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Discrimination Ability (discrimination + ability)
Selected AbstractsCOMPARISON OF DISCRIMINATION ABILITY BETWEEN A PANEL OF BLIND ASSESSORS AND A PANEL OF SIGHTED ASSESSORSJOURNAL OF SENSORY STUDIES, Issue 1 2005ANDREA MUCCI ABSTRACT The objective of this work was to compare a panel of blind assessors with one of sighted assessors in the discrimination of food products. Each panel had 20 screened and trained assessors. Five commercial food products were used: crackers, liver paste, powdered orange juice mix, Reggiano cheese and yogurt. Slight flavor and/or texture modifications were introduced for adequate discrimination difficulty. Each pair of products was tested by both panels using the triangle test and a scaled difference from control test. Numbers of correct answers for the triangle test were similar for both panels. There were minor differences between the panels in the difference from control test, due to the sighted panel having more training in the use of the scale. Overall the panels of trained blind and sighted assessors were equivalent in their performance. [source] Evidence of Early Language Discrimination Abilities in Infants From Bilingual EnvironmentsINFANCY, Issue 1 2001Laura Bosch Previous research data indicate that soon after birth, infants from monolingual families can discriminate utterances drawn from languages that differ prosodically, but discrimination between rhythmically similar languages, such as English and Dutch, has not yet been established by 2 months of age. In the case of bilinguals, the question of how early they can distinguish between the languages of exposure remains unanswered. The goal of this study was to analyze language discrimination capacities in 4-month-old bilingual infants simultaneously exposed to 2 Romance languages belonging to the same rhythmic category, Spanish and Catalan. Using a familiarization-preference procedure, 2 groups of bilingual-to-be infants showed a capacity to discriminate between these 2 familial languages. Moreover, when compared with 2 groups of infants from monolingual environments, the size of the observed effects was the same. These results can be taken as initial evidence of an early capacity to distinguish languages in simultaneous bilingual exposure, thus challenging the hypothesis that language discrimination capacities are delayed in bilinguals. [source] Measurement of development of cognitive and attention functions in children using continuous performance testPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 2 2008Noriko Kanaka ba Aim:, The development of attention function in children is still not sufficiently clear. Although it is difficult to objectively assess attention function, continuous performance tests (CPT) can be used to objectively assess cognitive function along with attention. The development of cognitive and attention functions was examined in children using a CPT. Methods:, A total of 541 healthy girls aged 5,12 years participated. Ten parameters were calculated: numbers of cancellations for either target stimuli (T-cancel) or non-target stimuli (N-cancel), numbers of omission errors (Omission) and commission errors (Commission), hit rate (Hit), false alarm rate (False), mean reaction time for correct response (RT), coefficient of variance for mean reaction time (CVRT), sensitivity index (d,), and ln,. Results:, The parameters were divided into three types based on pattern of change. T-cancel, False, and Commission, which are related to inhibition of response, N-cancel, Hit, and Omission, which are related to inattention to stimuli, and CVRT, which is related to stability of processing time, exhibited significant change until 5 or 6 years of age. d,, which is related to ability to discriminate between target or non-target, exhibited significant change until 8 years of age. RT, which is related to processing time, exhibited significant change until 11 years of age. ln, exhibited no significant differences among age groups. Conclusions:, These findings indicate that inhibition function, inattention to stimuli, and stability of processing time develop first. Discrimination ability subsequently increases based on these developments, and finally processing time is reduced. [source] Small and large number processing in infants and toddlers with Williams syndromeDEVELOPMENTAL SCIENCE, Issue 5 2008Jo Van Herwegen Previous studies have suggested that typically developing 6-month-old infants are able to discriminate between small and large numerosities. However, discrimination between small numerosities in young infants is only possible when variables continuous with number (e.g. area or circumference) are confounded. In contrast, large number discrimination is successful even when variables continuous with number are systematically controlled for. These findings suggest the existence of different systems underlying small and large number processing in infancy. How do these develop in atypical syndromes? Williams syndrome (WS) is a rare neurocognitive developmental disorder in which numerical cognition has been found to be impaired in older children and adults. Do impairments of number processing have their