 patients while they performed a facial affect discrimination task. Based on the source current density analysis results, we extracted voxels that showed a strong correlation between source activity and symptom scores. We then built a prediction model to estimate the symptom severity scores of each patient using the source activations of the selected voxels. The symptom scores of the Positive and Negative Syndrome Scale (PANSS) were estimated using the linear prediction model. The results of leave-one-out cross validation (LOOCV) showed that the mean errors of the estimated symptom scores were 3.34 ± 2.40 and 3.90 ± 3.01 for the Positive and Negative PANSS scores, respectively. The current pilot study is the first attempt to estimate symptom severity scores in schizophrenia using quantitative EEG features. It is expected that the present method can be extended to other cognitive paradigms or other psychological illnesses.

  8. Estimation of Symptom Severity Scores for Patients with Schizophrenia Using ERP Source Activations during a Facial Affect Discrimination Task

    Directory of Open Access Journals (Sweden)

    Do-Won Kim

    2017-08-01

    Full Text Available Precise diagnosis of psychiatric diseases and a comprehensive assessment of a patient's symptom severity are important in order to establish a successful treatment strategy for each patient. Although great efforts have been devoted to searching for diagnostic biomarkers of schizophrenia over the past several decades, no study has yet investigated how accurately these biomarkers are able to estimate an individual patient's symptom severity. In this study, we applied electrophysiological biomarkers obtained from electroencephalography (EEG analyses to an estimation of symptom severity scores of patients with schizophrenia. EEG signals were recorded from 23 patients while they performed a facial affect discrimination task. Based on the source current density analysis results, we extracted voxels that showed a strong correlation between source activity and symptom scores. We then built a prediction model to estimate the symptom severity scores of each patient using the source activations of the selected voxels. The symptom scores of the Positive and Negative Syndrome Scale (PANSS were estimated using the linear prediction model. The results of leave-one-out cross validation (LOOCV showed that the mean errors of the estimated symptom scores were 3.34 ± 2.40 and 3.90 ± 3.01 for the Positive and Negative PANSS scores, respectively. The current pilot study is the first attempt to estimate symptom severity scores in schizophrenia using quantitative EEG features. It is expected that the present method can be extended to other cognitive paradigms or other psychological illnesses.

  9. Gap junctions and memory: an investigation using a single trial discrimination avoidance task for the neonate chick.

    Science.gov (United States)

    Verwey, L J; Edwards, T M

    2010-02-01

    Gap junctions are important to how the brain functions but are relatively under-investigated with respect to their contribution towards behaviour. In the present study a single trial discrimination avoidance task was used to investigate the effect of the gap junction inhibitor 18-alpha-glycyrrhetinic acid (alphaGA) on retention. Past studies within our research group have implied a potential role for gap junctions during the short-term memory (STM) stage which decays by 15 min post-training. A retention function study comparing 10 microM alphaGA and vehicle given immediately post-training demonstrated a significant main effect for drug with retention loss at all times of test (10-180 min post-training). Given that the most common gap junction in the brain is that forming the astrocytic network it is reasonable to conclude that alphaGA was acting upon these. To confirm this finding and interpretation two additional investigations were undertaken using endothelin-1 (ET-1) and ET-1+tolbutamide. Importantly, a retention function study using 10nM ET-1 replicated the retention loss observed for alphaGA. In order to confirm that ET-1 was acting on astrocytic gap junctions the amnestic action of ET-1 was effectively challenged with increasing concentrations of tolbutamide. The present findings suggest that astrocytic gap junctions are important for memory processing. Copyright 2009 Elsevier Inc. All rights reserved.

  10. The Influence of Stimulus Discriminability on Young Children's Interference Control in the Stroop-Like Happy-Sad Task

    Science.gov (United States)

    Bluell, Alexandra M.; Montgomery, Derek E.

    2014-01-01

    The day-night paradigm, where children respond to a pair of pictures with opposite labels for a series of trials, is a widely used measure of interference control. Recent research has shown that a happy-sad variant of the day-night task was significantly more difficult than the standard day-night task. The present research examined whether the…

  11. GRace: a MATLAB-based application for fitting the discrimination-association model.

    Science.gov (United States)

    Stefanutti, Luca; Vianello, Michelangelo; Anselmi, Pasquale; Robusto, Egidio

    2014-10-28

    The Implicit Association Test (IAT) is a computerized two-choice discrimination task in which stimuli have to be categorized as belonging to target categories or attribute categories by pressing, as quickly and accurately as possible, one of two response keys. The discrimination association model has been recently proposed for the analysis of reaction time and accuracy of an individual respondent to the IAT. The model disentangles the influences of three qualitatively different components on the responses to the IAT: stimuli discrimination, automatic association, and termination criterion. The article presents General Race (GRace), a MATLAB-based application for fitting the discrimination association model to IAT data. GRace has been developed for Windows as a standalone application. It is user-friendly and does not require any programming experience. The use of GRace is illustrated on the data of a Coca Cola-Pepsi Cola IAT, and the results of the analysis are interpreted and discussed.

  12. The Emergence of Symmetry in a Conditional Discrimination Task Using Different Responses as Propioceptive Samples in Pigeons

    Science.gov (United States)

    Garcia, Andres; Benjumea, Santiago

    2006-01-01

    In Experiment 1, 10 pigeons were exposed to a successive symbolic matching-to-sample procedure in which the sample was generated by the pigeons' own behavior. Each trial began with both response keys illuminated white, one being the "correct" key and the other the "incorrect" key. The pigeons had no way of discriminating which key was correct and…

  13. Hippocampal-dependent memory in the plus-maze discriminative avoidance task: The role of spatial cues and CA1 activity.

    Science.gov (United States)

    Leão, Anderson H F F; Medeiros, André M; Apolinário, Gênedy K S; Cabral, Alícia; Ribeiro, Alessandra M; Barbosa, Flávio F; Silva, Regina H

    2016-05-01

    The plus-maze discriminative avoidance task (PMDAT) has been used to investigate interactions between aversive memory and an anxiety-like response in rodents. Suitable performance in this task depends on the activity of the basolateral amygdala, similar to other aversive-based memory tasks. However, the role of spatial cues and hippocampal-dependent learning in the performance of PMDAT remains unknown. Here, we investigated the role of proximal and distal cues in the retrieval of this task. Animals tested under misplaced proximal cues had diminished performance, and animals tested under both misplaced proximal cues and absent distal cues could not discriminate the aversive arm. We also assessed the role of the dorsal hippocampus (CA1) in this aversive memory task. Temporary bilateral inactivation of dorsal CA1 was conducted with muscimol (0.05 μg, 0.1 μg, and 0.2 μg) prior to the training session. While the acquisition of the task was not altered, muscimol impaired the performance in the test session and reduced the anxiety-like response in the training session. We also performed a spreading analysis of a fluorophore-conjugated muscimol to confirm selective inhibition of CA1. In conclusion, both distal and proximal cues are required to retrieve the task, with the latter being more relevant to spatial orientation. Dorsal CA1 activity is also required for aversive memory formation in this task, and interfered with the anxiety-like response as well. Importantly, both effects were detected by different parameters in the same paradigm, endorsing the previous findings of independent assessment of aversive memory and anxiety-like behavior in the PMDAT. Taken together, these findings suggest that the PMDAT probably requires an integration of multiple systems for memory formation, resembling an episodic-like memory rather than a pure conditioning behavior. Furthermore, the concomitant and independent assessment of emotionality and memory in rodents is relevant to

  14. Context-Dependent Modulation of Functional Connectivity: Secondary Somatosensory Cortex to Prefrontal Cortex Connections in Two-Stimulus-Interval Discrimination Tasks

    OpenAIRE

    Chow, Stephanie S.; Romo, Ranulfo; Brody, Carlos D.

    2009-01-01

    In a complex world, a sensory cue may prompt different actions in different contexts. A laboratory example of context-dependent sensory processing is the two-stimulus-interval discrimination task. In each trial, a first stimulus (f1) must be stored in short-term memory and later compared with a second stimulus (f2), for the animal to come to a binary decision. Prefrontal cortex (PFC) neurons need to interpret the f1 information in one way (perhaps with a positive weight) and the f2 informatio...

  15. Sensitivity to Measurement Errors in Studies on Prosocial Choice using a Two-Choice Paradigm

    Directory of Open Access Journals (Sweden)

    Sikorska Julia

    2016-12-01

    Full Text Available Research on prosocial behaviors in primates often relies on the two-choice paradigm. Motoric lateralization is a surprisingly big problem in this field of research research, as it may influence which lever will ultimately be chosen by the actor. The results of lateralization studies on primates do not form a clear picture of that phenomenon, which makes it difficult to address the problem during research. The authors discuss possible ways of managing this confounding variable.

  16. Relationship between the changes in blood flow and volume in the finger during a Braille character discrimination task.

    Science.gov (United States)

    Murata, J; Murata, S; Soma, M; Nakae, H; Sato, Y; Kogo, H; Umeki, N

    2017-11-01

    We hypothesized that skin blood flow (SBF) of fingers are modulated during concentrated finger perception and that the changes in SBF reflect fluctuations in finger volume (FV). The aim of this study, therefore, was examine the relationship between the changes in SBF and FV during Braille reading. We measured SBF of the finger, cutaneous vascular conductance (CVC), FV, and arterial blood pressure during Braille reading performed under blind conditions in thirty healthy subjects. The subjects were instructed to read a flat plate with raised letters (Braille reading) for 15 seconds using their forefinger, and to touch a blank plate as a control for the Braille discrimination procedure. Arterial blood pressure slightly increased during Braille reading but remained unchanged during the touching of the blank plate. SBF, CVC, and FV were reduced during Braille reading (decreased by -26%, -29%, and -0.3 mL/100 mL respectively). Furthermore, a significant relationship was observed between the changes in SBF and FV (r=.613) during Braille reading. These results suggested that SBF of fingers is modulated during concentrated finger perception, and that the variability of blood flow reflects the response in FV. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Dogs can discriminate human smiling faces from blank expressions.

    Science.gov (United States)

    Nagasawa, Miho; Murai, Kensuke; Mogi, Kazutaka; Kikusui, Takefumi

    2011-07-01

    Dogs have a unique ability to understand visual cues from humans. We investigated whether dogs can discriminate between human facial expressions. Photographs of human faces were used to test nine pet dogs in two-choice discrimination tasks. The training phases involved each dog learning to discriminate between a set of photographs of their owner's smiling and blank face. Of the nine dogs, five fulfilled these criteria and were selected for test sessions. In the test phase, 10 sets of photographs of the owner's smiling and blank face, which had previously not been seen by the dog, were presented. The dogs selected the owner's smiling face significantly more often than expected by chance. In subsequent tests, 10 sets of smiling and blank face photographs of 20 persons unfamiliar to the dogs were presented (10 males and 10 females). There was no statistical difference between the accuracy in the case of the owners and that in the case of unfamiliar persons with the same gender as the owner. However, the accuracy was significantly lower in the case of unfamiliar persons of the opposite gender to that of the owner, than with the owners themselves. These results suggest that dogs can learn to discriminate human smiling faces from blank faces by looking at photographs. Although it remains unclear whether dogs have human-like systems for visual processing of human facial expressions, the ability to learn to discriminate human facial expressions may have helped dogs adapt to human society.

  18. Describing three-class task performance: three-class linear discriminant analysis and three-class ROC analysis

    Science.gov (United States)

    He, Xin; Frey, Eric C.

    2007-03-01

    Binary ROC analysis has solid decision-theoretic foundations and a close relationship to linear discriminant analysis (LDA). In particular, for the case of Gaussian equal covariance input data, the area under the ROC curve (AUC) value has a direct relationship to the Hotelling trace. Many attempts have been made to extend binary classification methods to multi-class. For example, Fukunaga extended binary LDA to obtain multi-class LDA, which uses the multi-class Hotelling trace as a figure-of-merit, and we have previously developed a three-class ROC analysis method. This work explores the relationship between conventional multi-class LDA and three-class ROC analysis. First, we developed a linear observer, the three-class Hotelling observer (3-HO). For Gaussian equal covariance data, the 3- HO provides equivalent performance to the three-class ideal observer and, under less strict conditions, maximizes the signal to noise ratio for classification of all pairs of the three classes simultaneously. The 3-HO templates are not the eigenvectors obtained from multi-class LDA. Second, we show that the three-class Hotelling trace, which is the figureof- merit in the conventional three-class extension of LDA, has significant limitations. Third, we demonstrate that, under certain conditions, there is a linear relationship between the eigenvectors obtained from multi-class LDA and 3-HO templates. We conclude that the 3-HO based on decision theory has advantages both in its decision theoretic background and in the usefulness of its figure-of-merit. Additionally, there exists the possibility of interpreting the two linear features extracted by the conventional extension of LDA from a decision theoretic point of view.

  19. Stimulus properties of nicotine, amphetamine, and chlordiazepoxide as positive features in a pavlovian appetitive discrimination task in rats.

    Science.gov (United States)

    Palmatier, Matthew I; Wilkinson, Jamie L; Metschke, Dawn M; Bevins, Rick A

    2005-04-01

    Recent experiments from our laboratory have demonstrated that drug states can signal when environmental cues will be followed by rewarding outcomes (ie Pavlovian conditioning). However, little is known about the generality of this approach and whether it can be used for studying the pharmacological properties of drug states. Accordingly, the present experiments tested the pharmacological specificity of nicotine (0.4 mg/kg), amphetamine (1 mg/kg), and chlordiazepoxide (CDP, 5 mg/kg) in this Pavlovian drug discrimination procedure. Following drug administration, presentation of a conditional stimulus (CS) was followed by brief access to sucrose. When saline was administered, the same CS was presented but sucrose was withheld. In substitution tests, rats in each condition received varying doses of all training drugs and caffeine. Anticipatory food seeking developed during the CS on drug sessions but not on saline sessions for all drug features (ie drug state-specific conditional response (CR)). In generalization tests, this CR decreased as a function of decreases in the training dose. Median effective doses (ED50s) were calculated for nicotine (0.054 mg/kg), amphetamine (0.26 mg/kg), and CDP (2.48 mg/kg). No compound tested substituted for the CDP training drug. Partial substitution was evident between nicotine and amphetamine; CDP did not substitute for either of these drug features. Caffeine fully substituted for nicotine (ED50 = 15.45 mg/kg) and amphetamine (ED50 = 3.70 mg/kg), but not for CDP. These results are consistent with the hypothesis that drug states can occasion appetitive Pavlovian CRs in a pharmacologically specific manner.

  20. Comparison of learning ability and memory retention in altricial (Bengalese finch, Lonchura striata var. domestica) and precocial (blue-breasted quail, Coturnix chinensis) birds using a color discrimination task.

    Science.gov (United States)

    Ueno, Aki; Suzuki, Kaoru

    2014-02-01

    The present study sought to assess the potential application of avian models with different developmental modes to studies on cognition and neuroscience. Six altricial Bengalese finches (Lonchura striata var. domestica), and eight precocial blue-breasted quails (Coturnix chinensis) were presented with color discrimination tasks to compare their respective faculties for learning and memory retention within the context of the two developmental modes. Tasks consisted of presenting birds with discriminative cues in the form of colored feeder lids, and birds were considered to have learned a task when 80% of their attempts at selecting the correctly colored lid in two consecutive blocks of 10 trials were successful. All of the finches successfully performed the required experimental tasks, whereas only half of the quails were able to execute the same tasks. In the learning test, finches required significantly fewer trials than quails to learn the task (finches: 13.5 ± 9.14 trials, quails: 45.8 ± 4.35 trials, P memory retention tests, which were conducted 45 days after the learning test, finches retained the ability to discriminate between colors correctly (95.0 ± 4.47%), whereas quails did not retain any memory of the experimental procedure and so could not be tested. These results suggested that altricial and precocial birds both possess the faculty for learning and retaining discrimination-type tasks, but that altricial birds perform better than precocial birds in both faculties. The present findings imply that developmental mode is an important consideration for assessing the suitability of bird species for particular experiments. © 2013 Japanese Society of Animal Science.

  1. The Effects of Static and Dynamic Visual Representations as Aids for Primary School Children in Tasks of Auditory Discrimination of Sound Patterns. An Intervention-based Study.

    Directory of Open Access Journals (Sweden)

    Jesus Tejada

    2018-02-01

    Full Text Available It has been proposed that non-conventional presentations of visual information could be very useful as a scaffolding strategy in the learning of Western music notation. As a result, this study has attempted to determine if there is any effect of static and dynamic presentation modes of visual information in the recognition of sound patterns. An intervention-based quasi-experimental design was adopted with two groups of fifth-grade students in a Spanish city. Students did tasks involving discrimination, auditory recognition and symbolic association of the sound patterns with non-musical representations, either static images (S group, or dynamic images (D group. The results showed neither statistically significant differences in the scores of D and S, nor influence of the covariates on the dependent variable, although statistically significant intra-group differences were found for both groups. This suggests that both types of graphic formats could be effective as digital learning mediators in the learning of Western musical notation.

  2. Protein hydrolysates are avoided by herbivores but not by omnivores in two-choice preference tests.

    Directory of Open Access Journals (Sweden)

    Kristin L Field

    Full Text Available The negative sensory properties of casein hydrolysates (HC often limit their usage in products intended for human consumption, despite HC being nutritious and having many functional benefits. Recent, but taxonomically limited, evidence suggests that other animals also avoid consuming HC when alternatives exist.We evaluated ingestive responses of five herbivorous species (guinea pig, mountain beaver, gopher, vole, and rabbit and five omnivorous species (rat, coyote, house mouse, white-footed mouse, and deer mouse; N = 16-18/species using solid foods containing 20% HC in a series of two-choice preference tests that used a non-protein, cellulose-based alternative. Individuals were also tested with collagen hydrolysate (gelatin; GE to determine whether it would induce similar ingestive responses to those induced by HC. Despite HC and GE having very different nutritional and sensory qualities, both hydrolysates produced similar preference score patterns. We found that the herbivores generally avoided the hydrolysates while the omnivores consumed them at similar levels to the cellulose diet or, more rarely, preferred them (HC by the white-footed mouse; GE by the rat. Follow-up preference tests pairing HC and the nutritionally equivalent intact casein (C were performed on the three mouse species and the guinea pigs. For the mice, mean HC preference scores were lower in the HC v C compared to the HC v Cel tests, indicating that HC's sensory qualities negatively affected its consumption. However, responses were species-specific. For the guinea pigs, repeated exposure to HC or C (4.7-h sessions; N = 10 were found to increase subsequent HC preference scores in an HC v C preference test, which was interpreted in the light of conservative foraging strategies thought to typify herbivores.This is the first empirical study of dietary niche-related taxonomic differences in ingestive responses to protein hydrolysates using multiple species under comparable

  3. Structural Discrimination

    DEFF Research Database (Denmark)

    Thorsen, Mira Skadegård

    discrimination as two ways of articulating particular, opaque forms of racial discrimination that occur in everyday Danish (and other) contexts, and have therefore become normalized. I present and discuss discrimination as it surfaces in data from my empirical studies of discrimination in Danish contexts...

  4. Blind rats are not profoundly impaired in the reference memory Morris water maze and cannot be clearly discriminated from rats with cognitive deficits in the cued platform task.

    Science.gov (United States)

    Lindner, M D; Plone, M A; Schallert, T; Emerich, D F

    1997-06-01

    The Morris water maze is commonly used to test cognitive function in rodent models of neurological disorders including age-related cognitive deficits. It is often assumed that the most profoundly impaired aged rats may be blind due to retinal degeneration, and it has been reported that animals with visual sensory deficits can be identified based on their performance in a cued platform task. The results of the present study demonstrate that blind rats can perform surprisingly well in the reference memory version of the Morris water maze, and that blind rats cannot be selectively excluded based on performance in the cued platform task since atropine-treated rats also perform poorly in the cued platform task. Future studies may be able to develop screening procedures that help to eliminate subjects with non-cognitive deficits, but the present results do not support the use of the cued platform or straight swim task as screening procedures. Experimenters must be careful to consider the role that visual sensory function and other non-cognitive factors may have in performance of the spatial learning Morris water maze, and also the role that severe cognitive deficits may have in performance of the cued platform task.

  5. Diagnostic Value of a Tablet-Based Drawing Task for Discrimination of Patients in the Early Course of Alzheimer's Disease from Healthy Individuals.

    Science.gov (United States)

    Müller, Stephan; Preische, Oliver; Heymann, Petra; Elbing, Ulrich; Laske, Christoph

    2017-01-01

    There is a considerable delay in the diagnosis of dementia, which may reduce the effectiveness of available treatments. Thus, it is of great interest to develop fast and easy to perform, non-invasive and non-expensive diagnostic measures for the early detection of cognitive impairment and dementia. Here we investigate movement kinematics between 20 patients with early dementia due to Alzheimer's disease (eDAT), 30 patients with amnestic mild cognitive impairment (aMCI), and 20 cognitively healthy control (HC) individuals while copying a three-dimensional house using a digitizing tablet. Receiver-operating characteristic (ROC) curves and logistic regression analyzes have been conducted to explore whether alterations in movement kinematics could be used to discriminate patients with aMCI and eDAT from healthy individuals. Time-in-air (i.e., transitioning from one stroke to the next without touching the surface) differed significantly between patients with aMCI, eDAT, and HCs demonstrating an excellent sensitivity and a moderate specificity to discriminate aMCI subjects from normal elderly and an excellent sensitivity and specificity to discriminate patients affected by mild Alzheimer's disease from healthy individuals. Time-on-surface (i.e., time while stylus is touching the surface) differed only between HCs and patients with eDAT but not between HCs and patients with aMCI. Furthermore, total-time (i.e., time-in-air plus time-on-surface) did not differ between patients with aMCI and early dementia due to AD. Modern digitizing devices offer the opportunity to measure a broad range of visuoconstructive abilities that may be used as a fast and easy to perform screening instrument for the early detection of cognitive impairment and dementia in primary care.

  6. Discrimination Learning in Children

    Science.gov (United States)

    Ochocki, Thomas E.; And Others

    1975-01-01

    Examined the learning performance of 192 fourth-, fifth-, and sixth-grade children on either a two or four choice simultaneous color discrimination task. Compared the use of verbal reinforcement and/or punishment, under conditions of either complete or incomplete instructions. (Author/SDH)

  7. Discriminative Shape Alignment

    DEFF Research Database (Denmark)

    Loog, M.; de Bruijne, M.

    2009-01-01

    , not taking into account that eventually the shapes are to be assigned to two or more different classes. This work introduces a discriminative variation to well-known Procrustes alignment and demonstrates its benefit over this classical method in shape classification tasks. The focus is on two...

  8. Sex Differences in Discrimination of Forms by Elementary School Children

    Science.gov (United States)

    Etaugh, Claire; Turton, William J.

    1977-01-01

    Boys and girls in second and fourth grades were presented with a two-choice simultaneous form discrimination. The forms were five or ten-sided and symmetrical or asymmetrical. Boys performed better than girls and older children were more accurate than younger ones. (MS)

  9. Differential discriminator

    International Nuclear Information System (INIS)

    Dukhanov, V.I.; Mazurov, I.B.

    1981-01-01

    A principal flowsheet of a differential discriminator intended for operation in a spectrometric circuit with statistical time distribution of pulses is described. The differential discriminator includes four integrated discriminators and a channel of piled-up signal rejection. The presence of the rejection channel enables the discriminator to operate effectively at loads of 14x10 3 pulse/s. The temperature instability of the discrimination thresholds equals 250 μV/ 0 C. The discrimination level changes within 0.1-5 V, the level shift constitutes 0.5% for the filling ratio of 1:10. The rejection coefficient is not less than 90%. Alpha spectrum of the 228 Th source is presented to evaluate the discriminator operation with the rejector. The rejector provides 50 ns time resolution

  10. Prestimulus alpha-band power biases visual discrimination confidence, but not accuracy.

    Science.gov (United States)

    Samaha, Jason; Iemi, Luca; Postle, Bradley R

    2017-09-01

    The magnitude of power in the alpha-band (8-13Hz) of the electroencephalogram (EEG) prior to the onset of a near threshold visual stimulus predicts performance. Together with other findings, this has been interpreted as evidence that alpha-band dynamics reflect cortical excitability. We reasoned, however, that non-specific changes in excitability would be expected to influence signal and noise in the same way, leaving actual discriminability unchanged. Indeed, using a two-choice orientation discrimination task, we found that discrimination accuracy was unaffected by fluctuations in prestimulus alpha power. Decision confidence, on the other hand, was strongly negatively correlated with prestimulus alpha power. This finding constitutes a clear dissociation between objective and subjective measures of visual perception as a function of prestimulus cortical excitability. This dissociation is predicted by a model where the balance of evidence supporting each choice drives objective performance but only the magnitude of evidence supporting the selected choice drives subjective reports, suggesting that human perceptual confidence can be suboptimal with respect to tracking objective accuracy. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Concurrent deployment of visual attention and response selection bottleneck in a dual-task: Electrophysiological and behavioural evidence.

    Science.gov (United States)

    Reimer, Christina B; Strobach, Tilo; Schubert, Torsten

    2017-12-01

    Visual attention and response selection are limited in capacity. Here, we investigated whether visual attention requires the same bottleneck mechanism as response selection in a dual-task of the psychological refractory period (PRP) paradigm. The dual-task consisted of an auditory two-choice discrimination Task 1 and a conjunction search Task 2, which were presented at variable temporal intervals (stimulus onset asynchrony, SOA). In conjunction search, visual attention is required to select items and to bind their features resulting in a serial search process around the items in the search display (i.e., set size). We measured the reaction time of the visual search task (RT2) and the N2pc, an event-related potential (ERP), which reflects lateralized visual attention processes. If the response selection processes in Task 1 influence the visual attention processes in Task 2, N2pc latency and amplitude would be delayed and attenuated at short SOA compared to long SOA. The results, however, showed that latency and amplitude were independent of SOA, indicating that visual attention was concurrently deployed to response selection. Moreover, the RT2 analysis revealed an underadditive interaction of SOA and set size. We concluded that visual attention does not require the same bottleneck mechanism as response selection in dual-tasks.

  12. Spatial discrimination and visual discrimination

    DEFF Research Database (Denmark)

    Haagensen, Annika M. J.; Grand, Nanna; Klastrup, Signe

    2013-01-01

    Two methods investigating learning and memory in juvenile Gottingen minipigs were evaluated for potential use in preclinical toxicity testing. Twelve minipigs were tested using a spatial hole-board discrimination test including a learning phase and two memory phases. Five minipigs were tested...... in a visual discrimination test. The juvenile minipigs were able to learn the spatial hole-board discrimination test and showed improved working and reference memory during the learning phase. Performance in the memory phases was affected by the retention intervals, but the minipigs were able to remember...... the concept of the test in both memory phases. Working memory and reference memory were significantly improved in the last trials of the memory phases. In the visual discrimination test, the minipigs learned to discriminate between the three figures presented to them within 9-14 sessions. For the memory test...

  13. Mass discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Broeckman, A. [Rijksuniversiteit Utrecht (Netherlands)

    1978-12-15

    In thermal ionization mass spectrometry the phenomenon of mass discrimination has led to the use of a correction factor for isotope ratio-measurements. The correction factor is defined as the measured ratio divided by the true or accepted value of this ratio. In fact this factor corrects for systematic errors of the whole procedure; however mass discrimination is often associated just with the mass spectrometer.

  14. How discriminating are discriminative instruments?

    Science.gov (United States)

    Hankins, Matthew

    2008-05-27

    The McMaster framework introduced by Kirshner & Guyatt is the dominant paradigm for the development of measures of health status and health-related quality of life (HRQL). The framework defines the functions of such instruments as evaluative, predictive or discriminative. Evaluative instruments are required to be sensitive to change (responsiveness), but there is no corresponding index of the degree to which discriminative instruments are sensitive to cross-sectional differences. This paper argues that indices of validity and reliability are not sufficient to demonstrate that a discriminative instrument performs its function of discriminating between individuals, and that the McMaster framework would be augmented by the addition of a separate index of discrimination. The coefficient proposed by Ferguson (Delta) is easily adapted to HRQL instruments and is a direct, non-parametric index of the degree to which an instrument distinguishes between individuals. While Delta should prove useful in the development and evaluation of discriminative instruments, further research is required to elucidate the relationship between the measurement properties of discrimination, reliability and responsiveness.

  15. How discriminating are discriminative instruments?

    Directory of Open Access Journals (Sweden)

    Hankins Matthew

    2008-05-01

    Full Text Available Abstract The McMaster framework introduced by Kirshner & Guyatt is the dominant paradigm for the development of measures of health status and health-related quality of life (HRQL. The framework defines the functions of such instruments as evaluative, predictive or discriminative. Evaluative instruments are required to be sensitive to change (responsiveness, but there is no corresponding index of the degree to which discriminative instruments are sensitive to cross-sectional differences. This paper argues that indices of validity and reliability are not sufficient to demonstrate that a discriminative instrument performs its function of discriminating between individuals, and that the McMaster framework would be augmented by the addition of a separate index of discrimination. The coefficient proposed by Ferguson (Delta is easily adapted to HRQL instruments and is a direct, non-parametric index of the degree to which an instrument distinguishes between individuals. While Delta should prove useful in the development and evaluation of discriminative instruments, further research is required to elucidate the relationship between the measurement properties of discrimination, reliability and responsiveness.

  16. More insight into the interplay of response selection and visual attention in dual-tasks: masked visual search and response selection are performed in parallel.

    Science.gov (United States)

    Reimer, Christina B; Schubert, Torsten

    2017-09-15

    Both response selection and visual attention are limited in capacity. According to the central bottleneck model, the response selection processes of two tasks in a dual-task situation are performed sequentially. In conjunction search, visual attention is required to select the items and to bind their features (e.g., color and form), which results in a serial search process. Search time increases as items are added to the search display (i.e., set size effect). When the search display is masked, visual attention deployment is restricted to a brief period of time and target detection decreases as a function of set size. Here, we investigated whether response selection and visual attention (i.e., feature binding) rely on a common or on distinct capacity limitations. In four dual-task experiments, participants completed an auditory Task 1 and a conjunction search Task 2 that were presented with an experimentally modulated temporal interval between them (Stimulus Onset Asynchrony, SOA). In Experiment 1, Task 1 was a two-choice discrimination task and the conjunction search display was not masked. In Experiment 2, the response selection difficulty in Task 1 was increased to a four-choice discrimination and the search task was the same as in Experiment 1. We applied the locus-of-slack method in both experiments to analyze conjunction search time, that is, we compared the set size effects across SOAs. Similar set size effects across SOAs (i.e., additive effects of SOA and set size) would indicate sequential processing of response selection and visual attention. However, a significantly smaller set size effect at short SOA compared to long SOA (i.e., underadditive interaction of SOA and set size) would indicate parallel processing of response selection and visual attention. In both experiments, we found underadditive interactions of SOA and set size. In Experiments 3 and 4, the conjunction search display in Task 2 was masked. Task 1 was the same as in Experiments 1 and 2

  17. Dissociation between spontaneously hypertensive (SHR) andWistar–Kyoto (WKY) rats in baseline performance and methylphenidate response on measures of attention, impulsivity and hyperactivity in a Visual Stimulus Position Discrimination Task

    Energy Technology Data Exchange (ETDEWEB)

    Thanos, P.K.

    2009-10-08

    The spontaneously hypertensive rat (SHR) is a widely accepted rodent model of Attention Deficit/Hyperactivity Disorder (ADHD), and methylphenidate (MP) is a central nervous systemstimulant that has been shown to have a dose-related positive effect on attention task performance in humans with ADHD. The current study was undertaken to compare SHR to its typical control strain, Wistar-Kyoto(WKY) rats, on the performance of a Visual Stimulus Position Discrimination Task (VSPDT) as well as of the responsiveness of the two rat strains to MP treatment. The rats were initially trained on the VSPDT, in which a light cue was presented randomly at three different cue-light intervals (1 s, 300 ms and 100 ms) over one of two levers, and presses on the lever corresponding to the light cue were reinforced with a food pellet. Once rats reached stable performance, the treatment phase of the study began, during which they received daily intraperitoneal (IP) injections of saline, 2 mg/kg, 5 mg/kg, and 10 mg/kg of MP in a randomized order immediately prior to being tested on the VSPDT. Baseline performance accuracy on the VSPDT did not differ between the groups. Furthermore, a striking strain dissociation was evident in the response of the two strains to treatment; VSPDT performance was substantially disrupted by the 5 and 10 mg/kg dose in the WKY rats but only mildly in the SHR rats. Response omissions were also increased only in WKY rats. Finally, both strains had increased locomotor activity in the operant chamber following MP treatment. These findings point to an important difference in response tendency toMP in the two strains that supports a view that a critical difference between these strains may suggest neurochemical and neuroadaptive differences associated with the behavioral impairments of ADHD.

  18. Paintings discrimination by mice: Different strategies for different paintings.

    Science.gov (United States)

    Watanabe, Shigeru

    2017-09-01

    C57BL/6 mice were trained on simultaneous discrimination of paintings with multiple exemplars, using an operant chamber with a touch screen. The number of exemplars was successively increased up to six. Those mice trained in Kandinsky/Mondrian discrimination showed improved learning and generalization, whereas those trained in Picasso/Renoir discrimination showed no improvements in learning or generalization. These results suggest category-like discrimination in the Kandinsky/Mondrian task, but item-to-item discrimination in the Picasso/Renoir task. Mice maintained their discriminative behavior in a pixelization test with various paintings; however, mice in the Picasso/Renoir task showed poor performance in a test that employed scrambling processing. These results do not indicate that discrimination strategy for any Kandinsky/Mondrian combinations differed from that for any Picasso/Monet combinations but suggest the mice employed different strategies of discrimination tasks depending upon stimuli. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Anti-discrimination Analysis Using Privacy Attack Strategies

    KAUST Repository

    Ruggieri, Salvatore; Hajian, Sara; Kamiran, Faisal; Zhang, Xiangliang

    2014-01-01

    Social discrimination discovery from data is an important task to identify illegal and unethical discriminatory patterns towards protected-by-law groups, e.g., ethnic minorities. We deploy privacy attack strategies as tools for discrimination

  20. Discriminative Transfer Learning for General Image Restoration

    KAUST Repository

    Xiao, Lei

    2018-04-30

    Recently, several discriminative learning approaches have been proposed for effective image restoration, achieving convincing trade-off between image quality and computational efficiency. However, these methods require separate training for each restoration task (e.g., denoising, deblurring, demosaicing) and problem condition (e.g., noise level of input images). This makes it time-consuming and difficult to encompass all tasks and conditions during training. In this paper, we propose a discriminative transfer learning method that incorporates formal proximal optimization and discriminative learning for general image restoration. The method requires a single-pass discriminative training and allows for reuse across various problems and conditions while achieving an efficiency comparable to previous discriminative approaches. Furthermore, after being trained, our model can be easily transferred to new likelihood terms to solve untrained tasks, or be combined with existing priors to further improve image restoration quality.

  1. Discriminative Transfer Learning for General Image Restoration

    KAUST Repository

    Xiao, Lei; Heide, Felix; Heidrich, Wolfgang; Schö lkopf, Bernhard; Hirsch, Michael

    2018-01-01

    Recently, several discriminative learning approaches have been proposed for effective image restoration, achieving convincing trade-off between image quality and computational efficiency. However, these methods require separate training for each restoration task (e.g., denoising, deblurring, demosaicing) and problem condition (e.g., noise level of input images). This makes it time-consuming and difficult to encompass all tasks and conditions during training. In this paper, we propose a discriminative transfer learning method that incorporates formal proximal optimization and discriminative learning for general image restoration. The method requires a single-pass discriminative training and allows for reuse across various problems and conditions while achieving an efficiency comparable to previous discriminative approaches. Furthermore, after being trained, our model can be easily transferred to new likelihood terms to solve untrained tasks, or be combined with existing priors to further improve image restoration quality.

  2. Don't demotivate, discriminate

    NARCIS (Netherlands)

    J.J.A. Kamphorst (Jurjen); O.H. Swank (Otto)

    2013-01-01

    markdownabstract__Abstract__ This paper offers a new theory of discrimination in the workplace. We consider a manager who has to assign two tasks to two employees. The manager has superior information about the employees' abilities. We show that besides an equilibrium where the manager does not

  3. Data preprocessing techniques for classification without discrimination

    NARCIS (Netherlands)

    Kamiran, F.; Calders, T.G.K.

    2012-01-01

    Recently, the following Discrimination-Aware Classification Problem was introduced: Suppose we are given training data that exhibit unlawful discrimination; e.g., toward sensitive attributes such as gender or ethnicity. The task is to learn a classifier that optimizes accuracy, but does not have

  4. Pattern recognition in bees : orientation discrimination

    NARCIS (Netherlands)

    Hateren, J.H. van; Srinivasan, M.V.; Wait, P.B.

    1990-01-01

    Honey bees (Apis mellifera, worker) were trained to discriminate between two random gratings oriented perpendicularly to each other. This task was quickly learned with vertical, horizontal, and oblique gratings. After being trained on perpendicularly-oriented random gratings, bees could discriminate

  5. The influence of different doses of caffeine on visual task performance

    NARCIS (Netherlands)

    Lorist, MM; Snel, J; Ruijter, J

    1999-01-01

    Tn this study the influence of caffeine as an energy-increasing substance on visual information processing was examined. Subjects were presented with a dual-task consisting of two choice reaction time tasks. In addition, one of the tasks was presented at two levels of difficulty, influencing the

  6. Pitch discrimination associated with phonological awareness: Evidence from congenital amusia.

    Science.gov (United States)

    Sun, Yanan; Lu, Xuejing; Ho, Hao Tam; Thompson, William Forde

    2017-03-13

    Research suggests that musical skills are associated with phonological abilities. To further investigate this association, we examined whether phonological impairments are evident in individuals with poor music abilities. Twenty individuals with congenital amusia and 20 matched controls were assessed on a pure-tone pitch discrimination task, a rhythm discrimination task, and four phonological tests. Amusic participants showed deficits in discriminating pitch and discriminating rhythmic patterns that involve a regular beat. At a group level, these individuals performed similarly to controls on all phonological tests. However, eight amusics with severe pitch impairment, as identified by the pitch discrimination task, exhibited significantly worse performance than all other participants in phonological awareness. A hierarchical regression analysis indicated that pitch discrimination thresholds predicted phonological awareness beyond that predicted by phonological short-term memory and rhythm discrimination. In contrast, our rhythm discrimination task did not predict phonological awareness beyond that predicted by pitch discrimination thresholds. These findings suggest that accurate pitch discrimination is critical for phonological processing. We propose that deficits in early-stage pitch discrimination may be associated with impaired phonological awareness and we discuss the shared role of pitch discrimination for processing music and speech.

  7. Fighting discrimination.

    Science.gov (United States)

    Wientjens, Wim; Cairns, Douglas

    2012-10-01

    In the fight against discrimination, the IDF launched the first ever International Charter of Rights and Responsibilities of People with Diabetes in 2011: a balance between rights and duties to optimize health and quality of life, to enable as normal a life as possible and to reduce/eliminate the barriers which deny realization of full potential as members of society. It is extremely frustrating to suffer blanket bans and many examples exist, including insurance, driving licenses, getting a job, keeping a job and family affairs. In this article, an example is given of how pilots with insulin treated diabetes are allowed to fly by taking the responsibility of using special blood glucose monitoring protocols. At this time the systems in the countries allowing flying for pilots with insulin treated diabetes are applauded, particularly the USA for private flying, and Canada for commercial flying. Encouraging developments may be underway in the UK for commercial flying and, if this materializes, could be used as an example for other aviation authorities to help adopt similar protocols. However, new restrictions implemented by the new European Aviation Authority take existing privileges away for National Private Pilot Licence holders with insulin treated diabetes in the UK. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. Universal programmable devices for unambiguous discrimination

    International Nuclear Information System (INIS)

    Zhang Chi; Ying Mingsheng; Qiao, Bo

    2006-01-01

    We discuss the problem of designing unambiguous programmable discriminators for any n unknown quantum states in an m-dimensional Hilbert space. The discriminator is a fixed measurement that has two kinds of input registers: the program registers and the data register. The quantum state in the data register is what users want to identify, which is confirmed to be among the n states in program registers. The task of the discriminator is to tell the users which state stored in the program registers is equivalent to that in the data register. First, we give a necessary and sufficient condition for judging an unambiguous programmable discriminator. Then, if m=n, we present an optimal unambiguous programmable discriminator for them, in the sense of maximizing the worst-case probability of success. Finally, we propose a universal unambiguous programmable discriminator for arbitrary n quantum states

  9. Discrimination and Anti-discrimination in Denmark

    DEFF Research Database (Denmark)

    Olsen, Tore Vincents

    The purpose of this report is to describe and analyse Danish anti-discrimination legislation and the debate about discrimination in Denmark in order to identify present and future legal challenges. The main focus is the implementation of the EU anti-discrimination directives in Danish law...

  10. Performance Enhancements Under Dual-task Conditions

    Science.gov (United States)

    Kramer, A. F.; Wickens, C. D.; Donchin, E.

    1984-01-01

    Research on dual-task performance has been concerned with delineating the antecedent conditions which lead to dual-task decrements. Capacity models of attention, which propose that a hypothetical resource structure underlies performance, have been employed as predictive devices. These models predict that tasks which require different processing resources can be more successfully time shared than tasks which require common resources. The conditions under which such dual-task integrality can be fostered were assessed in a study in which three factors likely to influence the integrality between tasks were manipulated: inter-task redundancy, the physical proximity of tasks and the task relevant objects. Twelve subjects participated in three experimental sessions in which they performed both single and dual-tasks. The primary task was a pursuit step tracking task. The secondary tasks required the discrimination between different intensities or different spatial positions of a stimulus. The results are discussed in terms of a model of dual-task integrality.

  11. Pulse duration discriminator

    International Nuclear Information System (INIS)

    Kosakovskij, L.F.

    1980-01-01

    Basic circuits of a discriminator for discrimination of pulses with the duration greater than the preset one, and of a multifunctional discriminator allowing to discriminate pulses with the duration greater (tsub(p)>tsub(s)) and lesser (tsub(p) tsub(s) and with the duration tsub(p) [ru

  12. Binocular contrast discrimination needs monocular multiplicative noise

    Science.gov (United States)

    Ding, Jian; Levi, Dennis M.

    2016-01-01

    The effects of signal and noise on contrast discrimination are difficult to separate because of a singularity in the signal-detection-theory model of two-alternative forced-choice contrast discrimination (Katkov, Tsodyks, & Sagi, 2006). In this article, we show that it is possible to eliminate the singularity by combining that model with a binocular combination model to fit monocular, dichoptic, and binocular contrast discrimination. We performed three experiments using identical stimuli to measure the perceived phase, perceived contrast, and contrast discrimination of a cyclopean sine wave. In the absence of a fixation point, we found a binocular advantage in contrast discrimination both at low contrasts (discrimination mechanisms: a nonlinear contrast transducer and multiplicative noise (MN). A binocular combination model (the DSKL model; Ding, Klein, & Levi, 2013b) was first fitted to both the perceived-phase and the perceived-contrast data sets, then combined with either the nonlinear contrast transducer or the MN mechanism to fit the contrast-discrimination data. We found that the best model combined the DSKL model with early MN. Model simulations showed that, after going through interocular suppression, the uncorrelated noise in the two eyes became anticorrelated, resulting in less binocular noise and therefore a binocular advantage in the discrimination task. Combining a nonlinear contrast transducer or MN with a binocular combination model (DSKL) provides a powerful method for evaluating the two putative contrast-discrimination mechanisms. PMID:26982370

  13. Quantum-state comparison and discrimination

    Science.gov (United States)

    Hayashi, A.; Hashimoto, T.; Horibe, M.

