Measures and interpretations of vigilance performance: evidence against the detection criterion

Operators' performance in a vigilance task is often assumed to depend on their choice of a detection criterion. When the signal rate is low this criterion is set high, causing the hit and false alarm rates to be low. With increasing time on task the criterion presumably tends to increase even further, thereby further decreasing the hit and false alarm rates. Virtually all of the empirical evidence for this simple interpretation is based on estimates of the bias measure beta from signal detection theory. In this article, I describe a new approach to studying decision making that does not require the technical assumptions of signal detection theory. The results of this new analysis suggest that the detection criterion is never biased toward either response, even when the signal rate is low and the time on task is long. Two modifications of the signal detection theory framework are considered to account for this seemingly paradoxical result. The first assumes that the signal rate affects the relative sizes of the variances of the information distributions; the second assumes that the signal rate affects the logic of the operator's stopping rule. Actual or potential applications of this research include the improved training and performance assessment of operators in areas such as product quality control, air traffic control, and medical and clinical diagnosis.     

Display characteristics in inspection tasks.

Tested 8 female undergraduates on detection of pin-hole defects in a visual scanning task. Display type (static vs. dynamic) and display arrangement (random vs. ordered) were combined factorially in a within-S design. Static (inspector-paced) displays yielded more defect detections and fewer false alarm errors; whereas, display arrangement did not effect detections or false alarm errors. It is concluded that inspector-paced displays seem to be more beneficial than externally paced displays when rapid scanning rates are required. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A table for the calculation of d' and BETA.

The methodology of signal detection theory is a preferred technique for assessing an S's ability to discriminate the occurrence of discrete binary events. A compact table is presented which will permit precise calculation of signal detection parameters, d' (discrimination index) and BETA (response bias), for hit and false alarm rate combinations in the range from .01-.99. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于深度学习的圆钢表面缺陷检测系统

圆钢表面缺陷是影响圆钢质量的重要因素。随着钢铁生产轧制节奏提升和智能化升级,人工检测、传统表面缺陷检测等方法已经难以同时满足多种类缺陷、高速在线检测等方面的需求。因此,设计了适用于圆钢表面缺陷检测的成像系统,提出分类优先网络与目标检测网络融合的圆钢表面缺陷检测方法,并将一种非缺陷样本加入网络模型的训练以提升检测精度。试验结果及应用效果表明,该方法针对凹坑、裂纹、耳子、划伤、翘皮等表面缺陷的准确识别率达到95.61%,能有效减少缺陷误报、漏报的问题。     

Digital mammography: M-channel quadrature mirror filters (QMFs) for microcalcification extraction

Multiresolution methods are reported for feature extraction in breast cancer screening using digital mammography. The initial application is directed at the detection of microcalcification clusters (MCCs). Quadrature mirror filter (QMF) banks, using both two and three channel are proposed for the first time for both multiresolution decomposition and reconstruction. These filters are specifically tailored for automatic extraction of MCCs. The QMF multiresolution methods are compared to two channel tree structured wavelet transforms (TSWTs) methods previously reported. The QMF filters are preceded by an advanced tree structured nonlinear filter for noise suppression, prior to feature extraction, in order to minimize the false positive (FP) detection rate in digital mammography. The relative performance of these methods were evaluated using both simulated images and fifteen representative digitized mammograms containing biopsy proven microcalcification clusters. Similar high sensitivity (true positive (TP) detection rate (100%) and high specificity (0.6 average false positive (FP) MCC's/image) were observed, substantially better than more traditional approaches using single scale filters. The three channel QMF method, however, demonstrated better detail preservation of MCC's extracted compared to the two channel method. Detail preservation is important for the characterization of MCC's or individual microcalcifications in cancer screening.     