origins in infancy? Here this question is investigated by testing the small and large number discrimination abilities of infants and toddlers with WS. While infants with WS were able to discriminate between 2 and 3 elements when total area was confounded with numerosity, the same infants did not discriminate between 8 and 16 elements, when number was not confounded with continuous variables. These findings suggest that a system for tracking the features of small numbers of object (object-file representation) may be functional in WS, while large number discrimination is impaired from an early age onwards. Finally, we argue that individual differences in large number processing in infancy are more likely than small number processing to be predictive of later development of numerical cognition. [source] Finding the Signal by Adding Noise: The Role of Noncontrastive Phonetic Variability in Early Word LearningINFANCY, Issue 6 2010Gwyneth C. Rost It is well attested that 14-month-olds have difficulty learning similar sounding words (e.g., bih/dih), despite their excellent phonetic discrimination abilities. By contrast, Rost and McMurray (2009) recently demonstrated that 14-month-olds' minimal-pair learning can be improved by the presentation of words by multiple talkers. This study investigates which components of the variability found in multitalker input improved infants' processing, assessing both the phonologically contrastive aspects of the speech stream and phonologically irrelevant indexical and suprasegmental aspects. In the first two experiments, speaker was held constant while cues to word-initial voicing were systematically manipulated. Infants failed in both cases. The third experiment introduced variability in speaker, but voicing cues were invariant within each category. Infants in this condition learned the words. We conclude that aspects of the speech signal that have been typically thought of as noise are in fact valuable information,signal,for the young word learner. [source] Blunt egg pole holds cues for alien egg discrimination: experimental evidenceJOURNAL OF AVIAN BIOLOGY, Issue 2 2010L. Pola, iková Eggshell colour patterns play a crucial role in avian host,parasite coevolution. In contrast to many experiments investigating general host egg discrimination abilities, studies testing where specific recognition cues are located on the eggshells (on blunt, sharp or both egg poles) are lacking. Previous studies suggested that discrimination cues might be located at the blunt egg pole, where the shell patterning is typically concentrated. We tested this hypothesis experimentally in species subject to interspecific (great reed warblers Acrocephalus arundinaceus, reed warblers A. scirpaceus), and also intraspecific parasitism (song thrushes Turdus philomelos, blackbirds T. merula). We examined host responses towards two types of intraspecific eggs painted non-mimetic immaculate blue either at blunt or sharp poles. All four species rejected eggs manipulated at the blunt pole at significantly higher rates, indicating that they perceive the critical recognition cues in the same egg part. Thus, the presence of egg recognition cues at the blunt egg pole may be a general phenomenon in birds parasitized by both intraspecific and interspecific parasites. [source] Why is mimicry in cuckoo eggs sometimes so poor?JOURNAL OF AVIAN BIOLOGY, Issue 3 2002I propose that the existence of imperfect adaptations (e.g. egg mimicry) in brood parasites and their hosts (e.g. discrimination abilities) could reflect age-dependent territory and nest-site selection patterns of the host. Studies of various passerines indicate that (1) older breeders tend to occupy nest sites of higher quality than do young birds (ideal despotic distribution resulting from interference competition), (2) nest-site selection affects the risk of parasitism in various habitats, (3) egg recognition in passerines has a strong learning component (therefore naive breeders tend to accept whereas older birds tend to reject parasitic eggs). Because young naive birds, who tend to accept parasitic eggs, usually breed in low-quality areas where they are frequently parasitised, while old experienced birds, who tend to reject parasitic eggs, breed in high-quality areas where they are rarely parasitised, the distribution of acceptors and rejecters with respect to the risk of parasitism is non-random, i.e. populations of some host species may consist of heavily parasitised acceptors and weakly parasitised rejecters. Therefore, the selection pressure exerted by the host on the parasite should be weaker than if brood parasitism was randomly distributed among naive and experienced breeders and affect adaptations such as egg mimicry. This could explain the existence of imperfect adaptations in some brood parasite-host systems. [source] Effects of search experience in a resource-heterogeneous environment on the oviposition decisions of the seed beetle, Callosobruchus maculatus (F.)ECOLOGICAL ENTOMOLOGY, Issue 4 2006ROU-LING YANG Abstract 1.,This study investigates how female seed beetles, Callosobruchus maculatus, distribute their eggs on various-sized seeds when the size of seed was varied during the egg-laying period. 