    2018-05-01

    We investigate the performance of discrimination strategy in the comparison task of known quantum states. In the discrimination strategy, one infers whether or not two quantum systems are in the same state on the basis of the outcomes of separate discrimination measurements on each system. In some cases with more than two possible states, the optimal strategy in minimum-error comparison is that one should infer the two systems are in different states without any measurement, implying that the discrimination strategy performs worse than the trivial "no-measurement" strategy. We present a sufficient condition for this phenomenon to happen. For two pure states with equal prior probabilities, we determine the optimal comparison success probability with an error margin, which interpolates the minimum-error and unambiguous comparison. We find that the discrimination strategy is not optimal except for the minimum-error case.

  14. Contextual Advantage for State Discrimination

    Science.gov (United States)

    Schmid, David; Spekkens, Robert W.

    2018-02-01

    Finding quantitative aspects of quantum phenomena which cannot be explained by any classical model has foundational importance for understanding the boundary between classical and quantum theory. It also has practical significance for identifying information processing tasks for which those phenomena provide a quantum advantage. Using the framework of generalized noncontextuality as our notion of classicality, we find one such nonclassical feature within the phenomenology of quantum minimum-error state discrimination. Namely, we identify quantitative limits on the success probability for minimum-error state discrimination in any experiment described by a noncontextual ontological model. These constraints constitute noncontextuality inequalities that are violated by quantum theory, and this violation implies a quantum advantage for state discrimination relative to noncontextual models. Furthermore, our noncontextuality inequalities are robust to noise and are operationally formulated, so that any experimental violation of the inequalities is a witness of contextuality, independently of the validity of quantum theory. Along the way, we introduce new methods for analyzing noncontextuality scenarios and demonstrate a tight connection between our minimum-error state discrimination scenario and a Bell scenario.

  15. Contextual Advantage for State Discrimination

    Directory of Open Access Journals (Sweden)

    David Schmid

    2018-02-01

    Full Text Available Finding quantitative aspects of quantum phenomena which cannot be explained by any classical model has foundational importance for understanding the boundary between classical and quantum theory. It also has practical significance for identifying information processing tasks for which those phenomena provide a quantum advantage. Using the framework of generalized noncontextuality as our notion of classicality, we find one such nonclassical feature within the phenomenology of quantum minimum-error state discrimination. Namely, we identify quantitative limits on the success probability for minimum-error state discrimination in any experiment described by a noncontextual ontological model. These constraints constitute noncontextuality inequalities that are violated by quantum theory, and this violation implies a quantum advantage for state discrimination relative to noncontextual models. Furthermore, our noncontextuality inequalities are robust to noise and are operationally formulated, so that any experimental violation of the inequalities is a witness of contextuality, independently of the validity of quantum theory. Along the way, we introduce new methods for analyzing noncontextuality scenarios and demonstrate a tight connection between our minimum-error state discrimination scenario and a Bell scenario.

  16. Impaired somatosensory discrimination of shape in Parkinson's disease : Association with caudate nucleus dopaminergic function

    NARCIS (Netherlands)

    Weder, BJ; Leenders, KL; Vontobel, P; Nienhusmeier, M; Keel, A; Zaunbauer, W; Vonesch, T; Ludin, HP

    1999-01-01

    Tactile discrimination of macrogeometric objects in a two-alternative forced-choice procedure represents a demanding task involving somatosensory pathways and higher cognitive processing. The objects for somatosensory discrimination, i.e., rectangular parallelepipeds differing only in oblongness,

  17. Handling conditional discrimination

    NARCIS (Netherlands)

    Zliobaite, I.; Kamiran, F.; Calders, T.G.K.

    2011-01-01

    Historical data used for supervised learning may contain discrimination. We study how to train classifiers on such data, so that they are discrimination free with respect to a given sensitive attribute, e.g., gender. Existing techniques that deal with this problem aim at removing all discrimination

  18. The Badness of Discrimination

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2006-01-01

    . In this paper I address these issues. First, I offer a taxonomy of discrimination. I then argue that discrimination is bad, when it is, because it harms people. Finally, I criticize a rival, disrespect-based account according to which discrimination is bad regardless of whether it causes harm....

  19. Mind the gap: temporal discrimination and dystonia.

    Science.gov (United States)

    Sadnicka, A; Daum, C; Cordivari, C; Bhatia, K P; Rothwell, J C; Manohar, S; Edwards, M J

    2017-06-01

    One of the most widely studied perceptual measures of sensory dysfunction in dystonia is the temporal discrimination threshold (TDT) (the shortest interval at which subjects can perceive that there are two stimuli rather than one). However the elevated thresholds described may be due to a number of potential mechanisms as current paradigms test not only temporal discrimination but also extraneous sensory and decision-making parameters. In this study two paradigms designed to better quantify temporal processing are presented and a decision-making model is used to assess the influence of decision strategy. 22 patients with cervical dystonia and 22 age-matched controls completed two tasks (i) temporal resolution (a randomized, automated version of existing TDT paradigms) and (ii) interval discrimination (rating the length of two consecutive intervals). In the temporal resolution task patients had delayed (P = 0.021) and more variable (P = 0.013) response times but equivalent discrimination thresholds. Modelling these effects suggested this was due to an increased perceptual decision boundary in dystonia with patients requiring greater evidence before committing to decisions (P = 0.020). Patient performance on the interval discrimination task was normal. Our work suggests that previously observed abnormalities in TDT may not be due to a selective sensory deficit of temporal processing as decision-making itself is abnormal in cervical dystonia. © 2017 EAN.

  20. Pigeons' Discrimination of Michotte's Launching Effect

    Science.gov (United States)

    Young, Michael E.; Beckmann, Joshua S.; Wasserman, Edward A.

    2006-01-01

    We trained four pigeons to discriminate a Michotte launching animation from three other animations using a go/no-go task. The pigeons received food for pecking at one of the animations, but not for pecking at the others. The four animations featured two types of interactions among objects: causal (direct launching) and noncausal (delayed, distal,…

  1. Pulse-width discriminators

    International Nuclear Information System (INIS)

    Budyashov, Yu.G.; Grebenyuk, V.M.; Zinov, V.G.

    1978-01-01

    A pulse duration discriminator is described which is intended for processing signals from multilayer scintillators. The basic elements of the scintillator are: an input gate, a current generator, an integrating capacitor, a Schmidt trigger and an anticoincidence circuit. The basic circuit of the discriminator and its time diagrams explaining its operating are given. The discriminator is based on microcircuits. Pulse duration discrimination threshold changes continuously from 20 to 100 ns, while its amplitude threshold changes within 20 to 100 mV. The temperature instability of discrimination thresholds (both in pulse width and in amplitude) is better than 0.1 per cent/deg C

  2. Awake, long-term intranasal insulin treatment does not affect object memory, odor discrimination, or reversal learning in mice.

    Science.gov (United States)

    Bell, Genevieve A; Fadool, Debra Ann

    2017-05-15

    Intranasal insulin delivery is currently being used in clinical trials to test for improvement in human memory and cognition, and in particular, for lessening memory loss attributed to neurodegenerative diseases. Studies have reported the effects of short-term intranasal insulin treatment on various behaviors, but less have examined long-term effects. The olfactory bulb contains the highest density of insulin receptors in conjunction with the highest level of insulin transport within the brain. Previous research from our laboratory has demonstrated that acute insulin intranasal delivery (IND) enhanced both short- and long-term memory as well as increased two-odor discrimination in a two-choice paradigm. Herein, we investigated the behavioral and physiological effects of chronic insulin IND. Adult, male C57BL6/J mice were intranasally treated with 5μg/μl of insulin twice daily for 30 and 60days. Metabolic assessment indicated no change in body weight, caloric intake, or energy expenditure following chronic insulin IND, but an increase in the frequency of meal bouts selectively in the dark cycle. Unlike acute insulin IND, which has been shown to cause enhanced performance in odor habituation/dishabituation and two-odor discrimination tasks in mice, chronic insulin IND did not enhance olfactometry-based odorant discrimination or olfactory reversal learning. In an object memory recognition task, insulin IND-treated mice did not perform differently than controls, regardless of task duration. Biochemical analyses of the olfactory bulb revealed a modest 1.3 fold increase in IR kinase phosphorylation but no significant increase in Kv1.3 phosphorylation. Substrate phosphorylation of IR kinase downstream effectors (MAPK/ERK and Akt signaling) proved to be highly variable. These data indicate that chronic administration of insulin IND in mice fails to enhance olfactory ability, object memory recognition, or a majority of systems physiology metabolic factors - as reported to

  3. Face-gender discrimination is possible in the near-absence of attention.

    Science.gov (United States)

    Reddy, Leila; Wilken, Patrick; Koch, Christof

    2004-03-02

    The attentional cost associated with the visual discrimination of the gender of a face was investigated. Participants performed a face-gender discrimination task either alone (single-task) or concurrently (dual-task) with a known attentional demanding task (5-letter T/L discrimination). Overall performance on face-gender discrimination suffered remarkably little under the dual-task condition compared to the single-task condition. Similar results were obtained in experiments that controlled for potential training effects or the use of low-level cues in this discrimination task. Our results provide further evidence against the notion that only low-level representations can be accessed outside the focus of attention.

  4. LABOR DISCRIMINATION IN BULGARIA

    Directory of Open Access Journals (Sweden)

    Vyara Slavyanska

    2017-03-01

    Full Text Available Labor discrimination is a phenomenon with very serious social and economic consequences, which has increased actuality and importance in Bulgaria nowadays. Because of the high price of discrimination, building effective anti-discrimination legislation occupies a special place in the policy of the European Union. Despite the European directives, the presence of anti-discrimination legislation and the broadly declared anti-discrimination inclinations in our country, these are absolutely not enough for providing environment of equality, with a climate of respect and tolerance to the differences. It turns out that certain groups are definitely victims of labor discrimination. In this connection the present article consecutively identifies these groups, as well as the reasons for their discrimination, underlining the necessity and benefits of the integration of the different.

  5. Anti-discrimination Analysis Using Privacy Attack Strategies

    KAUST Repository

    Ruggieri, Salvatore

    2014-09-15

    Social discrimination discovery from data is an important task to identify illegal and unethical discriminatory patterns towards protected-by-law groups, e.g., ethnic minorities. We deploy privacy attack strategies as tools for discrimination discovery under hard assumptions which have rarely tackled in the literature: indirect discrimination discovery, privacy-aware discrimination discovery, and discrimination data recovery. The intuition comes from the intriguing parallel between the role of the anti-discrimination authority in the three scenarios above and the role of an attacker in private data publishing. We design strategies and algorithms inspired/based on Frèchet bounds attacks, attribute inference attacks, and minimality attacks to the purpose of unveiling hidden discriminatory practices. Experimental results show that they can be effective tools in the hands of anti-discrimination authorities.

  6. Different Neuroplasticity for Task Targets and Distractors

    Science.gov (United States)

    Spingath, Elsie Y.; Kang, Hyun Sug; Plummer, Thane; Blake, David T.

    2011-01-01

    Adult learning-induced sensory cortex plasticity results in enhanced action potential rates in neurons that have the most relevant information for the task, or those that respond strongly to one sensory stimulus but weakly to its comparison stimulus. Current theories suggest this plasticity is caused when target stimulus evoked activity is enhanced by reward signals from neuromodulatory nuclei. Prior work has found evidence suggestive of nonselective enhancement of neural responses, and suppression of responses to task distractors, but the differences in these effects between detection and discrimination have not been directly tested. Using cortical implants, we defined physiological responses in macaque somatosensory cortex during serial, matched, detection and discrimination tasks. Nonselective increases in neural responsiveness were observed during detection learning. Suppression of responses to task distractors was observed during discrimination learning, and this suppression was specific to cortical locations that sampled responses to the task distractor before learning. Changes in receptive field size were measured as the area of skin that had a significant response to a constant magnitude stimulus, and these areal changes paralleled changes in responsiveness. From before detection learning until after discrimination learning, the enduring changes were selective suppression of cortical locations responsive to task distractors, and nonselective enhancement of responsiveness at cortical locations selective for target and control skin sites. A comparison of observations in prior studies with the observed plasticity effects suggests that the non-selective response enhancement and selective suppression suffice to explain known plasticity phenomena in simple spatial tasks. This work suggests that differential responsiveness to task targets and distractors in primary sensory cortex for a simple spatial detection and discrimination task arise from nonselective

  7. Different neuroplasticity for task targets and distractors.

    Directory of Open Access Journals (Sweden)

    Elsie Y Spingath

    2011-01-01

    Full Text Available Adult learning-induced sensory cortex plasticity results in enhanced action potential rates in neurons that have the most relevant information for the task, or those that respond strongly to one sensory stimulus but weakly to its comparison stimulus. Current theories suggest this plasticity is caused when target stimulus evoked activity is enhanced by reward signals from neuromodulatory nuclei. Prior work has found evidence suggestive of nonselective enhancement of neural responses, and suppression of responses to task distractors, but the differences in these effects between detection and discrimination have not been directly tested. Using cortical implants, we defined physiological responses in macaque somatosensory cortex during serial, matched, detection and discrimination tasks. Nonselective increases in neural responsiveness were observed during detection learning. Suppression of responses to task distractors was observed during discrimination learning, and this suppression was specific to cortical locations that sampled responses to the task distractor before learning. Changes in receptive field size were measured as the area of skin that had a significant response to a constant magnitude stimulus, and these areal changes paralleled changes in responsiveness. From before detection learning until after discrimination learning, the enduring changes were selective suppression of cortical locations responsive to task distractors, and nonselective enhancement of responsiveness at cortical locations selective for target and control skin sites. A comparison of observations in prior studies with the observed plasticity effects suggests that the non-selective response enhancement and selective suppression suffice to explain known plasticity phenomena in simple spatial tasks. This work suggests that differential responsiveness to task targets and distractors in primary sensory cortex for a simple spatial detection and discrimination task arise from

  8. Quantum-state discrimination

    International Nuclear Information System (INIS)

    Roa, Luis; Retamal, Juan Carlos; Saavedra, Carlos

    2002-01-01

    A proposal for a physical implementation of a quantum-state discrimination protocol using an ion in a linear trap is studied, where two nonorthogonal quantum states are codified using two electronic states of the ion. In addition, a protocol is given for discriminating superpositions of nonorthogonal entangled states between ions inside widely separated optical cavities. The discrimination protocol is extended to the case of N linearly independent nonorthogonal quantum states lying in a space of 2N-1 dimensions

  9. Socially-Tolerable Discrimination

    OpenAIRE

    Amegashie, J. Atsu

    2008-01-01

    History is replete with overt discrimination on the basis of race, gender, age, citizenship, ethnicity, marital status, academic performance, health status, volume of market transactions, religion, sexual orientation, etc. However, these forms of discrimination are not equally tolerable. For example, discrimination based on immutable or prohibitively unalterable characteristics such as race, gender, or ethnicity is much less acceptable. Why? I develop a simple rent-seeking model of conflict w...

  10. INTERSECTIONAL DISCRIMINATION AGAINST CHILDREN

    DEFF Research Database (Denmark)

    Ravnbøl, Camilla Ida

    This paper adds a perspective to existing research on child protection by engaging in a debate on intersectional discrimination and its relationship to child protection. The paper has a twofold objective, (1) to further establish intersectionality as a concept to address discrimination against...... children, and (2) to illustrate the importance of addressing intersectionality within rights-based programmes of child protection....

  11. Discrimination and delusional ideation.

    Science.gov (United States)

    Janssen, I; Hanssen, M; Bak, M; Bijl, R V; de Graaf, R; Vollebergh, W; McKenzie, K; van Os, J

    2003-01-01

    In the UK and The Netherlands, people with high rates of psychosis are chronically exposed to discrimination. To test whether perceived discrimination is associated longitudinally with onset of psychosis. A 3-year prospective study of cohorts with no history of psychosis and differential rates of reported discrimination on the basis of age, gender, disability, appearance, skin colour or ethnicity and sexual orientation was conducted in the Dutch general population (n=4076). The main outcome was onset of psychotic symptoms (delusions and hallucinations). The rate of delusional ideation was 0.5% (n=19) in those who did not report discrimination, 0.9% (n=4) in those who reported discrimination in one domain, and 2.7% (n=3) in those who reported discrimination in more than one domain (exact P=0.027). This association remained after adjustment for possible confounders. No association was found between baseline discrimination and onset of hallucinatory experiences. Perceived discrimination may induce delusional ideation and thus contribute to the high observed rates of psychotic disorder in exposed minority populations.

  12. Discrimination and delusional ideation

    NARCIS (Netherlands)

    Janssen, I.C.M.; Hanssen, M.S.S.; Bak, M.L.F.J.; Bijl, R.V.; Graaf, R. de; Vollebergh, W.A.M.; McKenzie, K.; Os, J. van

    2003-01-01

    Background In the UK and The Netherlands, people with high rates of psychosis are chronically exposed to discrimination. Aims To test whether perceived discrimination is associated longitudinally with onset of psychosis. Method A 3-year prospective study of cohorts with no history of psychosis and

  13. Flash-Type Discrimination

    Science.gov (United States)

    Koshak, William J.

    2010-01-01

    This viewgraph presentation describes the significant progress made in the flash-type discrimination algorithm development. The contents include: 1) Highlights of Progress for GLM-R3 Flash-Type discrimination Algorithm Development; 2) Maximum Group Area (MGA) Data; 3) Retrieval Errors from Simulations; and 4) Preliminary Global-scale Retrieval.

  14. Discrimination against Black Students

    Science.gov (United States)

    Aloud, Ashwaq; Alsulayyim, Maryam

    2016-01-01

    Discrimination is a structured way of abusing people based on racial differences, hence barring them from accessing wealth, political participation and engagement in many spheres of human life. Racism and discrimination are inherently rooted in institutions in the society, the problem has spread across many social segments of the society including…

  15. Digital voltage discriminator

    International Nuclear Information System (INIS)

    Zhou Zhicheng

    1992-01-01

    A digital voltage discriminator is described, which is synthesized by digital comparator and ADC. The threshold is program controllable with high stability. Digital region of confusion is approximately equal to 1.5 LSB. This discriminator has a single channel analyzer function model with channel width of 1.5 LSB

  16. Introduction to integral discriminants

    International Nuclear Information System (INIS)

    Morozov, A.; Shakirov, Sh.

    2009-01-01

    The simplest partition function, associated with homogeneous symmetric forms S of degree r in n variables, is integral discriminant J n|r (S) = ∫e -S(x 1 ,...,x n ) dx 1 ...dx n . Actually, S-dependence remains the same if e -S in the integrand is substituted by arbitrary function f(S), i.e. integral discriminant is a characteristic of the form S itself, and not of the averaging procedure. The aim of the present paper is to calculate J n|r in a number of non-Gaussian cases. Using Ward identities - linear differential equations, satisfied by integral discriminants - we calculate J 2|3 ,J 2|4 ,J 2|5 and J 3|3 . In all these examples, integral discriminant appears to be a generalized hypergeometric function. It depends on several SL(n) invariants of S, with essential singularities controlled by the ordinary algebraic discriminant of S.

  17. Genetic pleiotropy explains associations between musical auditory discrimination and intelligence.

    Science.gov (United States)

    Mosing, Miriam A; Pedersen, Nancy L; Madison, Guy; Ullén, Fredrik

    2014-01-01

    Musical aptitude is commonly measured using tasks that involve discrimination of different types of musical auditory stimuli. Performance on such different discrimination tasks correlates positively with each other and with intelligence. However, no study to date has explored these associations using a genetically informative sample to estimate underlying genetic and environmental influences. In the present study, a large sample of Swedish twins (N = 10,500) was used to investigate the genetic architecture of the associations between intelligence and performance on three musical auditory discrimination tasks (rhythm, melody and pitch). Phenotypic correlations between the tasks ranged between 0.23 and 0.42 (Pearson r values). Genetic modelling showed that the covariation between the variables could be explained by shared genetic influences. Neither shared, nor non-shared environment had a significant effect on the associations. Good fit was obtained with a two-factor model where one underlying shared genetic factor explained all the covariation between the musical discrimination tasks and IQ, and a second genetic factor explained variance exclusively shared among the discrimination tasks. The results suggest that positive correlations among musical aptitudes result from both genes with broad effects on cognition, and genes with potentially more specific influences on auditory functions.

  18. Brain activations during bimodal dual tasks depend on the nature and combination of component tasks

    Directory of Open Access Journals (Sweden)

    Emma eSalo

    2015-02-01

    Full Text Available We used functional magnetic resonance imaging to investigate brain activations during nine different dual tasks in which the participants were required to simultaneously attend to concurrent streams of spoken syllables and written letters. They performed a phonological, spatial or simple (speaker-gender or font-shade discrimination task within each modality. We expected to find activations associated specifically with dual tasking especially in the frontal and parietal cortices. However, no brain areas showed systematic dual task enhancements common for all dual tasks. Further analysis revealed that dual tasks including component tasks that were according to Baddeley’s model modality atypical, that is, the auditory spatial task or the visual phonological task, were not associated with enhanced frontal activity. In contrast, for other dual tasks, activity specifically associated with dual tasking was found in the left or bilateral frontal cortices. Enhanced activation in parietal areas, however, appeared not to be specifically associated with dual tasking per se, but rather with intermodal attention switching. We also expected effects of dual tasking in left frontal supramodal phonological processing areas when both component tasks required phonological processing and in right parietal supramodal spatial processing areas when both tasks required spatial processing. However, no such effects were found during these dual tasks compared with their component tasks performed separately. Taken together, the current results indicate that activations during dual tasks depend in a complex manner on specific demands of component tasks.

  19. Braille character discrimination in blindfolded human subjects.

    Science.gov (United States)

    Kauffman, Thomas; Théoret, Hugo; Pascual-Leone, Alvaro

    2002-04-16

    Visual deprivation may lead to enhanced performance in other sensory modalities. Whether this is the case in the tactile modality is controversial and may depend upon specific training and experience. We compared the performance of sighted subjects on a Braille character discrimination task to that of normal individuals blindfolded for a period of five days. Some participants in each group (blindfolded and sighted) received intensive Braille training to offset the effects of experience. Blindfolded subjects performed better than sighted subjects in the Braille discrimination task, irrespective of tactile training. For the left index finger, which had not been used in the formal Braille classes, blindfolding had no effect on performance while subjects who underwent tactile training outperformed non-stimulated participants. These results suggest that visual deprivation speeds up Braille learning and may be associated with behaviorally relevant neuroplastic changes.

  20. Using postmeasurement information in state discrimination

    International Nuclear Information System (INIS)

    Gopal, Deepthi; Wehner, Stephanie

    2010-01-01

    We consider a special form of state discrimination in which after the measurement we are given additional information that may help us identify the state. This task plays a central role in the analysis of quantum cryptographic protocols in the noisy-storage model, where the identity of the state corresponds to a certain bit string, and the additional information is typically a choice of encoding that is initially unknown to the cheating party. We first provide simple optimality conditions for measurements for any such problem and show upper and lower bounds on the success probability. For a certain class of problems, we furthermore provide tight bounds on how useful postmeasurement information can be. In particular, we show that for this class finding the optimal measurement for the task of state discrimination with postmeasurement information does in fact reduce to solving a different problem of state discrimination without such information. However, we show that for the corresponding classical state discrimination problems with postmeasurement information such a reduction is impossible, by relating the success probability to the violation of Bell inequalities. This suggests the usefulness of postmeasurement information as another feature that distinguishes the classical from a quantum world.

  1. Set discrimination of quantum states

    International Nuclear Information System (INIS)

    Zhang Shengyu; Ying Mingsheng

    2002-01-01

    We introduce a notion of set discrimination, which is an interesting extension of quantum state discrimination. A state is secretly chosen from a number of quantum states, which are partitioned into some disjoint sets. A set discrimination is required to identify which set the given state belongs to. Several essential problems are addressed in this paper, including the condition of perfect set discrimination, unambiguous set discrimination, and in the latter case, the efficiency of the discrimination. This generalizes some important results on quantum state discrimination in the literature. A combination of state and set discrimination and the efficiency are also studied

  2. Neuronal discrimination capacity

    International Nuclear Information System (INIS)

    Deng Yingchun; Williams, Peter; Feng Jianfeng; Liu Feng

    2003-01-01

    We explore neuronal mechanisms of discriminating between masked signals. It is found that when the correlation between input signals is zero, the output signals are separable if and only if input signals are separable. With positively (negatively) correlated signals, the output signals are separable (mixed) even when input signals are mixed (separable). Exact values of discrimination capacity are obtained for two most interesting cases: the exactly balanced inhibitory and excitatory input case and the uncorrelated input case. Interestingly, the discrimination capacity obtained in these cases is independent of model parameters, input distribution and is universal. Our results also suggest a functional role of inhibitory inputs and correlated inputs or, more generally, the large variability of efferent spike trains observed in in vivo experiments: the larger the variability of efferent spike trains, the easier it is to discriminate between masked input signals

  3. Neuronal discrimination capacity

    Energy Technology Data Exchange (ETDEWEB)

    Deng Yingchun [Department of Mathematics, Hunan Normal University 410081, Changsha (China); COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Williams, Peter; Feng Jianfeng [COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Liu Feng [COGS, University of Sussex at Brighton, BN1 9QH (United Kingdom); Physics Department, Nanjing University (China)

    2003-12-19

    We explore neuronal mechanisms of discriminating between masked signals. It is found that when the correlation between input signals is zero, the output signals are separable if and only if input signals are separable. With positively (negatively) correlated signals, the output signals are separable (mixed) even when input signals are mixed (separable). Exact values of discrimination capacity are obtained for two most interesting cases: the exactly balanced inhibitory and excitatory input case and the uncorrelated input case. Interestingly, the discrimination capacity obtained in these cases is independent of model parameters, input distribution and is universal. Our results also suggest a functional role of inhibitory inputs and correlated inputs or, more generally, the large variability of efferent spike trains observed in in vivo experiments: the larger the variability of efferent spike trains, the easier it is to discriminate between masked input signals.

  4. Discrimination in Textbooks

    OpenAIRE

    大津, 尚志

    1996-01-01

    In this paper, I deal with the issues which concern discriminations in textbooks.In America, they have paid special attentions to these problems since 1960's. They made guidelines for textbooks to check various kinds of discriminative descriptions and tried to make textbooks to meet these standards. In this respects I would examine the present states about textbooks in America and would compare them to the Japanese ones. That would be useful, I believe, when we consider these issues in Japan.

  5. Quantum state discrimination and its applications

    International Nuclear Information System (INIS)

    Bae, Joonwoo; Kwek, Leong-Chuan

    2015-01-01

    Quantum state discrimination underlies various applications in quantum information processing tasks. It essentially describes the distinguishability of quantum systems in different states, and the general process of extracting classical information from quantum systems. It is also useful in quantum information applications, such as the characterization of mutual information in cryptographic protocols, or as a technique for deriving fundamental theorems on quantum foundations. It has deep connections to physical principles such as relativistic causality. Quantum state discrimination traces a long history of several decades, starting with the early attempts to formalize information processing of physical systems such as optical communication with photons. Nevertheless, in most cases, the problems of finding optimal strategies of quantum state discrimination remain unsolved, and related applications are valid in some limited cases only. The present review aims to provide an overview on quantum state discrimination, covering some recent progress, and addressing applications in some selected areas. This review serves to strengthen the link between results in quantum state discrimination and quantum information applications, by showing the ways in which the fundamental results are exploited in applications and vice versa. (topical review)

  6. Probabilistic numerical discrimination in mice.

    Science.gov (United States)

    Berkay, Dilara; Çavdaroğlu, Bilgehan; Balcı, Fuat

    2016-03-01

    Previous studies showed that both human and non-human animals can discriminate between different quantities (i.e., time intervals, numerosities) with a limited level of precision due to their endogenous/representational uncertainty. In addition, other studies have shown that subjects can modulate their temporal categorization responses adaptively by incorporating information gathered regarding probabilistic contingencies into their time-based decisions. Despite the psychophysical similarities between the interval timing and nonverbal counting functions, the sensitivity of count-based decisions to probabilistic information remains an unanswered question. In the current study, we investigated whether exogenous probabilistic information can be integrated into numerosity-based judgments by mice. In the task employed in this study, reward was presented either after few (i.e., 10) or many (i.e., 20) lever presses, the last of which had to be emitted on the lever associated with the corresponding trial type. In order to investigate the effect of probabilistic information on performance in this task, we manipulated the relative frequency of different trial types across different experimental conditions. We evaluated the behavioral performance of the animals under models that differed in terms of their assumptions regarding the cost of responding (e.g., logarithmically increasing vs. no response cost). Our results showed for the first time that mice could adaptively modulate their count-based decisions based on the experienced probabilistic contingencies in directions predicted by optimality.

  7. Learning discriminant face descriptor.

    Science.gov (United States)

    Lei, Zhen; Pietikäinen, Matti; Li, Stan Z

    2014-02-01

    Local feature descriptor is an important module for face recognition and those like Gabor and local binary patterns (LBP) have proven effective face descriptors. Traditionally, the form of such local descriptors is predefined in a handcrafted way. In this paper, we propose a method to learn a discriminant face descriptor (DFD) in a data-driven way. The idea is to learn the most discriminant local features that minimize the difference of the features between images of the same person and maximize that between images from different people. In particular, we propose to enhance the discriminative ability of face representation in three aspects. First, the discriminant image filters are learned. Second, the optimal neighborhood sampling strategy is soft determined. Third, the dominant patterns are statistically constructed. Discriminative learning is incorporated to extract effective and robust features. We further apply the proposed method to the heterogeneous (cross-modality) face recognition problem and learn DFD in a coupled way (coupled DFD or C-DFD) to reduce the gap between features of heterogeneous face images to improve the performance of this challenging problem. Extensive experiments on FERET, CAS-PEAL-R1, LFW, and HFB face databases validate the effectiveness of the proposed DFD learning on both homogeneous and heterogeneous face recognition problems. The DFD improves POEM and LQP by about 4.5 percent on LFW database and the C-DFD enhances the heterogeneous face recognition performance of LBP by over 25 percent.

  8. The pigeon's discrimination of visual entropy: a logarithmic function.

    Science.gov (United States)

    Young, Michael E; Wasserman, Edward A

    2002-11-01

    We taught 8 pigeons to discriminate 16-icon arrays that differed in their visual variability or "entropy" to see whether the relationship between entropy and discriminative behavior is linear (in which equivalent differences in entropy should produce equivalent changes in behavior) or logarithmic (in which higher entropy values should be less discriminable from one another than lower entropy values). Pigeons received a go/no-go task in which the lower entropy arrays were reinforced for one group and the higher entropy arrays were reinforced for a second group. The superior discrimination of the second group was predicted by a theoretical analysis in which excitatory and inhibitory stimulus generalization gradients fall along a logarithmic, but not a linear scale. Reanalysis of previously published data also yielded results consistent with a logarithmic relationship between entropy and discriminative behavior.

  9. Conditioning procedure and color discrimination in the honeybee Apis mellifera

    Science.gov (United States)

    Giurfa, Martin

    We studied the influence of the conditioning procedure on color discrimination by free-flying honeybees. We asked whether absolute and differential conditioning result in different discrimination capabilities for the same pairs of colored targets. In absolute conditioning, bees were rewarded on a single color; in differential conditioning, bees were rewarded on the same color but an alternative, non-rewarding, similar color was also visible. In both conditioning procedures, bees learned their respective task and could also discriminate the training stimulus from a novel stimulus that was perceptually different from the trained one. Discrimination between perceptually closer stimuli was possible after differential conditioning but not after absolute conditioning. Differences in attention inculcated by these training procedures may underlie the different discrimination performances of the bees.

  10. Disturbance by optimal discrimination

    Science.gov (United States)

    Kawakubo, Ryûitirô; Koike, Tatsuhiko

    2018-03-01

    We discuss the disturbance by measurements which unambiguously discriminate between given candidate states. We prove that such an optimal measurement necessarily changes distinguishable states indistinguishable when the inconclusive outcome is obtained. The result was previously shown by Chefles [Phys. Lett. A 239, 339 (1998), 10.1016/S0375-9601(98)00064-4] under restrictions on the class of quantum measurements and on the definition of optimality. Our theorems remove these restrictions and are also applicable to infinitely many candidate states. Combining with our previous results, one can obtain concrete mathematical conditions for the resulting states. The method may have a wide variety of applications in contexts other than state discrimination.

  11. The dark side of ambiguous discrimination: how state self-esteem moderates emotional and behavioural responses to ambiguous and unambiguous discrimination.

    Science.gov (United States)

    Cihangir, Sezgin; Barreto, Manuela; Ellemers, Naomi

    2010-03-01

    Two experiments examine how experimentally induced differences in state self-esteem moderate emotional and behavioural responses to ambiguous and unambiguous discrimination. Study 1 (N=108) showed that participants who were exposed to ambiguous discrimination report more negative self-directed emotions when they have low compared to high self-esteem. These differences did not emerge when participants were exposed to unambiguous discrimination. Study 2 (N=118) additionally revealed that self-esteem moderated the effect of ambiguous discrimination on self-concern, task performance, and self-stereotyping. Results show that ambiguous discrimination caused participants with low self-esteem to report more negative self-directed emotions, more self-concern, an inferior task performance, and more self-stereotyping, compared to participants in the high self-esteem condition. Emotional and behavioural responses to unambiguous discrimination did not depend on the induced level of self-esteem in these studies.

  12. Challenges in discriminating profanity from hate speech

    Science.gov (United States)

    Malmasi, Shervin; Zampieri, Marcos

    2018-03-01

    In this study, we approach the problem of distinguishing general profanity from hate speech in social media, something which has not been widely considered. Using a new dataset annotated specifically for this task, we employ supervised classification along with a set of features that includes ?-grams, skip-grams and clustering-based word representations. We apply approaches based on single classifiers as well as more advanced ensemble classifiers and stacked generalisation, achieving the best result of ? accuracy for this 3-class classification task. Analysis of the results reveals that discriminating hate speech and profanity is not a simple task, which may require features that capture a deeper understanding of the text not always possible with surface ?-grams. The variability of gold labels in the annotated data, due to differences in the subjective adjudications of the annotators, is also an issue. Other directions for future work are discussed.

  13. Auditory phase and frequency discrimination: a comparison of nine procedures.

    Science.gov (United States)

    Creelman, C D; Macmillan, N A

    1979-02-01

    Two auditory discrimination tasks were thoroughly investigated: discrimination of frequency differences from a sinusoidal signal of 200 Hz and discrimination of differences in relative phase of mixed sinusoids of 200 Hz and 400 Hz. For each task psychometric functions were constructed for three observers, using nine different psychophysical measurement procedures. These procedures included yes-no, two-interval forced-choice, and various fixed- and variable-standard designs that investigators have used in recent years. The data showed wide ranges of apparent sensitivity. For frequency discrimination, models derived from signal detection theory for each psychophysical procedure seem to account for the performance differences. For phase discrimination the models do not account for the data. We conclude that for some discriminative continua the assumptions of signal detection theory are appropriate, and underlying sensitivity may be derived from raw data by appropriate transformations. For other continua the models of signal detection theory are probably inappropriate; we speculate that phase might be discriminable only on the basis of comparison or change and suggest some tests of our hypothesis.

  14. Intonation processing in congenital amusia: discrimination, identification and imitation.

    Science.gov (United States)

    Liu, Fang; Patel, Aniruddh D; Fourcin, Adrian; Stewart, Lauren

    2010-06-01

    This study investigated whether congenital amusia, a neuro-developmental disorder of musical perception, also has implications for speech intonation processing. In total, 16 British amusics and 16 matched controls completed five intonation perception tasks and two pitch threshold tasks. Compared with controls, amusics showed impaired performance on discrimination, identification and imitation of statements and questions that were characterized primarily by pitch direction differences in the final word. This intonation-processing deficit in amusia was largely associated with a psychophysical pitch direction discrimination deficit. These findings suggest that amusia impacts upon one's language abilities in subtle ways, and support previous evidence that pitch processing in language and music involves shared mechanisms.

  15. Discrimination in Employment

    Science.gov (United States)

    Abzug, Bella

    1975-01-01

    This testimony, before a public hearing of the New York City Commission on Human Rights in May 1974, expressly focuses on discrimination in employment, asserting that this has had the most direct effect on minorities and women in the country; while legal protections have grown stronger, they have not been used effectively. (Author/JM)

  16. Discrimination? - Exhibition of posters

    OpenAIRE

    Jakimovska, Jana

    2017-01-01

    Participation in the exhibition with the students form the Art Academy. The exhibition consisted of 15 posters tackling the subjects of hate speech and discrimination. The exhibition happened thanks to the invitation of the Faculty of Law at UGD, and it was a part of a larger event of launching books on the aforementioned subjects.

  17. Education and Gender Discrimination

    Science.gov (United States)

    Sumi, V. S.

    2012-01-01

    This paper discusses the status of women education in present education system and some measures to overcome the lags existing. Discrimination against girls and women in the developing world is a devastating reality. It results in millions of individual tragedies, which add up to lost potential for entire countries. Gender bias in education is an…

  18. Airborne particulate discriminator

    Science.gov (United States)

    Creek, Kathryn Louise [San Diego, CA; Castro, Alonso [Santa Fe, NM; Gray, Perry Clayton [Los Alamos, NM

    2009-08-11

    A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

  19. Individual differences in attention strategies during detection, fine discrimination, and coarse discrimination

    Science.gov (United States)

    Hecker, Elizabeth A.; Serences, John T.; Srinivasan, Ramesh

    2013-01-01

    Interacting with the environment requires the ability to flexibly direct attention to relevant features. We examined the degree to which individuals attend to visual features within and across Detection, Fine Discrimination, and Coarse Discrimination tasks. Electroencephalographic (EEG) responses were measured to an unattended peripheral flickering (4 or 6 Hz) grating while individuals (n = 33) attended to orientations that were offset by 0°, 10°, 20°, 30°, 40°, and 90° from the orientation of the unattended flicker. These unattended responses may be sensitive to attentional gain at the attended spatial location, since attention to features enhances early visual responses throughout the visual field. We found no significant differences in tuning curves across the three tasks in part due to individual differences in strategies. We sought to characterize individual attention strategies using hierarchical Bayesian modeling, which grouped individuals into families of curves that reflect attention to the physical target orientation (“on-channel”) or away from the target orientation (“off-channel”) or a uniform distribution of attention. The different curves were related to behavioral performance; individuals with “on-channel” curves had lower thresholds than individuals with uniform curves. Individuals with “off-channel” curves during Fine Discrimination additionally had lower thresholds than those assigned to uniform curves, highlighting the perceptual benefits of attending away from the physical target orientation during fine discriminations. Finally, we showed that a subset of individuals with optimal curves (“on-channel”) during Detection also demonstrated optimal curves (“off-channel”) during Fine Discrimination, indicating that a subset of individuals can modulate tuning optimally for detection and discrimination. PMID:23678013

  20. Speed and accuracy of visual image discrimination by rats

    Directory of Open Access Journals (Sweden)

    Pamela eReinagel

    2013-12-01

    Full Text Available The trade-off between speed and accuracy of sensory discrimination has most often been studying using sensory stimuli that evolve over time, such as random dot motion discrimination tasks. We previously reported that when rats perform motion discrimination, correct trials have longer reaction times than errors, accuracy increases with reaction time, and reaction time increases with stimulus ambiguity. In such experiments, new sensory information is continually presented, which could partly explain interactions between reaction time and accuracy. The present study shows that a changing physical stimulus is not essential to those findings. Freely behaving rats were trained to discriminate between two static visual images in a self-paced, 2-alternative forced-choice (2AFC reaction time task. Each trial was initiated by the rat, and the two images were presented simultaneously and persisted until the rat responded, with no time limit. Reaction times were longer in correct trials than in error trials, and accuracy increased with reaction time, comparable to results previously reported for rats performing motion discrimination. In the motion task, coherence has been used to vary discrimination difficulty. Here morphs between the previously learned images were used to parametrically vary the image similarity. In randomly interleaved trials, rats took more time on average to respond in trials in which they had to discriminate more similar stimuli. For both the motion and image tasks, the dependence of reaction time on ambiguity is weak, as if rats prioritized speed over accuracy. Therefore we asked whether rats can change the priority of speed and accuracy adaptively in response to a change in reward contingencies. For two rats, the penalty delay was increased from two to six seconds. When the penalty was longer, reaction times increased, and accuracy improved. This demonstrates that rats can flexibly adjust their behavioral strategy in response to the

  1. Examining Workplace Discrimination in a Discrimination-Free Environment

    OpenAIRE

    Braxton, Shawn Lamont

    2010-01-01

    Examining Workplace Discrimination in a Discrimination-Free Environment Shawn L. Braxton Abstract The purpose of this study is to explore how racial and gender discrimination is reproduced in concrete workplace settings even when anti-discrimination policies are present, and to understand the various reactions utilized by those who commonly experience it. I have selected a particular medical center, henceforth referred to by a pseudonym, â The Bliley Medical Centerâ as my case ...

