An ERP Analysis of Recognition and Categorization Decisions in a Prototype-Distortion Task

Background

Theories of categorization make different predictions about the underlying processes used to represent categories. Episodic theories suggest that categories are represented in memory by storing previously encountered exemplars in memory. Prototype theories suggest that categories are represented in the form of a prototype independently of memory. A number of studies that show dissociations between categorization and recognition are often cited as evidence for the prototype account. These dissociations have compared recognition judgements made to one set of items to categorization judgements to a different set of items making a clear interpretation difficult. Instead of using different stimuli for different tests this experiment compares the processes by which participants make decisions about category membership in a prototype-distortion task and with recognition decisions about the same set of stimuli by examining the Event Related Potentials (ERPs) associated with them.

Method

Sixty-three participants were asked to make categorization or recognition decisions about stimuli that either formed an artificial category or that were category non-members. We examined the ERP components associated with both kinds of decision for pre-exposed and control participants.

Conclusion

In contrast to studies using different items we observed no behavioural differences between the two kinds of decision; participants were equally able to distinguish category members from non-members, regardless of whether they were performing a recognition or categorisation judgement. Interestingly, this did not interact with prior-exposure. However, the ERP data demonstrated that the early visual evoked response that discriminated category members from non-members was modulated by which judgement participants performed and whether they had been pre-exposed to category members. We conclude from this that any differences between categorization and recognition reflect differences in the information that participants focus on in the stimuli to make the judgements at test, rather than any differences in encoding or process.     

A two-step model of acute CD4 T-cell mediated cardiac allograft rejection

CD4 T cells are both necessary and sufficient to mediate acute cardiac allograft rejection in mice. This process requires "direct" engagement of donor MHC class II molecules. That is, acute rejection by CD4+ T cells requires target MHC class II expression by the donor and not by the host. However, it is unclear whether CD4+ T cell rejection requires MHC class II expression on donor hemopoietic cells, nonhemopoietic cells, or both. To address this issue, bone marrow transplantation in mice was used to generate chimeric heart donors in which MHC class II was expressed either on somatic or on hemopoietic cells. We report that direct recognition of hemopoietic and nonhemopoietic cells are individually rate limiting for CD4+ T cell-mediated rejection in vivo. Importantly, active immunization with MHC class II(+) APCs triggered acute rejection of hearts expressing MHC class II only on the somatic compartment. Thus, donor somatic cells, including endothelial cells, are not sufficient to initiate acute rejection; but they are necessary as targets of direct alloreactive CD4 T cells. Taken together, results support a two-stage model in which donor passenger leukocytes are required to activate the CD4 response while direct interaction with the somatic compartment is necessary for the efferent phase of acute graft rejection.     

Incisor microwear and diet in three species of Colobus

Examination of incisor microwear in three species of Colobus revealed that the predominantly folivorous C. badius more closely resembles C. satanas, a seed predator/folivore, than C. guereza, another predominantly folivorous species. This demonstrates that species of the same broad dietary category can have very different patterns of incisor microwear, indicative of differences in food procurement behavior and/or the physical properties of dietary items for some portion of the diet. Conversely, species of different categories can have microwear patterns that, superficially at least, are quite similar. The dissimilarity in incisor microwear between C. badius and C. guereza is mirrored to a certain extent in molar microwear, although the differences are not nearly so great on the molars. The differences between C. badius and C. guereza may involve different food items in the major, folivorous portions of their diets, or they may relate to differences in the very minor fruit and bark components. The similar microwear patterns of C. badius and C. satanas demonstrate that incisor microwear by itself is unreliable for assigning fossil species to broad dietary categories. Incisor microwear can be used to infer finer dietary distinctions in fossil species for which dietary category has been determined by other means.     