Perceived symptoms in the recognition of hypoglycemia

For people with diabetes, detection of hypoglycemic symptoms is a critical tool for the recognition and treatment of hypoglycemia. This is not a simple process involving only the occurrence of a hypoglycemic-relevant physiological event, such as sweating. We propose a four-step biological and psychological model that leads to the accurate recognition of hypoglycemia through symptoms. The model illustrates both the chronic and transient modifiers that can enhance and interfere with recognition of hypoglycemia. Three common methods are used to investigate the occurrence and utility of hypoglycemic symptoms that relate to this model. This article reviews the advantages and disadvantages of these methods, providing previously unpublished illustrative data. The field study hit/false alarm approach was shown to be the most useful method. The relevance of this model and data to the concept of hypoglycemic awareness/unawareness and blood glucose awareness training is discussed.     

Comparison of four methods for the detection of fecal streptococci in water

The objective of this study was to select an effective and fast method for the detection of socalled fecal streptococci in water by comparing a method according to the German drinking water standard, a membrane filtration method according to the ISO-draft standard 7899/2, the Chromocult Enterococcus Broth (Merck) and the Enterolert-System (IDEXX). The study was based on a collective of 297 water samples derived from different stages of water treatment and distribution, as well as from individual water supplies. The sensitivity, reliability, and selectivity of the single methods in relation to their practicability was evaluated. Concerning false positive and false negative results, the tests were proved by metabolic characterization of the isolated strains. The advantages and disadvantages of the methods resulting from the investigated criteria are discussed. The work is part of a comparative study within the scope of the DIN ad-hoc-committee "fecal streptococci".     

False recognition and the right frontal lobe: a case study

We described a patient, BG, who exhibited a striking pattern of false recognition after an infarction of the right frontal lobe. Seven experiments document the existence of the phenomenon, explore its characteristics, and demonstrate how it can be eliminated. BG showed pathologically high false alarm rates when stimuli were visual words (experiments 1 and 4), auditory words (experiment 2), environmental sounds (experiment 3), pseudowords (experiment 5), and pictures (experiment 7). His false alarms were not merely attributable to the semantic or physical similarity of studied and non-studied items (experiments 4 and 5). However, BG's false recognitions were virtually eliminated by presenting him with categorized stimuli and testing him with new stimuli from non-studied categories (experiments 6 and 7). The results suggest that BG's false alarms may be attributable to an over-reliance on memory for general characteristics of the study episode, along with impaired memory for specific items. The damaged right frontal lobe mechanisms may normally support the monitoring and/or retrieval processes that are necessary for item-specific recognition.     

Sex differences in monitoring performance.

220 male and 220 female undergraduates monitored a visual display for 1 hr. Although the results indicate females were poorer monitors, detecting 10% fewer signals and committing more false alarms, these sex differences accounted for only 4% of the variance of detection performance and less than 1% of the variance of the false alarm measure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Subtracted, unique-sequence, in situ hybridization: experimental and diagnostic applications

Nonrandom chromosomal aberrations, particularly in cancer, identify pathogenic biological pathways and, in some cases, have clinical relevance as diagnostic or prognostic markers. Fluorescence and colorimetric in situ hybridization methods facilitate identification of numerical and structural chromosome abnormalities. We report the development of robust, unique-sequence in situ hybridization probes that have several novel features: 1) they are constructed from multimegabase contigs of yeast artificial chromosome (YAC) clones; 2) they are in the form of adapter-ligated, short-fragment, DNA libraries that may be amplified by polymerase chain reaction; and 3) they have had repetitive sequences (eg, Alu and LINE elements) quantitatively removed by subtractive hybridization. These subtracted probes are labeled conveniently, and the fluorescence or colorimetric detection signals are extremely bright. Moreover, they constitute a stable resource that may be amplified through at least four rounds of polymerase chain reaction without diminishing signal intensity. We demonstrate applications of subtracted probes for the MYC and EWS oncogene regions, including 1) characterization of a novel EWS-region translocation in Ewing's sarcoma, 2) identification of chromosomal translocations in paraffin sections, and 3) identification of chromosomal translocations by conventional bright-field microscopy.     

Investigating strength and frequency effects in recognition memory using type-2 signal detection theory.