  2. Learning for pitch and melody discrimination in congenital amusia.

    Science.gov (United States)

    Whiteford, Kelly L; Oxenham, Andrew J

    2018-03-23

    Congenital amusia is currently thought to be a life-long neurogenetic disorder in music perception, impervious to training in pitch or melody discrimination. This study provides an explicit test of whether amusic deficits can be reduced with training. Twenty amusics and 20 matched controls participated in four sessions of psychophysical training involving either pure-tone (500 Hz) pitch discrimination or a control task of lateralization (interaural level differences for bandpass white noise). Pure-tone pitch discrimination at low, medium, and high frequencies (500, 2000, and 8000 Hz) was measured before and after training (pretest and posttest) to determine the specificity of learning. Melody discrimination was also assessed before and after training using the full Montreal Battery of Evaluation of Amusia, the most widely used standardized test to diagnose amusia. Amusics performed more poorly than controls in pitch but not localization discrimination, but both groups improved with practice on the trained stimuli. Learning was broad, occurring across all three frequencies and melody discrimination for all groups, including those who trained on the non-pitch control task. Following training, 11 of 20 amusics no longer met the global diagnostic criteria for amusia. A separate group of untrained controls (n = 20), who also completed melody discrimination and pretest, improved by an equal amount as trained controls on all measures, suggesting that the bulk of learning for the control group occurred very rapidly from the pretest. Thirty-one trained participants (13 amusics) returned one year later to assess long-term maintenance of pitch and melody discrimination. On average, there was no change in performance between posttest and one-year follow-up, demonstrating that improvements on pitch- and melody-related tasks in amusics and controls can be maintained. The findings indicate that amusia is not always a life-long deficit when using the current standard

  3. Temporal Resolution and Active Auditory Discrimination Skill in Vocal Musicians

    Directory of Open Access Journals (Sweden)

    Kumar, Prawin

    2015-12-01

    Full Text Available Introduction Enhanced auditory perception in musicians is likely to result from auditory perceptual learning during several years of training and practice. Many studies have focused on biological processing of auditory stimuli among musicians. However, there is a lack of literature on temporal resolution and active auditory discrimination skills in vocal musicians. Objective The aim of the present study is to assess temporal resolution and active auditory discrimination skill in vocal musicians. Method The study participants included 15 vocal musicians with a minimum professional experience of 5 years of music exposure, within the age range of 20 to 30 years old, as the experimental group, while 15 age-matched non-musicians served as the control group. We used duration discrimination using pure-tones, pulse-train duration discrimination, and gap detection threshold tasks to assess temporal processing skills in both groups. Similarly, we assessed active auditory discrimination skill in both groups using Differential Limen of Frequency (DLF. All tasks were done using MATLab software installed in a personal computer at 40dBSL with maximum likelihood procedure. The collected data were analyzed using SPSS (version 17.0. Result Descriptive statistics showed better threshold for vocal musicians compared with non-musicians for all tasks. Further, independent t-test showed that vocal musicians performed significantly better compared with non-musicians on duration discrimination using pure tone, pulse train duration discrimination, gap detection threshold, and differential limen of frequency. Conclusion The present study showed enhanced temporal resolution ability and better (lower active discrimination threshold in vocal musicians in comparison to non-musicians.

  4. A new semantic vigilance task: vigilance decrement, workload, and sensitivity to dual-task costs.

    Science.gov (United States)

    Epling, Samantha L; Russell, Paul N; Helton, William S

    2016-01-01

    Cognitive resource theory is a common explanation for both the performance decline in vigilance tasks, known as the vigilance decrement, and the limited ability to perform multiple tasks simultaneously. The limited supply of cognitive resources may be utilized faster than they are replenished resulting in a performance decrement, or may need to be allocated among multiple tasks with some performance cost. Researchers have proposed both domain-specific, for example spatial versus verbal processing resources, and domain general cognitive resources. One challenge in testing the domain specificity of cognitive resources in vigilance is the current lack of difficult semantic vigilance tasks which reliably produce a decrement. In the present research, we investigated whether the vigilance decrement was found in a new abbreviated semantic discrimination vigilance task, and whether there was a performance decrement in said vigilance task when paired with a word recall task, as opposed to performed individually. As hypothesized, a vigilance decrement in the semantic vigilance task was found in both the single-task and dual-task conditions, along with reduced vigilance performance in the dual-task condition and reduced word recall in the dual-task condition. This is consistent with cognitive resource theory. The abbreviated semantic vigilance task will be a useful tool for researchers interested in determining the specificity of cognitive resources utilized in vigilance tasks.

  5. Effects of harmonic roving on pitch discrimination

    DEFF Research Database (Denmark)

    Santurette, Sébastien; de Kérangal, Mathilde le Gal; Joshi, Suyash Narendra

    2015-01-01

    Performance in pitch discrimination tasks is limited by variability intrinsic to listeners which may arise from peripheral auditory coding limitations or more central noise sources. The present study aimed at quantifying such “internal noise” by estimating the amount of harmonic roving required...... to impair pitch discrimination performance. Fundamental-frequency difference limens (F0DLs) were obtained in normal-hearing listeners with and without musical training for complex tones filtered between 1.5 and 3.5 kHz with F0s of 300 Hz (resolved harmonics) and 75 Hz (unresolved harmonics). The harmonicity...... that could be used to quantify the internal noise and provide strong constraints for physiologically inspired models of pitch perception....

  6. A quantitative method for determining spatial discriminative capacity

    Directory of Open Access Journals (Sweden)

    Dennis Robert G

    2008-03-01

    Full Text Available Abstract Background The traditional two-point discrimination (TPD test, a widely used tactile spatial acuity measure, has been criticized as being imprecise because it is based on subjective criteria and involves a number of non-spatial cues. The results of a recent study showed that as two stimuli were delivered simultaneously, vibrotactile amplitude discrimination became worse when the two stimuli were positioned relatively close together and was significantly degraded when the probes were within a subject's two-point limen. The impairment of amplitude discrimination with decreasing inter-probe distance suggested that the metric of amplitude discrimination could possibly provide a means of objective and quantitative measurement of spatial discrimination capacity. Methods A two alternative forced-choice (2AFC tracking procedure was used to assess a subject's ability to discriminate the amplitude difference between two stimuli positioned at near-adjacent skin sites. Two 25 Hz flutter stimuli, identical except for a constant difference in amplitude, were delivered simultaneously to the hand dorsum. The stimuli were initially spaced 30 mm apart, and the inter-stimulus distance was modified on a trial-by-trial basis based on the subject's performance of discriminating the stimulus with higher intensity. The experiment was repeated via sequential, rather than simultaneous, delivery of the same vibrotactile stimuli. Results Results obtained from this study showed that the performance of the amplitude discrimination task was significantly degraded when the stimuli were delivered simultaneously and were near a subject's two-point limen. In contrast, subjects were able to correctly discriminate between the amplitudes of the two stimuli when they were sequentially delivered at all inter-probe distances (including those within the two-point limen, and improved when an adapting stimulus was delivered prior to simultaneously delivered stimuli. Conclusion

  7. Spatial Frequency Discrimination: Effects of Age, Reward, and Practice.

    Directory of Open Access Journals (Sweden)

    Carlijn van den Boomen

    Full Text Available Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of higher spatial frequency discrimination. Secondly, it developed and validated a novel design that could be applied to improve atypically developed vision. Specifically, this study examined the effect of age and reward on task performance, practice effects, and motivation (i.e., number of trials completed in a higher spatial frequency (reference frequency: 6 cycles per degree discrimination task. We measured discrimination thresholds in children aged between 7 to 12 years and adults (N = 135. Reward was manipulated by presenting either positive reinforcement or punishment. Results showed a decrease in discrimination thresholds with age, thus revealing that higher spatial frequency discrimination continues to develop after 12 years of age. This development continues longer than previously shown for discrimination of lower spatial frequencies. Moreover, thresholds decreased during the run, indicating that discrimination abilities improved. Reward did not affect performance or improvement. However, in an additional group of 5-6 year-olds (N = 28 punishments resulted in the completion of fewer trials compared to reinforcements. In both reward conditions children aged 5-6 years completed only a fourth or half of the run (64 to 128 out of 254 trials and were not motivated to continue. The design thus needs further adaptation before it can be applied to this age group. Children aged 7-12 years and adults completed the run, suggesting that the design is successful and motivating for children aged 7-12 years. This study thus presents developmental differences in higher spatial frequency discrimination thresholds. Furthermore, it presents a design that can be

  8. Spatial Frequency Discrimination: Effects of Age, Reward, and Practice.

    Science.gov (United States)

    van den Boomen, Carlijn; Peters, Judith Carolien

    2017-01-01

    Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of higher spatial frequency discrimination. Secondly, it developed and validated a novel design that could be applied to improve atypically developed vision. Specifically, this study examined the effect of age and reward on task performance, practice effects, and motivation (i.e., number of trials completed) in a higher spatial frequency (reference frequency: 6 cycles per degree) discrimination task. We measured discrimination thresholds in children aged between 7 to 12 years and adults (N = 135). Reward was manipulated by presenting either positive reinforcement or punishment. Results showed a decrease in discrimination thresholds with age, thus revealing that higher spatial frequency discrimination continues to develop after 12 years of age. This development continues longer than previously shown for discrimination of lower spatial frequencies. Moreover, thresholds decreased during the run, indicating that discrimination abilities improved. Reward did not affect performance or improvement. However, in an additional group of 5-6 year-olds (N = 28) punishments resulted in the completion of fewer trials compared to reinforcements. In both reward conditions children aged 5-6 years completed only a fourth or half of the run (64 to 128 out of 254 trials) and were not motivated to continue. The design thus needs further adaptation before it can be applied to this age group. Children aged 7-12 years and adults completed the run, suggesting that the design is successful and motivating for children aged 7-12 years. This study thus presents developmental differences in higher spatial frequency discrimination thresholds. Furthermore, it presents a design that can be used in future

  9. Fast timing discriminator

    International Nuclear Information System (INIS)

    Lo, C.C.

    1977-01-01

    The processing of pulses with very fast risetimes for timing purposes involves many problems because of the large equivalent bandwidths involved. For pulses with risetimes in the 150 ps range (and full widths at half maximum (FWHM) of 400 ps) bandwidths in excess of 1GHz are required. Furthermore, these very narrow pulses with current amplitudes as small as 1 mA carry very small charges ( -12 coulomb), therefore, requiring very sensitive trigger circuits. The difficulty increases when timing characteristics in the picosecond range are sought especially when a wide input signal amplitude range causes a time-walk problem. The fast timing discriminator described has a time-walk of approximately +-75 ps over the input signal range from 80 mV to 3V. A schematic of the discriminator is included, and operation and performance are discussed

  10. Gender wage discrimination

    OpenAIRE

    Hirsch, Boris

    2016-01-01

    There are pronounced and persistent wage differences between men and women in all parts of the world. A significant element of these wage disparities can be attributed to differences in worker and workplace characteristics, which are likely to mirror differences in worker productivity. However, a large part of these differences remains unexplained, and it is common to attribute them to discrimination by the employer that is rooted in prejudice against female workers. Yet recent empirical evid...

  11. Diversity, discrimination, and performance

    OpenAIRE

    Leonard, Jonathan S.; Levine, David I.

    2003-01-01

    Employee diversity may affect business performance both as a result of customer discrimination and as a result of how members of a group work with each other in teams. We test for both channels with data from more than 800 retail stores employing over 70,000 individuals matched to Census data on the demographics of the community. We find little payoff to matching employee demographics to those of potential customers except when the customers do not speak English. Although age diversity doe...

  12. [Comment on] Statistical discrimination

    Science.gov (United States)

    Chinn, Douglas

    In the December 8, 1981, issue of Eos, a news item reported the conclusion of a National Research Council study that sexual discrimination against women with Ph.D.'s exists in the field of geophysics. Basically, the item reported that even when allowances are made for motherhood the percentage of female Ph.D.'s holding high university and corporate positions is significantly lower than the percentage of male Ph.D.'s holding the same types of positions. The sexual discrimination conclusion, based only on these statistics, assumes that there are no basic psychological differences between men and women that might cause different populations in the employment group studied. Therefore, the reasoning goes, after taking into account possible effects from differences related to anatomy, such as women stopping their careers in order to bear and raise children, the statistical distributions of positions held by male and female Ph.D.'s ought to be very similar to one another. Any significant differences between the distributions must be caused primarily by sexual discrimination.

  13. Workplace discrimination and cancer.

    Science.gov (United States)

    McKenna, Maureen A; Fabian, Ellen; Hurley, Jessica E; McMahon, Brian T; West, Steven L

    2007-01-01

    Data from the Equal Employment Opportunity Commission (EEOC) Integrated Mission System database were analyzed with specific reference to allegations of workplace discrimination filed by individuals with cancer under ADA Title One. These 6,832 allegations, filed between July 27, 1992 and September 30, 2003, were compared to 167,798 allegations from a general disability population on the following dimensions: type of workplace discrimination; demographic characteristics of the charging parties (CPs); the industry designation, location, and size of employers; and the outcome or resolution of EEOC investigations. Results showed allegations derived from CPs with cancer were more likely than those in the general disability population to include issues involving discharge, terms and conditions of employment, lay-off, wages, and demotion. Compared to the general disability group, CPs with cancer were more likely to be female, older, and White. Allegations derived from CPs with cancer were also more likely to be filed against smaller employers (15-100 workers) or those in service industries. Finally, the resolution of allegations by CPs with cancer were more likely to be meritorious than those filed from the general disability population; that is, actual discrimination is more likely to have occurred.

  14. Price Discrimination: A Classroom Experiment

    Science.gov (United States)

    Aguiló, Paula; Sard, Maria; Tugores, Maria

    2016-01-01

    In this article, the authors describe a classroom experiment aimed at familiarizing students with different types of price discrimination (first-, second-, and third-degree price discrimination). During the experiment, the students were asked to decide what tariffs to set as monopolists for each of the price discrimination scenarios under…

  15. Transgender Discrimination and the Law

    Science.gov (United States)

    Trotter, Richard

    2010-01-01

    An emerging area of law is developing regarding sex/gender identity discrimination, also referred to as transgender discrimination, as distinguished from discrimination based on sexual orientation. A transgendered individual is defined as "a person who has a gender-identity disorder which is a persistent discomfort about one?s assigned sex or…

  16. Russian blues reveal effects of language on color discrimination.

    Science.gov (United States)

    Winawer, Jonathan; Witthoft, Nathan; Frank, Michael C; Wu, Lisa; Wade, Alex R; Boroditsky, Lera

    2007-05-08

    English and Russian color terms divide the color spectrum differently. Unlike English, Russian makes an obligatory distinction between lighter blues ("goluboy") and darker blues ("siniy"). We investigated whether this linguistic difference leads to differences in color discrimination. We tested English and Russian speakers in a speeded color discrimination task using blue stimuli that spanned the siniy/goluboy border. We found that Russian speakers were faster to discriminate two colors when they fell into different linguistic categories in Russian (one siniy and the other goluboy) than when they were from the same linguistic category (both siniy or both goluboy). Moreover, this category advantage was eliminated by a verbal, but not a spatial, dual task. These effects were stronger for difficult discriminations (i.e., when the colors were perceptually close) than for easy discriminations (i.e., when the colors were further apart). English speakers tested on the identical stimuli did not show a category advantage in any of the conditions. These results demonstrate that (i) categories in language affect performance on simple perceptual color tasks and (ii) the effect of language is online (and can be disrupted by verbal interference).

  17. Melody Track Selection Using Discriminative Language Model

    Science.gov (United States)

    Wu, Xiao; Li, Ming; Suo, Hongbin; Yan, Yonghong

    In this letter we focus on the task of selecting the melody track from a polyphonic MIDI file. Based on the intuition that music and language are similar in many aspects, we solve the selection problem by introducing an n-gram language model to learn the melody co-occurrence patterns in a statistical manner and determine the melodic degree of a given MIDI track. Furthermore, we propose the idea of using background model and posterior probability criteria to make modeling more discriminative. In the evaluation, the achieved 81.6% correct rate indicates the feasibility of our approach.

  18. Aging effects on ERP correlates of emotional word discrimination

    NARCIS (Netherlands)

    Molnar, M.; Toth, B.; Boha, R.; Gaal, Z.A.; Kardos, Z.; File, B.; Stam, C.J.

    2013-01-01

    ObjectiveTo explore age-, and valence specific ERP-characteristics of word-discrimination processes. Methods: A group of young (mean age: 21.26. yrs) and elderly (mean age: 65.73. yrs) individuals participated. The task was to respond to a word (target) with valence (neutral, negative, positive) and

  19. Reduced Chromatic Discrimination in Children with Autism Spectrum Disorders

    Science.gov (United States)

    Franklin, Anna; Sowden, Paul; Notman, Leslie; Gonzalez-Dixon, Melissa; West, Dorotea; Alexander, Iona; Loveday, Stephen; White, Alex

    2010-01-01

    Atypical perception in Autism Spectrum Disorders (ASD) is well documented (Dakin & Frith, 2005). However, relatively little is known about colour perception in ASD. Less accurate performance on certain colour tasks has led some to argue that chromatic discrimination is reduced in ASD relative to typical development (Franklin, Sowden, Burley,…

  20. Low power constant fraction discriminator

    International Nuclear Information System (INIS)

    Krishnan, Shanti; Raut, S.M.; Mukhopadhyay, P.K.

    2001-01-01

    This paper describes the design of a low power ultrafast constant fraction discriminator, which significantly reduces the power consumption. A conventional fast discriminator consumes about 1250 MW of power whereas this low power version consumes about 440 MW. In a multi detector system, where the number of discriminators is very large, reduction of power is of utmost importance. This low power discriminator is being designed for GRACE (Gamma Ray Atmospheric Cerenkov Experiments) telescope where 1000 channels of discriminators are required. A novel method of decreasing power consumption has been described. (author)

  1. Simultaneous and Sequential Feature Negative Discriminations: Elemental Learning and Occasion Setting in Human Pavlovian Conditioning

    Science.gov (United States)

    Baeyens, Frank; Vervliet, Bram; Vansteenwegen, Debora; Beckers, Tom; Hermans, Dirk; Eelen, Paul

    2004-01-01

    Using a conditioned suppression task, we investigated simultaneous (XA-/A+) vs. sequential (X [right arrow] A-/A+) Feature Negative (FN) discrimination learning in humans. We expected the simultaneous discrimination to result in X (or alternatively the XA configuration) becoming an inhibitor acting directly on the US, and the sequential…

  2. When Less Is More: Poor Discrimination but Good Colour Memory in Autism

    Science.gov (United States)

    Heaton, Pamela; Ludlow, Amanda; Roberson, Debi

    2008-01-01

    In two experiments children with autism and two groups of controls matched for either chronological or non-verbal mental age were tested on tasks of colour discrimination and memory. The results from experiment 1 showed significantly poorer colour discrimination in children with autism in comparison to typically developing chronological age…

  3. Pitch Discrimination Learning: Specificity for Pitch and Harmonic Resolvability, and Electrophysiological Correlates

    OpenAIRE

    Carcagno, Samuele; Plack, Christopher J.

    2011-01-01

    Multiple-hour training on a pitch discrimination task dramatically decreases the threshold for detecting a pitch difference between two harmonic complexes. Here, we investigated the specificity of this perceptual learning with respect to the pitch and the resolvability of the trained harmonic complex, as well as its cortical electrophysiological correlates. We trained 24 participants for 12 h on a pitch discrimination task using one of four different harmonic complexes. The complexes differed...

  4. Dorso-Lateral Frontal Cortex of the Ferret Encodes Perceptual Difficulty during Visual Discrimination

    OpenAIRE

    Zhe Charles Zhou; Chunxiu Yu; Kristin K. Sellers; Flavio Fröhlich

    2016-01-01

    Visual discrimination requires sensory processing followed by a perceptual decision. Despite a growing understanding of visual areas in this behavior, it is unclear what role top-down signals from prefrontal cortex play, in particular as a function of perceptual difficulty. To address this gap, we investigated how neurons in dorso-lateral frontal cortex (dl-FC) of freely-moving ferrets encode task variables in a two-alternative forced choice visual discrimination task with high- and low-contr...

  5. Pigeons can discriminate "good" and "bad" paintings by children.

    Science.gov (United States)

    Watanabe, Shigeru

    2010-01-01

    Humans have the unique ability to create art, but non-human animals may be able to discriminate "good" art from "bad" art. In this study, I investigated whether pigeons could be trained to discriminate between paintings that had been judged by humans as either "bad" or "good". To do this, adult human observers first classified several children's paintings as either "good" (beautiful) or "bad" (ugly). Using operant conditioning procedures, pigeons were then reinforced for pecking at "good" paintings. After the pigeons learned the discrimination task, they were presented with novel pictures of both "good" and "bad" children's paintings to test whether they had successfully learned to discriminate between these two stimulus categories. The results showed that pigeons could discriminate novel "good" and "bad" paintings. Then, to determine which cues the subjects used for the discrimination, I conducted tests of the stimuli when the paintings were of reduced size or grayscale. In addition, I tested their ability to discriminate when the painting stimuli were mosaic and partial occluded. The pigeons maintained discrimination performance when the paintings were reduced in size. However, discrimination performance decreased when stimuli were presented as grayscale images or when a mosaic effect was applied to the original stimuli in order to disrupt spatial frequency. Thus, the pigeons used both color and pattern cues for their discrimination. The partial occlusion did not disrupt the discriminative behavior suggesting that the pigeons did not attend to particular parts, namely upper, lower, left or right half, of the paintings. These results suggest that the pigeons are capable of learning the concept of a stimulus class that humans name "good" pictures. The second experiment showed that pigeons learned to discriminate watercolor paintings from pastel paintings. The subjects showed generalization to novel paintings. Then, as the first experiment, size reduction test

  6. Improved discrimination of visual stimuli following repetitive transcranial magnetic stimulation.

    Directory of Open Access Journals (Sweden)

    Michael L Waterston

    Full Text Available BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS at certain frequencies increases thresholds for motor-evoked potentials and phosphenes following stimulation of cortex. Consequently rTMS is often assumed to introduce a "virtual lesion" in stimulated brain regions, with correspondingly diminished behavioral performance. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the effects of rTMS to visual cortex on subjects' ability to perform visual psychophysical tasks. Contrary to expectations of a visual deficit, we find that rTMS often improves the discrimination of visual features. For coarse orientation tasks, discrimination of a static stimulus improved consistently following theta-burst stimulation of the occipital lobe. Using a reaction-time task, we found that these improvements occurred throughout the visual field and lasted beyond one hour post-rTMS. Low-frequency (1 Hz stimulation yielded similar improvements. In contrast, we did not find consistent effects of rTMS on performance in a fine orientation discrimination task. CONCLUSIONS/SIGNIFICANCE: Overall our results suggest that rTMS generally improves or has no effect on visual acuity, with the nature of the effect depending on the type of stimulation and the task. We interpret our results in the context of an ideal-observer model of visual perception.

  7. Haptic Discrimination of Distance

    Science.gov (United States)

    van Beek, Femke E.; Bergmann Tiest, Wouter M.; Kappers, Astrid M. L.

    2014-01-01

    While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive) and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices. PMID:25116638

  8. Haptic discrimination of distance.

    Directory of Open Access Journals (Sweden)

    Femke E van Beek

    Full Text Available While quite some research has focussed on the accuracy of haptic perception of distance, information on the precision of haptic perception of distance is still scarce, particularly regarding distances perceived by making arm movements. In this study, eight conditions were measured to answer four main questions, which are: what is the influence of reference distance, movement axis, perceptual mode (active or passive and stimulus type on the precision of this kind of distance perception? A discrimination experiment was performed with twelve participants. The participants were presented with two distances, using either a haptic device or a real stimulus. Participants compared the distances by moving their hand from a start to an end position. They were then asked to judge which of the distances was the longer, from which the discrimination threshold was determined for each participant and condition. The precision was influenced by reference distance. No effect of movement axis was found. The precision was higher for active than for passive movements and it was a bit lower for real stimuli than for rendered stimuli, but it was not affected by adding cutaneous information. Overall, the Weber fraction for the active perception of a distance of 25 or 35 cm was about 11% for all cardinal axes. The recorded position data suggest that participants, in order to be able to judge which distance was the longer, tried to produce similar speed profiles in both movements. This knowledge could be useful in the design of haptic devices.

  9. Discriminative Relational Topic Models.

    Science.gov (United States)

    Chen, Ning; Zhu, Jun; Xia, Fei; Zhang, Bo

    2015-05-01

    Relational topic models (RTMs) provide a probabilistic generative process to describe both the link structure and document contents for document networks, and they have shown promise on predicting network structures and discovering latent topic representations. However, existing RTMs have limitations in both the restricted model expressiveness and incapability of dealing with imbalanced network data. To expand the scope and improve the inference accuracy of RTMs, this paper presents three extensions: 1) unlike the common link likelihood with a diagonal weight matrix that allows the-same-topic interactions only, we generalize it to use a full weight matrix that captures all pairwise topic interactions and is applicable to asymmetric networks; 2) instead of doing standard Bayesian inference, we perform regularized Bayesian inference (RegBayes) with a regularization parameter to deal with the imbalanced link structure issue in real networks and improve the discriminative ability of learned latent representations; and 3) instead of doing variational approximation with strict mean-field assumptions, we present collapsed Gibbs sampling algorithms for the generalized relational topic models by exploring data augmentation without making restricting assumptions. Under the generic RegBayes framework, we carefully investigate two popular discriminative loss functions, namely, the logistic log-loss and the max-margin hinge loss. Experimental results on several real network datasets demonstrate the significance of these extensions on improving prediction performance.

  10. Neural correlates of face gender discrimination learning.

    Science.gov (United States)

    Su, Junzhu; Tan, Qingleng; Fang, Fang

    2013-04-01

    Using combined psychophysics and event-related potentials (ERPs), we investigated the effect of perceptual learning on face gender discrimination and probe the neural correlates of the learning effect. Human subjects were trained to perform a gender discrimination task with male or female faces. Before and after training, they were tested with the trained faces and other faces with the same and opposite genders. ERPs responding to these faces were recorded. Psychophysical results showed that training significantly improved subjects' discrimination performance and the improvement was specific to the trained gender, as well as to the trained identities. The training effect indicates that learning occurs at two levels-the category level (gender) and the exemplar level (identity). ERP analyses showed that the gender and identity learning was associated with the N170 latency reduction at the left occipital-temporal area and the N170 amplitude reduction at the right occipital-temporal area, respectively. These findings provide evidence for the facilitation model and the sharpening model on neuronal plasticity from visual experience, suggesting a faster processing speed and a sparser representation of face induced by perceptual learning.

  11. Abstract numerical discrimination learning in rats.

    Science.gov (United States)

    Taniuchi, Tohru; Sugihara, Junko; Wakashima, Mariko; Kamijo, Makiko

    2016-06-01

    In this study, we examined rats' discrimination learning of the numerical ordering positions of objects. In Experiments 1 and 2, five out of seven rats successfully learned to respond to the third of six identical objects in a row and showed reliable transfer of this discrimination to novel stimuli after being trained with three different training stimuli. In Experiment 3, the three rats from Experiment 2 continued to be trained to respond to the third object in an object array, which included an odd object that needed to be excluded when identifying the target third object. All three rats acquired this selective-counting task of specific stimuli, and two rats showed reliable transfer of this selective-counting performance to test sets of novel stimuli. In Experiment 4, the three rats from Experiment 3 quickly learned to respond to the third stimulus in object rows consisting of either six identical or six different objects. These results offer strong evidence for abstract numerical discrimination learning in rats.

  12. MIDAS: Regionally linear multivariate discriminative statistical mapping.

    Science.gov (United States)

    Varol, Erdem; Sotiras, Aristeidis; Davatzikos, Christos

    2018-07-01

    Statistical parametric maps formed via voxel-wise mass-univariate tests, such as the general linear model, are commonly used to test hypotheses about regionally specific effects in neuroimaging cross-sectional studies where each subject is represented by a single image. Despite being informative, these techniques remain limited as they ignore multivariate relationships in the data. Most importantly, the commonly employed local Gaussian smoothing, which is important for accounting for registration errors and making the data follow Gaussian distributions, is usually chosen in an ad hoc fashion. Thus, it is often suboptimal for the task of detecting group differences and correlations with non-imaging variables. Information mapping techniques, such as searchlight, which use pattern classifiers to exploit multivariate information and obtain more powerful statistical maps, have become increasingly popular in recent years. However, existing methods may lead to important interpretation errors in practice (i.e., misidentifying a cluster as informative, or failing to detect truly informative voxels), while often being computationally expensive. To address these issues, we introduce a novel efficient multivariate statistical framework for cross-sectional studies, termed MIDAS, seeking highly sensitive and specific voxel-wise brain maps, while leveraging the power of regional discriminant analysis. In MIDAS, locally linear discriminative learning is applied to estimate the pattern that best discriminates between two groups, or predicts a variable of interest. This pattern is equivalent to local filtering by an optimal kernel whose coefficients are the weights of the linear discriminant. By composing information from all neighborhoods that contain a given voxel, MIDAS produces a statistic that collectively reflects the contribution of the voxel to the regional classifiers as well as the discriminative power of the classifiers. Critically, MIDAS efficiently assesses the

  13. Colour discrimination and categorisation in Williams syndrome.

    Science.gov (United States)

    Farran, Emily K; Cranwell, Matthew B; Alvarez, James; Franklin, Anna

    2013-10-01

    Individuals with Williams syndrome (WS) present with impaired functioning of the dorsal visual stream relative to the ventral visual stream. As such, little attention has been given to ventral stream functions in WS. We investigated colour processing, a predominantly ventral stream function, for the first time in nineteen individuals with Williams syndrome. Colour discrimination was assessed using the Farnsworth-Munsell 100 hue test. Colour categorisation was assessed using a match-to-sample test and a colour naming task. A visual search task was also included as a measure of sensitivity to the size of perceptual colour difference. Results showed that individuals with WS have reduced colour discrimination relative to typically developing participants matched for chronological age; performance was commensurate with a typically developing group matched for non-verbal ability. In contrast, categorisation was typical in WS, although there was some evidence that sensitivity to the size of perceptual colour differences was reduced in this group. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Women Status and their Discrimination

    OpenAIRE

    PEŠKOVÁ, Pavlína

    2008-01-01

    My work deal with women status and their discrimination. Chapter one contains women status in different historical periods and development of their status to bigger equal with men. There is also written about present feminist trends. Chapter two is about women discrimination. There is about women´ job discrimination, job segregation according to gender and inequality in payment. There is also written about women status at home and unequal duties at home among family mates. Chapter three is ab...

  15. Large number discrimination in newborn fish.

    Directory of Open Access Journals (Sweden)

    Laura Piffer

    Full Text Available Quantitative abilities have been reported in a wide range of species, including fish. Recent studies have shown that adult guppies (Poecilia reticulata can spontaneously select the larger number of conspecifics. In particular the evidence collected in literature suggest the existence of two distinct systems of number representation: a precise system up to 4 units, and an approximate system for larger numbers. Spontaneous numerical abilities, however, seem to be limited to 4 units at birth and it is currently unclear whether or not the large number system is absent during the first days of life. In the present study, we investigated whether newborn guppies can be trained to discriminate between large quantities. Subjects were required to discriminate between groups of dots with a 0.50 ratio (e.g., 7 vs. 14 in order to obtain a food reward. To dissociate the roles of number and continuous quantities that co-vary with numerical information (such as cumulative surface area, space and density, three different experiments were set up: in Exp. 1 number and continuous quantities were simultaneously available. In Exp. 2 we controlled for continuous quantities and only numerical information was available; in Exp. 3 numerical information was made irrelevant and only continuous quantities were available. Subjects successfully solved the tasks in Exp. 1 and 2, providing the first evidence of large number discrimination in newborn fish. No discrimination was found in experiment 3, meaning that number acuity is better than spatial acuity. A comparison with the onset of numerical abilities observed in shoal-choice tests suggests that training procedures can promote the development of numerical abilities in guppies.

  16. Digital pulse shape discrimination

    International Nuclear Information System (INIS)

    Miller, L. F.; Preston, J.; Pozzi, S.; Flaska, M.; Neal, J.

    2007-01-01

    Pulse-shape discrimination (PSD) has been utilised for about 40 years as a method to obtain estimates for dose in mixed neutron and photon fields. Digitizers that operate close to GHz are currently available at a reasonable cost, and they can be used to directly sample signals from photomultiplier tubes. This permits one to perform digital PSD rather than the traditional, and well-established, analogous techniques. One issue that complicates PSD for neutrons in mixed fields is that the light output characteristics of typical scintillators available for PSD, such as BC501A, vary as a function of energy deposited in the detector. This behaviour is more easily accommodated with digital processing of signals than with analogous signal processing. Results illustrate the effectiveness of digital PSD. (authors)

  17. Genetic discrimination: international perspectives.

    Science.gov (United States)

    Otlowski, M; Taylor, S; Bombard, Y

    2012-01-01

    Genetic discrimination (GD) is a complex, multifaceted ethical, psychosocial, and legal phenomenon. It is defined as the differential treatment of asymptomatic individuals or their relatives on the basis of their real or assumed genetic characteristics. This article presents an overview of GD within the contemporary international context. It describes the concept of GD and its contextual features, reviews research evidence regarding people's experiences of GD and the impact of GD within a range of domains, and provides an overview of legal and policy responses to GD that have emerged globally. We argue that GD is a significant and internationally established phenomenon that requires multilevel responses to ensure social justice and equitable outcomes for all citizens. Future research should monitor GD and its impacts within the community as well as institutions and should evaluate the effectiveness of legislative, policy, community education, and systemic responses.

  18. Gaussian discriminating strength

    Science.gov (United States)

    Rigovacca, L.; Farace, A.; De Pasquale, A.; Giovannetti, V.

    2015-10-01

    We present a quantifier of nonclassical correlations for bipartite, multimode Gaussian states. It is derived from the Discriminating Strength measure, introduced for finite dimensional systems in Farace et al., [New J. Phys. 16, 073010 (2014), 10.1088/1367-2630/16/7/073010]. As the latter the new measure exploits the quantum Chernoff bound to gauge the susceptibility of the composite system with respect to local perturbations induced by unitary gates extracted from a suitable set of allowed transformations (the latter being identified by posing some general requirements). Closed expressions are provided for the case of two-mode Gaussian states obtained by squeezing or by linearly mixing via a beam splitter a factorized two-mode thermal state. For these density matrices, we study how nonclassical correlations are related with the entanglement present in the system and with its total photon number.

  19. Weight discrimination and bullying.

    Science.gov (United States)

    Puhl, Rebecca M; King, Kelly M

    2013-04-01

    Despite significant attention to the medical impacts of obesity, often ignored are the negative outcomes that obese children and adults experience as a result of stigma, bias, and discrimination. Obese individuals are frequently stigmatized because of their weight in many domains of daily life. Research spanning several decades has documented consistent weight bias and stigmatization in employment, health care, schools, the media, and interpersonal relationships. For overweight and obese youth, weight stigmatization translates into pervasive victimization, teasing, and bullying. Multiple adverse outcomes are associated with exposure to weight stigmatization, including depression, anxiety, low self-esteem, body dissatisfaction, suicidal ideation, poor academic performance, lower physical activity, maladaptive eating behaviors, and avoidance of health care. This review summarizes the nature and extent of weight stigmatization against overweight and obese individuals, as well as the resulting consequences that these experiences create for social, psychological, and physical health for children and adults who are targeted. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Dynamic functional brain networks involved in simple visual discrimination learning.

    Science.gov (United States)

    Fidalgo, Camino; Conejo, Nélida María; González-Pardo, Héctor; Arias, Jorge Luis

    2014-10-01

    Visual discrimination tasks have been widely used to evaluate many types of learning and memory processes. However, little is known about the brain regions involved at different stages of visual discrimination learning. We used cytochrome c oxidase histochemistry to evaluate changes in regional brain oxidative metabolism during visual discrimination learning in a water-T maze at different time points during training. As compared with control groups, the results of the present study reveal the gradual activation of cortical (prefrontal and temporal cortices) and subcortical brain regions (including the striatum and the hippocampus) associated to the mastery of a simple visual discrimination task. On the other hand, the brain regions involved and their functional interactions changed progressively over days of training. Regions associated with novelty, emotion, visuo-spatial orientation and motor aspects of the behavioral task seem to be relevant during the earlier phase of training, whereas a brain network comprising the prefrontal cortex was found along the whole learning process. This study highlights the relevance of functional interactions among brain regions to investigate learning and memory processes. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Introduction to multivariate discrimination

    Science.gov (United States)

    Kégl, Balázs

    2013-07-01

    Multivariate discrimination or classification is one of the best-studied problem in machine learning, with a plethora of well-tested and well-performing algorithms. There are also several good general textbooks [1-9] on the subject written to an average engineering, computer science, or statistics graduate student; most of them are also accessible for an average physics student with some background on computer science and statistics. Hence, instead of writing a generic introduction, we concentrate here on relating the subject to a practitioner experimental physicist. After a short introduction on the basic setup (Section 1) we delve into the practical issues of complexity regularization, model selection, and hyperparameter optimization (Section 2), since it is this step that makes high-complexity non-parametric fitting so different from low-dimensional parametric fitting. To emphasize that this issue is not restricted to classification, we illustrate the concept on a low-dimensional but non-parametric regression example (Section 2.1). Section 3 describes the common algorithmic-statistical formal framework that unifies the main families of multivariate classification algorithms. We explain here the large-margin principle that partly explains why these algorithms work. Section 4 is devoted to the description of the three main (families of) classification algorithms, neural networks, the support vector machine, and AdaBoost. We do not go into the algorithmic details; the goal is to give an overview on the form of the functions these methods learn and on the objective functions they optimize. Besides their technical description, we also make an attempt to put these algorithm into a socio-historical context. We then briefly describe some rather heterogeneous applications to illustrate the pattern recognition pipeline and to show how widespread the use of these methods is (Section 5). We conclude the chapter with three essentially open research problems that are either

  2. Introduction to multivariate discrimination

    International Nuclear Information System (INIS)

    Kegl, B.

    2013-01-01

    Multivariate discrimination or classification is one of the best-studied problem in machine learning, with a plethora of well-tested and well-performing algorithms. There are also several good general textbooks [1-9] on the subject written to an average engineering, computer science, or statistics graduate student; most of them are also accessible for an average physics student with some background on computer science and statistics. Hence, instead of writing a generic introduction, we concentrate here on relating the subject to a practitioner experimental physicist. After a short introduction on the basic setup (Section 1) we delve into the practical issues of complexity regularization, model selection, and hyper-parameter optimization (Section 2), since it is this step that makes high-complexity non-parametric fitting so different from low-dimensional parametric fitting. To emphasize that this issue is not restricted to classification, we illustrate the concept on a low-dimensional but non-parametric regression example (Section 2.1). Section 3 describes the common algorithmic-statistical formal framework that unifies the main families of multivariate classification algorithms. We explain here the large-margin principle that partly explains why these algorithms work. Section 4 is devoted to the description of the three main (families of) classification algorithms, neural networks, the support vector machine, and AdaBoost. We do not go into the algorithmic details; the goal is to give an overview on the form of the functions these methods learn and on the objective functions they optimize. Besides their technical description, we also make an attempt to put these algorithm into a socio-historical context. We then briefly describe some rather heterogeneous applications to illustrate the pattern recognition pipeline and to show how widespread the use of these methods is (Section 5). We conclude the chapter with three essentially open research problems that are either

  3. Perceived discrimination: why applicants and employees expect and perceive discrimination

    NARCIS (Netherlands)

    Abu Ghazaleh, N.

    2012-01-01

    In this dissertation we have investigated perceptions of discrimination. We have shown discrimination exists in the eyes of applicants and employees and especially when from an ethnic minority group. There are psychological variables that influence these perceptions differently for minority and

  4. Meta-analytic review of the development of face discrimination in infancy: Face race, face gender, infant age, and methodology moderate face discrimination.

    Science.gov (United States)

    Sugden, Nicole A; Marquis, Alexandra R

    2017-11-01

    Infants show facility for discriminating between individual faces within hours of birth. Over the first year of life, infants' face discrimination shows continued improvement with familiar face types, such as own-race faces, but not with unfamiliar face types, like other-race faces. The goal of this meta-analytic review is to provide an effect size for infants' face discrimination ability overall, with own-race faces, and with other-race faces within the first year of life, how this differs with age, and how it is influenced by task methodology. Inclusion criteria were (a) infant participants aged 0 to 12 months, (b) completing a human own- or other-race face discrimination task, (c) with discrimination being determined by infant looking. Our analysis included 30 works (165 samples, 1,926 participants participated in 2,623 tasks). The effect size for infants' face discrimination was small, 6.53% greater than chance (i.e., equal looking to the novel and familiar). There was a significant difference in discrimination by race, overall (own-race, 8.18%; other-race, 3.18%) and between ages (own-race: 0- to 4.5-month-olds, 7.32%; 5- to 7.5-month-olds, 9.17%; and 8- to 12-month-olds, 7.68%; other-race: 0- to 4.5-month-olds, 6.12%; 5- to 7.5-month-olds, 3.70%; and 8- to 12-month-olds, 2.79%). Multilevel linear (mixed-effects) models were used to predict face discrimination; infants' capacity to discriminate faces is sensitive to face characteristics including race, gender, and emotion as well as the methods used, including task timing, coding method, and visual angle. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. Discrimination of optical coherent states using a photon number resolving detector

    DEFF Research Database (Denmark)

    Wittmann, C.; Andersen, Ulrik Lund; Leuchs, G.

    2010-01-01

    The discrimination of non-orthogonal quantum states with reduced or without errors is a fundamental task in quantum measurement theory. In this work, we investigate a quantum measurement strategy capable of discriminating two coherent states probabilistically with significantly smaller error...... probabilities than can be obtained using non-probabilistic state discrimination. We find that appropriate postselection of the measurement data of a photon number resolving detector can be used to discriminate two coherent states with small error probability. We compare our new receiver to an optimal...

  6. Temporal discrimination, a cervical dystonia endophenotype: penetrance and functional correlates.

    Science.gov (United States)

    Kimmich, Okka; Molloy, Anna; Whelan, Robert; Williams, Laura; Bradley, David; Balsters, Joshua; Molloy, Fiona; Lynch, Tim; Healy, Daniel G; Walsh, Cathal; O'Riordan, Seán; Reilly, Richard B; Hutchinson, Michael

    2014-05-01

    The pathogenesis of adult-onset primary dystonia remains poorly understood. There is variable age-related and gender-related expression of the phenotype, the commonest of which is cervical dystonia. Endophenotypes may provide insight into underlying genetic and pathophysiological mechanisms of dystonia. The temporal discrimination threshold (TDT)-the shortest time interval at which two separate stimuli can be detected as being asynchronous-is abnormal both in patients with cervical dystonia and in their unaffected first-degree relatives. Functional magnetic resonance imaging (fMRI) studies have shown that putaminal activation positively correlates with the ease of temporal discrimination between two stimuli in healthy individuals. We hypothesized that abnormal temporal discrimination would exhibit similar age-related and gender-related penetrance as cervical dystonia and that unaffected relatives with an abnormal TDT would have reduced putaminal activation during a temporal discrimination task. TDTs were examined in a group of 192 healthy controls and in 158 unaffected first-degree relatives of 84 patients with cervical dystonia. In 24 unaffected first-degree relatives, fMRI scanning was performed during a temporal discrimination task. The prevalence of abnormal TDTs in unaffected female relatives reached 50% after age 48 years; whereas, in male relatives, penetrance of the endophenotype was reduced. By fMRI, relatives who had abnormal TDTs, compared with relatives who had normal TDTs, had significantly less activation in the putamina and in the middle frontal and precentral gyri. Only the degree of reduction of putaminal activity correlated significantly with worsening of temporal discrimination. These findings further support abnormal temporal discrimination as an endophenotype of cervical dystonia involving disordered basal ganglia circuits. © 2014 International Parkinson and Movement Disorder Society.