2.,Beetles were allowed to lay eggs on one of three arrays of 64 adzuki beans (Vigna angularis). Each array contained four size classes of seed, ranging from small (5.0,5.5 mm diameter) to large (6.5,7.0 mm), but differed in how they were distributed within the environment. In the most heterogeneous condition (the 64-patch design), the four sizes were interspersed, while in the least heterogeneous condition (the four-patch design) they were grouped into four separate blocks. Thus, a beetle exploring the 64-patch design would frequently encounter all four seed sizes, whereas a beetle exploring the four-patch design would only rarely encounter a change in bean size. 3.,Beetles experiencing greater seed size heterogeneity were more likely to lay eggs on larger seeds, whereas those in the blocked condition were more likely to oviposit on small seeds. Beetle responses to seed size heterogeneity suggest that the degree of preference for large seeds depends on a female's recent experience. 4.,Female beetles exhibited size discrimination throughout their egg-laying process; however, there was a trade-off between seed size and egg discrimination (i.e. avoiding those seeds already containing developing eggs) in response to the change in fitness gained from either laying on larger seeds or lower egg-load seeds during the egg-laying process. 5.,Our model provides the first evidence that evolving seed size discrimination ability is adaptive for the seed beetle with egg-discrimination ability. [source] Nestmate discrimination in the queenless ponerine ant Diacamma sp. from JapanENTOMOLOGICAL SCIENCE, Issue 1 2007Mayuko SUWABE Abstract We examined the nestmate discrimination ability of Diacamma sp., an ant that reproduces by colony budding. We also tested for a relationship between internest distance and hostility. Hostility toward non-nestmates was significantly stronger than that toward nestmates, suggesting that Diacamma sp. discriminates between nestmates and non-nestmates. There was no significant correlation between internest hostility and internest distance, which indicates the absence of a "dear enemy" phenomenon in this species. [source] Rapid functional plasticity in the primary somatomotor cortex and perceptual changes after nerve blockEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2004Thomas Weiss Abstract The mature human primary somatosensory cortex displays a striking plastic capacity to reorganize itself in response to changes in sensory input. Following the elimination of afferent return, produced by either amputation, deafferentation by dorsal rhizotomy, or nerve block, there is a well-known but little-understood ,invasion' of the deafferented region of the brain by the cortical representation zones of still-intact portions of the brain adjacent to it. We report here that within an hour of abolishing sensation from the radial and medial three-quarters of the hand by pharmacological blockade of the radial and median nerves, magnetic source imaging showed that the cortical representation of the little finger and the skin beneath the lower lip, whose intact cortical representation zones are adjacent to the deafferented region, had moved closer together, presumably because of their expansion across the deafferented area. A paired-pulse transcranial magnetic stimulation procedure revealed a motor cortex disinhibition for two muscles supplied by the unaffected ulnar nerve. In addition, two notable perceptual changes were observed: increased two-point discrimination ability near the lip and mislocalization of touch of the intact ulnar portion of the fourth finger to the neighbouring third finger whose nerve supply was blocked. We suggest that disinhibition within the somatosensory system as a functional correlate for the known enlargement of cortical representation zones might account for not only the ,invasion' phenomenon, but also for the observed behavioural correlates of the nerve block. [source] The police officer's terrorist dilemma: trust resilience following fatal errorsEUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 6 2008Mathew P. White Suicide attacks have raised the stakes for officers deciding whether or not to shoot a suspect (,Police Officer's Terrorist Dilemma'). Despite high-profile errors we know little about how trust in the police is affected by their response to the terrorist threat. Building on a conceptualisation of lay observers as intuitive signal detection theorists, a general population sample (N,=,1153) were presented with scenarios manipulated in terms of suspect status (Armed/Unarmed), officer decision (Shoot/Not Shoot) and outcome severity (e.g. suspect armed with Bomb/Knife; police shoot suspect/suspect plus child bystander). Supporting predictions, people showed higher trust in officers who made correct decisions, reflecting good discrimination ability and who decided to shoot, reflecting an ,appropriate' response bias given the relative costs and benefits. This latter effect was moderated by (a) outcome severity, suggesting it did not simply reflect a preference for a particular type of action, and (b) preferences for a tough stance towards terrorism indexed by Right-Wing Authoritarianism (RWA). Despite