Criterion- versus distribution-shift accounts of frequency and strength effects in recognition memory were investigated with Type-2 signal detection receiver operating characteristic (ROC) analysis, which provides a measure of metacognitive monitoring. Experiment 1 demonstrated a frequency-based mirror effect, with a higher hit rate and lower false alarm rate, for low frequency words compared with high frequency words. In Experiment 2, the authors manipulated item strength with repetition, which showed an increased hit rate but no effect on the false alarm rate. Whereas Type-1 indices were ambiguous as to whether these effects were based on a criterion- or distribution-shift model, the two models predict opposite effects on Type-2 distractor monitoring under some assumptions. Hence, Type-2 ROC analysis discriminated between potential models of recognition that could not be discriminated using Type-1 indices alone. In Experiment 3, the authors manipulated Type-1 response bias by varying the number of old versus new response categories to confirm the assumptions made in Experiments 1 and 2. The authors conclude that Type-2 analyses are a useful tool for investigating recognition memory when used in conjunction with more traditional Type-1 analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dual X-ray absorptiometry quality control: comparison of visual examination and process-control charts

Dual X-ray absorptiometry (DXA) is widely used to monitor treatment efficacy in reducing the rate of bone mineral loss. In order to assure the validity of these measurements, instrument quality control of the DXA scanners becomes very important. This paper compares five quality control procedures (visual inspection, Shewhart chart with sensitizing rules, Shewhart chart with sensitizing rules and a filter for clinically insignificant mean changes, moving average chart and standard deviation, and cumulative sum chart [CUSUM]) in their ability to identify scanner malfunction by means of (1) an analysis of five longitudinal phantom data sets that had been collected during a clinical trial and (2) an analysis of simulated data sets. The visual inspection method is relatively subjective and depends on the operator's experience and attention. The regular Shewhart chart with sensitizing rules has a high false alarm rate. The Shewhart chart with sensitizing rules and an additional filter for clinically insignificant mean changes has the lowest false alarm rate but a relatively low sensitivity. The CUSUM method has good sensitivity and a low false alarm rate. In addition, this method provides an estimate of the date a change in the DXA scanner performance might have occurred. The method combining a moving average chart and a moving standard deviation chart came closest to the performance of the CUSUM method. Comparing the advantages and disadvantages of all methods, we propose the use of the CUSUM method as a quality control procedure for monitoring DXA scanner performance. For clinical trials use of the more intuitive Shewhart charts may be acceptable at the individual sites provided their scanner performance is followed up by CUSUM analysis at a central quality assurance center.     

The mirror effect and mixture signal detection theory.

The mirror effect for word frequency refers to the finding that low-frequency words have higher hit rates and lower false alarm rates than high-frequency words. This result is typically interpreted in terms of conventional signal detection theory (SDT), in which case it indicates that the order of the underlying old item distributions mirrors the order of the new item distributions. However, when viewed in terms of a mixture version of SDT, the order of hits and false alarms does not necessarily imply the same order in the underlying distributions because of possible effects of mixing. A reversal in underlying distributions did not appear for fits of mixture SDT models to data from 4 experiments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional scenes in peripheral vision: Selective orienting and gist processing, but not content identification.

Emotional-neutral pairs of visual scenes were presented peripherally (with their inner edges 5.2° away from fixation) as primes for 150 to 900 ms, followed by a centrally presented recognition probe scene, which was either identical in specific content to one of the primes or related in general content and affective valence. Results indicated that (a) if no foveal fixations on the primes were allowed, the false alarm rate for emotional probes was increased; (b) hit rate and sensitivity (A') were higher for emotional than for neutral probes only when a fixation was possible on only one prime; and (c) emotional scenes were more likely to attract the first fixation than neutral scenes. It is concluded that the specific content of emotional or neutral scenes is not processed in peripheral vision. Nevertheless, a coarse impression of emotional scenes may be extracted, which then leads to selective attentional orienting or--in the absence of overt attention--causes false alarms for related probes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comprehensive, interdisciplinary approach to the care of the institutionalized person with epilepsy

The methods of assessing the diagnostic usefulness of exercise testing in detecting coronary obstructive disease are examined. The limitations of long-term clinical follow-up and coronary angiography as standards for the determination of disease are described as are the effects of test methodology, criteria for positivity, prevalence of disease in the study population, reliability of the standard and recognition of false positive and false negative results in determining reliability of such testing. High values were found for sensitivity and specificity for exercise testing of patients with coronary artery disease referred for consultation to medical center cardiology services. Maximal exercise testing and consideration of symptomatic and hemodynamic as well as electrocardiographic criteria for identification of myocardial ischemia are helpful in improving reliability. Diagnostic accuracy is greatly enhanced by recognition of known causes for false positive and false negative results.     