  7. Perceived weight discrimination and obesity.

    Directory of Open Access Journals (Sweden)

    Angelina R Sutin

    Full Text Available Weight discrimination is prevalent in American society. Although associated consistently with psychological and economic outcomes, less is known about whether weight discrimination is associated with longitudinal changes in obesity. The objectives of this research are (1 to test whether weight discrimination is associated with risk of becoming obese (Body Mass Index≥30; BMI by follow-up among those not obese at baseline, and (2 to test whether weight discrimination is associated with risk of remaining obese at follow-up among those already obese at baseline. Participants were drawn from the Health and Retirement Study, a nationally representative longitudinal survey of community-dwelling US residents. A total of 6,157 participants (58.6% female completed the discrimination measure and had weight and height available from the 2006 and 2010 assessments. Participants who experienced weight discrimination were approximately 2.5 times more likely to become obese by follow-up (OR = 2.54, 95% CI = 1.58-4.08 and participants who were obese at baseline were three times more likely to remain obese at follow up (OR = 3.20, 95% CI = 2.06-4.97 than those who had not experienced such discrimination. These effects held when controlling for demographic factors (age, sex, ethnicity, education and when baseline BMI was included as a covariate. These effects were also specific to weight discrimination; other forms of discrimination (e.g., sex, race were unrelated to risk of obesity at follow-up. The present research demonstrates that, in addition to poorer mental health outcomes, weight discrimination has implications for obesity. Rather than motivating individuals to lose weight, weight discrimination increases risk for obesity.

  8. Perceived Discrimination in LGBTIQ Discourse: A Typology of Verbal Discrimination

    Directory of Open Access Journals (Sweden)

    Sol Rojas Lizana

    2014-08-01

    Full Text Available New within the field of Discourse Analysis, Perceived Discrimination (PD is the study of discourse that focuses on the perspective of the victims of discrimination. This article explores the experiences of verbal discrimination as reported by eighteen LGBTIQ participants during semi-structured, co-constructed interviews. Data were classified in order to develop a taxonomy of discrimination based on Mellor’s (2003, 2004. This taxonomy foregrounds two types of discrimination: verbal and behavioural. In this paper, I exemplify the forms of verbal discrimination encountered and offer an analysis of the discourse used in the construction of the experiences and of the effects reported. The results show that verbal discrimination is an overt phenomenon and that participants are stressed by the ever present possibility of facing it. Verbal discrimination is mainly triggered by a perceived transgression to the normalised standards of people’s behaviour, movements and look in a heterosexist society. It presents three subtypes: name calling, abuse and remarks. These subtypes are described through the analysis of keywords, effects and expressions (such as faggot, gay, dyke, queer, the pronoun ‘it’, religious comments and other remarks. The type of discrimination used was associated with the level of acquaintance perpetrators have with the experiencers; that is, name calling was used by people unknown to the victims while abuse and remarks by acquaintances and family members. Participants resorted to several discursive strategies to convey their intentions. They used mitigation strategies when wanting to minimize the experience, hedging and repetition were used for emphasis, and to convey urgency and pervasiveness. Metaphorical expressions related to internal or external injuries were also used to express the powerful effect of verbal discrimination on people.

  9. The Influence of Eye Closure on Somatosensory Discrimination: A Trade-off Between Simple Perception and Discrimination.

    Science.gov (United States)

    Götz, Theresa; Hanke, David; Huonker, Ralph; Weiss, Thomas; Klingner, Carsten; Brodoehl, Stefan; Baumbach, Philipp; Witte, Otto W

    2017-06-01

    We often close our eyes to improve perception. Recent results have shown a decrease of perception thresholds accompanied by an increase in somatosensory activity after eye closure. However, does somatosensory spatial discrimination also benefit from eye closure? We previously showed that spatial discrimination is accompanied by a reduction of somatosensory activity. Using magnetoencephalography, we analyzed the magnitude of primary somatosensory (somatosensory P50m) and primary auditory activity (auditory P50m) during a one-back discrimination task in 21 healthy volunteers. In complete darkness, participants were requested to pay attention to either the somatosensory or auditory stimulation and asked to open or close their eyes every 6.5 min. Somatosensory P50m was reduced during a task requiring the distinguishing of stimulus location changes at the distal phalanges of different fingers. The somatosensory P50m was further reduced and detection performance was higher during eyes open. A similar reduction was found for the auditory P50m during a task requiring the distinguishing of changing tones. The function of eye closure is more than controlling visual input. It might be advantageous for perception because it is an effective way to reduce interference from other modalities, but disadvantageous for spatial discrimination because it requires at least one top-down processing stage. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Memory-Based Quantity Discrimination in Coyotes (Canis latrans

    Directory of Open Access Journals (Sweden)

    Salif Mahamane

    2014-08-01

    Full Text Available Previous research has shown that the ratio between competing quantities of food significantly mediates coyotes‘ (Canis latrans ability to choose the larger of two food options. These previous findings are consistent with predictions made by Weber‘s Law and indicate that coyotes possess quantity discrimination abilities that are similar to other species. Importantly, coyotes‘ discrimination abilities are similar to domestic dogs (Canis lupus familiaris, indicating that quantitative discrimination may remain stable throughout certain species‘ evolution. However, while previously shown in two domestic dogs, it is unknown whether coyotes possess the ability to discriminate visual quantities from memory. Here, we address this question by displaying different ratios of food quantities to 14 coyotes before placing the choices out of sight. The coyotes were then allowed to select one of either non-visible food quantities. Coyotes‘ discrimination of quantity from memory does not follow Weber‘s Law in this particular task. These results suggest that working memory in coyotes may not be adapted to maintain information regarding quantity as well as in domestic dogs. The likelihood of a coyote‘s choosing the large option increased when it was presented with difficult ratios of food options first, before it was later presented with trials using more easily discriminable ratios, and when the large option was placed on one particular side. This suggests that learning or motivation increased across trials when coyotes experienced difficult ratios first, and that location of food may have been more salient in working memory than quantity of food.

  11. Children's Perceptions of Gender Discrimination

    Science.gov (United States)

    Brown, Christia Spears; Bigler, Rebecca S.

    2004-01-01

    Children (N = 76; ages 5-10 years) participated in a study designed to examine perceptions of gender discrimination. Children were read scenarios in which a teacher determined outcomes for 2 students (1 boy and 1 girl). Contextual information (i.e., teacher's past behavior), the gender of the target of discrimination (i.e., student), and the…

  12. Discrimination aware decision tree learning

    NARCIS (Netherlands)

    Kamiran, F.; Calders, T.G.K.; Pechenizkiy, M.

    2010-01-01

    Recently, the following problem of discrimination aware classification was introduced: given a labeled dataset and an attribute B, find a classifier with high predictive accuracy that at the same time does not discriminate on the basis of the given attribute B. This problem is motivated by the fact

  13. Discrimination aware decision tree learning

    NARCIS (Netherlands)

    Kamiran, F.; Calders, T.G.K.; Pechenizkiy, M.

    2010-01-01

    Recently, the following discrimination aware classification problem was introduced: given a labeled dataset and an attribute B, find a classifier with high predictive accuracy that at the same time does not discriminate on the basis of the given attribute B. This problem is motivated by the fact

  14. Discrimination against Muslim American Adolescents

    Science.gov (United States)

    Aroian, Karen J.

    2012-01-01

    Although there is ample evidence of discrimination toward Muslim Americans in general, there is limited information specific to Muslim American adolescents. The few existing studies specific to this age group suggest that Muslim American adolescents encounter much discrimination from teachers, school administrators, and classmates. This…

  15. Perceived discrimination in the Netherlands

    NARCIS (Netherlands)

    Iris Andriessen; Henk Fernee; Karin Wittebrood

    2014-01-01

    Only available in electronic version There is no systematic structure in the Netherlands for mapping out the discrimination experiences of different groups in different areas of society. As in many other countries, discrimination studies in the Netherlands mostly focus on the experiences

  16. Gender Discrimination in Jessica's Career.

    Science.gov (United States)

    Cook, Ellen Piel

    1997-01-01

    Focuses on the sexual harassment and other gender-related difficulties faced by a Chinese-American woman. Profiles her encounters with gender discrimination and how it hindered career advancement and led to professional isolation. Relates how this case study can be used to sensitize workers to gender discrimination. (RJM)

  17. Caffeine induces differential cross tolerance to the amphetamine-like discriminative stimulus effects of dopaminergic agonists.

    Science.gov (United States)

    Jain, Raka; Holtzman, Stephen G

    2005-05-15

    The purpose of this study was to determine if caffeine induces cross tolerance to the amphetamine-like discriminative stimulus effects of dopaminergic drugs that act through distinct mechanisms (e.g., release, uptake inhibition, direct activation of dopamine D(1)- or D(2)-family receptors). Rats were trained to discriminate 1.0 mg/kg d-amphetamine from saline in a two-choice discrete-trial procedure. Stimulus-generalization curves were generated by cumulative dosing for d-amphetamine (0.1-1.0 mg/kg), methylphenidate (0.3-5.6 mg/kg), SKF 81297 (0.3-3.0 mg/kg), and R-(-)-propylnorapomorphine (NPA; 0.001-1.78 mg/kg), as well as for caffeine (3.0-56 mg/kg); curves were re-determined after twice daily injections of caffeine (30 mg/kg) for 3.5 days. The rats generalized dose dependently to the four dopaminergic drugs, but only to a limited extent to caffeine. Twice daily injections of caffeine induced significant cross tolerance (i.e., increased ED(50)) to the amphetamine-like discriminative effects of methylphenidate and SKF 81297, attenuated non-significantly the effects of NPA, and did not alter the effects of amphetamine. Thus, caffeine produces differential cross tolerance to the amphetamine-like discriminative effects of dopaminergic drugs, a phenomenon in which the dopamine D(1) receptor appears to have an important role.

  18. Children's perceptions of gender discrimination.

    Science.gov (United States)

    Spears Brown, Christia; Bigler, Rebecca S

    2004-09-01

    Children (N = 76; ages 5-10 years) participated in a study designed to examine perceptions of gender discrimination. Children were read scenarios in which a teacher determined outcomes for 2 students (1 boy and 1 girl). Contextual information (i.e., teacher's past behavior), the gender of the target of discrimination (i.e., student), and the gender of the perpetrator (i.e., teacher) were manipulated. Results indicated that older children were more likely than younger children to make attributions to discrimination when contextual information suggested that it was likely. Girls (but not boys) were more likely to view girls than boys as victims of discrimination, and children with egalitarian gender attitudes were more likely to perceive discrimination than were their peers. Copyright 2004 American Psychological Association

  19. Development of Gender Discrimination: Effect of Sex-Typical and Sex-Atypical Toys.

    Science.gov (United States)

    Etaugh, Claire; Duits, Terri L.

    Toddlers (41 girls and 35 boys) between 18 and 37 months of age were given four gender discrimination tasks each consisting of 6 pairs of color drawings. Three of the tasks employed color drawings of preschool girls and boys holding either a sex-typical toy, a sex-atypical toy, or no toy. The fourth employed pictures of sex-typical masculine and…

  20. Validation of the Mnemonic Similarity Task – Context Version

    Directory of Open Access Journals (Sweden)

    Giulia A. Aldi

    2018-02-01

    Full Text Available Objective: Pattern separation (PS is the ability to represent similar experiences as separate, non-overlapping representations. It is usually assessed via the Mnemonic Similarity Task – Object Version (MST-O which, however, assesses PS performance without taking behavioral context discrimination into account, since it is based on pictures of everyday simple objects on a white background. We here present a validation study for a new task, the Mnemonic Similarity Task – Context Version (MST-C, which is designed to measure PS while taking behavioral context discrimination into account by using real-life context photographs. Methods: Fifty healthy subjects underwent the two MST tasks to assess convergent evidence. Instruments assessing memory and attention were also administered to study discriminant evidence. The test-retest reliability of MST-C was analyzed. Results: Weak evidence supports convergent validity between the MST-C task and the MST-O as measures of PS (rs = 0.464; p < 0.01; PS performance assessed via the MST-C did not correlate with memory or attention; a moderate test-retest reliability was found (rs = 0.595; p < 0.01. Conclusion: The MST-C seems useful for assessing PS performance conceptualized as the ability to discriminate complex and realistic spatial contexts. Future studies are welcome to evaluate the validity of the MST-C task as a measure of PS in clinical populations.

  1. Racial/Ethnic Workplace Discrimination

    Science.gov (United States)

    Chavez, Laura J.; Ornelas, India J.; Lyles, Courtney R.; Williams, Emily C.

    2014-01-01

    Background Experiences of discrimination are associated with tobacco and alcohol use, and work is a common setting where individuals experience racial/ethnic discrimination. Few studies have evaluated the association between workplace discrimination and these behaviors, and none have described associations across race/ethnicity. Purpose To examine the association between workplace discrimination and tobacco and alcohol use in a large, multistate sample of U.S. adult respondents to the Behavioral Risk Factor Surveillance System survey Reactions to Race Module (2004–2010). Methods Multivariable logistic regression analyses evaluated cross-sectional associations between self-reported workplace discrimination and tobacco (current and daily smoking) and alcohol use (any and heavy use, and binge drinking) among all participants and stratified by race/ethnicity, adjusting for relevant covariates. Data were analyzed in 2013. Results Among respondents, 70,080 completed the workplace discrimination measure. Discrimination was more common among black non-Hispanic (21%), Hispanic (12%), and other race respondents (11%) than white non-Hispanics (4%) (pdiscrimination was associated with current smoking (risk ratio [RR]=1.32, 95% CI=1.19, 1.47), daily smoking (RR=1.41, 95% CI=1.24, 1.61), and heavy drinking (RR=1.11, 95% CI=1.01, 1.22), but not binge or any drinking. Among Hispanics, workplace discrimination was associated with increased heavy and binge drinking, but not any alcohol use or smoking. Workplace discrimination among black non-Hispanics and white Non-Hispanics was associated with increased current and daily smoking, but not alcohol outcomes. Conclusions Workplace discrimination is common, associated with smoking and alcohol use, and merits further policy attention given the impact of these behaviors on morbidity and mortality. PMID:25441232

  2. Hierarchical Discriminant Analysis

    Directory of Open Access Journals (Sweden)

    Di Lu

    2018-01-01

    Full Text Available The Internet of Things (IoT generates lots of high-dimensional sensor intelligent data. The processing of high-dimensional data (e.g., data visualization and data classification is very difficult, so it requires excellent subspace learning algorithms to learn a latent subspace to preserve the intrinsic structure of the high-dimensional data, and abandon the least useful information in the subsequent processing. In this context, many subspace learning algorithms have been presented. However, in the process of transforming the high-dimensional data into the low-dimensional space, the huge difference between the sum of inter-class distance and the sum of intra-class distance for distinct data may cause a bias problem. That means that the impact of intra-class distance is overwhelmed. To address this problem, we propose a novel algorithm called Hierarchical Discriminant Analysis (HDA. It minimizes the sum of intra-class distance first, and then maximizes the sum of inter-class distance. This proposed method balances the bias from the inter-class and that from the intra-class to achieve better performance. Extensive experiments are conducted on several benchmark face datasets. The results reveal that HDA obtains better performance than other dimensionality reduction algorithms.

  3. Studies in genetic discrimination. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    We have screened 1006 respondents in a study of genetic discrimination. Analysis of these responses has produced evidence of the range of institutions engaged in genetic discrimination and demonstrates the impact of this discrimination on the respondents to the study. We have found that both ignorance and policy underlie genetic discrimination and that anti-discrimination laws are being violated.

  4. JUSTIFICATION FOR INDIRECT DISCRIMINATION IN EU

    Directory of Open Access Journals (Sweden)

    Cătălina-Adriana Ivănuş

    2014-11-01

    Full Text Available The right to non-discrimination is very important for a civilized society. EU legislation establishes direct and indirect discrimination, harassment, sexual harassment, instruction to discriminate and any less favourable treatment of a woman related to pregnancy or maternity leave as forms of discrimination. The law and the Court of Justice permit the justification of indirect discrimination.

  5. JUSTIFICATION FOR INDIRECT DISCRIMINATION IN EU

    OpenAIRE

    Cătălina-Adriana Ivănuş

    2014-01-01

    The right to non-discrimination is very important for a civilized society. EU legislation establishes direct and indirect discrimination, harassment, sexual harassment, instruction to discriminate and any less favourable treatment of a woman related to pregnancy or maternity leave as forms of discrimination. The law and the Court of Justice permit the justification of indirect discrimination.

  6. Effects of early postnatal X-irradiation of the hippocampus on discrimination learning in adult rats

    International Nuclear Information System (INIS)

    Gazzara, R.A.

    1980-01-01

    Rats with x-irradiation-produced degranulation of the hippocampal dentate gyrus were trained in the acquisition and reversal of simultaneous visual and tactile discriminations in a T-maze. These experiments employed the same treatment, apparatus, and procedure, but varied in task difficulty. In the brightness and roughness discriminations, the irradiated rats were not handicapped in acquiring or reversing discriminations of low or low-moderate task-difficulty. However, these rats were handicapped in acquiring and reversing discriminations of moderate and high task-difficulty. In a Black/White discrimination, in which the stimuli were restricted to the goal-arm walls, the irradiated rats were handicapped in the acquisition (low task-difficulty) and reversal (moderate task-difficulty) phases of the task. These results suggest that the irradiated rats were not handicapped when the noticeability of the stimuli was high, irrespective of modality used, but were handicapped when the noticeability of the stimuli was low. In addition, these results are consistent with the hypothesis that hippocampal-damaged rats are inattentive due to hyperactivity

  7. Early postnatal x-irradiation of the hippocampus and discrimination learning in adult rats

    International Nuclear Information System (INIS)

    Gazzara, R.A.; Altman, J.

    1981-01-01

    Rats with X-irradiation-produced degranulation of the hippocampal dentate gyrus were trained in the acquisition and reversal of simultaneous visual and tactile discriminations in a T-maze. These experiments employed the same treatment, apparatus, and procedure but varied in task difficulty. In the brightness and roughness discriminations, the irradiated rats were not handicapped in acquiring or reversing discriminations of low or low-moderate task difficulty. However, these rats were handicapped in acquiring and reversing discriminations of moderate and high task difficulty. In a Black/White discrimination, in which the stimuli were restricted to the goal-arm walls, the irradiated rats were handicapped in the acquisition (low task difficulty) and reversal (moderate task difficulty) phases of the task. These results suggest that the irradiated rats were not handicapped when the noticeability of the stimuli was high, irrespective of modality used, but were handicapped when the noticeability of the stimuli was low. In addition, these results are consistent with the hypothesis that rats with hippocampal damage are inattentive due to hyperactivity

  8. Social and nonsocial category discriminations in a chimpanzee (Pan troglodytes) and American black bears (Ursus americanus).

    Science.gov (United States)

    Vonk, Jennifer; Johnson-Ulrich, Zoe

    2014-09-01

    One captive adult chimpanzee and 3 adult American black bears were presented with a series of natural category discrimination tasks on a touch-screen computer. This is the first explicit comparison of bear and primate abilities using identical tasks, and the first test of a social concept in a carnivore. The discriminations involved a social relationship category (mother/offspring) and a nonsocial category involving food items. The social category discrimination could be made using knowledge of the overarching mother/offspring concept, whereas the nonsocial category discriminations could be made only by using perceptual rules, such as "choose images that show larger and smaller items of the same type." The bears failed to show above-chance transfer on either the social or nonsocial discriminations, indicating that they did not use either the perceptual rule or knowledge of the overarching concept of mother/offspring to guide their choices in these tasks. However, at least 1 bear remembered previously reinforced stimuli when these stimuli were recombined, later. The chimpanzee showed transfer on a control task and did not consistently apply a perceptual rule to solve the nonsocial task, so it is possible that he eventually acquired the social concept. Further comparisons between species on identical tasks assessing social knowledge will help illuminate the selective pressures responsible for a range of social cognitive skills.

  9. Tactile Acuity in the Blind: A Closer Look Reveals Superiority over the Sighted in Some but Not All Cutaneous Tasks

    Science.gov (United States)

    Alary, Flamine; Duquette, Marco; Goldstein, Rachel; Chapman, C. Elaine; Voss, Patrice; La Buissonniere-Ariza, Valerie; Lepore, Franco

    2009-01-01

    Previous studies have shown that blind subjects may outperform the sighted on certain tactile discrimination tasks. We recently showed that blind subjects outperformed the sighted in a haptic 2D-angle discrimination task. The purpose of this study was to compare the performance of the same blind (n = 16) and sighted (n = 17, G1) subjects in three…

  10. Active listening: task-dependent plasticity of spectrotemporal receptive fields in primary auditory cortex.

    Science.gov (United States)

    Fritz, Jonathan; Elhilali, Mounya; Shamma, Shihab

    2005-08-01

    Listening is an active process in which attentive focus on salient acoustic features in auditory tasks can influence receptive field properties of cortical neurons. Recent studies showing rapid task-related changes in neuronal spectrotemporal receptive fields (STRFs) in primary auditory cortex of the behaving ferret are reviewed in the context of current research on cortical plasticity. Ferrets were trained on spectral tasks, including tone detection and two-tone discrimination, and on temporal tasks, including gap detection and click-rate discrimination. STRF changes could be measured on-line during task performance and occurred within minutes of task onset. During spectral tasks, there were specific spectral changes (enhanced response to tonal target frequency in tone detection and discrimination, suppressed response to tonal reference frequency in tone discrimination). However, only in the temporal tasks, the STRF was changed along the temporal dimension by sharpening temporal dynamics. In ferrets trained on multiple tasks, distinctive and task-specific STRF changes could be observed in the same cortical neurons in successive behavioral sessions. These results suggest that rapid task-related plasticity is an ongoing process that occurs at a network and single unit level as the animal switches between different tasks and dynamically adapts cortical STRFs in response to changing acoustic demands.

  11. Influence of Task Difficulty and Background Music on Working Memory Activity: Developmental Considerations.

    Science.gov (United States)

    Kaniel, Shlomo; Aram, Dorit

    1998-01-01

    A study of 300 children in kindergarten, grade 2, and grade 6 found that background music improved visual discrimination task performance at the youngest and middle ages and had no effect on the oldest participants. On a square identification task, background music had no influence on easy and difficult tasks but lowered performance on…

  12. Something worth remembering: visual discrimination in sharks.

    Science.gov (United States)

    Fuss, Theodora; Schluessel, Vera

    2015-03-01

    This study investigated memory retention capabilities of juvenile gray bamboo sharks (Chiloscyllium griseum) using two-alternative forced-choice experiments. The sharks had previously been trained in a range of visual discrimination tasks, such as distinguishing between squares, triangles and lines, and their corresponding optical illusions (i.e., the Kanizsa figures or Müller-Lyer illusions), and in the present study, we tested them for memory retention. Despite the absence of reinforcement, sharks remembered the learned information for a period of up to 50 weeks, after which testing was terminated. In fish, as in other vertebrates, memory windows vary in duration depending on species and task; while it may seem beneficial to retain some information for a long time or even indefinitely, other information may be forgotten more easily to retain flexibility and save energy. The results of this study indicate that sharks are capable of long-term memory within the framework of selected cognitive skills. These could aid sharks in activities such as food retrieval, predator avoidance, mate choice or habitat selection and therefore be worth being remembered for extended periods of time. As in other cognitive tasks, intraspecific differences reflected the behavioral breadth of the species.

  13. Object recognition with hierarchical discriminant saliency networks.

    Science.gov (United States)

    Han, Sunhyoung; Vasconcelos, Nuno

    2014-01-01

    The benefits of integrating attention and object recognition are investigated. While attention is frequently modeled as a pre-processor for recognition, we investigate the hypothesis that attention is an intrinsic component of recognition and vice-versa. This hypothesis is tested with a recognition model, the hierarchical discriminant saliency network (HDSN), whose layers are top-down saliency detectors, tuned for a visual class according to the principles of discriminant saliency. As a model of neural computation, the HDSN has two possible implementations. In a biologically plausible implementation, all layers comply with the standard neurophysiological model of visual cortex, with sub-layers of simple and complex units that implement a combination of filtering, divisive normalization, pooling, and non-linearities. In a convolutional neural network implementation, all layers are convolutional and implement a combination of filtering, rectification, and pooling. The rectification is performed with a parametric extension of the now popular rectified linear units (ReLUs), whose parameters can be tuned for the detection of target object classes. This enables a number of functional enhancements over neural network models that lack a connection to saliency, including optimal feature denoising mechanisms for recognition, modulation of saliency responses by the discriminant power of the underlying features, and the ability to detect both feature presence and absence. In either implementation, each layer has a precise statistical interpretation, and all parameters are tuned by statistical learning. Each saliency detection layer learns more discriminant saliency templates than its predecessors and higher layers have larger pooling fields. This enables the HDSN to simultaneously achieve high selectivity to target object classes and invariance. The performance of the network in saliency and object recognition tasks is compared to those of models from the biological and

  14. Timbre discrimination in musical patterns.

    Science.gov (United States)

    Grey, J M

    1978-08-01

    Most research on timbre perception has studied isolated tones. This study compares timbre discrimination of isolated tones with discrimination in various musical contexts, both single-voiced and multivoiced. Twelve different contexts were used (four isolated tonal comparisons, four single-voice musical patterns, and four multivoice patterns). Listerners judged whether the timbre remained the same or changed during the trial. Two possible versions of any instrumental timbre differed in the physical information used in their synthesis. Three instrumental timbres were tested in all contexts: clarinet, trumpet, and bassoon. The effects of context upon discrimination varied across instruments. The clarinet and trumpet versions were best discriminated in isolated contexts, with discrimination progressively worse in single-voice and multivoice patterns. The bassoon versions were best discriminated in the single-voice patterns, with equal discrimination in the isolated and multivoice cases. It is suggested that these results were due to pronounced physical differences observed between the spectra of the two versions of the bassoon that were not apparent between the versions of the clarinet or trumpet.

  15. Large number discrimination by mosquitofish.

    Directory of Open Access Journals (Sweden)

    Christian Agrillo

    Full Text Available BACKGROUND: Recent studies have demonstrated that fish display rudimentary numerical abilities similar to those observed in mammals and birds. The mechanisms underlying the discrimination of small quantities (<4 were recently investigated while, to date, no study has examined the discrimination of large numerosities in fish. METHODOLOGY/PRINCIPAL FINDINGS: Subjects were trained to discriminate between two sets of small geometric figures using social reinforcement. In the first experiment mosquitofish were required to discriminate 4 from 8 objects with or without experimental control of the continuous variables that co-vary with number (area, space, density, total luminance. Results showed that fish can use the sole numerical information to compare quantities but that they preferentially use cumulative surface area as a proxy of the number when this information is available. A second experiment investigated the influence of the total number of elements to discriminate large quantities. Fish proved to be able to discriminate up to 100 vs. 200 objects, without showing any significant decrease in accuracy compared with the 4 vs. 8 discrimination. The third experiment investigated the influence of the ratio between the numerosities. Performance was found to decrease when decreasing the numerical distance. Fish were able to discriminate numbers when ratios were 1:2 or 2:3 but not when the ratio was 3:4. The performance of a sample of undergraduate students, tested non-verbally using the same sets of stimuli, largely overlapped that of fish. CONCLUSIONS/SIGNIFICANCE: Fish are able to use pure numerical information when discriminating between quantities larger than 4 units. As observed in human and non-human primates, the numerical system of fish appears to have virtually no upper limit while the numerical ratio has a clear effect on performance. These similarities further reinforce the view of a common origin of non-verbal numerical systems in all

  16. Efficiency of observer brightness discrimination in original and subracted images

    International Nuclear Information System (INIS)

    Swensson, R.G.; Kazda, I.; Nawfel, R.; Judy, P.F.

    1990-01-01

    This paper reports that, for an optimal image calculation, discriminating pairs of objects that differ only in brightness is equivalent to discriminating polarity differences in their subtraction images. This experiment measured and compared how efficiently human observers could perform the two different discriminations posed by such original and subtracted images. Disks of equal size, separated by their diameter, were superimposed on incorrelated, Gaussian noise backgrounds at different contrasts that made the two disks readily visible on the displayed radiographs. The digitally subtracted image-regions containing the two disks of each pair (shifted to registration) produced subtraction images with low-contrast disks that were either brighter or darker than the background. Observer performances in each task (measured by receiver operating characteristic [ROC] analysis) was compared with that of an optimal calculation (cross- correlator)

  17. Cognitive task analysis

    NARCIS (Netherlands)

    Schraagen, J.M.C.

    2000-01-01

    Cognitive task analysis is defined as the extension of traditional task analysis techniques to yield information about the knowledge, thought processes and goal structures that underlie observable task performance. Cognitive task analyses are conducted for a wide variety of purposes, including the

  18. A shared system of representation governing quantity discrimination in canids

    Directory of Open Access Journals (Sweden)

    Joseph M Baker

    2012-10-01

    Full Text Available One way to investigate the evolution of cognition is to compare the abilities of phylogenetically related species. The domestic dog (Canis lupus familiaris, for example, still shares cognitive abilities with the coyote (C. latrans. Both of these canids possess the ability to make psychophysical less/more discriminations of food based on quantity. Like many other species including humans, this ability is mediated by Weber’s Law: discrimination of continuous quantities is dependent on the ratio between the two quantities. As two simultaneously presented quantities of food become more similar, choice of the large or small option becomes random in both dogs and coyotes. It remains unknown, however, whether these closely related species within the same family—one domesticated, and one wild—make such quantitative comparisons with comparable accuracy. Has domestication honed or diminished this quantitative ability? Might different selective and ecological pressures facing coyotes drive them to be more or less able to accurately represent and discriminate food quantity than domesticated dogs? This study is an effort to elucidate this question concerning the evolution of non-verbal quantitative cognition.Here, we tested the quantitative discrimination ability of 16 domesticated dogs. Each animal was given 9 trials in which two different quantities of food were simultaneously displayed to them. The domesticated dogs’ performance on this task was then compared directly to the data from 16 coyotes’ performance on this same task reported by Baker and colleagues (2011.The quantitative discrimination abilities between the two species were strikingly similar. Domesticated dogs demonstrated similar quantitative sensitivity as coyotes, suggesting that domestication may not have significantly altered the psychophysical discrimination abilities of canids. Instead, this study provides further evidence for similar nonverbal quantitative abilities across

  19. Discriminant analysis of functional optical topography for schizophrenia diagnosis

    Science.gov (United States)

    Chuang, Ching-Cheng; Nakagome, Kazuyuki; Pu, Shenghong; Lan, Tsuo-Hung; Lee, Chia-Yen; Sun, Chia-Wei

    2014-01-01

    Abnormal prefrontal function plays a central role in the cognition deficits of schizophrenic patients; however, the character of the relationship between discriminant analysis and prefrontal activation remains undetermined. Recently, evidence of low prefrontal cortex (PFC) activation in individuals with schizophrenia has also been found during verbal fluency tests (VFT) and other cognitive tests with several neuroimaging methods. The purpose of this study is to assess the hemodynamic changes of the PFC and discriminant analysis between schizophrenia patients and healthy controls during VFT task by utilizing functional optical topography. A total of 99 subjects including 53 schizophrenic patients and 46 age- and gender-matched healthy controls were studied. The results showed that the healthy group had larger activation in the right and left PFC than in the middle PFC. Besides, the schizophrenic group showed weaker task performance and lower activation in the whole PFC than the healthy group. The result of the discriminant analysis showed a significant difference with P value <0.001 in six channels (CH 23, 29, 31, 40, 42, 52) between the schizophrenic and healthy groups. Finally, 68.69% and 71.72% of subjects are correctly classified as being schizophrenic or healthy with all 52 channels and six significantly different channels, respectively. Our findings suggest that the left PFC can be a feature region for discriminant analysis of schizophrenic diagnosis.

  20. Hand proximity facilitates spatial discrimination of auditory tones

    Directory of Open Access Journals (Sweden)

    Philip eTseng

    2014-06-01

    Full Text Available The effect of hand proximity on vision and visual attention has been well documented. In this study we tested whether such effect(s would also be present in the auditory modality. With hands placed either near or away from the audio sources, participants performed an auditory-spatial discrimination (Exp 1: left or right side, pitch discrimination (Exp 2: high, med, or low tone, and spatial-plus-pitch (Exp 3: left or right; high, med, or low discrimination task. In Exp 1, when hands were away from the audio source, participants consistently responded faster with their right hand regardless of stimulus location. This right hand advantage, however, disappeared in the hands-near condition because of a significant improvement in left hand’s reaction time. No effect of hand proximity was found in Exp 2 or 3, where a choice reaction time task requiring pitch discrimination was used. Together, these results suggest that the effect of hand proximity is not exclusive to vision alone, but is also present in audition, though in a much weaker form. Most important, these findings provide evidence from auditory attention that supports the multimodal account originally raised by Reed et al. in 2006.

  1. Quantity discrimination in wolves (Canis lupus

    Directory of Open Access Journals (Sweden)

    Ewelina eUtrata

    2012-11-01

    Full Text Available Quantity discrimination has been studied extensively in different non-human animal species. In the current study, we tested eleven hand-raised wolves (Canis lupus in a two-way choice task. We placed a number of food items (one to four sequentially into two opaque cans and asked the wolves to choose the larger amount. Moreover, we conducted two additional control conditions to rule out non-numerical properties of the presentation that the animals might have used to make the correct choice. Our results showed that wolves are able to make quantitative judgments at the group, but also at the individual level even when alternative strategies such as paying attention to the surface area or time and total amount are ruled out. In contrast to previous canine studies on dogs (Canis familiaris and coyotes (Canis latrans, our wolves’ performance did not improve with decreasing ratio, referred to as Weber’s law. However, further studies using larger quantities than we used in the current setup are still needed to determine whether and when wolves’ quantity discrimination conforms to Weber’s law.

  2. Face adaptation improves gender discrimination.

    Science.gov (United States)

    Yang, Hua; Shen, Jianhong; Chen, Juan; Fang, Fang

    2011-01-01

    Adaptation to a visual pattern can alter the sensitivities of neuronal populations encoding the pattern. However, the functional roles of adaptation, especially in high-level vision, are still equivocal. In the present study, we performed three experiments to investigate if face gender adaptation could affect gender discrimination. Experiments 1 and 2 revealed that adapting to a male/female face could selectively enhance discrimination for male/female faces. Experiment 3 showed that the discrimination enhancement induced by face adaptation could transfer across a substantial change in three-dimensional face viewpoint. These results provide further evidence suggesting that, similar to low-level vision, adaptation in high-level vision could calibrate the visual system to current inputs of complex shapes (i.e. face) and improve discrimination at the adapted characteristic. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Discrimination of chromosome by autoradiography

    International Nuclear Information System (INIS)

    Masubuchi, Masanori

    1975-01-01

    This paper describes discrimination of chromosome by autoradiography. In this method, the difference in DNA synthetic phase between each chromosome was used as a standard, and the used chromosome was in metaphase, as morphological characteristics were markedly in this phase. Cell cycle and autoradiography with 3 H-thymidine were also examined. In order to discriminate chromosome by autoradiography, it was effective to utilize the labelled pattern in late DNA synthetic phase, where asynchronous replication of chromosome appeared most obviously. DNA synthesis in chromosome was examined in each DNA synthetic phase by culturing the chromosome after the treatment with 3 H-thymidine and altering the time to prepare chromosome specimen. Discrimination of chromosome in plants and animals by autoradiography was also mentioned. It was noticed as a structural and functional discrimination of chromosome to observe amino acid uptake into chromosome protein and to utilize the difference in labelled pattern between the sites of chromosome. (K. Serizawa)

  4. EU Law and Multiple Discrimination

    DEFF Research Database (Denmark)

    Nielsen, Ruth

    2006-01-01

    In EU law, nationality and gender were the only equality issues on the legal agenda from the outset in 1958 and for about 40 years. Multiple discrimination was not addressed until the 1990's. The intersectionality approach which has been widely discussed outside Europe has mainly been used...... with a view to gendermainstreaming the fight against other kinds of discrimination (on grounds of ethnic origin, age, etc)....

  5. Discrimination and Equality of Opportunity

    OpenAIRE

    J. Ignacio García-Pérez; Antonio Villar

    2009-01-01

    This paper presents a measure of social discrimination based on the principle of equality of opportunity. According to this principle we only have to care about the inequality derived from people’s differential circumstances (and not about outcome differences due to people’s diverse degree of effort). We propose approaching the measurement of group discrimination as the “welfare loss” attributed to the inequality between social groups of similar characteristics. We also provide an empirical a...

  6. Sexual orientation discrimination in hiring

    OpenAIRE

    Doris Weichselbaumer

    2000-01-01

    Little research has been done to examine discrimination against gays and lesbians in the labor market. Badgett (1995) conducted the only previous study investigating labor market outcomes of gays and lesbians using a random data set. However, due to the structure of the data, the wage differential between heterosexuals and gays and lesbians that is found can not be directly assigned to employer discrimination. Some gays and lesbians might deploy passing strategies to hide their sexual orienta...

  7. Unambiguous discrimination among oracle operators

    International Nuclear Information System (INIS)

    Chefles, Anthony; Kitagawa, Akira; Takeoka, Masahiro; Sasaki, Masahide; Twamley, Jason

    2007-01-01

    We address the problem of unambiguous discrimination among oracle operators. The general theory of unambiguous discrimination among unitary operators is extended with this application in mind. We prove that entanglement with an ancilla cannot assist any discrimination strategy for commuting unitary operators. We also obtain a simple, practical test for the unambiguous distinguishability of an arbitrary set of unitary operators on a given system. Using this result, we prove that the unambiguous distinguishability criterion is the same for both standard and minimal oracle operators. We then show that, except in certain trivial cases, unambiguous discrimination among all standard oracle operators corresponding to integer functions with fixed domain and range is impossible. However, we find that it is possible to unambiguously discriminate among the Grover oracle operators corresponding to an arbitrarily large unsorted database. The unambiguous distinguishability of standard oracle operators corresponding to totally indistinguishable functions, which possess a strong form of classical indistinguishability, is analysed. We prove that these operators are not unambiguously distinguishable for any finite set of totally indistinguishable functions on a Boolean domain and with arbitrary fixed range. Sets of such functions on a larger domain can have unambiguously distinguishable standard oracle operators, and we provide a complete analysis of the simplest case, that of four functions. We also examine the possibility of unambiguous oracle operator discrimination with multiple parallel calls and investigate an intriguing unitary superoperator transformation between standard and entanglement-assisted minimal oracle operators

  8. The Caledonian face test: A new test of face discrimination.

    Science.gov (United States)

    Logan, Andrew J; Wilkinson, Frances; Wilson, Hugh R; Gordon, Gael E; Loffler, Gunter

    2016-02-01

    This study aimed to develop a clinical test of face perception which is applicable to a wide range of patients and can capture normal variability. The Caledonian face test utilises synthetic faces which combine simplicity with sufficient realism to permit individual identification. Face discrimination thresholds (i.e. minimum difference between faces required for accurate discrimination) were determined in an "odd-one-out" task. The difference between faces was controlled by an adaptive QUEST procedure. A broad range of face discrimination sensitivity was determined from a group (N=52) of young adults (mean 5.75%; SD 1.18; range 3.33-8.84%). The test is fast (3-4 min), repeatable (test-re-test r(2)=0.795) and demonstrates a significant inversion effect. The potential to identify impairments of face discrimination was evaluated by testing LM who reported a lifelong difficulty with face perception. While LM's impairment for two established face tests was close to the criterion for significance (Z-scores of -2.20 and -2.27) for the Caledonian face test, her Z-score was -7.26, implying a more than threefold higher sensitivity. The new face test provides a quantifiable and repeatable assessment of face discrimination ability. The enhanced sensitivity suggests that the Caledonian face test may be capable of detecting more subtle impairments of face perception than available tests. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Discriminability of Single and Multichannel Intracortical Microstimulation within Somatosensory Cortex

    Directory of Open Access Journals (Sweden)

    Cynthia Kay Overstreet

    2016-12-01

    Full Text Available The addition of tactile and proprioceptive feedback to neuroprosthetic limbs is expected to significantly improve the control of these devices. Intracortical microstimulation (ICMS of somatosensory cortex is a promising method of delivering this sensory feedback. To date, the main focus of somatosensory ICMS studies has been to deliver discriminable signals, corresponding to varying intensity, to a single location in cortex. However, multiple independent and simultaneous streams of sensory information will need to be encoded by ICMS to provide functionally relevant feedback for a neuroprosthetic limb (e.g. encoding contact events and pressure on multiple digits.In this study, we evaluated the ability of an awake, behaving non-human primate (Macaca mulatta to discriminate ICMS stimuli delivered on multiple electrodes spaced within somatosensory cortex. We delivered serial stimulation on single electrodes to evaluate the discriminability of sensations corresponding to ICMS of distinct cortical locations. Additionally, we delivered trains of multichannel stimulation, derived from a tactile sensor, synchronously across multiple electrodes. Our results indicate that discrimination of multiple ICMS stimuli is a challenging task, but that discriminable sensory percepts can be elicited by both single and multichannel ICMS on electrodes spaced within somatosensory cortex.

  10. Influence of musical and psychoacoustical training on pitch discrimination.

    Science.gov (United States)

    Micheyl, Christophe; Delhommeau, Karine; Perrot, Xavier; Oxenham, Andrew J

    2006-09-01

    This study compared the influence of musical and psychoacoustical training on auditory pitch discrimination abilities. In a first experiment, pitch discrimination thresholds for pure and complex tones were measured in 30 classical musicians and 30 non-musicians, none of whom had prior psychoacoustical training. The non-musicians' mean thresholds were more than six times larger than those of the classical musicians initially, and still about four times larger after 2h of training using an adaptive two-interval forced-choice procedure; this difference is two to three times larger than suggested by previous studies. The musicians' thresholds were close to those measured in earlier psychoacoustical studies using highly trained listeners, and showed little improvement with training; this suggests that classical musical training can lead to optimal or nearly optimal pitch discrimination performance. A second experiment was performed to determine how much additional training was required for the non-musicians to obtain thresholds as low as those of the classical musicians from experiment 1. Eight new non-musicians with no prior training practiced the frequency discrimination task for a total of 14 h. It took between 4 and 8h of training for their thresholds to become as small as those measured in the classical musicians from experiment 1. These findings supplement and qualify earlier data in the literature regarding the respective influence of musical and psychoacoustical training on pitch discrimination performance.

  11. Social Interaction and Conditional Self-Discrimination under a Paradigm of Avoidance and Positive Reinforcement in Wistar Rats

    Science.gov (United States)

    Penagos-Corzo, Julio C.; Pérez-Acosta, Andrés M.; Hernández, Ingrid

    2015-01-01

    The experiment reported here uses a conditional self-discrimination task to examine the influence of social interaction on the facilitation of self-discrimination in rats. The study is based on a previous report (Penagos- Corzo et al., 2011) showing positive evidence of such facilitation, but extending the exposition to social interaction…

  12. Functional discrimination of membrane proteins using machine learning techniques

    Directory of Open Access Journals (Sweden)

    Yabuki Yukimitsu

    2008-03-01

    Full Text Available Abstract Background Discriminating membrane proteins based on their functions is an important task in genome annotation. In this work, we have analyzed the characteristic features of amino acid residues in membrane proteins that perform major functions, such as channels/pores, electrochemical potential-driven transporters and primary active transporters. Results We observed that the residues Asp, Asn and Tyr are dominant in channels/pores whereas the composition of hydrophobic residues, Phe, Gly, Ile, Leu and Val is high in electrochemical potential-driven transporters. The composition of all the amino acids in primary active transporters lies in between other two classes of proteins. We have utilized different machine learning algorithms, such as, Bayes rule, Logistic function, Neural network, Support vector machine, Decision tree etc. for discriminating these classes of proteins. We observed that most of the algorithms have discriminated them with similar accuracy. The neural network method discriminated the channels/pores, electrochemical potential-driven transporters and active transporters with the 5-fold cross validation accuracy of 64% in a data set of 1718 membrane proteins. The application of amino acid occurrence improved the overall accuracy to 68%. In addition, we have discriminated transporters from other α-helical and β-barrel membrane proteins with the accuracy of 85% using k-nearest neighbor method. The classification of transporters and all other proteins (globular and membrane showed the accuracy of 82%. Conclusion The performance of discrimination with amino acid occurrence is better than that with amino acid composition. We suggest that this method could be effectively used to discriminate transporters from all other globular and membrane proteins, and classify them into channels/pores, electrochemical and active transporters.