Influence of Emotionally Charged Information on Category-Based Induction

Categories help us make predictions, or inductions, about new objects. However, we cannot always be certain that a novel object belongs to the category we are using to make predictions. In such cases, people should use multiple categories to make inductions. Past research finds that people often use only the most likely category to make inductions, even if it is not certain. In two experiments, subjects read stories and answered questions about items whose categorization was uncertain. In Experiment 1, the less likely category was either emotionally neutral or dangerous (emotionally charged or likely to pose a threat). Subjects used multiple categories in induction when one of the categories was dangerous but not when they were all neutral. In Experiment 2, the most likely category was dangerous. Here, people used multiple categories, but there was also an effect of avoidance, in which people denied that dangerous categories were the most likely. The attention-grabbing power of dangerous categories may be balanced by a higher-level strategy to reject them.     

Eliminating the diagnosis atypical squamous cells of undetermined significance: impact on the accuracy of the Papanicolaou test

OBJECTIVE: To assess eliminating the diagnosis "atypical squamous cells of undetermined significance" (ASCUS) from the Bethesda System for Reporting Cervical/Vaginal Cytological Diagnoses and analyze its impact on the sensitivity and positive predictive value of Pap smears. STUDY DESIGN: A total of 166 previously diagnosed ASCUS cases with follow-up biopsy results available were prospectively downgraded to within normal limits/benign cellular changes or upgraded to specific squamous intraepithelial lesions (SILs) or the malignant category. These review cytodiagnoses were compared with the histologic outcome. The impact on the sensitivity and positive predictive value of Pap smears was also assessed. RESULTS: Though there was a decrease in the sensitivity of the Pap smear from 100% to 76.3% for SIL overall and from 100% to 80% for high grade SIL (HSIL) alone, there was an improvement in the positive predictive value of diagnosing SIL from 46% to 85% and from 6% to 15% for HSIL alone. CONCLUSION: The ASCUS diagnosis can be minimized to a great extent, if not eliminated completely. The "ASCUS-favor reactive" group can be eliminated, while the diagnoses "ASCUS favor SIL" and "ASCUS-not otherwise specified" should be used sparingly.     

PRODUCT TESTING 2: MODELING VERSUS MAPPING AND THEIR INTEGRATION

Evaluations of multiple products in a category proceed with two different, unstated objectives, and two distinct analytic approaches. The first objective is to "map" the category - viz., to put the products in a category onto some type of geometrical map with the property that products lying close to each other on the map share aspects in common. Researchers use mapping to identify which products compete with each other, as well as to discover whether or not there exist in the category unfilled "holes" that have promise. Researchers use modeling, in contrast, to identify the salient dimensions along which consumers differentiate products in the category. Modeling assumes that the researcher will create a relation between two or more attributes in the category. The analysis generates equations (or even only correlations) rather than maps. Mapping and modeling are complementary, yet often one approach is used to the exclusion of the other because of internal biases and points of view held by the researcher. This paper shows how the two are used, and how they can be integrated to create a more powerful analytic approach.     

Fluoride Alters Serum Elemental (Calcium,Magnesium, Copper,and Zinc) Homeostasis Along with Erythrocyte Carbonic Anhydrase Activity in Fluorosis Endemic Villages and Restores on Supply of Safe Drinking Water in School-Going Children of Nalgonda District,India

The present study aimed to determine the serum trace elements (copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg)) along with erythrocyte carbonic anhydrase (CA) activity and effect of intervention with safe drinking water for 5 years in the school children of fluorosis endemic area. For this purpose, three categories of villages were selected based on drinking water fluoride (F): Category I (control, F?=?1.68 mg/L), category II (affected F?=?3.77 mg/L), and category III (intervention village) where initial drinking water F was 4.51 mg/L, and since the last 5 years, they were drinking water containing <?1.0 mg/L F. The results revealed that urinary F was significantly (P?<?0.05) higher in category II compared to categories I and III. A significant (P?<?0.05) increase in serum Cu and Mg was observed in category II compared to category I. Serum Zn and Ca was significantly (P?<?0.05) decreased in categories II and III compared to category I. The erythrocyte CA activity was decreased in the category II compared to category I. However, in the category III, erythrocyte CA activity was comparable to the control group. In conclusion, F exposure altered elemental homeostasis which has restored to some extent on intervention by safe drinking water for 5 years in school-going children.     

