Motoric and symbolic mediation in observational learning.

The observers' motoric and symbolic representations of a model's behavior are important mediators in observational learning. The observers' spontaneous use of these mediators may be influenced by their familiarity with responses performed by a model and by their intention to learn these responses. Unfamiliar observers do not have symbolic codes available for the model's responses, so they may rely on motor mimicry. Familiar observers have symbolic codes available, so they may employ those codes and, possibly, motor mimicry as mediators. Spontaneous mediation may also depend on whether observers intend to learn these responses. Three experiments with 132 undergraduates revealed that familiar observers used motoric and symbolic mediators, whereas unfamiliar observers primarily used motor mimicry. Symbolic coding facilitated familiar but not unfamiliar observers' learning; unfamiliar observers' learning was related to motor mimicry. Intention to learn increased motor mimicry but not symbolic coding. An interpretation is offered for the observers' pervasive use of motor mimicry. (3 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identification of the eye–brain–hand system with point processes: A new approach to simple reaction time.

By presenting a Poisson process of flashes to observers who hit a button as quickly as possible after each, the authors identified the system involved in simple reaction time (RT). The nonlinear kernels up to 2nd order were measured from the stimulus and response point processes. The 1st-order kernel is analogous to a histogram of simple RTs. The 2nd-order kernel shows complex patterns of nonlinear suppression and facilitation between pairs of flashes. Simple RT measured as the lag of the 1st-order kernel's peak agrees with RT from conventional discrete trial experiments. RTs are shorter and less variable when the flashes are separated by uniform rather than exponential delays, which shows that observers use the stimulus hazard function to become prepared to detect and respond to the flash. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The validity of visual observation to assess posture in a laboratory-simulated, manual material handling task

A wide range of methods to evaluate posture in work situations relies on simple, unaided visual observation. In the present study the validity of visual observation to assess posture in a dynamic job was evaluated. Postural aspects were observed and recorded during a manual materials handling job simulated in a laboratory. The results from these observations, concerning gross body posture, torso flexion, arms and legs position, and load to be handled, were compared to the results obtained by direct opto-electronic recording. The agreement on a sample-to-sample basis (expressed by Cohen's kappa) was poor for the variables torso flexion (mean value for kappa = 0.38), position of arms (kappa = 0.43) and legs (kappa = 0.46) and load to be handled (kappa = 0.50) and acceptable only for the gross body posture (kappa = 0.79). Moreover, for each variable except gross body posture, the crude distributions of all observations and recordings across categories (irrespective of time) were significantly different. The results demonstrate that the observations are not valid. It is concluded that dynamic work situations require less simple, more time consuming methods (e.g., analyzing film or video records of the job) than a posture registration method based on direct visual observation.     

On specifying the null model for incremental fit indices in structural equation modeling.

In structural equation modeling, incremental fit indices are based on the comparison of the fit of a substantive model to that of a null model. The standard null model yields unconstrained estimates of the variance (and mean, if included) of each manifest variable. For many models, however, the standard null model is an improper comparison model. In these cases, incremental fit index values reported automatically by structural modeling software have no interpretation and should be disregarded. The authors explain how to formulate an acceptable, modified null model, predict changes in fit index values accompanying its use, provide examples illustrating effects on fit index values when using such a model, and discuss implications for theory and practice of structural equation modeling. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Choice behavior in transition: Development of preference with ratio and interval schedules.

In Exp 1, the choice responses of 8 pigeons were observed during 50 periods of transition. Each condition began with equal probabilities of reinforcement on 2 response keys and switched to unequal probabilities. With the ratio of the 2 probabilities held constant, preference for the higher probability developed more rapidly when the 2 probabilities were high than when they were low. In Exp 2, each condition began with 2 equal variable interval (VI) schedules, but later 1 key delivered 60%, 75%, or 90% of the reinforcers. The rate of approach to asymptotic performance was roughly the same with all 3 reinforcement percentages. These and previous results pose difficulties for some well-known models of acquisition, but the results are well described by a simple model that states that the strength of each response is independently increased by reinforcement and decreased by nonreinforcement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ankle fracture classification: a comparison of reliability of three X-ray views versus two

Our hypothesis was that malleolar ankle fractures could be classified with two radiographic views as reliably as with three views. Four different observers independently evaluated 99 sets of ankle radiographs. The examiners classified the ankle fractures by using both the Lauge-Hansen and Danis-Weber systems. The interobserver and intraobserver variations were analyzed by kappa statistics. With regard to intraexaminer reliability, the examiners demonstrated excellent accord in classifying the fractures in the Danis-Weber system with either three views or two views. The kappa values were comparable. In the Lauge-Hansen system, three examiners demonstrated excellent accord and one examiner demonstrated good accord in classifying the fractures. Similar kappa values were generated when examiners classified fractures with either three views or two views. With regard to interexaminer reliability, good to excellent accord was demonstrated overall among the four examiners when they used the Danis-Weber system with either three views or two views. The examiners were in good agreement when they used the Lauge-Hansen system. Similar kappa values were generated whether the examiners used three views or two views. Three radiographic views are usually ordered for evaluation of an acute ankle injury. Previous studies have shown that only two views are needed for diagnosis of a malleolar ankle fracture. This study demonstrates that malleolar ankle fractures can be classified with two views, lateral or mortise, with a reliability as good as that achieved with three views. The best agreement is achieved with lateral and mortise views.     

Ethics: Virtue and politics in the science and practice of psychology.