  13. The Effect of Task Duration on Event-Based Prospective Memory: A Multinomial Modeling Approach

    Directory of Open Access Journals (Sweden)

    Hongxia Zhang

    2017-11-01

    Full Text Available Remembering to perform an action when a specific event occurs is referred to as Event-Based Prospective Memory (EBPM. This study investigated how EBPM performance is affected by task duration by having university students (n = 223 perform an EBPM task that was embedded within an ongoing computer-based color-matching task. For this experiment, we separated the overall task’s duration into the filler task duration and the ongoing task duration. The filler task duration is the length of time between the intention and the beginning of the ongoing task, and the ongoing task duration is the length of time between the beginning of the ongoing task and the appearance of the first Prospective Memory (PM cue. The filler task duration and ongoing task duration were further divided into three levels: 3, 6, and 9 min. Two factors were then orthogonally manipulated between-subjects using a multinomial processing tree model to separate the effects of different task durations on the two EBPM components. A mediation model was then created to verify whether task duration influences EBPM via self-reminding or discrimination. The results reveal three points. (1 Lengthening the duration of ongoing tasks had a negative effect on EBPM performance while lengthening the duration of the filler task had no significant effect on it. (2 As the filler task was lengthened, both the prospective and retrospective components show a decreasing and then increasing trend. Also, when the ongoing task duration was lengthened, the prospective component decreased while the retrospective component significantly increased. (3 The mediating effect of discrimination between the task duration and EBPM performance was significant. We concluded that different task durations influence EBPM performance through different components with discrimination being the mediator between task duration and EBPM performance.

  14. Task demand, task management, and teamwork

    Energy Technology Data Exchange (ETDEWEB)

    Braarud, Per Oeivind; Brendryen, Haavar

    2001-03-15

    The current approach to mental workload assessment in process control was evaluated in 3 previous HAMMLAB studies, by analysing the relationship between workload related measures and performance. The results showed that subjective task complexity rating was related to team's control room performance, that mental effort (NASA-TLX) was weakly related to performance, and that overall activity level was unrelated to performance. The results support the argument that general cognitive measures, i.e., mental workload, are weakly related to performance in the process control domain. This implies that other workload concepts than general mental workload are needed for valid assessment of human reliability and for valid assessment of control room configurations. An assessment of task load in process control suggested that how effort is used to handle task demand is more important then the level of effort invested to solve the task. The report suggests two main workload related concepts with a potential as performance predictors in process control: task requirements, and the work style describing how effort is invested to solve the task. The task requirements are seen as composed of individual task demand and team demand. In a similar way work style are seen as composed of individual task management and teamwork style. A framework for the development of the concepts is suggested based on a literature review and experiences from HAMMLAB research. It is suggested that operational definitions of workload concepts should be based on observable control room behaviour, to assure a potential for developing performance-shaping factors. Finally an explorative analysis of teamwork measures and performance in one study indicated that teamwork concepts are related to performance. This lends support to the suggested development of team demand and teamwork style as elements of a framework for the analysis of workload in process control. (Author)

  15. LLNL's Regional Seismic Discrimination Research

    International Nuclear Information System (INIS)

    Hanley, W; Mayeda, K; Myers, S; Pasyanos, M; Rodgers, A; Sicherman, A; Walter, W

    1999-01-01

    As part of the Department of Energy's research and development effort to improve the monitoring capability of the planned Comprehensive Nuclear-Test-Ban Treaty international monitoring system, Lawrence Livermore Laboratory (LLNL) is testing and calibrating regional seismic discrimination algorithms in the Middle East, North Africa and Western Former Soviet Union. The calibration process consists of a number of steps: (1) populating the database with independently identified regional events; (2) developing regional boundaries and pre-identifying severe regional phase blockage zones; (3) measuring and calibrating coda based magnitude scales; (4a) measuring regional amplitudes and making magnitude and distance amplitude corrections (MDAC); (4b) applying the DOE modified kriging methodology to MDAC results using the regionalized background model; (5) determining the thresholds of detectability of regional phases as a function of phase type and frequency; (6) evaluating regional phase discriminant performance both singly and in combination; (7) combining steps 1-6 to create a calibrated discrimination surface for each stations; (8) assessing progress and iterating. We have now developed this calibration procedure to the point where it is fairly straightforward to apply earthquake-explosion discrimination in regions with ample empirical data. Several of the steps outlined above are discussed in greater detail in other DOE papers in this volume or in recent publications. Here we emphasize the results of the above process: station correction surfaces and their improvement to discrimination results compared with simpler calibration methods. Some of the outstanding discrimination research issues involve cases in which there is little or no empirical data. For example in many cases there is no regional nuclear explosion data at IMS stations or nearby surrogates. We have taken two approaches to this problem, first finding and using mining explosion data when available, and

  16. Dynamic, continuous multitasking training leads to task-specific improvements but does not transfer across action selection tasks

    Science.gov (United States)

    Bender, Angela D.; Filmer, Hannah L.; Naughtin, Claire K.; Dux, Paul E.

    2017-12-01

    The ability to perform multiple tasks concurrently is an ever-increasing requirement in our information-rich world. Despite this, multitasking typically compromises performance due to the processing limitations associated with cognitive control and decision-making. While intensive dual-task training is known to improve multitasking performance, only limited evidence suggests that training-related performance benefits can transfer to untrained tasks that share overlapping processes. In the real world, however, coordinating and selecting several responses within close temporal proximity will often occur in high-interference environments. Over the last decade, there have been notable reports that training on video action games that require dynamic multitasking in a demanding environment can lead to transfer effects on aspects of cognition such as attention and working memory. Here, we asked whether continuous and dynamic multitasking training extends benefits to tasks that are theoretically related to the trained tasks. To examine this issue, we asked a group of participants to train on a combined continuous visuomotor tracking task and a perceptual discrimination task for six sessions, while an active control group practiced the component tasks in isolation. A battery of tests measuring response selection, response inhibition, and spatial attention was administered before and immediately after training to investigate transfer. Multitasking training resulted in substantial, task-specific gains in dual-task ability, but there was no evidence that these benefits generalized to other action control tasks. The findings suggest that training on a combined visuomotor tracking and discrimination task results in task-specific benefits but provides no additional value for untrained action selection tasks.

  17. Project Tasks in Robotics

    DEFF Research Database (Denmark)

    Sørensen, Torben; Hansen, Poul Erik

    1998-01-01

    Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics......Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics...

  18. An FMRI-compatible Symbol Search task.

    Science.gov (United States)

    Liebel, Spencer W; Clark, Uraina S; Xu, Xiaomeng; Riskin-Jones, Hannah H; Hawkshead, Brittany E; Schwarz, Nicolette F; Labbe, Donald; Jerskey, Beth A; Sweet, Lawrence H

    2015-03-01

    Our objective was to determine whether a Symbol Search paradigm developed for functional magnetic resonance imaging (FMRI) is a reliable and valid measure of cognitive processing speed (CPS) in healthy older adults. As all older adults are expected to experience cognitive declines due to aging, and CPS is one of the domains most affected by age, establishing a reliable and valid measure of CPS that can be administered inside an MR scanner may prove invaluable in future clinical and research settings. We evaluated the reliability and construct validity of a newly developed FMRI Symbol Search task by comparing participants' performance in and outside of the scanner and to the widely used and standardized Symbol Search subtest of the Wechsler Adult Intelligence Scale (WAIS). A brief battery of neuropsychological measures was also administered to assess the convergent and discriminant validity of the FMRI Symbol Search task. The FMRI Symbol Search task demonstrated high test-retest reliability when compared to performance on the same task administered out of the scanner (r=.791; pSymbol Search (r=.717; pSymbol Search task were also observed. The FMRI Symbol Search task is a reliable and valid measure of CPS in healthy older adults and exhibits expected sensitivity to the effects of age on CPS performance.

  19. Task assignment and coaching

    OpenAIRE

    Dominguez-Martinez, S.

    2009-01-01

    An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching from a manager, the junior employee only has information about his past performance. Based on his past performance, a talented junior who has performed a difficult task sometimes decides to leave the...

  20. Functional Task Test (FTT)

    Science.gov (United States)

    Bloomberg, Jacob J.; Mulavara, Ajitkumar; Peters, Brian T.; Rescheke, Millard F.; Wood, Scott; Lawrence, Emily; Koffman, Igor; Ploutz-Snyder, Lori; Spiering, Barry A.; Feeback, Daniel L.; hide

    2009-01-01

    This slide presentation reviews the Functional Task Test (FTT), an interdisciplinary testing regimen that has been developed to evaluate astronaut postflight functional performance and related physiological changes. The objectives of the project are: (1) to develop a set of functional tasks that represent critical mission tasks for the Constellation Program, (2) determine the ability to perform these tasks after space flight, (3) Identify the key physiological factors that contribute to functional decrements and (4) Use this information to develop targeted countermeasures.

  1. 45 CFR 1624.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Discrimination prohibited. 1624.4 Section 1624.4... AGAINST DISCRIMINATION ON THE BASIS OF DISABILITY § 1624.4 Discrimination prohibited. (a) No qualified... the benefits of, or otherwise be subjected to discrimination by any legal services program, directly...

  2. 20 CFR 405.30 - Discrimination complaints.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Discrimination complaints. 405.30 Section 405... INITIAL DISABILITY CLAIMS Introduction, General Description, and Definitions § 405.30 Discrimination... that an adjudicator has improperly discriminated against you, you may file a discrimination complaint...

  3. 14 CFR 399.36 - Unreasonable discrimination.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Unreasonable discrimination. 399.36 Section... Unreasonable discrimination. (a) As used in this section: (1) Unreasonable discrimination means unjust discrimination or unreasonable preference or prejudice; and (2) Rate means rate, fare, or charge. (b) Except in...

  4. Unambiguous discrimination of mixed quantum states

    International Nuclear Information System (INIS)

    Zhang Chi; Feng Yuan; Ying Mingsheng

    2006-01-01

    The problem of unambiguous discrimination between mixed quantum states is addressed by isolating the part of each mixed state which has no contribution to discrimination and by employing the strategy of set discrimination of pure states. A necessary and sufficient condition of unambiguous mixed state discrimination is presented. An upper bound of the efficiency is also derived

  5. International Trade and Labor Market Discrimination

    NARCIS (Netherlands)

    R. Chisik (Richard); J.E. Namini (Julian Emami)

    2016-01-01

    textabstractWe embed a competitive search model with labor market discrimination, or nepotism, into a two-sector, two-country framework in order to analyze how labor market discrimination impacts the pattern of international trade and also how trade trade affects discrimination. Discrimination, or

  6. Task assignment and coaching

    NARCIS (Netherlands)

    Dominguez-Martinez, S.

    2009-01-01

    An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching

  7. Orthogonal sparse linear discriminant analysis

    Science.gov (United States)

    Liu, Zhonghua; Liu, Gang; Pu, Jiexin; Wang, Xiaohong; Wang, Haijun

    2018-03-01

    Linear discriminant analysis (LDA) is a linear feature extraction approach, and it has received much attention. On the basis of LDA, researchers have done a lot of research work on it, and many variant versions of LDA were proposed. However, the inherent problem of LDA cannot be solved very well by the variant methods. The major disadvantages of the classical LDA are as follows. First, it is sensitive to outliers and noises. Second, only the global discriminant structure is preserved, while the local discriminant information is ignored. In this paper, we present a new orthogonal sparse linear discriminant analysis (OSLDA) algorithm. The k nearest neighbour graph is first constructed to preserve the locality discriminant information of sample points. Then, L2,1-norm constraint on the projection matrix is used to act as loss function, which can make the proposed method robust to outliers in data points. Extensive experiments have been performed on several standard public image databases, and the experiment results demonstrate the performance of the proposed OSLDA algorithm.

  8. Activation in the Right Inferior Parietal Lobule Reflects the Representation of Musical Structure beyond Simple Pitch Discrimination

    Science.gov (United States)

    Royal, Isabelle; Vuvan, Dominique T.; Zendel, Benjamin Rich; Robitaille, Nicolas; Schönwiesner, Marc; Peretz, Isabelle

    2016-01-01

    Pitch discrimination tasks typically engage the superior temporal gyrus and the right inferior frontal gyrus. It is currently unclear whether these regions are equally involved in the processing of incongruous notes in melodies, which requires the representation of musical structure (tonality) in addition to pitch discrimination. To this aim, 14 participants completed two tasks while undergoing functional magnetic resonance imaging, one in which they had to identify a pitch change in a series of non-melodic repeating tones and a second in which they had to identify an incongruous note in a tonal melody. In both tasks, the deviants activated the right superior temporal gyrus. A contrast between deviants in the melodic task and deviants in the non-melodic task (melodic > non-melodic) revealed additional activity in the right inferior parietal lobule. Activation in the inferior parietal lobule likely represents processes related to the maintenance of tonal pitch structure in working memory during pitch discrimination. PMID:27195523

  9. Deficits in discrimination after experimental frontal brain injury are mediated by motivation and can be improved by nicotinamide administration.

    Science.gov (United States)

    Vonder Haar, Cole; Maass, William R; Jacobs, Eric A; Hoane, Michael R

    2014-10-15

    One of the largest challenges in experimental neurotrauma work is the development of models relevant to the human condition. This includes both creating similar pathophysiology as well as the generation of relevant behavioral deficits. Recent studies have shown that there is a large potential for the use of discrimination tasks in rats to detect injury-induced deficits. The literature on discrimination and TBI is still limited, however. The current study investigated motivational and motor factors that could potentially contribute to deficits in discrimination. In addition, the efficacy of a neuroprotective agent, nicotinamide, was assessed. Rats were trained on a discrimination task and motivation task, given a bilateral frontal controlled cortical impact TBI (+3.0 AP, 0.0 ML from bregma), and then reassessed. They were also assessed on motor ability and Morris water maze (MWM) performance. Experiment 1 showed that TBI resulted in large deficits in discrimination and motivation. No deficits were observed on gross motor measures; however, the vehicle group showed impairments in fine motor control. Both injured groups were impaired on the reference memory MWM, but only nicotinamide-treated rats were impaired on the working memory MWM. Nicotinamide administration improved performance on discrimination and motivation measures. Experiment 2 evaluated retraining on the discrimination task and suggested that motivation may be a large factor underlying discrimination deficits. Retrained rats improved considerably on the discrimination task. The tasks evaluated in this study demonstrate robust deficits and may improve the detection of pharmaceutical effects by being very sensitive to pervasive cognitive deficits that occur after frontal TBI.

  10. Theoretical vs. empirical discriminability: the application of ROC methods to eyewitness identification.

    Science.gov (United States)

    Wixted, John T; Mickes, Laura

    2018-01-01

    Receiver operating characteristic (ROC) analysis was introduced to the field of eyewitness identification 5 years ago. Since that time, it has been both influential and controversial, and the debate has raised an issue about measuring discriminability that is rarely considered. The issue concerns the distinction between empirical discriminability (measured by area under the ROC curve) vs. underlying/theoretical discriminability (measured by d' or variants of it). Under most circumstances, the two measures will agree about a difference between two conditions in terms of discriminability. However, it is possible for them to disagree, and that fact can lead to confusion about which condition actually yields higher discriminability. For example, if the two conditions have implications for real-world practice (e.g., a comparison of competing lineup formats), should a policymaker rely on the area-under-the-curve measure or the theory-based measure? Here, we illustrate the fact that a given empirical ROC yields as many underlying discriminability measures as there are theories that one is willing to take seriously. No matter which theory is correct, for practical purposes, the singular area-under-the-curve measure best identifies the diagnostically superior procedure. For that reason, area under the ROC curve informs policy in a way that underlying theoretical discriminability never can. At the same time, theoretical measures of discriminability are equally important, but for a different reason. Without an adequate theoretical understanding of the relevant task, the field will be in no position to enhance empirical discriminability.

  11. Hippocampal-cortical contributions to strategic exploration during perceptual discrimination.

    Science.gov (United States)

    Voss, Joel L; Cohen, Neal J

    2017-06-01

    The hippocampus is crucial for long-term memory; its involvement in short-term or immediate expressions of memory is more controversial. Rodent hippocampus has been implicated in an expression of memory that occurs on-line during exploration termed "vicarious trial-and-error" (VTE) behavior. VTE occurs when rodents iteratively explore options during perceptual discrimination or at choice points. It is strategic in that it accelerates learning and improves later memory. VTE has been associated with activity of rodent hippocampal neurons, and lesions of hippocampus disrupt VTE and associated learning and memory advantages. Analogous findings of VTE in humans would support the role of hippocampus in active use of short-term memory to guide strategic behavior. We therefore measured VTE using eye-movement tracking during perceptual discrimination and identified relevant neural correlates with functional magnetic resonance imaging. A difficult perceptual-discrimination task was used that required visual information to be maintained during a several second trial, but with no long-term memory component. VTE accelerated discrimination. Neural correlates of VTE included robust activity of hippocampus and activity of a network of medial prefrontal and lateral parietal regions involved in memory-guided behavior. This VTE-related activity was distinct from activity associated with simply viewing visual stimuli and making eye movements during the discrimination task, which occurred in regions frequently associated with visual processing and eye-movement control. Subjects were mostly unaware of performing VTE, thus further distancing VTE from explicit long-term memory processing. These findings bridge the rodent and human literatures on neural substrates of memory-guided behavior, and provide further support for the role of hippocampus and a hippocampal-centered network of cortical regions in the immediate use of memory in on-line processing and the guidance of behavior. © 2017

  12. Numerosity but not texture-density discrimination correlates with math ability in children.

    Science.gov (United States)

    Anobile, Giovanni; Castaldi, Elisa; Turi, Marco; Tinelli, Francesca; Burr, David C

    2016-08-01

    Considerable recent work suggests that mathematical abilities in children correlate with the ability to estimate numerosity. Does math correlate only with numerosity estimation, or also with other similar tasks? We measured discrimination thresholds of school-age (6- to 12.5-years-old) children in 3 tasks: numerosity of patterns of relatively sparse, segregatable items (24 dots); numerosity of very dense textured patterns (250 dots); and discrimination of direction of motion. Thresholds in all tasks improved with age, but at different rates, implying the action of different mechanisms: In particular, in young children, thresholds were lower for sparse than textured patterns (the opposite of adults), suggesting earlier maturation of numerosity mechanisms. Importantly, numerosity thresholds for sparse stimuli correlated strongly with math skills, even after controlling for the influence of age, gender and nonverbal IQ. However, neither motion-direction discrimination nor numerosity discrimination of texture patterns showed a significant correlation with math abilities. These results provide further evidence that numerosity and texture-density are perceived by independent neural mechanisms, which develop at different rates; and importantly, only numerosity mechanisms are related to math. As developmental dyscalculia is characterized by a profound deficit in discriminating numerosity, it is fundamental to understand the mechanism behind the discrimination. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  13. Discriminative learning for speech recognition

    CERN Document Server

    He, Xiadong

    2008-01-01

    In this book, we introduce the background and mainstream methods of probabilistic modeling and discriminative parameter optimization for speech recognition. The specific models treated in depth include the widely used exponential-family distributions and the hidden Markov model. A detailed study is presented on unifying the common objective functions for discriminative learning in speech recognition, namely maximum mutual information (MMI), minimum classification error, and minimum phone/word error. The unification is presented, with rigorous mathematical analysis, in a common rational-functio

  14. Employment Discrimination against LGBT Utahns

    OpenAIRE

    Rosky, Clifford; Mallory, Christy; Smith, Jenni; Badgett, M.V. Lee

    2011-01-01

    This study analyzes data from a 2010 survey on the employment experiences of 939 LGBT people living in Utah.  The study found that 44% of LGB people and 66% of transgender people in Utah have experienced employment discrimination.  The data showed that employment discrimination based on sexual orientation and gender identity currently occurs in Utah, with close to 30% of LGB respondents and 45% of transgender respondents reporting that they experienced some form of workplace harassment on a w...

  15. Labor Market Discrimination: Vietnamese Immigrants

    Directory of Open Access Journals (Sweden)

    Linus Yamane

    2012-01-01

    Full Text Available Vietnamese and East European immigrants face similar obstacles in the U.S. labor market. This provides for an interesting test of racial discrimination in the labor market. Does it make any difference if an immigrant is Asian or White? When Vietnamese immigrants are compared to East European immigrants, Vietnamese men earn 7-9% less than comparable East European men, with more discrimination among the less educated, and in the larger Vietnamese population centers like California. Vietnamese women earn as much as comparable East European women. Vietnamese immigrants, male and female, are much less likely to hold managerial and supervisory positions than comparable East European immigrants.

  16. Labor Market Discrimination: Vietnamese Immigrants

    Directory of Open Access Journals (Sweden)

    Linus Yamane

    2012-01-01

    Full Text Available Vietnamese and East European immigrants face similar obstacles in the US labor market. This provides for an interesting test of racial discrimination in the labor market. Does it make any difference if an immigrant is Asian or White? When Vietnamese immigrants are compared to East European immigrants, Vietnamese men earn 7-9% less than comparable East European men, with more discrimination among the less educated, and in the larger Vietnamese population centers like California. Vietnamese women earn as much as comparable East European women. Vietnamese immigrants, male and female, are much less likely to hold managerial and supervisory positions than comparable East European immigrants.

  17. A scheme of quantum state discrimination over specified states via weak-value measurement

    Science.gov (United States)

    Chen, Xi; Dai, Hong-Yi; Liu, Bo-Yang; Zhang, Ming

    2018-04-01

    The commonly adopted projective measurements are invalid in the specified task of quantum state discrimination when the discriminated states are superposition of planar-position basis states whose complex-number probability amplitudes have the same magnitude but different phases. Therefore we propose a corresponding scheme via weak-value measurement and examine the feasibility of this scheme. Furthermore, the role of the weak-value measurement in quantum state discrimination is analyzed and compared with one in quantum state tomography in this Letter.

  18. Gender and the right to non-discrimination in international human rights law

    OpenAIRE

    Netkova, Bistra

    2016-01-01

    Discrimination against women based on the fact that they are women is a deeply rooted practice in all societies. However, the level of discrimination varies greatly with the level of development of the given society and strongly influences and vice versa it is influenced by the status of women in a given society. Addressing this gender-based discrimination is a difficult task because it is closely linked to the concept of equality, and state’s action and inactions. The article establishes tha...

  19. Purposeful Goal-Directed Movements Give Rise to Higher Tactile Discrimination Performance

    Directory of Open Access Journals (Sweden)

    Georgiana Juravle

    2011-10-01

    Full Text Available Tactile perception is inhibited during goal-directed reaching movements (sensory suppression. Here, participants performed simple reaching or exploratory movements (where contact with the table surface was maintained. We measured tactile discrimination thresholds for vibratory stimuli delivered to participants' wrists while executing the movement, and while at rest. Moreover, we measured discrimination performance (in a same vs. different task for the materials covering the table surface, during the execution of the different movements. The threshold and discrimination tasks could be performed either singly or together, both under active movement and passive conditions (ie, no movement required, but with tactile stimulation. Thresholds measured at rest were significantly lower than thresholds measured during both active movements and passive touches. This provides a clear indication of sensory suppression during movement execution. Moreover, the discrimination data revealed main effects of task (single vs. dual, movement execution type (passive vs. active, and movement type (reach vs. exploration: Discrimination performance was significantly higher under conditions of single-tasking, active movements, as well as exploratory movements. Therefore, active movement of the hand with the purpose of gaining tactual information about the surface of the table gives rise to enhanced performance, thus suggesting that we feel more when we need to; It would appear that tactual information is prioritized when relevant for the movement being executed.

  20. Mental workload while driving: effects on visual search, discrimination, and decision making.

    Science.gov (United States)

    Recarte, Miguel A; Nunes, Luis M

    2003-06-01

    The effects of mental workload on visual search and decision making were studied in real traffic conditions with 12 participants who drove an instrumented car. Mental workload was manipulated by having participants perform several mental tasks while driving. A simultaneous visual-detection and discrimination test was used as performance criteria. Mental tasks produced spatial gaze concentration and visual-detection impairment, although no tunnel vision occurred. According to ocular behavior analysis, this impairment was due to late detection and poor identification more than to response selection. Verbal acquisition tasks were innocuous compared with production tasks, and complex conversations, whether by phone or with a passenger, are dangerous for road safety.

  1. DISCRIMINATION BY ASSOCIATION IN EUROPEAN LAW

    Directory of Open Access Journals (Sweden)

    Cătălina-Adriana Ivănuș

    2013-11-01

    Full Text Available The european law prohibit direct and indirect discrimination and harrasment on grounds of sex, racial or ethnic, religion or belief, disability, age or sexual orientation. The question is what is the situation when someone is discriminated on can claim to be the victim of unlawful discrimination because he or she is associated with another person who has the protected characteristic. The the Court of Justice of the European Union’s judgment in Coleman v Attridge Law and Steve Law confirms, for the first time in European law, the existence of the concept of discrimination by association. In this article I examine the implications of this case on all conceps of discrimination concepts of discrimination in European law (direct discrimination, indirect discrimination and harassment. I also examine the application of discrimination by association to grounds other than disability.

  2. Spatial layout affects speed discrimination

    Science.gov (United States)

    Verghese, P.; Stone, L. S.

    1997-01-01

    We address a surprising result in a previous study of speed discrimination with multiple moving gratings: discrimination thresholds decreased when the number of stimuli was increased, but remained unchanged when the area of a single stimulus was increased [Verghese & Stone (1995). Vision Research, 35, 2811-2823]. In this study, we manipulated the spatial- and phase relationship between multiple grating patches to determine their effect on speed discrimination thresholds. In a fusion experiment, we merged multiple stimulus patches, in stages, into a single patch. Thresholds increased as the patches were brought closer and their phase relationship was adjusted to be consistent with a single patch. Thresholds increased further still as these patches were fused into a single patch. In a fission experiment, we divided a single large patch into multiple patches by superimposing a cross with luminance equal to that of the background. Thresholds decreased as the large patch was divided into quadrants and decreased further as the quadrants were maximally separated. However, when the cross luminance was darker than the background, it was perceived as an occluder and thresholds, on average, were unchanged from that for the single large patch. A control experiment shows that the observed trend in discrimination thresholds is not due to the differences in perceived speed of the stimuli. These results suggest that the parsing of the visual image into entities affects the combination of speed information across space, and that each discrete entity effectively provides a single independent estimate of speed.

  3. A Talk on Sex Discrimination.

    Science.gov (United States)

    Evers, Irving C.

    The topic of this speech covers the 1972 amendments to Title VII of the Civil Rights Act of 1964 and the subsequent court cases dealing with sex discrimination. The cases discussed cover maternity leaves for tenured as well as untenured teachers and other public employees. The issues basic to these cases involve mandatory maternity leaves at…

  4. Sex Discrimination in Employment Practices.

    Science.gov (United States)

    California Univ., Los Angeles. Univ. Extension.

    The conference on sex discrimination in employment practices was held at the University of California at Los Angeles in cooperation with the Women's Bureau of the Department of Labor. Speeches included: (1) "New Legislation--New Action" by Rosalind K. Loring and William Foster, (2) "Compliance Policies and Procedures for Business and Industry" by…

  5. Gender discrimination and job characteristics

    NARCIS (Netherlands)

    Dubbelt, L.; Rispens, S.; Demerouti, E.

    2016-01-01

    Purpose – The purpose of this paper is to examine the relationship between gender discrimination and the perceived job demands and job resources of women and men. This is important because it may provide insight into what factors contribute to women’s disadvantaged position at work.

  6. Quantifying explainable discrimination and removing illegal discrimination in automated decision making

    NARCIS (Netherlands)

    Kamiran, F.; Zliobaite, I.; Calders, T.G.K.

    2013-01-01

    Recently, the following discrimination-aware classification problem was introduced. Historical data used for supervised learning may contain discrimination, for instance, with respect to gender. The question addressed by discrimination-aware techniques is, given sensitive attribute, how to train

  7. Social Status Correlates of Reporting Racial Discrimination and Gender Discrimination among Racially Diverse Women

    OpenAIRE

    Ro, Annie E.; Choi, Kyung-Hee

    2009-01-01

    The growing body of research on discrimination and health indicates a deleterious effect of discrimination on various health outcomes. However, less is known about the sociodemographic correlates of reporting racial discrimination and gender discrimination among racially diverse women. We examined the associations of social status characteristics with lifetime experiences of racial discrimination and gender discrimination using a racially-diverse sample of 754 women attending family planning ...

  8. Are the effects of benzodiazepines on discrimination and punishment dissociable?

    Science.gov (United States)

    Hodges, H; Green, S

    1987-01-01

    Studies have shown that benzodiazepines (BZs) both disrupt discrimination and increase resistance to punishment. Using a delayed response task, we provide evidence that effects of BZs on discrimination cannot be fully explained by deficits in either short or long term memory, or by intolerance for delay of reward. A schedule with rewarded, nonrewarded (Time out: TO) and conflict components was used to investigate effects in rats of compounds active at the BZ receptor on successive discrimination and punished responding in parallel. The GABA transaminase inhibitor ethanolamine-O-sulphate exerted additive effects with chlordiazepoxide (CDP) on punished but not TO responding. Both GABA and CDP injected into the amygdala selectively increased conflict rates, but with peripheral treatment CDP also increased TO rates. Two inverse BZ agonists, CGS 8216 and FG 7142 antagonzied the anti-conflict effects of GABA and CDP, given within the amygdala or peripherally, but the increase in TO rates induced by systemic CDP was counteracted only by peripheral treatments. These compounds also reduced rates of conflict responding below baseline, consistent with anxiogenic activity. Effects of the BZ antagonist Ro 15-1788 were broadly similar to those of the inverse agonists, except that it did not antagonise the anti-conflict action of intra-amygdaloid GABA, nor significantly reduce punished responding at the single dose used. We conclude from these results that the anti-conflict effects of BZs are mediated by a GABAergic amygdaloid mechanism, but that the same mechanism is not involved in BZ effects on discrimination.

  9. An example of multidimensional analysis: Discriminant analysis

    International Nuclear Information System (INIS)

    Lutz, P.

    1990-01-01

    Among the approaches on the data multi-dimensional analysis, lectures on the discriminant analysis including theoretical and practical aspects are presented. The discrimination problem, the analysis steps and the discrimination categories are stressed. Examples on the descriptive historical analysis, the discrimination for decision making, the demonstration and separation of the top quark are given. In the linear discriminant analysis the following subjects are discussed: Huyghens theorem, projection, discriminant variable, geometrical interpretation, case for g=2, classification method, separation of the top events. Criteria allowing the obtention of relevant results are included [fr

  10. Transport Task Force Leadership, Task 4

    International Nuclear Information System (INIS)

    Callen, J.D.

    1991-07-01

    The Transport Task Force (TTF) was initiated as a broad-based US magnetic fusion community activity during the fall of 1988 to focus attention on and encourage development of an increased understanding of anomalous transport in tokamaks. The overall TTF goal is to make progress on Characterizing, Understanding and Identifying how to Reduce plasma transport in tokamaks -- to CUIR transport

  11. Left occipitotemporal cortex contributes to the discrimination of tool-associated hand actions: fMRI and TMS evidence

    Directory of Open Access Journals (Sweden)

    Francesca ePerini

    2014-08-01

    Full Text Available Functional neuroimaging studies have implicated the left lateral occipitotemporal cortex (LOTC in both tool and hand perception but the functional role of this region is not fully known. Here, by using a task manipulation, we tested whether tool-/hand-selective LOTC contributes to the discrimination of tool-associated hand actions. Participants viewed briefly presented pictures of kitchen and garage tools while they performed one of two tasks: in the action task, they judged whether the tool is associated with a hand rotation action (e.g., screwdriver or a hand squeeze action (e.g., garlic press, while in the location task they judged whether the tool is typically found in the kitchen (e.g., garlic press or in the garage (e.g., screwdriver. Both tasks were performed on the same stimulus set and were matched for difficulty. Contrasting fMRI responses between these tasks showed stronger activity during the action task than the location task in both tool- and hand-selective LOTC regions, which closely overlapped. No differences were found in nearby object- and motion-selective control regions. Importantly, these findings were confirmed by a TMS study, which showed that effective TMS over the tool-/hand-selective LOTC region significantly slowed responses for tool action discriminations relative to tool location discriminations, with no such difference during sham TMS. We conclude that left LOTC contributes to the discrimination of tool-associated hand actions.

  12. Left occipitotemporal cortex contributes to the discrimination of tool-associated hand actions: fMRI and TMS evidence.

    Science.gov (United States)

    Perini, Francesca; Caramazza, Alfonso; Peelen, Marius V

    2014-01-01

    Functional neuroimaging studies have implicated the left lateral occipitotemporal cortex (LOTC) in both tool and hand perception but the functional role of this region is not fully known. Here, by using a task manipulation, we tested whether tool-/hand-selective LOTC contributes to the discrimination of tool-associated hand actions. Participants viewed briefly presented pictures of kitchen and garage tools while they performed one of two tasks: in the action task, they judged whether the tool is associated with a hand rotation action (e.g., screwdriver) or a hand squeeze action (e.g., garlic press), while in the location task they judged whether the tool is typically found in the kitchen (e.g., garlic press) or in the garage (e.g., screwdriver). Both tasks were performed on the same stimulus set and were matched for difficulty. Contrasting fMRI responses between these tasks showed stronger activity during the action task than the location task in both tool- and hand-selective LOTC regions, which closely overlapped. No differences were found in nearby object- and motion-selective control regions. Importantly, these findings were confirmed by a TMS study, which showed that effective TMS over the tool-/hand-selective LOTC region significantly slowed responses for tool action discriminations relative to tool location discriminations, with no such difference during sham TMS. We conclude that left LOTC contributes to the discrimination of tool-associated hand actions.

  13. Bilateral lesions of nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS) selectively impair figure-ground discrimination in pigeons.

    Science.gov (United States)

    Scully, Erin N; Acerbo, Martin J; Lazareva, Olga F

    2014-01-01

    Earlier, we reported that nucleus rotundus (Rt) together with its inhibitory complex, nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS), had significantly higher activity in pigeons performing figure-ground discrimination than in the control group that did not perform any visual discriminations. In contrast, color discrimination produced significantly higher activity than control in the Rt but not in the SP/IPS. Finally, shape discrimination produced significantly lower activity than control in both the Rt and the SP/IPS. In this study, we trained pigeons to simultaneously perform three visual discriminations (figure-ground, color, and shape) using the same stimulus displays. When birds learned to perform all three tasks concurrently at high levels of accuracy, we conducted bilateral chemical lesions of the SP/IPS. After a period of recovery, the birds were retrained on the same tasks to evaluate the effect of lesions on maintenance of these discriminations. We found that the lesions of the SP/IPS had no effect on color or shape discrimination and that they significantly impaired figure-ground discrimination. Together with our earlier data, these results suggest that the nucleus Rt and the SP/IPS are the key structures involved in figure-ground discrimination. These results also imply that thalamic processing is critical for figure-ground segregation in avian brain.

  14. "Photographing money" task pricing

    Science.gov (United States)

    Jia, Zhongxiang

    2018-05-01

    "Photographing money" [1]is a self-service model under the mobile Internet. The task pricing is reasonable, related to the success of the commodity inspection. First of all, we analyzed the position of the mission and the membership, and introduced the factor of membership density, considering the influence of the number of members around the mission on the pricing. Multivariate regression of task location and membership density using MATLAB to establish the mathematical model of task pricing. At the same time, we can see from the life experience that membership reputation and the intensity of the task will also affect the pricing, and the data of the task success point is more reliable. Therefore, the successful point of the task is selected, and its reputation, task density, membership density and Multiple regression of task positions, according to which a nhew task pricing program. Finally, an objective evaluation is given of the advantages and disadvantages of the established model and solution method, and the improved method is pointed out.

  15. Board Task Performance

    DEFF Research Database (Denmark)

    Minichilli, Alessandro; Zattoni, Alessandro; Nielsen, Sabina

    2012-01-01

    identify three board processes as micro-level determinants of board effectiveness. Specifically, we focus on effort norms, cognitive conflicts and the use of knowledge and skills as determinants of board control and advisory task performance. Further, we consider how two different institutional settings....... The findings show that: (i) Board processes have a larger potential than demographic variables to explain board task performance; (ii) board task performance differs significantly between boards operating in different contexts; and (iii) national context moderates the relationships between board processes...... and board task performance....

  16. Response properties of neurons in the cat's putamen during auditory discrimination.

    Science.gov (United States)

    Zhao, Zhenling; Sato, Yu; Qin, Ling

    2015-10-01

    The striatum integrates diverse convergent input and plays a critical role in the goal-directed behaviors. To date, the auditory functions of striatum are less studied. Recently, it was demonstrated that auditory cortico-striatal projections influence behavioral performance during a frequency discrimination task. To reveal the functions of striatal neurons in auditory discrimination, we recorded the single-unit spike activities in the putamen (dorsal striatum) of free-moving cats while performing a Go/No-go task to discriminate the sounds with different modulation rates (12.5 Hz vs. 50 Hz) or envelopes (damped vs. ramped). We found that the putamen neurons can be broadly divided into four groups according to their contributions to sound discrimination. First, 40% of neurons showed vigorous responses synchronized to the sound envelope, and could precisely discriminate different sounds. Second, 18% of neurons showed a high preference of ramped to damped sounds, but no preference for modulation rate. They could only discriminate the change of sound envelope. Third, 27% of neurons rapidly adapted to the sound stimuli, had no ability of sound discrimination. Fourth, 15% of neurons discriminated the sounds dependent on the reward-prediction. Comparing to passively listening condition, the activities of putamen neurons were significantly enhanced by the engagement of the auditory tasks, but not modulated by the cat's behavioral choice. The coexistence of multiple types of neurons suggests that the putamen is involved in the transformation from auditory representation to stimulus-reward association. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Abilities in tactile discrimination of textures in adult rats exposed to enriched or impoverished environments.

    Science.gov (United States)

    Bourgeon, Stéphanie; Xerri, Christian; Coq, Jacques-Olivier

    2004-08-12

    In previous studies, we have shown that housing in enriched environment for about 3 months after weaning improved the topographic organization and decreased the size of the receptive fields (RFs) located on the glabrous skin surfaces in the forepaw maps of the primary somatosensory cortex (SI) in rats [Exp. Brain Res. 121 (1998) 191]. In contrast, housing in impoverished environment induced a degradation of the SI forepaw representation, characterized by topographic disruptions, a reduction of the cutaneous forepaw area and an enlargement of the glabrous RFs [Exp. Brain Res. 129 (1999) 518]. Based on these two studies, we postulated that these representational alterations could underlie changes in haptic perception. Therefore, the present study was aimed at determining the influence of housing conditions on the rat's abilities in tactile texture discrimination. After a 2-month exposure to enriched or impoverished environments, rats were trained to perform a discrimination task during locomotion on floorboards of different roughness. At the end of every daily behavioral session, rats were replaced in their respective housing environment. Rats had to discriminate homogeneous (low roughness) from heterogeneous floorboards (combination of two different roughness levels). To determine the maximum performance in texture discrimination, the roughness contrast of the heterogeneous texture was gradually reduced, so that homogeneous and heterogeneous floorboards became harder to differentiate. We found that the enriched rats learned the first steps of the behavioral task faster than the impoverished rats, whereas both groups exhibited similar performances in texture discrimination. An individual "predilection" for either homogeneous or heterogeneous floorboards, presumably reflecting a behavioral strategy, seemed to account for the absence of differences in haptic discrimination between groups. The sensory experience depending on the rewarded texture discrimination task

  18. View-invariant object recognition ability develops after discrimination, not mere exposure, at several viewing angles.

    Science.gov (United States)

    Yamashita, Wakayo; Wang, Gang; Tanaka, Keiji

    2010-01-01

    One usually fails to recognize an unfamiliar object across changes in viewing angle when it has to be discriminated from similar distractor objects. Previous work has demonstrated that after long-term experience in discriminating among a set of objects seen from the same viewing angle, immediate recognition of the objects across 30-60 degrees changes in viewing angle becomes possible. The capability for view-invariant object recognition should develop during the within-viewing-angle discrimination, which includes two kinds of experience: seeing individual views and discriminating among the objects. The aim of the present study was to determine the relative contribution of each factor to the development of view-invariant object recognition capability. Monkeys were first extensively trained in a task that required view-invariant object recognition (Object task) with several sets of objects. The animals were then exposed to a new set of objects over 26 days in one of two preparatory tasks: one in which each object view was seen individually, and a second that required discrimination among the objects at each of four viewing angles. After the preparatory period, we measured the monkeys' ability to recognize the objects across changes in viewing angle, by introducing the object set to the Object task. Results indicated significant view-invariant recognition after the second but not first preparatory task. These results suggest that discrimination of objects from distractors at each of several viewing angles is required for the development of view-invariant recognition of the objects when the distractors are similar to the objects.

  19. The influence of a working memory task on affective perception of facial expressions.

    Directory of Open Access Journals (Sweden)

    Seung-Lark Lim

    Full Text Available In a dual-task paradigm, participants performed a spatial location working memory task and a forced two-choice perceptual decision task (neutral vs. fearful with gradually morphed emotional faces (neutral ∼ fearful. Task-irrelevant word distractors (negative, neutral, and control were experimentally manipulated during spatial working memory encoding. We hypothesized that, if affective perception is influenced by concurrent cognitive load using a working memory task, task-irrelevant emotional distractors would bias subsequent perceptual decision-making on ambiguous facial expression. We found that when either neutral or negative emotional words were presented as task-irrelevant working-memory distractors, participants more frequently reported fearful face perception - but only at the higher emotional intensity levels of morphed faces. Also, the affective perception bias due to negative emotional distractors correlated with a decrease in working memory performance. Taken together, our findings suggest that concurrent working memory load by task-irrelevant distractors has an impact on affective perception of facial expressions.

  20. The influence of spatial congruency and movement preparation time on saccade curvature in simultaneous and sequential dual-tasks.