Assessment of fitness for surgical procedures and the variability of anaesthetists' judgments.

Ten anaesthetists were asked to make judgments on fitness for elective operation on data derived from 200 patients. The extent of their agreement was measured using a kappa statistic, and clusters of anaesthetists who agreed well with each other were identified. Using an alternative technique, the "true" fitness category of each patient was estimated using a maximum likelihood method which estimated the error involved in making judgments on limited amounts of information. It was possible to compare the performance of each anaesthetist against the consensus and to measure deviation on an "optimism--pessimism" continuum. A simple questionnaire predicted fitness for operation by all 10 anaesthetists in 96% of cases.     

Visual categorization of natural and abstract items in forest monkeys and humans

A preference for novelty paradigm was used to investigate whether mangabeys (Lophocebus albigena), an arboreal non-human primate species, were able to discriminate and to categorize different visual stimuli belonging to natural (food items) and abstract (non-food items) categories. In a comparative perspective human subjects were tested with the same procedure and the same stimuli. Two out of four mangabeys and three out of the four humans showed significant preference for novelty when comparing food versus non-food items. Hence they discriminated between these two sets of items. The two mangabeys and one non-adult human subject sorted the food items in one category, showing no preference for novelty when comparing known and unknown food-items and different views of the same food items. In contrast the two adult human subjects who showed preference for novelty in the between-category, did not show preference for novelty when comparing known and unknown food-items but did show such a preference when comparing different views of the same food items. Compared to human performances, the results suggest that mangabeys are able to form at least a perceptual category of natural, ecologically relevant stimuli.     

Use of proteomics to discover novel markers of cardiac allograft rejection

Endomyocardial biopsy remains the most reliable method of detecting rejection following cardiac transplantation. Despite numerous attempts to detect rejection using a blood assay, none have proved reliable enough to replace the biopsy. Here, we have investigated the hypothesis that proteomics has the potential to reveal many molecules which are upregulated in the heart during rejection, some of which may serve as novel blood markers of rejection. Initially, sequential cardiac biopsies (33 in total) from 4 patients were analysed by two-dimensional gel electrophoresis according to whether they showed rejection (n = 16) or no rejection (n = 17); over 100 proteins were found to be upregulated by between 2- and 50-fold during rejection. Of these, 13 were identified and were found to be cardiac specific or heat shock proteins. Two of these (alphaB-crystallin, tropomyosin) were measured by ELISA in the sera of 17 patients followed for 3 months after their transplants. Mean levels of alphaB-crystallin and tropomyosin were significantly higher in sera associated with biopsies showing 1A (p = 0.007) or all grades of rejection (p = 0.022) compared to no rejection. These studies demonstrate that proteomics is a powerful method that can be used to identify novel serum markers of human cardiac allograft rejection.     

Detecting Paroxysmal Coughing from Pertussis Cases Using Voice Recognition Technology

Background

Pertussis is highly contagious; thus, prompt identification of cases is essential to control outbreaks. Clinicians experienced with the disease can easily identify classic cases, where patients have bursts of rapid coughing followed by gasps, and a characteristic whooping sound. However, many clinicians have never seen a case, and thus may miss initial cases during an outbreak. The purpose of this project was to use voice-recognition software to distinguish pertussis coughs from croup and other coughs.