loss of civilian life, failure to prevent minor terror attacks resulted in no loss of trust amongst people low in RWA, whereas among people high in RWA trust was positive when police erroneously shot an unarmed suspect. Relations to alternative definitions of trust and procedural justice research are discussed. Copyright © 2007 John Wiley & Sons, Ltd. [source] Emotional processing in psychopathic personalityAGGRESSIVE BEHAVIOR, Issue 5 2002Ute Habel Abstract Emotional-processing deficits may be one of the characteristic features of impaired affect in individuals with psychopathy. These include shallowness and profound lack of remorse or empathy. Performances on standardized emotion discrimination tasks and mood induction tasks were compared between 17 patients with antisocial personality disorder (DSM-IV) and 17 nonpsychopaths. Subjects with psychopathic personality demonstrated poorer performance on emotion-discrimination tasks compared with controls. However, higher scores on factor "emotional detachment" of the Psychopathy Checklist (PCL-R) were associated with better discrimination ability. Subjective ratings were comparable between groups during mood induction. Although the findings support the hypothesis of a significant association between impaired emotional processing and psychopathy, they also suggest a relationship between emotional discrimination and the core personality features of psychopathy. Aggr. Behav. 28:394,400, 2002. © 2002 Wiley-Liss, Inc. [source] THE SIGNAL DETECTION THEORY ROC CURVE: SOME APPLICATIONS IN FOOD SENSORY SCIENCEJOURNAL OF SENSORY STUDIES, Issue 2 2008M. O'MAHONY ABSTRACT In psychology, the receiver operating characteristic (ROC) curve is a key part of Signal Detection Theory, which is used for calculating d, values in discrimination tests. In food sensory science, the ROC curve can also be a useful tool. To give a specific example, it is not always convenient to use forced-choice protocols for difference tests; foods may be fatiguing, and assessments with single presentations, like the Yes,No procedure, might be more appropriate. In this case, ROC curves provide a useful method for computing d, values. More generally, ROC curves give information about cognitive strategies. Cognitive strategies are important for difference tests. Values of d, can only be computed if the cognitive strategy used in the test is known. PRACTICAL APPLICATIONS When using methods other than two-alternative forced-choice in difference testing, a receiver operating characteristic (ROC) curve would be required to compute d,. This is because when assessing discrimination ability, the cognitive strategy of the subject must be taken into account, and ROC curves can sometimes reveal the cognitive strategy used by the subject. This article describes how the cognitive strategy can be determined from the subject's ROC curve. The hidden assumptions made when using ROC curves and how these assumptions can be tested are also given. This information is essential to researchers in sensory evaluation as well as those using these methods in a practical setting. [source] THE MEULLENET-OWENS RAZOR SHEAR (MORS) FOR PREDICTING POULTRY MEAT TENDERNESS: ITS APPLICATIONS AND OPTIMIZATIONJOURNAL OF TEXTURE STUDIES, Issue 6 2008Y.S. LEE ABSTRACT The Meullenet-Owens Razor Shear (MORS), recently developed for the assessment of poultry meat tenderness, is a reliable instrumental method. Three different studies were conducted to (1) investigate the adaptation of MORS to an Instron InSpec 2200 tester (InSpec); (2) optimize the number of replications necessary per fillet to obtain a reliable instrumental tenderness mean; and (3) test the efficacy of a blunt version of MORS (BMORS). In study 1, the tenderness of 157 cooked broiler breast fillets was predicted by the MORS performed with both a texture analyzer (MORS standard) and InSpec. The correlation coefficient of 0.95 was reported for the MORS energy obtained from the both tests, indicating that the MORS performed with an InSpec is equivalent to that performed on the more expensive texture analyzer. In study 2, eight shears were taken on each cooked fillet (101 fillets) to determine a recommended number of shears per fillet for the MORS. The composite hypothesis test was conducted considering the average of 8 shears as Y (representative estimated tenderness of a fillet) and the average of 2, 3, 4, 5, 6 or 7 as X (potentials for recommended number of shears). The results showed that the optimal number of replications of the MORS for a reliable estimate of tenderness to be four shears or greater per fillet. A blunt version of MORS (BMORS) was introduced in study 3. A total of 288 broilers (576 fillets) were deboned at eight different postmortem deboning times. Tenderness of cooked fillets was assessed by both the MORS and BMORS on the same individual fillets. Both methods were equivalent in performance for predicting broiler breast meat tenderness, giving a correlation coefficient of 0.99 with all instrumental parameters obtained from both methods. Tenderness intensity perceived by consumers was slightly more highly correlated to BMORS energy (r = ,0.90) than MORS energy (r = ,0.87). The BMORS was recommended to use