    Science.gov (United States)

    Moehler, Tobias; Fiehler, Katja

    2015-11-01

    Saccade curvature represents a sensitive measure of oculomotor inhibition with saccades curving away from covertly attended locations. Here we investigated whether and how saccade curvature depends on movement preparation time when a perceptual task is performed during or before saccade preparation. Participants performed a dual-task including a visual discrimination task at a cued location and a saccade task to the same location (congruent) or to a different location (incongruent). Additionally, we varied saccade preparation time (time between saccade cue and Go-signal) and the occurrence of the discrimination task (during saccade preparation=simultaneous vs. before saccade preparation=sequential). We found deteriorated perceptual performance in incongruent trials during simultaneous task performance while perceptual performance was unaffected during sequential task performance. Saccade accuracy and precision were deteriorated in incongruent trials during simultaneous and, to a lesser extent, also during sequential task performance. Saccades consistently curved away from covertly attended non-saccade locations. Saccade curvature was unaffected by movement preparation time during simultaneous task performance but decreased and finally vanished with increasing movement preparation time during sequential task performance. Our results indicate that the competing saccade plan to the covertly attended non-saccade location is maintained during simultaneous task performance until the perceptual task is solved while in the sequential condition, in which the discrimination task is solved prior to the saccade task, oculomotor inhibition decays gradually with movement preparation time. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Perceptual learning of basic visual features remains task specific with Training-Plus-Exposure (TPE) training.

    Science.gov (United States)

    Cong, Lin-Juan; Wang, Ru-Jie; Yu, Cong; Zhang, Jun-Yun

    2016-01-01

    Visual perceptual learning is known to be specific to the trained retinal location, feature, and task. However, location and feature specificity can be eliminated by double-training or TPE training protocols, in which observers receive additional exposure to the transfer location or feature dimension via an irrelevant task besides the primary learning task Here we tested whether these new training protocols could even make learning transfer across different tasks involving discrimination of basic visual features (e.g., orientation and contrast). Observers practiced a near-threshold orientation (or contrast) discrimination task. Following a TPE training protocol, they also received exposure to the transfer task via performing suprathreshold contrast (or orientation) discrimination in alternating blocks of trials in the same sessions. The results showed no evidence for significant learning transfer to the untrained near-threshold contrast (or orientation) discrimination task after discounting the pretest effects and the suprathreshold practice effects. These results thus do not support a hypothetical task-independent component in perceptual learning of basic visual features. They also set the boundary of the new training protocols in their capability to enable learning transfer.

  2. Construct Validity in TOEFL iBT Speaking Tasks: Insights from Natural Language Processing

    Science.gov (United States)

    Kyle, Kristopher; Crossley, Scott A.; McNamara, Danielle S.

    2016-01-01

    This study explores the construct validity of speaking tasks included in the TOEFL iBT (e.g., integrated and independent speaking tasks). Specifically, advanced natural language processing (NLP) tools, MANOVA difference statistics, and discriminant function analyses (DFA) are used to assess the degree to which and in what ways responses to these…

  3. Newborns' Discrimination of Chromatic from Achromatic Stimuli.

    Science.gov (United States)

    Adams, Russell J.; And Others

    1986-01-01

    Two experiments assessed the extent of newborns' ability to discriminate color. Results imply that newborns have some, albeit limited, capacity to discriminate chromatic from achromatic stimuli, and hence, are at least dichromats. (Author/DR)

  4. 14 CFR 1250.103 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Discrimination prohibited. 1250.103 Section 1250.103 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NONDISCRIMINATION IN... Discrimination prohibited. ...

  5. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo

    2015-01-01

    , is fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...

  6. Task leaders reports

    International Nuclear Information System (INIS)

    Loriaux, E.F.; Jehee, J.N.T.

    1995-01-01

    Report on CRP-OSS Task 4.1.1. ''Survey of existing documentation relevant to this programme's goals'' and report on CRP-OSS Task 4.1.2. ''Survey of existing Operator Support Systems and the experience with them'' are presented. 2 tabs

  7. Pitch Discrimination in Musicians and Non-Musicians: Effects of Harmonic Resolvability and Processing Effort

    DEFF Research Database (Denmark)

    Bianchi, Federica; Santurette, Sébastien; Wendt, Dorothea

    2016-01-01

    -musicians, suggesting similar peripheral frequency selectivity in the two groups of listeners. In a follow-up experiment, listeners’ pupil dilations were measured as an indicator of the required effort in performing the same pitch discrimination task for conditions of varying resolvability and task difficulty...... abilities in musicians are unlikely to be related to higher peripheral frequency selectivity and may suggest an enhanced pitch representation at more central stages of the auditory system in musically trained listeners....

  8. The time course of shape discrimination in the human brain.

    Science.gov (United States)

    Ales, Justin M; Appelbaum, L Gregory; Cottereau, Benoit R; Norcia, Anthony M

    2013-02-15

    The lateral occipital cortex (LOC) activates selectively to images of intact objects versus scrambled controls, is selective for the figure-ground relationship of a scene, and exhibits at least some degree of invariance for size and position. Because of these attributes, it is considered to be a crucial part of the object recognition pathway. Here we show that human LOC is critically involved in perceptual decisions about object shape. High-density EEG was recorded while subjects performed a threshold-level shape discrimination task on texture-defined figures segmented by either phase or orientation cues. The appearance or disappearance of a figure region from a uniform background generated robust visual evoked potentials throughout retinotopic cortex as determined by inverse modeling of the scalp voltage distribution. Contrasting responses from trials containing shape changes that were correctly detected (hits) with trials in which no change occurred (correct rejects) revealed stimulus-locked, target-selective activity in the occipital visual areas LOC and V4 preceding the subject's response. Activity that was locked to the subjects' reaction time was present in the LOC. Response-locked activity in the LOC was determined to be related to shape discrimination for several reasons: shape-selective responses were silenced when subjects viewed identical stimuli but their attention was directed away from the shapes to a demanding letter discrimination task; shape-selectivity was present across four different stimulus configurations used to define the figure; LOC responses correlated with participants' reaction times. These results indicate that decision-related activity is present in the LOC when subjects are engaged in threshold-level shape discriminations. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Gender discrimination in exam grading?

    DEFF Research Database (Denmark)

    Rangvid, Beatrice Schindler

    2018-01-01

    Girls, on average, obtain higher test scores in school than boys, and recent research suggests that part of this difference may be due to discrimination against boys in grading. This bias is consequential if admission to subsequent education programs is based on exam scores. This study assesses t...... tendencies are in accordance with statistical discrimination as a mechanism for grading bias in essay writing and with gender-stereotyped beliefs of math being a male domain....... are scored twice (blind and non-blind). Both strategies use difference-in-differences methods. Although imprecisely estimated, the point estimates indicate a blind grading advantage for boys in essay writing of approximately 5-8% SD, corresponding to 9-15% of the gender gap in essay exam grades. The effect...

  10. Structural Discrimination and Autonomous Vehicles

    DEFF Research Database (Denmark)

    Liu, Hin-Yan

    2016-01-01

    This paper examines the potential for structural discrimination to be woven into the fabric of autonomous vehicle developments, which remain underexplored and undiscussed. The prospect for structural discrimination arises as a result of the coordinated modes of autonomous vehicle behaviour...... individual identity, and potentially relative worth, to autonomous vehicles engaging in a crash damage calculus. At the risk of introducing these ideas into the development of autonomous vehicles, this paper hopes to spark a debate to foreclose these eventualities....... that is prescribed by its code. This leads to the potential for individuated outcomes to be networked and thereby multiplied consistently to any number of vehicles implementing such a code. The aggregated effects of such algorithmic policy preferences will thus cumulate in the reallocation of benefits and burdens...

  11. Limited taste discrimination in Drosophila.

    Science.gov (United States)

    Masek, Pavel; Scott, Kristin

    2010-08-17

    In the gustatory systems of mammals and flies, different populations of sensory cells recognize different taste modalities, such that there are cells that respond selectively to sugars and others to bitter compounds. This organization readily allows animals to distinguish compounds of different modalities but may limit the ability to distinguish compounds within one taste modality. Here, we developed a behavioral paradigm in Drosophila melanogaster to evaluate directly the tastes that a fly distinguishes. These studies reveal that flies do not discriminate among different sugars, or among different bitter compounds, based on chemical identity. Instead, flies show a limited ability to distinguish compounds within a modality based on intensity or palatability. Taste associative learning, similar to olfactory learning, requires the mushroom bodies, suggesting fundamental similarities in brain mechanisms underlying behavioral plasticity. Overall, these studies provide insight into the discriminative capacity of the Drosophila gustatory system and the modulation of taste behavior.

  12. Testing for Statistical Discrimination based on Gender

    OpenAIRE

    Lesner, Rune Vammen

    2016-01-01

    This paper develops a model which incorporates the two most commonly cited strands of the literature on statistical discrimination, namely screening discrimination and stereotyping. The model is used to provide empirical evidence of statistical discrimination based on gender in the labour market. It is shown that the implications of both screening discrimination and stereotyping are consistent with observable wage dynamics. In addition, it is found that the gender wage gap decreases in tenure...

  13. A simple neutron-gamma discriminating system

    International Nuclear Information System (INIS)

    Liu Zhongming; Xing Shilin; Wang Zhongmin

    1986-01-01

    A simple neutron-gamma discriminating system is described. A detector and a pulse shape discriminator are suitable for the neutron-gamma discriminating system. The influence of the constant fraction discriminator threshold energy on the neutron-gamma resolution properties is shown. The neutron-gamma timing distributions from an 241 Am-Be source, 2.5 MeV neutron beam and 14 MeV neutron beam are presented

  14. Discrimination Against Migrant Workers in Malaysia

    OpenAIRE

    Badarulzaman, Muhammad Hafiz; Ayub, Zainal A; Yusoff, Zuryati M; Wahab, Harlida A

    2016-01-01

    AbstractMigrant workers are often discriminated against in almost every aspect of life. Discrimination against them is due to irrational dislike of them and also negative perception towards them. It is alleged that migrant workers contribute to the crimes hike in Malaysia. Using doctrinal research methodology, this article discusses direct and perceptive discrimination against them. This article concludes that physical discriminations are mostly happened because ineffective enforcement of the...

  15. Age discrimination: the new Regulations

    OpenAIRE

    Sprack, John

    2006-01-01

    A summary of the principal changes introduced by the Employment Equality (Age) Regulations 2006 as they came into effect in England and Wales. Extracts from the Regulations follow the commentary. Article by John Sprack (Barrister, part-time Chairman of Employment Tribunals and author of Tottel's Guide to the Age Discrimination Regulations 2006) published in Amicus Curiae – Journal of the Society for Advanced Legal Studies at the Institute of Advanced Legal Studies. The Journal is produced by ...

  16. A Trivial Linear Discriminant Function

    Directory of Open Access Journals (Sweden)

    Shuichi Shinmura

    2015-11-01

    Full Text Available In this paper, we focus on the new model selection procedure of the discriminant analysis. Combining re-sampling technique with k-fold cross validation, we develop a k-fold cross validation for small sample method. By this breakthrough, we obtain the mean error rate in the validation samples (M2 and the 95\\% confidence interval (CI of discriminant coefficient. Moreover, we propose the model  selection  procedure  in  which  the model having a minimum M2 was  chosen  to  the  best  model.  We  apply  this  new  method and procedure to the pass/ fail determination of  exam  scores.  In  this  case,  we  fix  the constant =1 for seven linear discriminant  functions  (LDFs  and  several  good  results  were obtained as follows: 1 M2 of Fisher's LDF are over 4.6\\% worse than Revised IP-OLDF. 2 A soft-margin  SVM  for  penalty c=1  (SVM1  is  worse  than  another  mathematical  programming (MP based LDFs and logistic regression . 3 The 95\\% CI of the best discriminant coefficients was obtained. Seven LDFs except for Fisher's LDF are almost the same as a trivial LDF for the linear separable model. Furthermore, if we choose the median of the coefficient of seven LDFs except for Fisher's LDF,  those are almost the same as the trivial LDF for the linear separable model.

  17. Competition, Takeovers, and Gender Discrimination

    OpenAIRE

    Fredrik Heyman; Helena Svaleryd; Jonas Vlachos

    2013-01-01

    Theories of taste-based discrimination predict that competitive pressures will drive discriminatory behaviour out of the market. Using detailed matched employer-employee data, we analyze how firm takeovers and product market competition are related to the gender composition of the firm’s workforce and the gender wage gap. Using a difference-in-difference framework and dealing with several endogeneity concerns, we find that the share of female employees increases as a result of an ownership ch...

  18. Mental illness and employment discrimination.

    Science.gov (United States)

    Stuart, Heather

    2006-09-01

    Work is a major determinant of mental health and a socially integrating force. To be excluded from the workforce creates material deprivation, erodes self-confidence, creates a sense of isolation and marginalization and is a key risk factor for mental disability. This review summarizes recent evidence pertaining to employment-related stigma and discrimination experienced by people with mental disabilities. A broad understanding of the stigmatization process is adopted, which includes cognitive, attitudinal, behavioural and structural disadvantages. Stigma is both a proximate and a distal cause of employment inequity for people with a mental disability who experience direct discrimination because of prejudicial attitudes from employers and workmates and indirect discrimination owing to historical patterns of disadvantage, structural disincentives against competitive employment and generalized policy neglect. Against this background, modern mental health rehabilitation models and legislative philosophies, which focus on citizenship rights and full social participation, are to be welcomed. Yet, recent findings demonstrate that the legislation remains vulnerable to the very prejudicial attitudes they are intended to abate. Research conducted during the past year continues to highlight multiple attitudinal and structural barriers that prevent people with mental disabilities from becoming active participants in the competitive labour market.

  19. A discrimination problem from seismology

    International Nuclear Information System (INIS)

    Elvers, E.

    1975-12-01

    Seismic discrimination between earthquakes and underground nuclear explosions is studied, utilizing magnitudes of two kinds from several seismic stations. A model is given first, where the mean values of the magnitudes are linear fuctions of a parameter describing event size. It is shown how the model parameters can be estimated after a minor restriction on their space. When the discrimination rule is derived from the model, a few different approaches are considered, and they are shown to coincide. It is found reasonabel to use a discriminant, which is linear in the magnitudes, and explicit formulas are obtained. The power of the method is expressed by a measure of separation between the alternatives, which also shows the importance of the individual magnitudes. Missing data is a frequent problem in practice, and the case is treated where there is a detection threshold for one of the magnitudes. The classicfication probabilities are computed when applying the rule to the available magnitudes, and they depend on the event size. The method is not optimal, and it is shown that it can be improved by using the technique of identification by negative evidence, i.e. by utilizing the threshold as upper bound for a missing magnitude. The model is one of general use, and the results thus have a wider applicability. (author)

  20. Discrimination ability of the Energy score

    DEFF Research Database (Denmark)

    Pinson, Pierre; Tastu, Julija

    as appealing since being proper, we show that its discrimination ability may be limited when focusing on the dependence structure of multivariate probabilistic forecasts. For the case of multivariate Gaussian process, a theoretical upper for such discrimination ability is derived and discussed. This limited...... discrimination ability may eventually get compromised by computational and sampling issues, as dimension increases....

  1. Non-discrimination and equality of women

    NARCIS (Netherlands)

    Oostland, Rolanda Carina

    2006-01-01

    Non-discrimination is considered to be a cornerstone of the human rights framework of the United Nations. Already in the UN Charter of 1945 it is stated that human rights should be promoted without discrimination as to, amongst other things, sex. This principle of non-discrimination on the ground of

  2. 50 CFR 3.1 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Discrimination prohibited. 3.1 Section 3.1... PROVISIONS NONDISCRIMINATION-CONTRACTS, PERMITS, AND USE OF FACILITIES § 3.1 Discrimination prohibited. No..., be denied the benefits of, or be otherwise subjected to any form of discrimination or segregation...

  3. 24 CFR 6.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Discrimination prohibited. 6.4... COMMUNITY DEVELOPMENT ACT OF 1974 General Provisions § 6.4 Discrimination prohibited. (a) Section 109... benefits of, or be subjected to discrimination under any program or activity funded in whole or in part...

  4. 49 CFR 27.7 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Discrimination prohibited. 27.7 Section 27.7... OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE General § 27.7 Discrimination prohibited. (a... participation in, be denied the benefits of, or otherwise be subjected to discrimination under any program or...

  5. 18 CFR 1307.5 - Employment discrimination.

    Science.gov (United States)

    2010-04-01

    ... discrimination. 1307.5 Section 1307.5 Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY NONDISCRIMINATION WITH RESPECT TO HANDICAP § 1307.5 Employment discrimination. (a) General. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or...

  6. 29 CFR 32.12 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Discrimination prohibited. 32.12 Section 32.12 Labor Office... § 32.12 Discrimination prohibited. (a) General. (1) No qualified handicapped individual shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity to which...

  7. 49 CFR 374.101 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Discrimination prohibited. 374.101 Section 374.101... REGULATIONS Discrimination in Operations of Interstate Motor Common Carriers of Passengers § 374.101 Discrimination prohibited. No motor common carrier of passengers subject to 49 U.S.C. subtitle IV, part B shall...

  8. 28 CFR 42.203 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Discrimination prohibited. 42.203 Section...) of the Justice System Improvement Act of 1979 § 42.203 Discrimination prohibited. (a) No person in... participation in, be denied the benefits of, be subjected to discrimination under, or denied employment in...

  9. 38 CFR 18.411 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Discrimination prohibited... Practices § 18.411 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity to which...

  10. 29 CFR 34.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Discrimination prohibited. 34.3 Section 34.3 Labor Office of... THE JOB TRAINING PARTNERSHIP ACT OF 1982, AS AMENDED (JTPA) General Provisions § 34.3 Discrimination... participation in JTPA, be excluded from participation in, denied the benefits of, subjected to discrimination...

  11. 45 CFR 84.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Discrimination prohibited. 84.21 Section 84.21... Discrimination prohibited. No qualified handicapped person shall, because a recipient's facilities are... in, or otherwise be subjected to discrimination under any program or activity to which this part...

  12. 24 CFR 8.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Discrimination prohibited. 8.4... DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT General Provisions § 8.4 Discrimination prohibited. (a) No... in, be denied the benefits of, or otherwise be subjected to discrimination under any program or...

  13. 45 CFR 1151.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 1151.21 Section 1151.21... HUMANITIES NATIONAL ENDOWMENT FOR THE ARTS NONDISCRIMINATION ON THE BASIS OF HANDICAP Discrimination Prohibited Accessibility § 1151.21 Discrimination prohibited. No qualified handicapped person shall, because...

  14. 5 CFR 900.404 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Discrimination prohibited. 900.404... § 900.404 Discrimination prohibited. (a) General. A person in the United States shall not, on the ground... be otherwise subjected to discrimination under, a program to which this subpart applies. (b) Specific...

  15. 34 CFR 104.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Discrimination prohibited. 104.11 Section 104.11... ASSISTANCE Employment Practices § 104.11 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or...

  16. 13 CFR 112.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Discrimination prohibited. 112.3... ASSISTED PROGRAMS OF SBA-EFFECTUATION OF TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 § 112.3 Discrimination... be otherwise subjected to discrimination by any business or other activity. (b) Specific...

  17. 28 CFR 35.149 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Discrimination prohibited. 35.149 Section... STATE AND LOCAL GOVERNMENT SERVICES Program Accessibility § 35.149 Discrimination prohibited. Except as... subjected to discrimination by any public entity. ...

  18. 14 CFR 1251.103 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Discrimination prohibited. 1251.103 Section... OF HANDICAP General Provisions § 1251.103 Discrimination prohibited. (a) General. No qualified... of, or otherwise be subjected to discrimination under any program or activity which receives Federal...

  19. 29 CFR 502.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Discrimination prohibited. 502.3 Section 502.3 Labor... IMMIGRATION AND NATIONALITY ACT (SUSPENDED 6-29-2009) General Provisions § 502.3 Discrimination prohibited. (a... Department regulation promulgated pursuant to sec. 218 of the INA. (b) Allegations of discrimination against...

  20. 14 CFR 372.22 - Discrimination.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Discrimination. 372.22 Section 372.22... REGULATIONS OVERSEAS MILITARY PERSONNEL CHARTERS Conditions and Limitations § 372.22 Discrimination. No... any unjust discrimination or any undue or unreasonable prejudice or disadvantage in any respect...

  1. 18 CFR 705.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Discrimination... Discrimination prohibited. (a) General. No person in the United States shall, on the grounds of race, color, or... discrimination under, any program to which this part applies. (b) Specific discriminatory actions prohibited. (1...

  2. 7 CFR 15b.12 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15b.12 Section 15b.12... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Employment Practices § 15b.12 Discrimination prohibited. (a... discrimination in employment under any program or activity receiving assistance from this Department. (2) A...

  3. 15 CFR 8b.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8b.4 Section 8b.4 Commerce and Foreign Trade Office of the Secretary of Commerce PROHIBITION OF DISCRIMINATION... Provisions § 8b.4 Discrimination prohibited. (a) General. No qualified handicapped individual shall, on the...

  4. 28 CFR 42.510 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Discrimination prohibited. 42.510 Section...-Implementation of Section 504 of the Rehabilitation Act of 1973 Employment § 42.510 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall on the basis of handicap be subjected to discrimination...

  5. 29 CFR 32.26 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Discrimination prohibited. 32.26 Section 32.26 Labor Office... RECEIVING FEDERAL FINANCIAL ASSISTANCE Accessibility § 32.26 Discrimination prohibited. No qualified... discrimination under any program or activity to which this part applies. ...

  6. 43 CFR 27.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Discrimination prohibited. 27.3 Section 27... ISSUED UNDER TITLE II OF PUBLIC LAW 93-153 § 27.3 Discrimination prohibited. (a) General. No person shall... through contractual or other arrangements, subject an individual to discrimination on the grounds of race...

  7. 29 CFR 32.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Discrimination prohibited. 32.4 Section 32.4 Labor Office of... FEDERAL FINANCIAL ASSISTANCE General Provisions § 32.4 Discrimination prohibited. (a) General. No... denied the benefits of, or otherwise be subjected to discrimination under any program or activity which...

  8. 7 CFR 15b.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15b.4 Section 15b.4... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE General Provisions § 15b.4 Discrimination prohibited. (a... in, be denied the benefits of, or otherwise be subjected to discrimination under any program or...

  9. 45 CFR 605.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 605.21 Section 605.21... Accessibility § 605.21 Discrimination prohibited. No qualified handicapped person shall, because a recipient's... from participation in, or otherwise be subjected to discrimination under any program or activity to...

  10. 7 CFR 15d.2 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15d.2 Section 15d.2... THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.2 Discrimination prohibited. (a) No agency, officer... participation in, deny the benefits of, or subject to discrimination any person in the United States under any...

  11. 29 CFR 500.9 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Discrimination prohibited. 500.9 Section 500.9 Labor... SEASONAL AGRICULTURAL WORKER PROTECTION General Provisions § 500.9 Discrimination prohibited. (a) It is a... Secretary alleging such discrimination. ...

  12. 28 CFR 42.520 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Discrimination prohibited. 42.520 Section...-Implementation of Section 504 of the Rehabilitation Act of 1973 Accessibility § 42.520 Discrimination prohibited... participation in, or otherwise subjected to discrimination under any program or activity receiving Federal...

  13. 10 CFR 1040.66 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Discrimination prohibited. 1040.66 Section 1040.66 Energy... Practices § 1040.66 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination employment under any program or activity to...

  14. 22 CFR 217.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 217.4 Section 217.4... PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE General Provisions § 217.4 Discrimination... participation in, be denied the benefits of, or otherwise be subjected to discrimination under any program or...

  15. 6 CFR 21.5 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Discrimination prohibited. 21.5 Section 21.5... FROM THE DEPARTMENT OF HOMELAND SECURITY § 21.5 Discrimination prohibited. (a) General. No person in... participation in, be denied the benefits of, or be otherwise subjected to discrimination under, any program to...

  16. 45 CFR 605.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 605.4 Section 605.4... Provisions § 605.4 Discrimination prohibited. (a) General. No qualified handicapped person shall, on the... subjected to discrimination under any program or activity which receives Federal financial assistance. (b...

  17. 15 CFR 8b.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8b.11 Section 8b.11 Commerce and Foreign Trade Office of the Secretary of Commerce PROHIBITION OF DISCRIMINATION... Practices § 8b.11 Discrimination prohibited. (a) General. (1) No qualified handicapped individual shall, on...

  18. 22 CFR 142.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 142.11 Section 142... PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Employment Practices § 142.11 Discrimination... discrimination in employment under any program or activity receiving Federal financial assistance. (2) A...

  19. 10 CFR 1040.63 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Discrimination prohibited. 1040.63 Section 1040.63 Energy... Provisions § 1040.63 Discrimination prohibited. (a) General. No qualified handicapped person shall, on the... subjected to discrimination under any program or activity that receives Federal financial assistance from...

  20. 45 CFR 84.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Discrimination prohibited. 84.11 Section 84.11... § 84.11 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity to which this...

  1. 5 CFR 900.704 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Discrimination prohibited. 900.704... Federally Assisted Programs of the Office of Personnel Management § 900.704 Discrimination prohibited. (a..., be denied the benefits of, or otherwise be subjected to discrimination under any program or activity...

  2. 45 CFR 1170.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 1170.21 Section 1170.21... ASSISTED PROGRAMS OR ACTIVITIES Employment Practices § 1170.21 Discrimination prohibited. (a) General. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment...

  3. 22 CFR 142.15 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 142.15 Section 142... PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Accessibility § 142.15 Discrimination... be subjected to discrimination under any program or activity to which the part applies. ...

  4. 10 CFR 19.32 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Discrimination prohibited. 19.32 Section 19.32 Energy... § 19.32 Discrimination prohibited. No person shall on the grounds of sex be excluded from participation in, be denied a license, be denied the benefit of, or be subjected to discrimination under any...

  5. 5 CFR 950.110 - Prohibited discrimination.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Prohibited discrimination. 950.110 Section 950.110 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE... PRIVATE VOLUNTARY ORGANIZATIONS General Provisions § 950.110 Prohibited discrimination. Discrimination for...

  6. 14 CFR 1251.200 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Discrimination prohibited. 1251.200 Section... OF HANDICAP Employment Practices § 1251.200 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any...

  7. 22 CFR 217.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 217.21 Section 217... Discrimination prohibited. No qualified handicapped person shall, because a recipient's facilities within the... excluded from participation in, or otherwise be subjected to discrimination under any program or activity...

  8. 45 CFR 1110.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 1110.3 Section 1110.3... HUMANITIES GENERAL NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS § 1110.3 Discrimination prohibited. (a... from participation in, be denied the benefits of, or be otherwise subjected, to discrimination under...

  9. 14 CFR 1251.300 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Discrimination prohibited. 1251.300 Section... OF HANDICAP Accessibility § 1251.300 Discrimination prohibited. No qualified handicapped person shall... benefits of, be excluded from participation in, or otherwise be subjected to discrimination under any...

  10. 38 CFR 18.404 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Discrimination prohibited... Provisions § 18.404 Discrimination prohibited. (a) General. No qualified handicapped person shall, on the... subjected to discrimination under any program or activity which receives Federal financial assistance. (b...

  11. 7 CFR 15b.17 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15b.17 Section 15b.17... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Accessibility § 15b.17 Discrimination prohibited. No... to discrimination under any program or activity receiving assistance from this Department. ...

  12. 28 CFR 42.503 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Discrimination prohibited. 42.503 Section...-Implementation of Section 504 of the Rehabilitation Act of 1973 General Provisions § 42.503 Discrimination... from participation in, be denied the benefits of, or otherwise be subjected to discrimination under any...

  13. 29 CFR 501.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Discrimination prohibited. 501.4 Section 501.4 Labor... IMMIGRATION AND NATIONALITY ACT General Provisions § 501.4 Discrimination prohibited. (a) A person may not... discrimination against any person under paragraph (a) of this section will be investigated by the WHD. Where the...

  14. 15 CFR 8b.16 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8b.16 Section 8b.16 Commerce and Foreign Trade Office of the Secretary of Commerce PROHIBITION OF DISCRIMINATION... Accessibility § 8b.16 Discrimination prohibited. No qualified handicapped individual shall, because a recipient...

  15. 18 CFR 1307.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Discrimination... NONDISCRIMINATION WITH RESPECT TO HANDICAP § 1307.4 Discrimination prohibited. (a) General. No qualified handicapped... otherwise be subjected to discrimination under any program or activity to which this part applies. (b...

  16. 45 CFR 605.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 605.11 Section 605.11... Employment Practices § 605.11 Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or...

  17. 10 CFR 1040.13 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Discrimination prohibited. 1040.13 Section 1040.13 Energy..., as Amended; and Section 401 of the Energy Reorganization Act of 1974 § 1040.13 Discrimination... benefits of, or be otherwise subjected to discrimination under any program to which this subpart applies...

  18. 43 CFR 34.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Discrimination prohibited. 34.4 Section 34... DURING CONSTRUCTION AND OPERATION OF THE ALASKA NATURAL GAS TRANSPORTATION SYSTEM § 34.4 Discrimination... part applies. (b) Specific actions in which discrimination is prohibited. No person shall directly or...

  19. 24 CFR 1.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Discrimination prohibited. 1.4... DEVELOPMENT-EFFECTUATION OF TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 § 1.4 Discrimination prohibited. (a... excluded from participation in, be denied the benefits of, or be otherwise subjected to discrimination...

  20. 43 CFR 17.203 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Discrimination prohibited. 17.203 Section... Discrimination prohibited. (a) General. No qualified handicapped person shall, on the basis of handicap, be excluded from participation in, be denied the benefits of, or otherwise be subjected to discrimination...

  1. 34 CFR 104.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Discrimination prohibited. 104.4 Section 104.4... ASSISTANCE General Provisions § 104.4 Discrimination prohibited. (a) General. No qualified handicapped person... otherwise be subjected to discrimination under any program or activitiy which receives Federal financial...

  2. 45 CFR 84.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Discrimination prohibited. 84.4 Section 84.4... § 84.4 Discrimination prohibited. (a) General. No qualified handicapped person shall, on the basis of... discrimination under any program or activity which receives Federal financial assistance. (b) Discriminatory...

  3. 38 CFR 18.421 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Discrimination prohibited... Accessibility § 18.421 Discrimination prohibited. No qualified handicapped person shall, because a recipient's... from participation in, or otherwise be subjected to discrimination under any program or activity to...

  4. 22 CFR 142.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 142.4 Section 142.4... OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE General Provisions § 142.4 Discrimination... participation in, be denied the benefits of, or otherwise be subjected to discrimination under any program or...

  5. Experienced discrimination amongst European old citizens

    NARCIS (Netherlands)

    van den Heuvel, Wim J. A.; van Santvoort, Marc M.

    2011-01-01

    This study analyses the experienced age discrimination of old European citizens and the factors related to this discrimination. Differences in experienced discrimination between old citizens of different European countries are explored. Data from the 2008 ESS survey are used. Old age is defined as

  6. 45 CFR 1170.31 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 1170.31 Section 1170.31... ASSISTED PROGRAMS OR ACTIVITIES Accessibility § 1170.31 Discrimination prohibited. No qualified handicapped... denied the benefits of, be excluded from participation in, or otherwise be subjected to discrimination...

  7. 14 CFR 380.26 - Discrimination.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Discrimination. 380.26 Section 380.26... REGULATIONS PUBLIC CHARTERS Requirements Applicable to Charter Operators § 380.26 Discrimination. No charter... unjust discrimination or any undue or unreasonable prejudice or disadvantage in any respect whatsoever. ...

  8. 34 CFR 104.21 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Discrimination prohibited. 104.21 Section 104.21... ASSISTANCE Accessibility § 104.21 Discrimination prohibited. No qualified handicapped person shall, because a... excluded from participation in, or otherwise be subjected to discrimination under any program or activity...

  9. 45 CFR 1203.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Discrimination prohibited. 1203.4 Section 1203.4... OF 1964 § 1203.4 Discrimination prohibited. (a) General. A person in the United States shall not, on... benefits of, or be otherwise subjected to discrimination under, a program to which this part applies. (b...

  10. 10 CFR 1040.71 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Discrimination prohibited. 1040.71 Section 1040.71 Energy... § 1040.71 Discrimination prohibited. No handicapped person shall, because a recipient's facilities are... in, or be subjected to discrimination under any program or activity that receives or benefits from...

  11. 49 CFR 21.5 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Discrimination prohibited. 21.5 Section 21.5... DEPARTMENT OF TRANSPORTATION-EFFECTUATION OF TITLE VI OF THE CIVIL RIGHTS ACT OF 1964 § 21.5 Discrimination... discrimination under, any program to which this part applies. (b) Specific discriminatory actions prohibited: (1...

  12. 22 CFR 217.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Discrimination prohibited. 217.11 Section 217... Discrimination prohibited. (a) General. (1) No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity to which this part applies. (2) A...

  13. 45 CFR 1151.31 - Discrimination prohibited.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Discrimination prohibited. 1151.31 Section 1151.31... HUMANITIES NATIONAL ENDOWMENT FOR THE ARTS NONDISCRIMINATION ON THE BASIS OF HANDICAP Discrimination Prohibited Employment § 1151.31 Discrimination prohibited. (a) No qualified handicapped person shall, on the...

  14. 38 CFR 18.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Discrimination prohibited... THE CIVIL RIGHTS ACT OF 1964 General § 18.3 Discrimination prohibited. (a) General. No person in the..., be denied the benefits of, or be otherwise subjected to discrimination under any program to which...

  15. 14 CFR 271.9 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Discrimination prohibited. 271.9 Section... TRANSPORTATION § 271.9 Discrimination prohibited. (a) All air carriers receiving subsidy under this part shall comply with the following: (1) The Age Discrimination Act of 1975; (2) The Civil Rights Act of 1964 and...

  16. Formal Derivation of Lotka-Volterra-Haken Amplitude Equations of Task-Related Brain Activity in Multiple, Consecutively Performed Tasks

    Science.gov (United States)

    Frank, T. D.

    The Lotka-Volterra-Haken equations have been frequently used in ecology and pattern formation. Recently, the equations have been proposed by several research groups as amplitude equations for task-related patterns of brain activity. In this theoretical study, the focus is on the circular causality aspect of pattern formation systems as formulated within the framework of synergetics. Accordingly, the stable modes of a pattern formation system inhibit the unstable modes, whereas the unstable modes excite the stable modes. Using this circular causality principle it is shown that under certain conditions the Lotka-Volterra-Haken amplitude equations can be derived from a general model of brain activity akin to the Wilson-Cowan model. The model captures the amplitude dynamics for brain activity patterns in experiments involving several consecutively performed multiple-choice tasks. This is explicitly demonstrated for two-choice tasks involving grasping and walking. A comment on the relevance of the theoretical framework for clinical psychology and schizophrenia is given as well.

  17. The influence of tongue strength on oral viscosity discrimination acuity.

    Science.gov (United States)

    Steele, Catriona M

    2018-06-01

    The ability to generate tongue pressures is widely considered to be critical for liquid bolus propulsion in swallowing. It has been proposed that the application of tongue pressure may also serve the function of collecting sensory information regarding bolus viscosity (resistance to flow). In this study, we explored the impact of age-related reductions in tongue strength on oral viscosity discrimination acuity. The experiment employed a triangle test discrimination protocol with an array of xanthan-gum thickened liquids in the mildly to moderately thick consistency range. A sample of 346 healthy volunteers was recruited, with age ranging from 12 to 86 (164 men, 182 women). On average, participants were able to detect a 0.29-fold increase in xanthan-gum concentration, corresponding to a 0.5-fold increase in viscosity at 50/s. Despite having significantly reduced tongue strength on maximum isometric tongue-palate pressure tasks, and regardless of sex, older participants in this study showed no reductions in viscosity discrimination acuity. In this article, the relationship between tongue strength and the ability to discriminate small differences in liquid viscosity during oral processing is explored. Given that tongue strength declines with age in healthy adults and is also reduced in individuals with dysphagia, it is interesting to determine whether reduced tongue strength might contribute to difficulties in evaluating liquid viscosity during the oral stage of swallowing. Using an array of mildly to moderately thick xanthan-gum thickened liquids, this experiment failed to find any evidence that reductions in tongue strength influence oral viscosity discrimination acuity. © 2017 Wiley Periodicals, Inc.

  18. Workplace discrimination: experiences of practicing physicians.

    Science.gov (United States)

    Coombs, Alice A Tolbert; King, Roderick K

    2005-04-01

    In response to a growing concern regarding physician discrimination in the workplace, this study was developed to: (1) describe the types of discrimination that exist for the practicing physician and (2) determine which groups of physicians are more likely to experience the various forms of discrimination. Surveys were mailed to 1930 practicing physicians in Massachusetts. Participants were asked if they had encountered discrimination, how significant the discrimination was against a specific group, the frequency of personal discrimination, and the type of discrimination. Factor analysis identified four types of discrimination: career advancement, punitive behaviors, practice barriers and hiring barriers. A total of 445 responses were received (a 24% response rate). Sixty-three percent of responding physicians had experienced some form of discrimination. Respondents were women (46%), racial/ethnic minorities (42%) and international medical graduates (IMGs) (40%). In addition, 26% of those classified as white were also IMGs. Over 60% of respondents believed discrimination against IMGs was very or somewhat significant. Almost 27% of males acknowledged that gender bias against females was very or somewhat significant. IMGs were more likely to indicate that discrimination against IMGs was significant in their current organization. Of U.S. medical graduates (USMGs) 44% reported that discrimination against IMGs in their current organization was significant. Nonwhites were more likely to report that discrimination based on race/ethnicity was significant. Nearly 29% of white respondents also believed that such discrimination was very or somewhat significant. Physicians practicing in academic, research, and private practice sectors experience discrimination based on gender, ethnic/racial, and IMG status.

  19. Differential effects of visual context on pattern discrimination by pigeons (Columba livia) and humans (Homo sapiens).

    Science.gov (United States)

    Kelly, Debbie M; Cook, Robert G

    2003-06-01

    Three experiment examined the role of contextual information during line orientation and line position discriminations by pigeons (Columba livia) and humans (Homo sapiens). Experiment 1 tested pigeons' performance with these stimuli in a target localization task using texture displays. Experiments 2 and 3 tested pigeons and humans, respectively, with small and large variations of these stimuli in a same-different task. Humans showed a configural superiority effect when tested with displays constructed from large elements but not when tested with the smaller, more densely packed texture displays. The pigeons, in contrast, exhibited a configural inferiority effect when required to discriminate line orientation, regardless of stimulus size. These contrasting results suggest a species difference in the perceptionand use of features and contextual information in the discrimination of line information.

  20. Visual discrimination following partial telencephalic ablations in nurse sharks (Ginglymostoma cirratum).

    Science.gov (United States)

    Graeber, R C; Schroeder, D M; Jane, J A; Ebbesson, S O

    1978-07-15

    An instrumental conditioning task was used to examine the role of the nurse shark telencephalon in black-white (BW) and horizontal-vertical stripes (HV) discrimination performance. In the first experiment, subjects initially received either bilateral anterior telencephalic control lesions or bilateral posterior telencephalic lesions aimed at destroying the central telencephalic nuclei (CN), which are known to receive direct input from the thalamic visual area. Postoperatively, the sharks were trained first on BW and then on HV. Those with anterior lesions learned both tasks as rapidly as unoperated subjects. Those with posterior lesions exhibited visual discrimination deficits related to the amount of damage to the CN and its connecting pathways. Severe damage resulted in an inability to learn either task but caused no impairments in motivation or general learning ability. In the second experiment, the sharks were first trained on BW and HV and then operated. Suction ablations were used to remove various portions of the CN. Sharks with 10% or less damage to the CN retained the preoperatively acquired discriminations almost perfectly. Those with 11-50% damage had to be retrained on both tasks. Almost total removal of the CN produced behavioral indications of blindness along with an inability to perform above the chance level on BW despite excellent retention of both discriminations over a 28-day period before surgery. It appears, however, that such sharks can still detect light. These results implicate the central telencephalic nuclei in the control of visually guided behavior in sharks.

  1. An Information Analysis of 2-, 3-, and 4-Word Verbal Discrimination Learning.

    Science.gov (United States)

    Arima, James K.; Gray, Francis D.

    Information theory was used to qualify the difficulty of verbal discrimination (VD) learning tasks and to measure VD performance. Words for VD items were selected with high background frequency and equal a priori probabilities of being selected as a first response. Three VD lists containing only 2-, 3-, or 4-word items were created and equated for…

  2. Spatiotemporal Relationships among Audiovisual Stimuli Modulate Auditory Facilitation of Visual Target Discrimination.

    Science.gov (United States)

    Li, Qi; Yang, Huamin; Sun, Fang; Wu, Jinglong

    2015-03-01

    Sensory information is multimodal; through audiovisual interaction, task-irrelevant auditory stimuli tend to speed response times and increase visual perception accuracy. However, mechanisms underlying these performance enhancements have remained unclear. We hypothesize that task-irrelevant auditory stimuli might provide reliable temporal and spatial cues for visual target discrimination and behavioral response enhancement. Using signal detection theory, the present study investigated the effects of spatiotemporal relationships on auditory facilitation of visual target discrimination. Three experiments were conducted where an auditory stimulus maintained reliable temporal and/or spatial relationships with visual target stimuli. Results showed that perception sensitivity (d') to visual target stimuli was enhanced only when a task-irrelevant auditory stimulus maintained reliable spatiotemporal relationships with a visual target stimulus. When only reliable spatial or temporal information was contained, perception sensitivity was not enhanced. These results suggest that reliable spatiotemporal relationships between visual and auditory signals are required for audiovisual integration during a visual discrimination task, most likely due to a spread of attention. These results also indicate that auditory facilitation of visual target discrimination follows from late-stage cognitive processes rather than early stage sensory processes. © 2015 SAGE Publications.

  3. Imitation and "Theory of Mind" Competencies in Discrimination of Autism from Other Neurodevelopmental Disorders

    Science.gov (United States)

    Perra, Oliver; Williams, Justin H. G.; Whiten, Andrew; Fraser, Lesley; Benzie, Helen; Perrett, David I.

    2008-01-01

    Several studies have reported imitative deficits in autism spectrum disorder (ASD). However, it is still debated if imitative deficits are specific to ASD or shared with clinical groups with similar mental impairment and motor difficulties. We investigated whether imitative tasks can be used to discriminate ASD children from typically developing…

  4. Hippocampus, Perirhinal Cortex, and Complex Visual Discriminations in Rats and Humans

    Science.gov (United States)

    Hales, Jena B.; Broadbent, Nicola J.; Velu, Priya D.; Squire, Larry R.; Clark, Robert E.

    2015-01-01

    Structures in the medial temporal lobe, including the hippocampus and perirhinal cortex, are known to be essential for the formation of long-term memory. Recent animal and human studies have investigated whether perirhinal cortex might also be important for visual perception. In our study, using a simultaneous oddity discrimination task, rats with…

  5. Aphasic Patients Exhibit a Reversal of Hemispheric Asymmetries in Categorical Color Discrimination

    Science.gov (United States)

    Paluy, Yulia; Gilbert, Aubrey L.; Baldo, Juliana V.; Dronkers, Nina F.; Ivry, Richard B.