Methods

We collected a series of recordings representing pertussis, croup and miscellaneous coughing by children. We manually categorized coughs as either pertussis or non-pertussis, and extracted features for each category. We used Mel-frequency cepstral coefficients (MFCC), a sampling rate of 16 KHz, a frame Duration of 25 msec, and a frame rate of 10 msec. The coughs were filtered. Each cough was divided into 3 sections of proportion 3-4-3. The average of the 13 MFCCs for each section was computed and made into a 39-element feature vector used for the classification. We used the following machine learning algorithms: Neural Networks, K-Nearest Neighbor (KNN), and a 200 tree Random Forest (RF). Data were reserved for cross-validation of the KNN and RF. The Neural Network was trained 100 times, and the averaged results are presented.

Results

After categorization, we had 16 examples of non-pertussis coughs and 31 examples of pertussis coughs. Over 90% of all pertussis coughs were properly classified as pertussis. The error rates were: Type I errors of 7%, 12%, and 25% and Type II errors of 8%, 0%, and 0%, using the Neural Network, Random Forest, and KNN, respectively.

Conclusion

Our results suggest that we can build a robust classifier to assist clinicians and the public to help identify pertussis cases in children presenting with typical symptoms.     

Singing for your supper: sentinel calling by kleptoparasites can mitigate the cost to victims

Parasitism generally imposes costs on victims, yet many victims appear to tolerate their parasites. We suggest that in some cases this may be because parasites provide victims with mitigating benefits, paradoxically giving rise to selection for advertisement rather than concealment by parasites. We investigate this possibility using the interaction between an avian kleptoparasite, the fork-tailed drongo (Dicrurus adsimilis), and one of its victims, the pied babbler (Turdoides bicolor). Combining field observations and a playback experiment, we demonstrate that a conspicuous vocal signal broadcast by drongos perched waiting to steal food from foraging babblers allows the latter to improve their own foraging efficiency, although not to the same extent as that experienced in response to conspecific sentinel calling. We argue that "sentinel" calling by drongos may originally have arisen as a means of manipulating babblers: because babblers find more food items and venture into the open more in response to these vocalizations, drongos are presented with more kleptoparasitism opportunities. However, the resulting benefit to babblers could be sufficient to reduce selection for the evolution of defenses against drongos, and the current situation may represent a rare example of an interspecific relationship in transition from a parasitism to a mutualism.     

Current status of bioassays in genetic toxicology--the dominant lethal assay. A report of the U.S. Environmental Protection Agency Gene-Tox Program

The term dominant lethal may be defined as death of the heterozygote arising through multiple chromosomal breaks. The assay is generally conducted by treating male animals, usually mice or rats, acutely (1 dose), subacutely (5 doses), or over the entire period of spermatogenesis. Animals treated acutely or subacutely are mated at weekly intervals to females for a sufficient number of weeks to cover the period of spermatogenesis. Those treated for the entire spermatogenic cycle are mated for 1 or 2 successive weeks at the termination of treatment. Females usually are killed at 14 days of pregnancy and examined for the number of total implantations in the uterus, the number of implantations classified as early deaths, and, in some cases, the number of corpora lutea. The category of early death is the most significant index of dominant lethality. A total of 249 papers were reviewed and 140 chemicals were evaluated. Of the 140 chemicals, 65 were positive by the criteria used by the Work Group in evaluating each publication. The category of "positive" includes those responses of a borderline nature. 99 chemicals were declared negative. There is considerable overlap of chemicals in both categories, which accounts for the incongruity in the total number of chemicals tested and the number considered positive and negative. A total of 44 animal carcinogens have been tested in the dominant lethal assay, 26 of which were positive and 18 negative for a correlation of 59%. The role of the assay should be that of confirming positive results from lower tier chromosomal aberration-detecting systems (confirming in the sense of indicating the ability of the chemical to penetrate gonadal tissue and to produce cytogenetic damage). The dominant lethal assay should not be used as a risk assessment method.     