Acute leukemia and chemotherapy: a modeling viewpoint

A couple of models of acute myeloblastic leukemia (AML) are proposed. Normal and leukemic cells are assumed to exist side-by-side with the two cell populations obeying Gompertzian dynamics but with the leukemic cells exercising inhibition over the normal cells. The kinetic equations and steady-state properties of one of the models is analytically obtained. Possible situations of detection or nondetection of malignancy are then discussed. Based on the models of AML, a treatment model is proposed and numerically simulated. Consequently, the option of aggressive treatment of the disease with heavy doses of drugs is shown to be a plausible and worthwhile chemotherapeutic strategy.     

Pain insensitivity in schizophrenia: a neglected phenomenon and some implications

The literature on insensitivity to pain in schizophrenia is reviewed. Numerous reports indicate that, relative to normals, individuals with schizophrenia are insensitive to physical pain associated with illness and injury. In addition, insensitivity to pain of various sorts administered in experimental studies has been reported frequently in this population. This extensive and diverse literature of clinical and experimental reports suggests that many individuals with schizophrenia are less sensitive to pain than normal individuals. However, because the experimental studies--almost all of which were conducted before 1980--suffer from a variety of methodological limitations, this research provides neither a satisfactory characterization nor an adequate explanation of pain insensitivity in schizophrenia. It is argued that this widely reported but currently neglected phenomenon has important implications for physical health, self-mutilation, homelessness, premorbid development, and affective flattening in individuals with schizophrenia.     

Subconscious detection of threat as reflected by an enhanced response bias

Neurobiological and cognitive models of unconscious information processing suggest that subconscious threat detection can lead to cognitive misinterpretations and false alarms, while conscious processing is assumed to be perceptually and conceptually accurate and unambiguous. Furthermore, clinical theories suggest that pathological anxiety results from a crude preattentive warning system predominating over more sophisticated and controlled modes of processing. We investigated the hypothesis that subconscious detection of threat in a cognitive task is reflected by enhanced "false signal" detection rather than by selectively enhanced discrimination of threat items in 30 patients with panic disorder and 30 healthy controls. We presented a tachistoscopic word-nonword discrimination task and a subsequent recognition task and analyzed the data by means of process-dissociation procedures. In line with our expectations, subjects of both groups showed more false signal detection to threat than to neutral stimuli as indicated by an enhanced response bias, whereas indices of discriminative sensitivity did not show this effect. In addition, patients with panic disorder showed a generally enhanced response bias in comparison to healthy controls. They also seemed to have processed the stimuli less elaborately and less differentially. Results are consistent with the assumption that subconscious threat detection can lead to misrepresentations of stimulus significance and that pathological anxiety is characterized by a hyperactive preattentive alarm system that is insufficiently controlled by higher cognitive processes.     

冶金工业建筑中火灾自动报警系统的设计

从系统形式的选择,火灾探测器和报警控制器的选配,报警区域和探测区域的划分,消防控制设备的功能和联动控制要求,以及系统布线等方面系统阐述了冶金工业建筑中火灾自动报警系统的设计方法和设计要点。     

Eyewitness identification: Psychological research and legal policy on lineups.

The risk of eyewitnesses making false identifications is influenced by the methods used to construct and conduct lineups. The legal system could impose 4 simple rules to reduce false identifications: (a) Eyewitnesses should be informed that the culprit might not be in the lineup, (b) the suspect should not stand out in the lineup, (c) lineups should be administered by someone who does not know who the suspect is, and (d) witnesses should be asked how certain they are of their choice before other information contaminates their judgment. The U.S. Supreme Court has acknowledged the dangers of mistaken identification but has not used exclusionary rules to control unnecessary risk. Judicial rulings should focus on risky lineup methods and impose standards to eliminate potential justice system contributions to false identification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)