    2011-01-01

    Patients with left hemisphere (LH) or right hemisphere (RH) brain injury due to stroke were tested on a speeded, color discrimination task in which two factors were manipulated: (1) the categorical relationship between the target and the distracters and (2) the visual field in which the target was presented. Similar to controls, the RH patients…

  6. Within centre evaluation of hypercalcaemia discriminant

    DEFF Research Database (Denmark)

    Nielsen, Bo Friis; Conradsen, Knut

    1996-01-01

    Diagnostic hypercalcaemia discriminant functions, discriminating between clinically significant and non-significant hypercalcaemia, were tested 5 years after their development in order to evaluate the impact of time on their diagnostic capacity. Two populations, consisting of 257 and 129 patients......). The discriminant functions correctly classified 81 and 80% of the women, respectively (NS) and respectively 75% and 64% of the men (NS) in the first and second recorded populations.......Diagnostic hypercalcaemia discriminant functions, discriminating between clinically significant and non-significant hypercalcaemia, were tested 5 years after their development in order to evaluate the impact of time on their diagnostic capacity. Two populations, consisting of 257 and 129 patients...

  7. Testing for Statistical Discrimination based on Gender

    DEFF Research Database (Denmark)

    Lesner, Rune Vammen

    . It is shown that the implications of both screening discrimination and stereotyping are consistent with observable wage dynamics. In addition, it is found that the gender wage gap decreases in tenure but increases in job transitions and that the fraction of women in high-ranking positions within a firm does......This paper develops a model which incorporates the two most commonly cited strands of the literature on statistical discrimination, namely screening discrimination and stereotyping. The model is used to provide empirical evidence of statistical discrimination based on gender in the labour market...... not affect the level of statistical discrimination by gender....

  8. THE JURIDICAL PROTECTION ON GLOBAL DISCRIMINATION

    Directory of Open Access Journals (Sweden)

    CRISTINA OTOVESCU FRĂSIE

    2012-05-01

    Full Text Available In this study I wished to evidence the main juridical documents referring to discrimination, adopted world wide by the United Nations Organization. Thus, can be identified several types of definitions concerning the discrimination against women, the race discrimination, the torture etc. within the analyzed documents. The democratic countries have laws that punish the discrimination, but, unfortunately, there are discrimination phenomena for example regarding the ethnicity, the gender, the language, the convictions, the age, at the working place, inside the family etc.

  9. Central as well as peripheral attentional bottlenecks in dual-task performance activate lateral prefrontal cortices

    Directory of Open Access Journals (Sweden)

    Andre J Szameitat

    2016-03-01

    Full Text Available Human information processing suffers from severe limitations in parallel processing. In particular, when required to respond to two stimuli in rapid succession, processing bottlenecks may appear at central and peripheral stages of task processing. Importantly, it has been suggested that executive functions are needed to resolve the interference arising at such bottlenecks. The aims of the present study were to test whether central attentional limitations (i.e., bottleneck at the decisional response selection stage as well as peripheral limitations (i.e., bottleneck at response initiation both demand executive functions located in the lateral prefrontal cortex. For this, we re-analysed two previous studies, in which a total of 33 participants performed a dual-task according to the paradigm of the psychological refractory period (PRP during fMRI. In one study (N=17, the PRP task consisted of two two-choice response tasks known to suffer from a central bottleneck (CB group. In the other study (N=16, the PRP task consisted of two simple-response tasks known to suffer from a peripheral bottleneck (PB group. Both groups showed considerable dual-task costs in form of slowing of the second response in the dual-task (PRP effect. Imaging results are based on the subtraction of both single-tasks from the dual-task within each group. In the CB group, the bilateral middle frontal gyri and inferior frontal gyri were activated. Higher activation in these areas was associated with lower dual-task costs. In the PB group, the right middle frontal and inferior frontal gyrus were activated. Here, higher activation was associated with higher dual-task costs. In conclusion we suggest that central and peripheral bottlenecks both demand executive functions located in lateral prefrontal cortices. Differences between the CB and PB groups with respect to the exact prefrontal areas activated and the correlational patterns suggest that the executive functions resolving

  10. Multipurpose discriminator with accurate time coupling

    International Nuclear Information System (INIS)

    Baldin, B.Yu.; Krumshtejn, Z.V.; Ronzhin, A.I.

    1977-01-01

    The principle diagram of a multipurpose discriminator is described, designed on the basis of a wide-band differential amplifier. The discriminator has three independent channels: the timing channel, the lower level discriminator and the control channel. The timing channel and the lower level discriminator are connected to a coincidence circuit. Three methods of timing are used: a single threshold, a double threshold with timing on the pulse front, and a constant fraction timing. The lower level discriminator is a wide-band amplifier with an adjustable threshold. The investigation of compensation characteristics of the discriminator has shown that the time shift of the discriminator output in the constant fraction timing regime does not exceed +-75 ns for the input signal range of 1:85. The time resolution was found to be 20 ns in the 20% energy range near the photo-peak maximum of 60 Co γ source

  11. Generic cognitive adaptations to task interference in task switching

    NARCIS (Netherlands)

    Poljac, E.; Bekkering, H.

    2009-01-01

    The present study investigated how the activation of previous tasks interferes with the execution of future tasks as a result of temporal manipulations. Color and shape matching tasks were organized in runs of two trials each. The tasks were specified by a cue presented before a task run, cueing

  12. Pitch discrimination learning: specificity for pitch and harmonic resolvability, and electrophysiological correlates.

    Science.gov (United States)

    Carcagno, Samuele; Plack, Christopher J

    2011-08-01

    Multiple-hour training on a pitch discrimination task dramatically decreases the threshold for detecting a pitch difference between two harmonic complexes. Here, we investigated the specificity of this perceptual learning with respect to the pitch and the resolvability of the trained harmonic complex, as well as its cortical electrophysiological correlates. We trained 24 participants for 12 h on a pitch discrimination task using one of four different harmonic complexes. The complexes differed in pitch and/or spectral resolvability of their components by the cochlea, but were filtered into the same spectral region. Cortical-evoked potentials and a behavioral measure of pitch discrimination were assessed before and after training for all the four complexes. The change in these measures was compared to that of two control groups: one trained on a level discrimination task and one without any training. The behavioral results showed that learning was partly specific to both pitch and resolvability. Training with a resolved-harmonic complex improved pitch discrimination for resolved complexes more than training with an unresolved complex. However, we did not find evidence that training with an unresolved complex leads to specific learning for unresolved complexes. Training affected the P2 component of the cortical-evoked potentials, as well as a later component (250-400 ms). No significant changes were found on the mismatch negativity (MMN) component, although a separate experiment showed that this measure was sensitive to pitch changes equivalent to the pitch discriminability changes induced by training. This result suggests that pitch discrimination training affects processes not measured by the MMN, for example, processes higher in level or parallel to those involved in MMN generation.

  13. Energy Efficient Task Light

    DEFF Research Database (Denmark)

    Logadottir, Asta; Ardkapan, Siamak Rahimi; Johnsen, Kjeld

    2014-01-01

    The objectives of this work is to develop a task light for office lighting that fulfils the minimum requirements of the European standard EN12464 - 1 : Light and lighting – Lighting of work places, Part 1: Indoor workplaces and the Danish standard DS 700 : Lys og belysning I arbejdsrum , or more...... specifically the requirements that apply to the work area and the immediate surrounding area. By providing a task light that fulfils the requirements for task lighting and the immediate surrounding area, the general lighting only needs to provide the illuminance levels required for background lighting...... and thereby a reduction in installed power for general lighting of about 40 % compared to the way illuminance levels are designed in an office environment in Denmark today. This lighting strategy is useful when the placement of the task area is not defined in the space before the lighting is design ed...

  14. Obesity discrimination: the role of physical appearance, personal ideology, and anti-fat prejudice.

    Science.gov (United States)

    O'Brien, K S; Latner, J D; Ebneter, D; Hunter, J A

    2013-03-01

    Self-report measures of anti-fat prejudice are regularly used by the field, however, there is no research showing a relationship between explicit measures of anti-fat prejudice and the behavioral manifestation of them; obesity discrimination. The present study examined whether a recently developed measure of anti-fat prejudice, the universal measure of bias (UMB), along with other correlates of prejudicial attitudes and beliefs (that is, authoritarianism, social dominance orientation; SDO, physical appearance investment) predict obesity discrimination. Under the guise of a personnel selection task, participants (n=102) gave assessments of obese and non-obese females applying for a managerial position across a number of selection criteria (for example, starting salary, likelihood of selecting). Participants viewed resumes that had attached either a photo of a pre-bariatric surgery obese female (body mass index (BMI)=38-41) or a photo of the same female post-bariatric surgery (BMI=22-24). Participants also completed measures of anti-fat prejudice (UMB) authoritarianism, SDO, physical appearance evaluation and orientation. Obesity discrimination was displayed across all selection criteria. Higher UMB subscale scores (distance and negative judgement), authoritarianism, physical appearance evaluation and orientation were associated with greater obesity discrimination. In regression models, UMB 'distance' was a predictor of obesity discrimination for perceived leadership potential, starting salary, and overall employability. UMB 'negative judgement' predicted discrimination for starting salary; and authoritarianism predicted likelihood of selecting an obese applicant and candidate ranking. Finally, physical appearance evaluation and appearance orientation predicted obesity discrimination for predicted career success and leadership potential, respectively. Self-report measures of prejudice act as surrogates for discrimination, but there has been no empirical support for

  15. Discrimination performance in aging is vulnerable to interference and dissociable from spatial memory

    Science.gov (United States)

    Johnson, Sarah A.; Sacks, Patricia K.; Turner, Sean M.; Gaynor, Leslie S.; Ormerod, Brandi K.; Maurer, Andrew P.; Bizon, Jennifer L.

    2016-01-01

    Hippocampal-dependent episodic memory and stimulus discrimination abilities are both compromised in the elderly. The reduced capacity to discriminate between similar stimuli likely contributes to multiple aspects of age-related cognitive impairment; however, the association of these behaviors within individuals has never been examined in an animal model. In the present study, young and aged F344×BN F1 hybrid rats were cross-characterized on the Morris water maze test of spatial memory and a dentate gyrus-dependent match-to-position test of spatial discrimination ability. Aged rats showed overall impairments relative to young in spatial learning and memory on the water maze task. Although young and aged learned to apply a match-to-position response strategy in performing easy spatial discriminations within a similar number of trials, a majority of aged rats were impaired relative to young in performing difficult spatial discriminations on subsequent tests. Moreover, all aged rats were susceptible to cumulative interference during spatial discrimination tests, such that error rate increased on later trials of test sessions. These data suggest that when faced with difficult discriminations, the aged rats were less able to distinguish current goal locations from those of previous trials. Increasing acetylcholine levels with donepezil did not improve aged rats’ abilities to accurately perform difficult spatial discriminations or reduce their susceptibility to interference. Interestingly, better spatial memory abilities were not significantly associated with higher performance on difficult spatial discriminations. This observation, along with the finding that aged rats made more errors under conditions in which interference was high, suggests that match-to-position spatial discrimination performance may rely on extra-hippocampal structures such as the prefrontal cortex, in addition to the dentate gyrus. PMID:27317194

  16. Dopamine modulates memory consolidation of discrimination learning in the auditory cortex.

    Science.gov (United States)

    Schicknick, Horst; Reichenbach, Nicole; Smalla, Karl-Heinz; Scheich, Henning; Gundelfinger, Eckart D; Tischmeyer, Wolfgang

    2012-03-01

    In Mongolian gerbils, the auditory cortex is critical for discriminating rising vs. falling frequency-modulated tones. Based on our previous studies, we hypothesized that dopaminergic inputs to the auditory cortex during and shortly after acquisition of the discrimination strategy control long-term memory formation. To test this hypothesis, we studied frequency-modulated tone discrimination learning of gerbils in a shuttle box GO/NO-GO procedure following differential treatments. (i) Pre-exposure of gerbils to the frequency-modulated tones at 1 day before the first discrimination training session severely impaired the accuracy of the discrimination acquired in that session during the initial trials of a second training session, performed 1 day later. (ii) Local injection of the D1/D5 dopamine receptor antagonist SCH-23390 into the auditory cortex after task acquisition caused a discrimination deficit of similar extent and time course as with pre-exposure. This effect was dependent on the dose and time point of injection. (iii) Injection of the D1/D5 dopamine receptor agonist SKF-38393 into the auditory cortex after retraining caused a further discrimination improvement at the beginning of subsequent sessions. All three treatments, which supposedly interfered with dopamine signalling during conditioning and/or retraining, had a substantial impact on the dynamics of the discrimination performance particularly at the beginning of subsequent training sessions. These findings suggest that auditory-cortical dopamine activity after acquisition of a discrimination of complex sounds and after retrieval of weak frequency-modulated tone discrimination memory further improves memory consolidation, i.e. the correct association of two sounds with their respective GO/NO-GO meaning, in support of future memory recall. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  17. Visual discrimination in the pigeon (Columba livia): effects of selective lesions of the nucleus rotundus

    Science.gov (United States)

    Laverghetta, A. V.; Shimizu, T.

    1999-01-01

    The nucleus rotundus is a large thalamic nucleus in birds and plays a critical role in many visual discrimination tasks. In order to test the hypothesis that there are functionally distinct subdivisions in the nucleus rotundus, effects of selective lesions of the nucleus were studied in pigeons. The birds were trained to discriminate between different types of stationary objects and between different directions of moving objects. Multiple regression analyses revealed that lesions in the anterior, but not posterior, division caused deficits in discrimination of small stationary stimuli. Lesions in neither the anterior nor posterior divisions predicted effects in discrimination of moving stimuli. These results are consistent with a prediction led from the hypothesis that the nucleus is composed of functional subdivisions.

  18. Lexical exposure to native language dialects can improve non-native phonetic discrimination.

    Science.gov (United States)

    Olmstead, Annie J; Viswanathan, Navin

    2018-04-01

    Nonnative phonetic learning is an area of great interest for language researchers, learners, and educators alike. In two studies, we examined whether nonnative phonetic discrimination of Hindi dental and retroflex stops can be improved by exposure to lexical items bearing the critical nonnative stops. We extend the lexical retuning paradigm of Norris, McQueen, and Cutler (Cognitive Psychology, 47, 204-238, 2003) by having naive American English (AE)-speaking participants perform a pretest-training-posttest procedure. They performed an AXB discrimination task with the Hindi retroflex and dental stops before and after transcribing naturally produced words from an Indian English speaker that either contained these tokens or not. Only those participants who heard words with the critical nonnative phones improved in their posttest discrimination. This finding suggests that exposure to nonnative phones in native lexical contexts supports learning of difficult nonnative phonetic discrimination.

  19. Individuals with 22q11.2 Deletion Syndrome Are Impaired at Explicit, but Not Implicit, Discrimination of Local Forms Embedded in Global Structures

    Science.gov (United States)

    Giersch, Anne; Glaser, Bronwyn; Pasca, Catherine; Chabloz, Mélanie; Debbané, Martin; Eliez, Stephan

    2014-01-01

    Individuals with 22q11.2 deletion syndrome (22q11.2DS) are impaired at exploring visual information in space; however, not much is known about visual form discrimination in the syndrome. Thirty-five individuals with 22q11.2DS and 41 controls completed a form discrimination task with global forms made up of local elements. Affected individuals…

  20. Altering sensorimotor feedback disrupts visual discrimination of facial expressions.

    Science.gov (United States)

    Wood, Adrienne; Lupyan, Gary; Sherrin, Steven; Niedenthal, Paula

    2016-08-01

    Looking at another person's facial expression of emotion can trigger the same neural processes involved in producing the expression, and such responses play a functional role in emotion recognition. Disrupting individuals' facial action, for example, interferes with verbal emotion recognition tasks. We tested the hypothesis that facial responses also play a functional role in the perceptual processing of emotional expressions. We altered the facial action of participants with a gel facemask while they performed a task that involved distinguishing target expressions from highly similar distractors. Relative to control participants, participants in the facemask condition demonstrated inferior perceptual discrimination of facial expressions, but not of nonface stimuli. The findings suggest that somatosensory/motor processes involving the face contribute to the visual perceptual-and not just conceptual-processing of facial expressions. More broadly, our study contributes to growing evidence for the fundamentally interactive nature of the perceptual inputs from different sensory modalities.

  1. Functional Activation during the Rapid Visual Information Processing Task in a Middle Aged Cohort: An fMRI Study

    OpenAIRE

    Neale, Chris; Johnston, Patrick; Hughes, Matthew; Scholey, Andrew

    2015-01-01

    The Rapid Visual Information Processing (RVIP) task, a serial discrimination task where task performance believed to reflect sustained attention capabilities, is widely used in behavioural research and increasingly in neuroimaging studies. To date, functional neuroimaging research into the RVIP has been undertaken using block analyses, reflecting the sustained processing involved in the task, but not necessarily the transient processes associated with individual trial performance. Furthermore...

  2. Adaptation improves face trustworthiness discrimination

    Directory of Open Access Journals (Sweden)

    Bruce D Keefe

    2013-06-01

    Full Text Available Adaptation to facial characteristics, such as gender and viewpoint, has been shown to both bias our perception of faces and improve facial discrimination. In this study, we examined whether adapting to two levels of face trustworthiness improved sensitivity around the adapted level. Facial trustworthiness was manipulated by morphing between trustworthy and untrustworthy prototypes, each generated by morphing eight trustworthy and eight untrustworthy faces respectively. In the first experiment, just-noticeable differences (JNDs were calculated for an untrustworthy face after participants adapted to an untrustworthy face, a trustworthy face, or did not adapt. In the second experiment, the three conditions were identical, except that JNDs were calculated for a trustworthy face. In the third experiment we examined whether adapting to an untrustworthy male face improved discrimination to an untrustworthy female face. In all experiments, participants completed a two-interval forced-choice adaptive staircase procedure, in which they judged which face was more untrustworthy. JNDs were derived from a psychometric function fitted to the data. Adaptation improved sensitivity to faces conveying the same level of trustworthiness when compared to no adaptation. When adapting to and discriminating around a different level of face trustworthiness there was no improvement in sensitivity and JNDs were equivalent to those in the no adaptation condition. The improvement in sensitivity was found to occur even when adapting to a face with different gender and identity. These results suggest that adaptation to facial trustworthiness can selectively enhance mechanisms underlying the coding of facial trustworthiness to improve perceptual sensitivity. These findings have implications for the role of our visual experience in the decisions we make about the trustworthiness of other individuals.

  3. Contaminated sediment research task: SHC Task 3.61.3

    Science.gov (United States)

    A poster presentation for the SHC BOSC review will summarize the research efforts under Sustainable and Healthy Communities Research Program (SHC) in the Contaminated Sediment Task within the Contaminated Sites Project. For the Task, Problem Summary & Decision Context; Task O...

  4. Social identity change in response to discrimination.

    Science.gov (United States)

    Perozzo, Cristina; de la Sablonnière, Roxane; Auger, Emilie; Caron-Diotte, Mathieu

    2016-09-01

    This study investigated the conditions under which discrimination can lead to social identity changes among members of a minority group. Both positive and negative relations between perceptions of discrimination and social identity have previously been reported. To explain the conflicting results and understand the complex reality of members of stigmatized groups, we argue that group-based emotions (e.g., group-based dissatisfaction) and ambiguity of discrimination cues (i.e., overt vs. ambiguous) need to be considered. We hypothesized that perceptions of discrimination would play a moderating role between group-based dissatisfaction and social identity change in a context of ambiguous, but not of overt, discrimination. The sample was comprised of 151 Arab Muslims living in the province of Quebec. Participants read fictitious newspaper articles portraying either overt (n = 76) or ambiguous (n = 75) discrimination towards in-group members. Results revealed that for participants in the overt discrimination condition, only group-based dissatisfaction was positively associated with social identity change. In contrast, for the participants in the ambiguous discrimination condition, those who perceived little discrimination and felt low group-based dissatisfaction reported a decrease in social identity. However, those who perceived low group discrimination and felt high group-based dissatisfaction reported a positive social identity change. © 2016 The British Psychological Society.

  5. Perceived age discrimination in older adults.

    Science.gov (United States)

    Rippon, Isla; Kneale, Dylan; de Oliveira, Cesar; Demakakos, Panayotes; Steptoe, Andrew

    2014-05-01

    to examine perceived age discrimination in a large representative sample of older adults in England. this cross-sectional study of over 7,500 individuals used data from the fifth wave of the English Longitudinal Study of Ageing (ELSA), a longitudinal cohort study of men and women aged 52 years and older in England. Wave 5 asked respondents about the frequency of five everyday discriminatory situations. Participants who attributed any experiences of discrimination to their age were treated as cases of perceived age discrimination. Multivariable logistic regression analysis was used to estimate the odds ratios of experiencing perceived age discrimination in relation to selected sociodemographic factors. approximately a third (33.3%) of all respondents experienced age discrimination, rising to 36.8% in those aged 65 and over. Perceived age discrimination was associated with older age, higher education, lower levels of household wealth and being retired or not in employment. The correlates of age discrimination across the five discriminatory situations were similar. understanding age discrimination is vital if we are to develop appropriate policies and to target future interventions effectively. These findings highlight the scale of the challenge of age discrimination for older adults in England and illustrate that those groups are particularly vulnerable to this form of discrimination.

  6. Influence of Spatial and Chromatic Noise on Luminance Discrimination.

    Science.gov (United States)

    Miquilini, Leticia; Walker, Natalie A; Odigie, Erika A; Guimarães, Diego Leite; Salomão, Railson Cruz; Lacerda, Eliza Maria Costa Brito; Cortes, Maria Izabel Tentes; de Lima Silveira, Luiz Carlos; Fitzgerald, Malinda E C; Ventura, Dora Fix; Souza, Givago Silva

    2017-12-05

    Pseudoisochromatic figures are designed to base discrimination of a chromatic target from a background solely on the chromatic differences. This is accomplished by the introduction of luminance and spatial noise thereby eliminating these two dimensions as cues. The inverse rationale could also be applied to luminance discrimination, if spatial and chromatic noise are used to mask those cues. In this current study estimate of luminance contrast thresholds were conducted using a novel stimulus, based on the use of chromatic and spatial noise to mask the use of these cues in a luminance discrimination task. This was accomplished by presenting stimuli composed of a mosaic of circles colored randomly. A Landolt-C target differed from the background only by the luminance. The luminance contrast thresholds were estimated for different chromatic noise saturation conditions and compared to luminance contrast thresholds estimated using the same target in a non-mosaic stimulus. Moreover, the influence of the chromatic content in the noise on the luminance contrast threshold was also investigated. Luminance contrast threshold was dependent on the chromaticity noise strength. It was 10-fold higher than thresholds estimated from non-mosaic stimulus, but they were independent of colour space location in which the noise was modulated. The present study introduces a new method to investigate luminance vision intended for both basic science and clinical applications.

  7. Simultaneous Assessment of Speech Identification and Spatial Discrimination

    Directory of Open Access Journals (Sweden)

    Jennifer K. Bizley

    2015-12-01

    Full Text Available With increasing numbers of children and adults receiving bilateral cochlear implants, there is an urgent need for assessment tools that enable testing of binaural hearing abilities. Current test batteries are either limited in scope or are of an impractical duration for routine testing. Here, we report a behavioral test that enables combined testing of speech identification and spatial discrimination in noise. In this task, multitalker babble was presented from all speakers, and pairs of speech tokens were sequentially presented from two adjacent speakers. Listeners were required to identify both words from a closed set of four possibilities and to determine whether the second token was presented to the left or right of the first. In Experiment 1, normal-hearing adult listeners were tested at 15° intervals throughout the frontal hemifield. Listeners showed highest spatial discrimination performance in and around the frontal midline, with a decline at more eccentric locations. In contrast, speech identification abilities were least accurate near the midline and showed an improvement in performance at more lateral locations. In Experiment 2, normal-hearing listeners were assessed using a restricted range of speaker locations designed to match those found in clinical testing environments. Here, speakers were separated by 15° around the midline and 30° at more lateral locations. This resulted in a similar pattern of behavioral results as in Experiment 1. We conclude, this test offers the potential to assess both spatial discrimination and the ability to use spatial information for unmasking in clinical populations.

  8. Robust infrared target tracking using discriminative and generative approaches

    Science.gov (United States)

    Asha, C. S.; Narasimhadhan, A. V.

    2017-09-01

    The process of designing an efficient tracker for thermal infrared imagery is one of the most challenging tasks in computer vision. Although a lot of advancement has been achieved in RGB videos over the decades, textureless and colorless properties of objects in thermal imagery pose hard constraints in the design of an efficient tracker. Tracking of an object using a single feature or a technique often fails to achieve greater accuracy. Here, we propose an effective method to track an object in infrared imagery based on a combination of discriminative and generative approaches. The discriminative technique makes use of two complementary methods such as kernelized correlation filter with spatial feature and AdaBoost classifier with pixel intesity features to operate in parallel. After obtaining optimized locations through discriminative approaches, the generative technique is applied to determine the best target location using a linear search method. Unlike the baseline algorithms, the proposed method estimates the scale of the target by Lucas-Kanade homography estimation. To evaluate the proposed method, extensive experiments are conducted on 17 challenging infrared image sequences obtained from LTIR dataset and a significant improvement of mean distance precision and mean overlap precision is accomplished as compared with the existing trackers. Further, a quantitative and qualitative assessment of the proposed approach with the state-of-the-art trackers is illustrated to clearly demonstrate an overall increase in performance.

  9. Combined discriminative global and generative local models for visual tracking

    Science.gov (United States)

    Zhao, Liujun; Zhao, Qingjie; Chen, Yanming; Lv, Peng

    2016-03-01

    It is a challenging task to develop an effective visual tracking algorithm due to factors such as pose variation, rotation, and so on. Combined discriminative global and generative local appearance models are proposed to address this problem. Specifically, we develop a compact global object representation by extracting the low-frequency coefficients of the color and texture of the object based on two-dimensional discrete cosine transform. Then, with the global appearance representation, we learn a discriminative metric classifier in an online fashion to differentiate the target object from its background, which is very important to robustly indicate the changes in appearance. Second, we develop a new generative local model that exploits the scale invariant feature transform and its spatial geometric information. To make use of the advantages of the global discriminative model and the generative local model, we incorporate them into Bayesian inference framework. In this framework, the complementary models help the tracker locate the target more accurately. Furthermore, we use different mechanisms to update global and local templates to capture appearance changes. The experimental results demonstrate that the proposed approach performs favorably against state-of-the-art methods in terms of accuracy.

  10. Discriminative Nonlinear Analysis Operator Learning: When Cosparse Model Meets Image Classification.

    Science.gov (United States)

    Wen, Zaidao; Hou, Biao; Jiao, Licheng

    2017-05-03

    Linear synthesis model based dictionary learning framework has achieved remarkable performances in image classification in the last decade. Behaved as a generative feature model, it however suffers from some intrinsic deficiencies. In this paper, we propose a novel parametric nonlinear analysis cosparse model (NACM) with which a unique feature vector will be much more efficiently extracted. Additionally, we derive a deep insight to demonstrate that NACM is capable of simultaneously learning the task adapted feature transformation and regularization to encode our preferences, domain prior knowledge and task oriented supervised information into the features. The proposed NACM is devoted to the classification task as a discriminative feature model and yield a novel discriminative nonlinear analysis operator learning framework (DNAOL). The theoretical analysis and experimental performances clearly demonstrate that DNAOL will not only achieve the better or at least competitive classification accuracies than the state-of-the-art algorithms but it can also dramatically reduce the time complexities in both training and testing phases.

  11. Concentrated pitch discrimination modulates auditory brainstem responses during contralateral noise exposure.

    Science.gov (United States)

    Ikeda, Kazunari; Sekiguchi, Takahiro; Hayashi, Akiko

    2010-03-31

    This study examined a notion that auditory discrimination is a requisite for attention-related modulation of the auditory brainstem response (ABR) during contralateral noise exposure. Given that the right ear was exposed continuously with white noise at an intensity of 60-80 dB sound pressure level, tone pips at 80 dB sound pressure level were delivered to the left ear through either single-stimulus or oddball procedures. Participants conducted reading (ignoring task) and counting target tones (attentive task) during stimulation. The oddball but not the single-stimulus procedures elicited task-related modulations in both early (ABR) and late (processing negativity) event-related potentials simultaneously. The elicitation of the attention-related ABR modulation during contralateral noise exposure is thus considered to require auditory discrimination and have the corticofugal nature evidently.

  12. Demonstration of Einstein-Podolsky-Rosen steering with enhanced subchannel discrimination

    Science.gov (United States)

    Sun, Kai; Ye, Xiang-Jun; Xiao, Ya; Xu, Xiao-Ye; Wu, Yu-Chun; Xu, Jin-Shi; Chen, Jing-Ling; Li, Chuan-Feng; Guo, Guang-Can

    2018-03-01

    Einstein-Podolsky-Rosen (EPR) steering describes a quantum nonlocal phenomenon in which one party can nonlocally affect the other's state through local measurements. It reveals an additional concept of quantum non-locality, which stands between quantum entanglement and Bell nonlocality. Recently, a quantum information task named as subchannel discrimination (SD) provides a necessary and sufficient characterization of EPR steering. The success probability of SD using steerable states is higher than using any unsteerable states, even when they are entangled. However, the detailed construction of such subchannels and the experimental realization of the corresponding task are still technologically challenging. In this work, we designed a feasible collection of subchannels for a quantum channel and experimentally demonstrated the corresponding SD task where the probabilities of correct discrimination are clearly enhanced by exploiting steerable states. Our results provide a concrete example to operationally demonstrate EPR steering and shine a new light on the potential application of EPR steering.

  13. Discrimination of mixed quantum states. Reversible maps and unambiguous strategies

    Energy Technology Data Exchange (ETDEWEB)

    Kleinmann, Matthias

    2008-06-30

    The discrimination of two mixed quantum states is a fundamental task in quantum state estimation and quantum information theory. In quantum state discrimination a quantum system is assumed to be in one of two possible - in general mixed - non-orthogonal quantum states. The discrimination then consists of a measurement strategy that allows to decide in which state the system was before the measurement. In unambiguous state discrimination the aim is to make this decision without errors, but it is allowed to give an inconclusive answer. Especially interesting are measurement strategies that minimize the probability of an inconclusive answer. A starting point for the analysis of this optimization problem was a result by Eldar et al. [Phys. Rev. A 69, 062318 (2004)], which provides non-operational necessary and sufficient conditions for a given measurement strategy to be optimal. These conditions are reconsidered and simplified in such a way that they become operational. The simplified conditions are the basis for further central results: It is shown that the optimal measurement strategy is unique, a statement that is e.g. of importance for the complexity analysis of optimal measurement devices. The optimal measurement strategy is derived for the case, where one of the possible input states has at most rank two, which was an open problem for many years. Furthermore, using the optimality criterion it is shown that there always exists a threshold probability for each state, such that below this probability it is optimal to exclude this state from the discrimination strategy. If the two states subject to discrimination can be brought to a diagonal structure with (2 x 2)-dimensional blocks, then the unambiguous discrimination of these states can be reduced to the unambiguous discrimination of pure states. A criterion is presented that allows to identify the presence of such a structure for two self-adjoint operators. This criterion consists of the evaluation of three

  14. Menstrual cycle phase affects discrimination of infant cuteness.

    Science.gov (United States)

    Lobmaier, Janek S; Probst, Fabian; Perrett, David I; Heinrichs, Markus

    2015-04-01

    Recent studies have shown that women are more sensitive than men to subtle cuteness differences in infant faces. It has been suggested that raised levels in estradiol and progesterone may be responsible for this advantage. We compared young women's sensitivity to computer-manipulated baby faces varying in cuteness. Thirty-six women were tested once during ovulation and once during the luteal phase of their menstrual cycle. In a two alternative forced-choice experiment, participants chose the baby which they thought was cuter (Task 1), younger (Task 2), or the baby that they would prefer to babysit (Task 3). Saliva samples to assess levels of estradiol, progesterone and testosterone were collected at each test session. During ovulation, women were more likely to choose the cuter baby than during the luteal phase, in all three tasks. These results suggest that cuteness discrimination may be driven by cyclic hormonal shifts. However none of the measured hormones were related to increased cuteness sensitivity. We speculate that other hormones than the ones measured here might be responsible for the increased sensitivity to subtle cuteness differences during ovulation. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Task Switching in a Hierarchical Task Structure: Evidence for the Fragility of the Task Repetition Benefit

    Science.gov (United States)

    Lien, Mei-Ching; Ruthruff, Eric

    2004-01-01

    This study examined how task switching is affected by hierarchical task organization. Traditional task-switching studies, which use a constant temporal and spatial distance between each task element (defined as a stimulus requiring a response), promote a flat task structure. Using this approach, Experiment 1 revealed a large switch cost of 238 ms.…

  16. Discriminant analysis of plasma fusion data

    International Nuclear Information System (INIS)

    Kardaun, O.J.W.F.; Kardaun, J.W.P.F.; Itoh, S.; Itoh, K.

    1992-06-01

    Several discriminant analysis methods has been applied and compared to predict the type of ELM's in H-mode discharges: (a) quadratic discriminant analysis (linear discriminant analysis being a special case), (b) discrimination by non-parametric (kernel-) density estimates, and (c) discrimination by a product multinomial model on a discretised scale. Practical evaluation was performed using SAS in the first two cases, and INDEP, a standard FORTRAN program, initially developed for medical applications, in the last case. We give here a flavour of the approach and its results. In summary, discriminant analysis can be used as a useful descriptive method of specifying regions where particular types of plasma discharges can be produced. Parametric methods have the advantage of a rather compact mathematical formulation . Pertinent graphical representations are useful to make the theory and the results more palatable to the experimental physicists. (J.P.N.)

  17. Robot task space analyzer

    International Nuclear Information System (INIS)

    Hamel, W.R.; Osborn, J.

    1997-01-01

    Many nuclear projects such as environmental restoration and waste management challenges involve radiation or other hazards that will necessitate the use of remote operations that protect human workers from dangerous exposures. Remote work is far more costly to execute than what workers could accomplish directly with conventional tools and practices because task operations are slow and tedious due to difficulties of remote manipulation and viewing. Decades of experience within the nuclear remote operations community show that remote tasks may take hundreds of times longer than hands-on work; even with state-of-the-art force- reflecting manipulators and television viewing, remote task performance execution is five to ten times slower than equivalent direct contact work. Thus the requirement to work remotely is a major cost driver in many projects. Modest improvements in the work efficiency of remote systems can have high payoffs by reducing the completion time of projects. Additional benefits will accrue from improved work quality and enhanced safety

  18. Performing Task Integration

    DEFF Research Database (Denmark)

    Elkjaer, Bente; Nickelsen, Niels Christian Mossfeldt

    by shared goals and knowledge as well as mutual respect and frequent, timely, accurate and problem-solving ways of communication with the purpose of dealing with the tasks at hand in an integrated way. We introduce and discuss relational coordination theory through a case-study within public healthcare....... Here cross-professional coordination of work was done by scheduled communication twice a day. When we proposed a way for further integration of tasks through an all-inclusive team organization, we were met with resistance. We use the study to discuss whether relational coordination theory is able to do...... away with differences regarding task definitions and working conditions as well as professional knowledge hierarchies and responsibilities for parts and wholes....

  19. Measuring pilot workload in a motion base simulator. III - Synchronous secondary task

    Science.gov (United States)

    Kantowitz, Barry H.; Bortolussi, Michael R.; Hart, Sandra G.

    1987-01-01

    This experiment continues earlier research of Kantowitz et al. (1983) conducted in a GAT-1 motion-base trainer to evaluate choice-reaction secondary tasks as measures of pilot work load. The earlier work used an asynchronous secondary task presented every 22 sec regardless of flying performance. The present experiment uses a synchronous task presented only when a critical event occurred on the flying task. Both two- and four-choice visual secondary tasks were investigated. Analysis of primary flying-task results showed no decrement in error for altitude, indicating that the key assumption necessary for using a choice secondary task was satisfied. Reaction times showed significant differences between 'easy' and 'hard' flight scenarios as well as the ability to discriminate among flight tasks.

  20. A dual-task investigation of automaticity in visual word processing

    Science.gov (United States)

    McCann, R. S.; Remington, R. W.; Van Selst, M.

    2000-01-01

    An analysis of activation models of visual word processing suggests that frequency-sensitive forms of lexical processing should proceed normally while unattended. This hypothesis was tested by having participants perform a speeded pitch discrimination task followed by lexical decisions or word naming. As the stimulus onset asynchrony between the tasks was reduced, lexical-decision and naming latencies increased dramatically. Word-frequency effects were additive with the increase, indicating that frequency-sensitive processing was subject to postponement while attention was devoted to the other task. Either (a) the same neural hardware shares responsibility for lexical processing and central stages of choice reaction time task processing and cannot perform both computations simultaneously, or (b) lexical processing is blocked in order to optimize performance on the pitch discrimination task. Either way, word processing is not as automatic as activation models suggest.

  1. Matching cue size and task properties in exogenous attention.

    Science.gov (United States)

    Burnett, Katherine E; d'Avossa, Giovanni; Sapir, Ayelet

    2013-01-01

    Exogenous attention is an involuntary, reflexive orienting response that results in enhanced processing at the attended location. The standard view is that this enhancement generalizes across visual properties of a stimulus. We test whether the size of an exogenous cue sets the attentional field and whether this leads to different effects on stimuli with different visual properties. In a dual task with a random-dot kinematogram (RDK) in each quadrant of the screen, participants discriminated the direction of moving dots in one RDK and localized one red dot. Precues were uninformative and consisted of either a large or a small luminance-change frame. The motion discrimination task showed attentional effects following both large and small exogenous cues. The red dot probe localization task showed attentional effects following a small cue, but not a large cue. Two additional experiments showed that the different effects on localization were not due to reduced spatial uncertainty or suppression of RDK dots in the surround. These results indicate that the effects of exogenous attention depend on the size of the cue and the properties of the task, suggesting the involvement of receptive fields with different sizes in different tasks. These attentional effects are likely to be driven by bottom-up mechanisms in early visual areas.

  2. Fast differential pulse discriminator-counter

    International Nuclear Information System (INIS)

    Shelevoj, K.D.

    1985-01-01

    The flowsheet of a differential pulse discriminator counter is described; the result of discrimination here is independent from the shape of the input pulse. Rate of the analysis of input pulses with minimum amplitude up to 0.3 mV coming out from the photomultiplier makes up 220 MHz. The flowsheet of the discriminator used in the system of photon counting for atmosphere probing is presented

  3. The monolithic double-threshold discriminator

    International Nuclear Information System (INIS)

    Baturitsky, M.A.; Dvornikov, O.V.

    1999-01-01

    A double-threshold discriminator capable of processing input signals of different duration is described. Simplicity of the discriminator circuitry makes it possible to embody the discriminator in multichannel ICs using microwave bipolar-JFET technology. Time walk is calculated to be less than 0.35 ns for the input ramp signals with rise times 25-100 ns and amplitudes 50 mV-1 V

  4. Preamplifier-discriminator for a photomultiplier

    International Nuclear Information System (INIS)

    Groshev, V.Ya.; Zabrodskij, V.A.

    1986-01-01

    A simple preamplifier-discriminator intended for processing fluxes of low-energy X-radiation in combination with a scintillation detector is suggested. Utilization of the 564LE5 microcircuit in the preamplifier-discriminator permits to use general supply, with digital logical microcircuits. Operation of the preamplifier-discriminator during some years as a part of the RPP-1 X-ray densitometer displayed good repeatibility of parameters of the device and its reliability

  5. Competitive targeted advertising with price discrimination

    OpenAIRE

    Esteves, Rosa Branca; Resende, Joana

    2013-01-01

    This paper investigates the effects of price discrimination by means of targeted advertising in a duopolistic market where the distribution of consumers’ preferences is discrete and where advertising plays two major roles. It is used by firms as a way to transmit relevant information to otherwise uninformed consumers and it is used as a price discrimination device. We compare the firms’ optimal marketing mix (advertising and pricing) when they adopt mass advertising/non-discrimination strateg...

  6. Age and Workplace Discrimination in Lithuania

    OpenAIRE

    Braziene, Ruta

    2017-01-01

    This paper aims to disclose an expression of age and workplace discrimination in the Lithuanian labor market. The paper is discussing theoretical aspects of age discrimination and presents the results of the sociological survey research results carried out in 2014. The purpose of this paper is to disclose age and workplace discrimination at the Lithuanian labor market. Analysis of scientific literature and quantitative research results allows to state that older adults are experiencing discri...

  7. Statistical Discrimination in a Competitive Labor Market

    OpenAIRE

    Jonathan B. Berk

    1999-01-01

    This paper studies the effect of employee job selection in a model of statistical discrimination in a competitive labor market. In an economy in which there are quality differences between groups, a surprisingly strong condition is required to guarantee discrimination against the worse qualified group --- MLRP must hold. In addition, because of the self-selection bias induced by competition, the resulting discrimination is small when compared to the magnitude of the underlying quality differe...

  8. The Economics of Discrimination: Evidence from Basketball

    OpenAIRE

    Kahn, Lawrence M.

    2009-01-01

    This Chapter reviews evidence on discrimination in basketball, primarily examining studies on race but with some discussion of gender as well. I focus on discrimination in pay, hiring, and retention against black NBA players and coaches and pay disparities by gender among college coaches. There was much evidence for each of these forms of discrimination against black NBA players in the 1980s. However, there appears to be less evidence of racial compensation, hiring and retention discriminatio...

  9. Gender Discrimination and Women's Development in India

    OpenAIRE

    sivakumar, marimuthu

    2008-01-01

    Gender is a common term where as gender discrimination is meant only for women, because females are the only victims of gender discrimination. Females are nearly 50 percent of the total population but their representation in public life is very low. Recognizing women’s right and believing their ability are essential for women’s empowerment and development. This study deals with gender discrimination in India, its various forms and its causes. Importance of women in development, legislation...

  10. Discrimination And Intolerance in the Art

    OpenAIRE

    Vitor Correia

    2014-01-01

    When the people speak about discrimination and intolerance, it is usually in reference to the racial, religious, political, sexual, age, problems, etc., and does not refer, or refers less, the discrimination and the intolerance determined by artistic reasons, or with these related : the age differences in art, the sexism in art, and the rejection of works of art. In this text we intend to show the existence of these forms of discrimination and intolerance, explain what they mean, its causes, ...

  11. Organizing Core Tasks

    DEFF Research Database (Denmark)

    Boll, Karen

    has remained much the same within the last 10 years. However, how the core task has been organized has changed considerable under the influence of various “organizing devices”. The paper focusses on how organizing devices such as risk assessment, output-focus, effect orientation, and treatment...... projects influence the organization of core tasks within the tax administration. The paper shows that the organizational transformations based on the use of these devices have had consequences both for the overall collection of revenue and for the employees’ feeling of “making a difference”. All in all...