Repeatability and reproducibility of decisions by latent fingerprint examiners

The interpretation of forensic fingerprint evidence relies on the expertise of latent print examiners. We tested latent print examiners on the extent to which they reached consistent decisions. This study assessed intra-examiner repeatability by retesting 72 examiners on comparisons of latent and exemplar fingerprints, after an interval of approximately seven months; each examiner was reassigned 25 image pairs for comparison, out of total pool of 744 image pairs. We compare these repeatability results with reproducibility (inter-examiner) results derived from our previous study. Examiners repeated 89.1% of their individualization decisions, and 90.1% of their exclusion decisions; most of the changed decisions resulted in inconclusive decisions. Repeatability of comparison decisions (individualization, exclusion, inconclusive) was 90.0% for mated pairs, and 85.9% for nonmated pairs. Repeatability and reproducibility were notably lower for comparisons assessed by the examiners as "difficult" than for "easy" or "moderate" comparisons, indicating that examiners' assessments of difficulty may be useful for quality assurance. No false positive errors were repeated (n = 4); 30% of false negative errors were repeated. One percent of latent value decisions were completely reversed (no value even for exclusion vs. of value for individualization). Most of the inter- and intra-examiner variability concerned whether the examiners considered the information available to be sufficient to reach a conclusion; this variability was concentrated on specific image pairs such that repeatability and reproducibility were very high on some comparisons and very low on others. Much of the variability appears to be due to making categorical decisions in borderline cases.     

Identification and Validation of Proteinase 3 and Latent Matrix-Metalloproteinase 9 as Potential Biomarkers for Chronic Lung Transplant Rejection

Introduction

This study examined potential biomarkers for the diagnosis and early detection of chronic allograft rejection after lung transplantation.

Methods

Protein ratios in pooled samples of bronchoalveolar lavage fluid (BALF) from lung transplant recipients at different stages of pre- and postchronic rejection were determined by iTRAQ labeling and mass spectrometry. The potential biomarkers were validated using enzyme-linked immunosorbent assay (ELISA) assay.

Results

Two hundred sixty-five proteins were identified, about two thirds of which showed more than a twofold difference between a pooled control sample (individuals who did not develop chronic rejection in 100 months) and a pooled sample from those with chronic rejection. Proteinase 3 (PR-3) and matrix metalloproteinase 9 (MMP-9) were validated by ELISA assay of 124 individual samples. PR-3 and the latent form of MMP-9 (proMMP9) both demonstrated a specificity of 92% with sensitivities of 76% and 82%, respectively, for disease diagnosis; both were also predictors of developing chronic rejection up to 15 months before diagnosis. While immunoglobulin M (IgM) was upregulated in the pooled samples, individual sample analysis revealed that this arose from outlier values.

Conclusions

iTRAQ can be used to detect a large number of proteins in pooled samples for the discovery of potential biomarkers, but the findings must be validated with technology capable of distinguishing broadly based changes from outcomes as a result of a few extreme cases. The proteins identified in this study expanded the panel of potential biomarkers for the diagnosis and prediction of chronic rejection and provided additional insight into the mechanism of the disease.     

Retrospective evaluation of gynecologic cytodiagnosis. II. Interlaboratory reproducibility as shown in rescreening large consecutive samples of reported cases

Two laboratories exchanged and rescreened a large sample of cases with cervicovaginal smears they had consecutively accessioned to examine the reproducibility of gynecologic cytodiagnosis under optimum conditions. At least a "working agreement" (diagnoses within +/- 1 category on a ten-category scale) was achieved in diagnoses of normal, benign reaction and squamous abnormality (from minimal dysplasia though invasive cancer) in 18,859 cases (96.8%), of endometrial abnormality in 21 cases (42%) and of "unsatisfactory" in 99 cases (20.7%). Larger differences occurred in greater than or equal to 30% of cases except in the categories of "normal" and "benign reaction," reaching a maximum of 82% for moderate dysplasia. Reexamining 382 cases decreased disagreement by category to the 20% to 65% range only in the five categories of dysplasia plus carcinoma in situ. Agreement was not predicated on the presence of endocervical cells or squamous metaplasia; the basis for "unsatisfactory" calls was not uniform. Comparison of the laboratories' diagnoses with referee diagnoses or, on 178 cases, with tissue diagnoses also demonstrated differences in diagnostic criteria.     