especially for tough meat because of its better discrimination ability among tough meat. Overall, both the MORS and BMORS were proven to be reliable predictors for broiler breast meat tenderness. PRACTICAL APPLICATIONS The incidence of tough meat has been a major issue the poultry industry faces. Therefore, the need to ensure consumer acceptance and the increased recognition of the importance of tenderness has led to the development of instrumental methods for monitoring meat tenderness. To date, a great deal of efforts has been devoted to the development of such instrumental methods. One promising method is the Meullenet-Owens Razor Shear (MORS). The method has gained in popularity for predicting poultry meat tenderness because of its high reliability as well as simplicity compared with that of other industry standards (Warner-Bratzler shear or Allo-Kramer shear). The MORS is not only as reliable as the industry standards, but also more rapid because of the elimination of the sample cutting steps. The application of the MORS will be of benefit to the poultry industry as it could significantly save labor or time to implement for routine quality control. [source] Electromagnetic field exposure and health among RF plastic sealer operatorsBIOELECTROMAGNETICS, Issue 1 2004Jonna Wilén Abstract Operators of RF plastic sealers (RF operators) are an occupational category highly exposed to radiofrequency electromagnetic fields. The aim of the present study was to make an appropriate exposure assessment of RF welding and examine the health status of the operators. In total, 35 RF operators and 37 controls were included. The leakage fields (electric and magnetic field strength) were measured, as well as induced and contact current. Information about welding time and productivity was used to calculate time integrated exposure. A neurophysiological examination and 24 h ECG were also carried out. The participants also had to answer a questionnaire about subjective symptoms. The measurements showed that RF operators were exposed to rather intense electric and magnetic fields. The mean values of the calculated 6 min, spatially averaged E and H field strengths, in line with ICNIRP reference levels, are 107 V/m and 0.24 A/m, respectively. The maximum measured field strengths were 2 kV/m and 1.5 A/m, respectively. The induced current in ankles and wrists varied, depending on the work situation, with a mean value of 101 mA and a maximum measured value of 1 A. In total, 11 out of 46 measured RF plastic sealers exceeded the ICNIRP reference levels. RF operators, especially the ready made clothing workers had a slightly disturbed two-point discrimination ability compared to a control group. A nonsignificant difference between RF operators and controls was found in the prevalence of subjective symptoms, but the time integrated exposure parameters seem to be of importance to the prevalence of some subjective symptoms: fatigue, headaches, and warmth sensations in the hands. Further, RF operators had a significantly lower heart rate (24 h registration) and more episodes of bradycardia compared to controls. Bioelectromagnetics 25:5,15, 2004. © 2003 Wiley-Liss, Inc. [source] Enantioselective Fluorescence Sensing of Amino Acids by Modified Cyclodextrins: Role of the Cavity and Sensing MechanismCHEMISTRY - A EUROPEAN JOURNAL, Issue 11 2004Sara Pagliari Dr. Abstract Two selectors based on modified cyclodextrins containing a metal binding site and a dansyl fluorophore,6-deoxy-6- N -(N, -[(5-dimethylamino-1-naphthalenesulfonyl)aminoethyl]phenylalanylamino-,-cyclodextrin,containing D -Phe (3) and L -Phe (4) moieties were synthesized. The conformations of the two selectors were studied by circular dichroism, two-dimensional NMR spectroscopy and time-resolved fluorescence spectroscopy. Cyclodextrin 4 was found to have a predominant conformation in which the dansyl group is self-included in the cyclodextrin cavity, while 3 showed a larger proportion of the conformation with the dansyl group outside the cavity. As a consequence, the two cyclodextrins were found to bind copper(II) with different affinities, as revealed by fluorescence quenching in competitive binding measurements. Addition of D - or L -amino acids induced increases in fluorescence intensity, which were dependent on the amino acid used and in some cases on its absolute configuration. The cyclodextrin 4 was found to be more enantioselective than 3, suggesting that the self-inclusion in the cyclodextrin cavity strongly increases the chiral discrimination ability of the copper(II) complex. Accordingly, a linear fluorescent ligand N, -[(5-dimethylamino-1-naphthalenesulfonyl)aminoethyl]- N1 -propyl-phenylalaninamide, which has the same binding site and absolute configuration as 4, showed very low chiral discrimination ability. The enantioselectivity in fluorescence response was found to be due to the formation of diastereomeric ternary complexes, which were detected by ESI-MS and by circular dichroism. Time-resolved fluorescence studies showed that the fluorescence of the dansyl group was completely quenched in the ternary complexes formed, and that the residual fluorescence was due to uncomplexed ligand. [source] | |||||||||||||||||||