  12. Earlier saccades to task-relevant targets irrespective of relative gain between peripheral and foveal information.

    Science.gov (United States)

    Wolf, Christian; Schütz, Alexander C

    2017-06-01

    Saccades bring objects of interest onto the fovea for high-acuity processing. Saccades to rewarded targets show shorter latencies that correlate negatively with expected motivational value. Shorter latencies are also observed when the saccade target is relevant for a perceptual discrimination task. Here we tested whether saccade preparation is equally influenced by informational value as it is by motivational value. We defined informational value as the probability that information is task-relevant times the ratio between postsaccadic foveal and presaccadic peripheral discriminability. Using a gaze-contingent display, we independently manipulated peripheral and foveal discriminability of the saccade target. Latencies of saccades with perceptual task were reduced by 36 ms in general, but they were not modulated by the information saccades provide (Experiments 1 and 2). However, latencies showed a clear negative linear correlation with the probability that the target is task-relevant (Experiment 3). We replicated that the facilitation by a perceptual task is spatially specific and not due to generally heightened arousal (Experiment 4). Finally, the facilitation only emerged when the perceptual task is in the visual but not in the auditory modality (Experiment 5). Taken together, these results suggest that saccade latencies are not equally modulated by informational value as by motivational value. The facilitation by a perceptual task only arises when task-relevant visual information is foveated, irrespective of whether the foveation is useful or not.

  13. Discriminant forest classification method and system

    Science.gov (United States)

    Chen, Barry Y.; Hanley, William G.; Lemmond, Tracy D.; Hiller, Lawrence J.; Knapp, David A.; Mugge, Marshall J.

    2012-11-06

    A hybrid machine learning methodology and system for classification that combines classical random forest (RF) methodology with discriminant analysis (DA) techniques to provide enhanced classification capability. A DA technique which uses feature measurements of an object to predict its class membership, such as linear discriminant analysis (LDA) or Andersen-Bahadur linear discriminant technique (AB), is used to split the data at each node in each of its classification trees to train and grow the trees and the forest. When training is finished, a set of n DA-based decision trees of a discriminant forest is produced for use in predicting the classification of new samples of unknown class.

  14. Optimal state discrimination using particle statistics

    International Nuclear Information System (INIS)

    Bose, S.; Ekert, A.; Omar, Y.; Paunkovic, N.; Vedral, V.

    2003-01-01

    We present an application of particle statistics to the problem of optimal ambiguous discrimination of quantum states. The states to be discriminated are encoded in the internal degrees of freedom of identical particles, and we use the bunching and antibunching of the external degrees of freedom to discriminate between various internal states. We show that we can achieve the optimal single-shot discrimination probability using only the effects of particle statistics. We discuss interesting applications of our method to detecting entanglement and purifying mixed states. Our scheme can easily be implemented with the current technology

  15. Discrimination And Intolerance in the Art

    Directory of Open Access Journals (Sweden)

    Vitor Correia

    2014-03-01

    Full Text Available When the people speak about discrimination and intolerance, it is usually in reference to the racial, religious, political, sexual, age, problems, etc., and does not refer, or refers less, the discrimination and the intolerance determined by artistic reasons, or with these related : the age differences in art, the sexism in art, and the rejection of works of art. In this text we intend to show the existence of these forms of discrimination and intolerance, explain what they mean, its causes, and its aftermath. We analyze the specificity of each of the discrimination and intolerance in the artistic field,  and the social weight they have in the world today.

  16. Genetic Discrimination: A Legal Or Biological Issue?

    Directory of Open Access Journals (Sweden)

    Bárbara Augusta de Paula Araujo Myssior

    2016-12-01

    Full Text Available This essay debates the technological evolution that, from the decoding of the human genome has opened up many scientific benefits, and yet brings up a new kind of segregation: genetic discrimination. Based on the right to privacy, as well as the concept of genetic identity, as well as data protection and information, worked up the genetic discrimination. Therefore, documentary research and critical analysis of scientific papers were taken, using up of the inductive reasoning method. As a result, elucidate how such discrimination affects individuals, it is possible to conclude that regardless of the type of discrimination, all should be restrained by law.

  17. Simple multifunction discriminator for multichannel triggers

    International Nuclear Information System (INIS)

    Maier, M.R.

    1982-10-01

    A simple version of a multifunction timing discriminator using only two integrated circuits is presented. It can be configured as a leading edge, a constant fraction, a zero cross or a dual threshold timing discriminator. Since so few parts are used, it is well suited for building multichannel timing discriminators. Two versions of this circuit are described: a quadruple multifunction discriminator and an octal constant fraction trigger. The different compromises made in these units are discussed. Results for walk and jitter obtained with these are presented and possible improvements are disussed

  18. Health care workplace discrimination and physician turnover.

    Science.gov (United States)

    Nunez-Smith, Marcella; Pilgrim, Nanlesta; Wynia, Matthew; Desai, Mayur M; Bright, Cedric; Krumholz, Harlan M; Bradley, Elizabeth H

    2009-12-01

    To examine the association between physician race/ ethnicity, workplace discrimination, and physician job turnover. Cross-sectional, national survey conducted in 2006-2007 of practicing physicians (n = 529) randomly identified via the American Medical Association Masterfile and the National Medical Association membership roster. We assessed the relationships between career racial/ethnic discrimination at work and several career-related dependent variables, including 2 measures of physician turnover, career satisfaction, and contemplation of career change. We used standard frequency analyses, odds ratios and chi2 statistics, and multivariate logistic regression modeling to evaluate these associations. Physicians who self-identified as nonmajority were significantly more likely to have left at least 1 job because of workplace discrimination (black, 29%; Asian, 24%; other race, 21%; Hispanic/Latino, 20%; white, 9%). In multivariate models, having experienced racial/ethnic discrimination at work was associated with high job turnover (adjusted odds ratio, 2.7; 95% CI, 1.4-4.9). Among physicians who experienced workplace discrimination, only 45% of physicians were satisfied with their careers (vs 88% among those who had not experienced workplace discrimination, p value workplace discrimination, p value Workplace discrimination is associated with physician job turnover, career dissatisfaction, and contemplation of career change. These findings underscore the importance of monitoring for workplace discrimination and responding when opportunities for intervention and retention still exist.

  19. Discrimination And Intolerance in the Art

    Directory of Open Access Journals (Sweden)

    Vitor Correia

    2014-04-01

    Full Text Available When the people speak about discrimination and intolerance, it is usually in reference to the racial, religious, political, sexual, age, problems, etc., and does not refer, or refers less, the discrimination and the intolerance determined by artistic reasons, or with these related : the age differences in art, the sexism in art, and the rejection of works of art. In this text we intend to show the existence of these forms of discrimination and intolerance, explain what they mean, its causes, and its aftermath. We analyze the specificity of each of the discrimination and intolerance in the artistic field,  and the social weight they have in the world today.

  20. Performance and strategy comparisons of human listeners and logistic regression in discriminating underwater targets.

    Science.gov (United States)

    Yang, Lixue; Chen, Kean

    2015-11-01

    To improve the design of underwater target recognition systems based on auditory perception, this study compared human listeners with automatic classifiers. Performances measures and strategies in three discrimination experiments, including discriminations between man-made and natural targets, between ships and submarines, and among three types of ships, were used. In the experiments, the subjects were asked to assign a score to each sound based on how confident they were about the category to which it belonged, and logistic regression, which represents linear discriminative models, also completed three similar tasks by utilizing many auditory features. The results indicated that the performances of logistic regression improved as the ratio between inter- and intra-class differences became larger, whereas the performances of the human subjects were limited by their unfamiliarity with the targets. Logistic regression performed better than the human subjects in all tasks but the discrimination between man-made and natural targets, and the strategies employed by excellent human subjects were similar to that of logistic regression. Logistic regression and several human subjects demonstrated similar performances when discriminating man-made and natural targets, but in this case, their strategies were not similar. An appropriate fusion of their strategies led to further improvement in recognition accuracy.

  1. Psilocybin modulates functional connectivity of the amygdala during emotional face discrimination.

    Science.gov (United States)

    Grimm, O; Kraehenmann, R; Preller, K H; Seifritz, E; Vollenweider, F X

    2018-04-24

    Recent studies suggest that the antidepressant effects of the psychedelic 5-HT2A receptor agonist psilocybin are mediated through its modulatory properties on prefrontal and limbic brain regions including the amygdala. To further investigate the effects of psilocybin on emotion processing networks, we studied for the first-time psilocybin's acute effects on amygdala seed-to-voxel connectivity in an event-related face discrimination task in 18 healthy volunteers who received psilocybin and placebo in a double-blind balanced cross-over design. The amygdala has been implicated as a salience detector especially involved in the immediate response to emotional face content. We used beta-series amygdala seed-to-voxel connectivity during an emotional face discrimination task to elucidate the connectivity pattern of the amygdala over the entire brain. When we compared psilocybin to placebo, an increase in reaction time for all three categories of affective stimuli was found. Psilocybin decreased the connectivity between amygdala and the striatum during angry face discrimination. During happy face discrimination, the connectivity between the amygdala and the frontal pole was decreased. No effect was seen during discrimination of fearful faces. Thus, we show psilocybin's effect as a modulator of major connectivity hubs of the amygdala. Psilocybin decreases the connectivity between important nodes linked to emotion processing like the frontal pole or the striatum. Future studies are needed to clarify whether connectivity changes predict therapeutic effects in psychiatric patients. Copyright © 2018 Elsevier B.V. and ECNP. All rights reserved.

  2. Relation between functional connectivity and rhythm discrimination in children who do and do not stutter

    Directory of Open Access Journals (Sweden)

    Soo-Eun Chang

    2016-01-01

    Full Text Available Our ability to perceive and produce rhythmic patterns in the environment supports fundamental human capacities ranging from music and language processing to the coordination of action. This article considers whether spontaneous correlated brain activity within a basal ganglia-thalamocortical (rhythm network is associated with individual differences in auditory rhythm discrimination. Moreover, do children who stutter with demonstrated deficits in rhythm perception have weaker links between rhythm network functional connectivity and rhythm discrimination? All children in the study underwent a resting-state fMRI session, from which functional connectivity measures within the rhythm network were extracted from spontaneous brain activity. In a separate session, the same children completed an auditory rhythm-discrimination task, where behavioral performance was assessed using signal detection analysis. We hypothesized that in typically developing children, rhythm network functional connectivity would be associated with behavioral performance on the rhythm discrimination task, but that this relationship would be attenuated in children who stutter. Results supported our hypotheses, lending strong support for the view that (1 children who stutter have weaker rhythm network connectivity and (2 the lack of a relation between rhythm network connectivity and rhythm discrimination in children who stutter may be an important contributing factor to the etiology of stuttering.

  3. Pitch ranking, electrode discrimination, and physiological spread-of-excitation using Cochlear's dual-electrode mode.

    Science.gov (United States)

    Goehring, Jenny L; Neff, Donna L; Baudhuin, Jacquelyn L; Hughes, Michelle L

    2014-08-01

    This study compared pitch ranking, electrode discrimination, and electrically evoked compound action potential (ECAP) spatial excitation patterns for adjacent physical electrodes (PEs) and the corresponding dual electrodes (DEs) for newer-generation Cochlear devices (Cochlear Ltd., Macquarie, New South Wales, Australia). The first goal was to determine whether pitch ranking and electrode discrimination yield similar outcomes for PEs and DEs. The second goal was to determine if the amount of spatial separation among ECAP excitation patterns (separation index, Σ) between adjacent PEs and the PE-DE pairs can predict performance on the psychophysical tasks. Using non-adaptive procedures, 13 subjects completed pitch ranking and electrode discrimination for adjacent PEs and the corresponding PE-DE pairs (DE versus each flanking PE) from the basal, middle, and apical electrode regions. Analysis of d' scores indicated that pitch-ranking and electrode-discrimination scores were not significantly different, but rather produced similar levels of performance. As expected, accuracy was significantly better for the PE-PE comparison than either PE-DE comparison. Correlations of the psychophysical versus ECAP Σ measures were positive; however, not all test/region correlations were significant across the array. Thus, the ECAP separation index is not sensitive enough to predict performance on behavioral tasks of pitch ranking or electrode discrimination for adjacent PEs or corresponding DEs.

  4. Temporal and spectral contributions to musical instrument identification and discrimination among cochlear implant users.

    Science.gov (United States)

    Prentiss, Sandra M; Friedland, David R; Fullmer, Tanner; Crane, Alison; Stoddard, Timothy; Runge, Christina L

    2016-09-01

    To investigate the contributions of envelope and fine-structure to the perception of timbre by cochlear implant (CI) users as compared to normal hearing (NH) listeners. This was a prospective cohort comparison study. Normal hearing and cochlear implant patients were tested. Three experiments were performed in sound field using musical notes altered to affect the characteristic pitch of an instrument and the acoustic envelope. Experiment 1 assessed the ability to identify the instrument playing each note, while experiments 2 and 3 assessed the ability to discriminate the different stimuli. Normal hearing subjects performed better than CI subjects in all instrument identification tasks, reaching statistical significance for 4 of 5 stimulus conditions. Within the CI population, acoustic envelope modifications did not significantly affect instrument identification or discrimination. With envelope and pitch cues removed, fine structure discrimination performance was similar between normal hearing and CI users for the majority of conditions, but some specific instrument comparisons were significantly more challenging for CI users. Cochlear implant users perform significantly worse than normal hearing listeners on tasks of instrument identification. However, cochlear implant listeners can discriminate differences in envelope and some fine structure components of musical instrument sounds as well as normal hearing listeners. The results indicated that certain fine structure cues are important for cochlear implant users to make discrimination judgments, and therefore may affect interpretation toward associating with a specific instrument for identification.

  5. Temporal and spectral contributions to musical instrument identification and discrimination among cochlear implant users

    Institute of Scientific and Technical Information of China (English)

    Sandra M. Prentiss; David R. Friedland; Tanner Fullmer; Alison Crane; Timothy Stoddard; Christina L. Runge

    2016-01-01

    Objective:To investigate the contributions of envelope and fine-structure to the perception of timbre by cochlear implant (CI) users as compared to normal hearing (NH) lis-teners. Methods: This was a prospective cohort comparison study. Normal hearing and cochlear implant patients were tested. Three experiments were performed in sound field using musical notes altered to affect the characteristic pitch of an instrument and the acoustic envelope. Experiment 1 assessed the ability to identify the instrument playing each note, while experi-ments 2 and 3 assessed the ability to discriminate the different stimuli. Results:Normal hearing subjects performed better than CI subjects in all instrument identifi-cation tasks, reaching statistical significance for 4 of 5 stimulus conditions. Within the CI pop-ulation, acoustic envelope modifications did not significantly affect instrument identification or discrimination. With envelope and pitch cues removed, fine structure discrimination perfor-mance was similar between normal hearing and CI users for the majority of conditions, but some specific instrument comparisons were significantly more challenging for CI users. Conclusions:Cochlear implant users perform significantly worse than normal hearing listeners on tasks of instrument identification. However, cochlear implant listeners can discriminate differences in envelope and some fine structure components of musical instrument sounds as well as normal hearing listeners. The results indicated that certain fine structure cues are important for cochlear implant users to make discrimination judgments, and therefore may affect interpretation toward associating with a specific instrument for identification.

  6. Spatial probability aids visual stimulus discrimination

    Directory of Open Access Journals (Sweden)

    Michael Druker

    2010-08-01

    Full Text Available We investigated whether the statistical predictability of a target's location would influence how quickly and accurately it was classified. Recent results have suggested that spatial probability can be a cue for the allocation of attention in visual search. One explanation for probability cuing is spatial repetition priming. In our two experiments we used probability distributions that were continuous across the display rather than relying on a few arbitrary screen locations. This produced fewer spatial repeats and allowed us to dissociate the effect of a high probability location from that of short-term spatial repetition. The task required participants to quickly judge the color of a single dot presented on a computer screen. In Experiment 1, targets were more probable in an off-center hotspot of high probability that gradually declined to a background rate. Targets garnered faster responses if they were near earlier target locations (priming and if they were near the high probability hotspot (probability cuing. In Experiment 2, target locations were chosen on three concentric circles around fixation. One circle contained 80% of targets. The value of this ring distribution is that it allowed for a spatially restricted high probability zone in which sequentially repeated trials were not likely to be physically close. Participant performance was sensitive to the high-probability circle in addition to the expected effects of eccentricity and the distance to recent targets. These two experiments suggest that inhomogeneities in spatial probability can be learned and used by participants on-line and without prompting as an aid for visual stimulus discrimination and that spatial repetition priming is not a sufficient explanation for this effect. Future models of attention should consider explicitly incorporating the probabilities of targets locations and features.

  7. Adversarial Advantage Actor-Critic Model for Task-Completion Dialogue Policy Learning

    OpenAIRE

    Peng, Baolin; Li, Xiujun; Gao, Jianfeng; Liu, Jingjing; Chen, Yun-Nung; Wong, Kam-Fai

    2017-01-01

    This paper presents a new method --- adversarial advantage actor-critic (Adversarial A2C), which significantly improves the efficiency of dialogue policy learning in task-completion dialogue systems. Inspired by generative adversarial networks (GAN), we train a discriminator to differentiate responses/actions generated by dialogue agents from responses/actions by experts. Then, we incorporate the discriminator as another critic into the advantage actor-critic (A2C) framework, to encourage the...

  8. Infant discrimination of humanoid robots

    Directory of Open Access Journals (Sweden)

    Goh eMatsuda

    2015-09-01

    Full Text Available Recently, extremely humanlike robots called androids have been developed, some of which are already being used in the field of entertainment. In the context of psychological studies, androids are expected to be used in the future as fully controllable human stimuli to investigate human nature. In this study, we used an android to examine infant discrimination ability between human beings and non-human agents. Participants (N = 42 infants were assigned to three groups based on their age, i.e., 6- to 8-month-olds, 9- to 11-month-olds, and 12- to 14-month-olds, and took part in a preferential looking paradigm. Of three types of agents involved in the paradigm—a human, an android modeled on the human, and a mechanical-looking robot made from the android—two at a time were presented side-by-side as they performed a grasping action. Infants’ looking behavior was measured using an eye tracking system, and the amount of time spent focusing on each of three areas of interest (face, goal, and body was analyzed. Results showed that all age groups predominantly looked at the robot and at the face area, and that infants aged over 9 months watched the goal area for longer than the body area. There was no difference in looking times and areas focused on between the human and the android. These findings suggest that 6- to 14-month-olds are unable to discriminate between the human and the android, although they can distinguish the mechanical robot from the human.

  9. Selective attention to task-irrelevant emotional distractors is unaffected by the perceptual load associated with a foreground task.

    Science.gov (United States)

    Hindi Attar, Catherine; Müller, Matthias M

    2012-01-01

    A number of studies have shown that emotionally arousing stimuli are preferentially processed in the human brain. Whether or not this preference persists under increased perceptual load associated with a task at hand remains an open question. Here we manipulated two possible determinants of the attentional selection process, perceptual load associated with a foreground task and the emotional valence of concurrently presented task-irrelevant distractors. As a direct measure of sustained attentional resource allocation in early visual cortex we used steady-state visual evoked potentials (SSVEPs) elicited by distinct flicker frequencies of task and distractor stimuli. Subjects either performed a detection (low load) or discrimination (high load) task at a centrally presented symbol stream that flickered at 8.6 Hz while task-irrelevant neutral or unpleasant pictures from the International Affective Picture System (IAPS) flickered at a frequency of 12 Hz in the background of the stream. As reflected in target detection rates and SSVEP amplitudes to both task and distractor stimuli, unpleasant relative to neutral background pictures more strongly withdrew processing resources from the foreground task. Importantly, this finding was unaffected by the factor 'load' which turned out to be a weak modulator of attentional processing in human visual cortex.

  10. Selective attention to task-irrelevant emotional distractors is unaffected by the perceptual load associated with a foreground task.

    Directory of Open Access Journals (Sweden)

    Catherine Hindi Attar

    Full Text Available A number of studies have shown that emotionally arousing stimuli are preferentially processed in the human brain. Whether or not this preference persists under increased perceptual load associated with a task at hand remains an open question. Here we manipulated two possible determinants of the attentional selection process, perceptual load associated with a foreground task and the emotional valence of concurrently presented task-irrelevant distractors. As a direct measure of sustained attentional resource allocation in early visual cortex we used steady-state visual evoked potentials (SSVEPs elicited by distinct flicker frequencies of task and distractor stimuli. Subjects either performed a detection (low load or discrimination (high load task at a centrally presented symbol stream that flickered at 8.6 Hz while task-irrelevant neutral or unpleasant pictures from the International Affective Picture System (IAPS flickered at a frequency of 12 Hz in the background of the stream. As reflected in target detection rates and SSVEP amplitudes to both task and distractor stimuli, unpleasant relative to neutral background pictures more strongly withdrew processing resources from the foreground task. Importantly, this finding was unaffected by the factor 'load' which turned out to be a weak modulator of attentional processing in human visual cortex.

  11. Short-term and long-term effects of diazepam on the memory for discrimination and generalization of scopolamine.

    Science.gov (United States)

    Casasola-Castro, C; Weissmann-Sánchez, L; Calixto-González, E; Aguayo-Del Castillo, A; Velázquez-Martínez, D N

    2017-10-01

    Benzodiazepines are among the most widely prescribed and misused psychopharmaceutical drugs. Although they are well-tolerated, they are also capable of producing amnestic effects similar to those observed after pharmacological or organic cholinergic dysfunction. To date, the effect of benzodiazepine diazepam on the memory for discrimination of anticholinergic drugs has not been reported. The aim of the present study was to analyze the immediate and long-term effects of diazepam on a drug discrimination task with scopolamine. Male Wistar rats were trained to discriminate between scopolamine and saline administration using a two-lever discrimination task. Once discrimination was acquired, the subjects were divided into three independent groups, (1) control, (2) diazepam, and (3) diazepam chronic administration (10 days). Subsequently, generalization curves for scopolamine were obtained. Additionally, the diazepam and control groups were revaluated after 90 days without having been given any other treatment. The results showed that diazepam produced a significant reduction in the generalization gradient for scopolamine, indicating an impairment of discrimination. The negative effect of diazepam persisted even 90 days after drug had been administered. Meanwhile, the previous administration of diazepam for 10 days totally abated the generalization curve and the general performance of the subjects. The results suggest that diazepam affects memory for the stimulus discrimination of anticholinergic drugs and does so persistently, which could be an important consideration during the treatment of amnesic patients with benzodiazepines.

  12. Data Center Tasking.

    Science.gov (United States)

    Temares, M. Lewis; Lutheran, Joseph A.

    Operations tasking for data center management is discussed. The original and revised organizational structures of the data center at the University of Miami are also described. The organizational strategy addresses the functions that should be performed by the data center, anticipates the specialized skills required, and addresses personnel…

  13. Biomedical applications engineering tasks

    Science.gov (United States)

    Laenger, C. J., Sr.

    1976-01-01

    The engineering tasks performed in response to needs articulated by clinicians are described. Initial contacts were made with these clinician-technology requestors by the Southwest Research Institute NASA Biomedical Applications Team. The basic purpose of the program was to effectively transfer aerospace technology into functional hardware to solve real biomedical problems.

  14. India's Unfinished Telecom Tasks

    Indian Academy of Sciences (India)

    India's Telecom Story is now well known · Indian Operators become an enviable force · At the same time · India Amongst the Leaders · Unfinished Tasks as Operators · LightGSM ON: Innovation for Rural Area from Midas · Broadband Access Options for India · Broadband driven by DSL: still too slow · Is Wireless the answer?

  15. Sexual Discrimination in the Use of Letters of Recommendation: A Case of Reverse Discrimination

    Science.gov (United States)

    Kryger, Barbara Rosenblum; Shikiar, Richard

    1978-01-01

    Possible sexual discrimination was examined in the use of letters of recommendation. Female applicants were preferred over male applicants in terms of proceeding with an interview, thus demonstrating a case of reverse discrimination. (Author)

  16. Does perceived discrimination affect health? Longitudinal relationships between work discrimination and women's physical and emotional health.

    Science.gov (United States)

    Pavalko, Eliza K; Mossakowski, Krysia N; Hamilton, Vanessa J

    2003-03-01

    This study uses longitudinal data to examine the causal relationships between perceived work discrimination and women's physical and emotional health. Using data on 1,778 employed women in the National Longitudinal Survey of Mature Women, we investigate the structural and individual characteristics that predict later perceptions of discrimination and the effects of those perceptions on subsequent health. We find that perceptions of discrimination are influenced by job attitudes, prior experiences of discrimination, and work contexts, but prior health is not related to later perceptions. However, perceptions of discrimination do impact subsequent health, and these effects remain significant after controlling for prior emotional health, physical health limitations, discrimination, and job characteristics. Overall, the results provide even stronger support for the health impact of workplace discrimination and suggest a need for further longitudinal analyses of causes and consequences of perceived discrimination.

  17. On discriminating and not discriminating between affect and representation.

    Science.gov (United States)

    Green, A

    1999-04-01

    The topic involves two issues. They can be related either to different clinical pictures or to divergent opinions about the same clinical facts. But the above mentioned opposition can be found in Freud's work. Listening in analysis differentiates between situations where the distinction of affect and representation is blurred within the general frame of communication and others where this distinction imposes itself because of the critical or chronic character of the predominance of affect. Problems about the discrimination between affect and representation in the unconscious are elucidated in the light of their structural differences. The notion of the psychical representative of the drive announces the reference to the further notion of instinctual impulse. Later on, in Freud's theory, the notion of instinctual impulse has encompassed the distinction between affects and representation. Contemporary authors have, in their vast majority, chosen to refer preferably to object relationships. Nevertheless, the problems raised by Freud remain unanswered. It is with the clinical picture of borderline personality disorders that the lack of discrimination between affect and representation becomes evident. A detailed description is presented of the forms of transference where the irrepresentable prevails, accompanied by feelings of being overwhelmed, repetition compulsion, acting out and somatic reactions. In the countertransference, the affects of helplessness, despair and even the impossibility of grasping the meaning of the patient's communication are frequently met in the analyst. In these clinical pictures, intermediary formations, i.e. psychic organisations where primary processes structures the unconscious, are impaired. One is struck by the limitation of the capacities of representation and by the importance of phenomena related to negative hallucinations specially focused on thought processes, The communication is frequently self-contradictory, the transference

  18. DISCRIMINATION OF WOMEN IN THE LABOUR MARKET OF SR AND MODELS OF DISCRIMINATION

    OpenAIRE

    Ján Vravec; Radovan Baèík

    2012-01-01

    IThe paper deals with the problem of women’s discrimination in the labour market. Significant differences, among women and men in the labour market, are especially in unemployment rate in reward system, and high horizontal and vertical segregation of women. The aspects of discrimination arise despite of existing legislation, which gender discrimination strictly prohibits. An analysis of arguments, consequences and models of women’s discrimination in the labour market can significantly help to...

  19. Bias and discriminability during emotional signal detection in melancholic depression.

    Science.gov (United States)

    Hyett, Matthew; Parker, Gordon; Breakspear, Michael

    2014-04-27

    Cognitive disturbances in depression are pernicious and so contribute strongly to the burden of the disorder. Cognitive function has been traditionally studied by challenging subjects with modality-specific psychometric tasks and analysing performance using standard analysis of variance. Whilst informative, such an approach may miss deeper perceptual and inferential mechanisms that potentially unify apparently divergent emotional and cognitive deficits. Here, we sought to elucidate basic psychophysical processes underlying the detection of emotionally salient signals across individuals with melancholic and non-melancholic depression. Sixty participants completed an Affective Go/No-Go (AGN) task across negative, positive and neutral target stimuli blocks. We employed hierarchical Bayesian signal detection theory (SDT) to model psychometric performance across three equal groups of those with melancholic depression, those with a non-melancholic depression and healthy controls. This approach estimated likely response profiles (bias) and perceptual sensitivity (discriminability). Differences in the means of these measures speak to differences in the emotional signal detection between individuals across the groups, while differences in the variance reflect the heterogeneity of the groups themselves. Melancholic participants showed significantly decreased sensitivity to positive emotional stimuli compared to those in the non-melancholic group, and also had a significantly lower discriminability than healthy controls during the detection of neutral signals. The melancholic group also showed significantly higher variability in bias to both positive and negative emotionally salient material. Disturbances of emotional signal detection in melancholic depression appear dependent on emotional context, being biased during the detection of positive stimuli, consistent with a noisier representation of neutral stimuli. The greater heterogeneity of the bias across the melancholic

  20. Social Status Correlates of Reporting Racial Discrimination and Gender Discrimination among Racially Diverse Women

    Science.gov (United States)

    Ro, Annie E.; Choi, Kyung-Hee

    2009-01-01

    The growing body of research on discrimination and health indicates a deleterious effect of discrimination on various health outcomes. However, less is known about the sociodemographic correlates of reporting racial discrimination and gender discrimination among racially diverse women. We examined the associations of social status characteristics with lifetime experiences of racial discrimination and gender discrimination using a racially-diverse sample of 754 women attending family planning clinics in Northern California (11.4% African American, 16.8% Latina, 10.1% Asian and 61.7% Caucasian). A multivariate analysis revealed that race, financial difficulty and marital status were significantly correlated with higher reports of racial discrimination, while race, education, financial difficulty and nativity were significantly correlated with gender discrimination scores. Our findings suggest that the social patterning of perceiving racial discrimination is somewhat different from that of gender discrimination. This has implications in the realm of discrimination research and applied interventions, as different forms of discrimination may have unique covariates that should be accounted for in research analysis or program design. PMID:19485231

  1. Social status correlates of reporting gender discrimination and racial discrimination among racially diverse women.

    Science.gov (United States)

    Ro, Annie E; Choi, Kyung-Hee

    2009-01-01

    The growing body of research on discrimination and health indicates a deleterious effect of discrimination on various health outcomes. However, less is known about the sociodemographic correlates of reporting racial discrimination and gender discrimination among racially diverse women. We examined the associations of social status characteristics with lifetime experiences of racial discrimination and gender discrimination using a racially-diverse sample of 754 women attending family planning clinics in North California (11.4% African American, 16.8% Latina, 10.1% Asian and 61.7% Caucasian). A multivariate analysis revealed that race, financial difficulty and marital status were significantly correlated with higher reports of racial discrimination, while race, education, financial difficulty and nativity were significantly correlated with gender discrimination scores. Our findings suggest that the social patterning of perceiving racial discrimination is somewhat different from that of gender discrimination. This has implications in the realm of discrimination research and applied interventions, as different forms of discrimination may have unique covariates that should be accounted for in research analysis or program design.

  2. Microprocessor multi-task monitor

    International Nuclear Information System (INIS)

    Ludemann, C.A.

    1983-01-01

    This paper describes a multi-task monitor program for microprocessors. Although written for the Intel 8085, it incorporates features that would be beneficial for implementation in other microprocessors used in controlling and monitoring experiments and accelerators. The monitor places permanent programs (tasks) arbitrarily located throughout ROM in a priority ordered queue. The programmer is provided with the flexibility to add new tasks or modified versions of existing tasks, without having to comply with previously defined task boundaries or having to reprogram all of ROM. Scheduling of tasks is triggered by timers, outside stimuli (interrupts), or inter-task communications. Context switching time is of the order of tenths of a milllisecond

  3. Pavlovian conditioning enhances resistance to disruption of dogs performing an odor discrimination.

    Science.gov (United States)

    Hall, Nathaniel J; Smith, David W; Wynne, Clive D L

    2015-05-01

    Domestic dogs are used to aid in the detection of a variety of substances such as narcotics and explosives. Under real-world detection situations there are many variables that may disrupt the dog's performance. Prior research on behavioral momentum theory suggests that higher rates of reinforcement produce greater resistance to disruption, and that this is heavily influenced by the stimulus-reinforcer relationship. The present study tests the Pavlovian interpretation of resistance to change using dogs engaged in an odor discrimination task. Dogs were trained on two odor discriminations that alternated every six trials akin to a multiple schedule in which the reinforcement probability for a correct response was always 1. Dogs then received several sessions of either odor Pavlovian conditioning to the S+ of one odor discrimination (Pavlovian group) or explicitly unpaired exposure to the S+ of one odor discrimination (Unpaired group). The remaining odor discrimination pair for each dog always remained an unexposed control. Resistance to disruption was assessed under presession feeding, a food-odor disruptor condition, and extinction, with baseline sessions intervening between disruption conditions. Equivalent baseline detection rates were observed across experimental groups and odorant pairs. Under disruption conditions, Pavlovian conditioning led to enhanced resistance to disruption of detection performance compared to the unexposed control odor discrimination. Unpaired odor conditioning did not influence resistance to disruption. These results suggest that changes in Pavlovian contingencies are sufficient to influence resistance to change. © Society for the Experimental Analysis of Behavior.

  4. Neural network consistent empirical physical formula construction for neutron–gamma discrimination in gamma ray tracking

    International Nuclear Information System (INIS)

    Yildiz, Nihat; Akkoyun, Serkan

    2013-01-01

    Highlights: ► Detector responses in neutron–gamma discrimination were estimated by neural networks. ► Novel consistent neural network empirical physical formulas (EPFs) were constructed for detector responses. ► The EPFs are of explicit mathematical functional form. ► The EPFs can be used to derive various physical functions relevant to neutron–gamma discrimination in gamma ray tracking. -- Abstract: Gamma ray tracking is an efficient detection technique in studying exotic nuclei which lies far from beta stability line. To achieve very powerful and extraordinary resolution ability, new detectors based on gamma ray tracking are currently being developed. To reach this achievement, the neutron–gamma discrimination in these detectors is also an important task. In this paper, by suitable layered feedforward neural networks (LFNNs), we have constructed novel and consistent empirical physical formulas (EPFs) for some highly nonlinear detector counts measured in neutron–gamma discrimination. The detector counts data used in the discrimination was actually borrowed from our previous paper. The counts used here had been originally measured versus the following parameters: energy deposited in the first interaction points, difference in the incoming direction of initial gamma rays, and finally figure of merit values of the clusters determined by tracking. The LFNN–EPFs are of explicit mathematical functional form. Therefore, by various suitable operations of mathematical analysis, these LFNN–EPFs can be used to derivate further physical functions which might be potentially relevant to neutron–gamma discrimination performance of gamma ray tracking.

  5. Discrimination among adults with craniofacial conditions.

    Science.gov (United States)

    Roberts, Rachel M

    2014-01-01

    The primary goal of this study was to establish the level of perceived discrimination experienced by adults with congenital craniofacial conditions in Australia and to examine predictors of discrimination. Specifically, this study tested whether social support mediates the relationship between discrimination and health. Adults (n = 93) who had been treated at the Australian Craniofacial Unit, Women's and Children's Hospital, Adelaide for congenital craniofacial conditions (not including cleft lip and/or palate) completed questionnaires examining satisfaction with life, quality of life, anxiety and depression, self-esteem, satisfaction with social support, and satisfaction with appearance. A substantial minority of adults with congenital craniofacial conditions reported that they experience discrimination almost every day in a range of areas. Higher reports of discrimination were related to older age, being male, and less education. Other factors related to higher discrimination included lower levels of satisfaction with life, self-esteem, satisfaction with appearance and mental quality of life, as well as higher levels of anxiety and depression. Social support partially mediated the relationship between discrimination and mental health outcomes. The current study shows that discrimination experiences continue into adulthood confirming the importance of ensuring patients are well supported both by psychosocial services as well as within their own social support networks.

  6. Meaning discrimination in bilingual Venda dictionaries | Mafela ...

    African Journals Online (AJOL)

    In most cases, the equivalents of the entry-words are provided without giving meaning discrimination. Without a good command of Venda and the provision of meaning discrimination, users will find it difficult to make a correct choice of the equivalent for which they are looking. Bilingual Venda dictionaries are therefore not ...

  7. Tunnel Diode Discriminator with Fixed Dead Time

    DEFF Research Database (Denmark)

    Diamond, J. M.

    1965-01-01

    A solid state discriminator for the range 0.4 to 10 V is described. Tunnel diodes are used for the discriminator element and in a special fixed dead time circuit. An analysis of temperature stability is presented. The regulated power supplies are described, including a special negative resistance...

  8. 18 CFR 8.3 - Discrimination prohibited.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Discrimination prohibited. 8.3 Section 8.3 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... LICENSED PROJECTS § 8.3 Discrimination prohibited. Every licensee maintaining recreation facilities for the...

  9. 30 CFR 270.4 - Discrimination prohibited.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Discrimination prohibited. 270.4 Section 270.4 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE NONDISCRIMINATION IN THE OUTER CONTINENTAL SHELF § 270.4 Discrimination prohibited. No contract or subcontract to which...

  10. Gender Discrimination and Women's Development in India

    Science.gov (United States)

    Sivakumar, M.

    2008-01-01

    Gender is a common term where as gender discrimination is meant only for women, because females are the only victims of gender discrimination. Females are nearly 50 percent of the total population but their representation in public life is very low. Recognizing women's right and believing their ability are essential for women's empowerment and…

  11. Chiral discrimination in biomimetic systems: Phenylalanine

    Indian Academy of Sciences (India)

    Chiral discrimination and recognition is important in peptide biosynthesis, amino acid synthesis and drug designing. Detailed structural information is available about the peptide synthesis in ribosome. However, no detailed study is available about the discrimination in peptide synthesis. We study the conformational energy ...

  12. Perceived Discrimination and Personality Development in Adulthood

    Science.gov (United States)

    Sutin, Angelina R.; Stephan, Yannick; Terracciano, Antonio

    2016-01-01

    Perceived discrimination is common and a significant source of stress that may have implications for personality development across adulthood. In this study, we examined whether experiences with discrimination were associated with maladaptive changes in the 5 major dimensions of personality using 2 longitudinal samples that differed in age and…

  13. Education: Woman Chemist Wins Discrimination Case.

    Science.gov (United States)

    Worthy, Ward

    1980-01-01

    Reports a recent award of compensatory damages to a woman chemistry professor who was denied a tenure-track faculty position in 1971. She filed a complaint with the university's ad hoc committee on discrimination, believing she had been discriminated against because of her sex and possibly her national origin. (CS)

  14. Mental illness - stigma and discrimination in Zambia

    African Journals Online (AJOL)

    their illness on the one side, and widespread stigma and discrimination on the other. Evidence from North America and paralleling findings from research in Western Europe suggest that stigma and discrimination are major problems in the community, with negative attitudes and behaviour towards people with mental illness ...

  15. Experienced discrimination in home mortgage lending

    DEFF Research Database (Denmark)

    Secchi, Davide; Seri, Raffaello

    2017-01-01

    This article proposes a framework for the analysis of experienced discrimination in home mortgages. It addresses the problem of home mortgage lending discrimination in one of the richest areas of northern Italy. Employees of a local hospital were interviewed to study their perception (or experien...

  16. Psychophysical Estimates of Frequency Discrimination: More than Just Limitations of Auditory Processing

    Directory of Open Access Journals (Sweden)

    Beate Sabisch

    2013-07-01

    Full Text Available Efficient auditory processing is hypothesized to support language and literacy development. However, behavioral tasks used to assess this hypothesis need to be robust to non-auditory specific individual differences. This study compared frequency discrimination abilities in a heterogeneous sample of adults using two different psychoacoustic task designs, referred to here as: 2I_6A_X and 3I_2AFC designs. The role of individual differences in nonverbal IQ (NVIQ, socioeconomic status (SES and musical experience in predicting frequency discrimination thresholds on each task were assessed using multiple regression analyses. The 2I_6A_X task was more cognitively demanding and hence more susceptible to differences specifically in SES and musical training. Performance on this task did not, however, relate to nonword repetition ability (a measure of language learning capacity. The 3I_2AFC task, by contrast, was only susceptible to musical training. Moreover, thresholds measured using it predicted some variance in nonword repetition performance. This design thus seems suitable for use in studies addressing questions regarding the role of auditory processing in supporting language and literacy development.

  17. Theta oscillation and neuronal activity in rat hippocampus areinvolved in temporal discrimination of time in seconds

    Directory of Open Access Journals (Sweden)

    Tomoaki eNakazono

    2015-06-01

    Full Text Available The discovery of time cells revealed that the rodent hippocampus has information of time.Previous studies have suggested that a role of hippocampal time cells is to integratetemporally segregated events into a sequence using working memory with time perception.However, it is unclear that hippocampal cells contribute to time perception itself becausemost previous studies employed delayed matching-to-sample tasks that did not evaluatetime perception separately from working memory processes. Here, we investigated thefunction of the rat hippocampus in time perception using a temporal discrimination task. Inthe task, rats had to discriminate between durations of 1 and 3 sec to get a reward, andmaintaining task-related information as working memory was not required. We found thatsome hippocampal neurons showed firing rate modulation similar to that of time cells.Moreover, theta oscillation of local field potentials (LFPs showed a transient enhancementof power during time discrimination periods. However, there were little relationshipsbetween the neuronal activities and theta oscillations. These results suggest that both theindividual neuronal activities and theta oscillations of LFPs in the hippocampus have a possibility to be engaged in seconds order time perception; however, they participate in different ways.

  18. Perception of musical timbre in congenital amusia: categorization, discrimination and short-term memory.

    Science.gov (United States)

    Marin, Manuela M; Gingras, Bruno; Stewart, Lauren

    2012-02-01

    Congenital amusia is a neurodevelopmental disorder that is characterized primarily by difficulties in the pitch domain. The aim of the present study was to investigate the perception of musical timbre in a group of individuals with congenital amusia by probing discrimination and short-term memory for real-world timbral stimuli as well as examining the ability of these individuals to sort instrumental tones according to their timbral similarity. Thirteen amusic individuals were matched with thirteen non-amusic controls on a range of background variables. The discrimination task included stimuli of two different durations and pairings of instrumental tones that reflected varying distances in a perceptual timbre space. Performance in the discrimination task was at ceiling for both groups. In contrast, amusic individuals scored lower than controls on the short-term timbral memory task. Amusic individuals also performed worse than controls on the sorting task, suggesting differences in the higher-order representation of musical timbre. These findings add to the emerging picture of amusia as a disorder that has consequences for the perception and memory of musical timbre, as well as pitch. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. LOGICAL-ORIENTED TASKS AS A FORM OF ORGANIZATION OF THE EDUCATIONAL MATERIAL CONTENT IN TEACHING MATHEMATICS TO STUDENTS

    Directory of Open Access Journals (Sweden)

    Oksana Smirnova

    2015-09-01

    Full Text Available The article substantiates the need to improve the logical preparation of students. The authors regard the logical-oriented tasks as a form of organization of the content of educational material in teaching Mathematics and discriminate the types of tasks aimed at the formation of logical methods and operations.

  20. Exploring the Performance Differences on the Flicker Task and the Conners' Continuous Performance Test in Adults with ADHD

    Science.gov (United States)

    Cohen, Andrew L.; Shapiro, Steven K.

    2007-01-01

    Objective: To examine the ability of the flicker task to demonstrate greater utility in discriminating performance in young adults with and without ADHD compared to the Conners' CPT (CCPT). Method: Flicker task and CCPT performance were compared between an ADHD (n = 28) and control (n = 30) group of college students. Results: This study replicated…