CUCKOO HOSTS SHIFT FROM ACCEPTING TO REJECTING PARASITIC EGGS ACROSS THEIR LIFETIME

One of the best‐known outcomes of coevolution between species is the rejection of mimetic parasite eggs by avian hosts, which has evolved to reduce costly cuckoo parasitism. How this behavioral adaptation varies along the life of individual hosts remains poorly understood. Here, we identify for the first time, lifetime patterns of egg rejection in a parasitized long‐lived bird, the magpie Pica pica and show that, during the years they were studied, some females accept, others reject, and some others modify their response to model eggs, in all cases switching from acceptance to rejection. Females tested in their first breeding attempt always accepted the model egg, even those individuals whose mothers were egg rejecters. A longitudinal analysis showed that the probability of egg rejection increased with the relative age of the female, but was not related to the risk of parasitism in the population. We conclude that ontogeny plays a fundamental role in the process leading to egg rejection in magpies.     

Pulmonary Disability in Coal Workers' Pneumoconiosis

Results from a correlation survey which compared radiological and physiological findings during life with detailed morbid anatomical findings in the lungs of 247 deceased miners and ex-miners with pneumoconiosis were used to assess the extent and significance of their pulmonary disability.Coal workers'' pneumoconiosis usually caused progressive impairment of ventilation, which in the simple type of disease was not related to radiological category. In such cases the presence of emphysema was found to be a more important factor in determining the impairment of ventilation than the radiological category of simple pneumoconiosis.     

临床医生在产前诊断咨询中面对伦理两难问题态度与选择 ——基于情景案例分析

目的 试图通过情景案例分析法,聚焦产前诊断中的伦理两难事件,探究临床医生的伦理道德抉择及可能的影响因素。 方法 采用分层随机抽样对624名临床医生进行了匿名问卷调查。 结果 针对相应的情景案例,大多数临床医生能够遵循尊重原则,保障孕妇夫妻双方知情权与自主权,但在具体案例的处理上,与其他国家的同类调查相比存在差异。 结论 临床医生的生命伦理意识有显著提升,但仍存在不足,应进一步加大相关法律与伦理理念知识的教育与普及;此外,对基因缺陷严重性的认知,在不同文化背景下也可能有所差异。     

BRAF Mutation Testing of Thyroid Fine-Needle Aspiration Specimens Enhances the Predictability of Malignancy in Thyroid Follicular Lesions of Undetermined Significance

Background/Objective: The Bethesda 2007 Thyroid Cytology Classification defines atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) as a heterogeneous category of cases that are neither convincingly benign nor sufficiently atypical for a diagnosis of follicular neoplasm or suspicious for malignancy. At our institution, we refer to these cases as 'indeterminate' and they are further subclassified into two categories. BRAF mutation occurs in 40-60% of papillary thyroid carcinoma (PTC). In this study, we examined cases in the AUS/FLUS category in correlation with BRAF mutation analysis and surgical pathology outcome. Study Design: Thyroid fine-needle aspiration (FNA) cytology specimens interpreted as 'indeterminate' were selected from our files, and available remnants of thin-layer processed specimens were used for BRAF mutation analysis. Surgical pathology reports were reviewed for the final outcomes in these patients. Results: Of the 84 indeterminate cases with BRAF mutation analysis, only 49 had follow-up with surgical intervention. Sixteen cases had BRAF mutation. All of the BRAF-positive cases had a final diagnosis of PTC. Conclusions: The sensitivity and specificity of BRAF mutation in detecting PTC in FNA specimens with indeterminate diagnosis was 59.3 and 100%, respectively, while the positive and negative predictive values were 100 and 65.6%, respectively. The limited data supports the use of BRAF mutation analysis to predict the risk of malignancy in patients with indeterminate thyroid FNAs.