Discusses the thesis that the discipline of psychology needs to re-discover and reclaim virtue and moral values as its base for ethical behavior, thinking, and being. Psychology has a short history in formalizing codes of ethics and codes of conduct. Current and historical events, and concepts and values, including those based on philosophy and religion, have influenced the development of psychology's scientific and professional codes. The ethical behavior of psychologists may be inspired by values, regulated by rules, determined by external pressures, or any combination of these. Emerging issues and challenges in today's changing and turbulent society require an incorporation of moral principles in finding acceptable strategies to achieve acceptable goals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Towards cost-effective dialysis therapy in Europe: the need for a multidisciplinary approach

BACKGROUND AND PURPOSE: Although the reliability of the assessment of severe 70% to 99% carotid stenosis by carotid angiography has been proven excellent, this may not necessarily be the case for a more detailed classification of carotid stenoses by 10% categories. METHODS: Angiograms of the carotid arteries were assessed pairwise by three independent, experienced observers. The measurements of the degree of stenosis of both the carotid bifurcation and the internal carotid artery were made according to the European Carotid Surgery Trial method. Kappa statistics were used to assess the agreement beyond chance for severe (70% to 99%) carotid stenosis (kappa 1) and for 10% categories of carotid stenosis (kappa 2). The penalty scores were adjusted by weights for the relative difference in risk (RDR) of stroke in the ipsilateral carotid distribution between the 10% categories (kappa 3). An adjustment of the RDR method was made by assuming that only patients with a severe carotid stenosis would undergo surgery, and the penalty would be 0 if no disagreement would exist about the indication for surgery (kappa 4). An even further adjustment (kappa 5) was made by assuming that assessment of the rate of carotid stenosis by one or both observers would lead to different treatment recommendations in 50% of the cases, and accordingly the penalty for disagreement (RDR) was halved. RESULTS: One hundred twenty-one carotid bifurcations in 65 patients with a transient ischemic attack or nondisabling stroke were assessed. The intraclass correlation between the exact estimates of carotid stenosis was .90 (95% confidence interval, .85 to .92). The mean difference in stenosis between the two raters was 0.8% (95% confidence interval, -2.1% to 3.7%). kappa 1 to kappa 5 equaled 0.80, 0.40, 0.79, 0.91, and 0.92, respectively. CONCLUSIONS: Interobserver agreement for distinct 10% categories of angiographic carotid stenosis is moderate, but when realistic risk- and decision-based weights are used, agreement between experienced observers can be almost perfect.     

Interobserver variation in the reporting of cervical colposcopic biopsy specimens: comparison of grading systems

AIMS: To assess interobserver variation in reporting cervical colposcopic biopsy specimens and to determine whether a modified Bethesda grading system results in better interobserver agreement than the traditional cervical intraepithelial neoplasia (CIN) grading system. METHODS: One hundred and twenty five consecutive cervical colposcopic biopsy specimens were assessed independently by six histopathologists. Specimens were classified using the traditional CIN grading system as normal, koilocytosis, CIN I, CIN II, or CIN III. The specimens were also classified using a modified Bethesda grading system as either normal, low grade squamous intraepithelial lesion (LSIL) or high grade squamous intraepithelial lesion (HSIL). Participants were also asked to categorise biopsy specimens by the CIN system with the addition of the recently proposed category "basal abnormalities of uncertain significance (BAUS)". The degree of agreement between participants was assessed by kappa statistics. RESULTS: Using the CIN system, interobserver agreement was generally poor: unweighted and weighted kappa values between individual pairs of observers ranging from 0.05 to 0.34 (average 0.20) and from 0.20 to 0.54 (average 0.36), respectively. With the modified Bethesda system, interobserver agreement was better but still poor: unweighted and weighted kappa values ranging from 0.15 to 0.58 (average 0.30) and from 0.21 to 0.61 (average 0.36), respectively. There was little or no agreement between observers in the diagnosis of BAUS. CONCLUSIONS: Interobserver agreement in the reporting of cervical colposcopic biopsy specimens using the CIN grading system is poor. Agreement, while still poor, is better when a modified Bethesda grading system is used. There is little or no consensus in the diagnosis of BAUS.     

A policy evaluation of simultaneous and sequential lineups.

Many states and communities are rewriting their eyewitness identification policies. Some of these jurisdictions are excluding simultaneous lineups altogether, and others are allowing them if double-blind administration of sequential lineups is not possible. The Innocence Project advocates the latter and puts forward blind sequential-lineup administration as the best form of lineup identification. Although sequential lineups are claimed to be superior, no explicit policy analysis has been done. In the present study, the author uses a policy-analysis model based on decision theory to examine the utility of simultaneous and sequential lineups, as well as to examine a range of values placed on identification outcomes and their probabilities. Simultaneous lineups are shown to be superior to sequential lineups under most conditions examined in this analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inter-observer reliability of the Spondylitis Functional Index Instrument for assessing spondylarthropathies

OBJECTIVE: To study the Spondylitis Functional Index (SFI) by having two physical therapists observe patients with spondylitis perform various tasks listed on the instrument. The physical therapists' observations were compared with each other and with the self-reported abilities of the patients. METHODS: Subjects (n = 30) were recruited from a cross-section of patients participating in a prospective randomized, multicenter, double-blind, parallel clinical trial of the efficacy of sulfasalazine on ankylosing spondylitis (n = 13), psoriatic arthritis (n = 13), and Reiter's syndrome (n = 4) conducted at the Veterans Affairs Medical Center in Salt Lake City. Percents of agreement and Cohen's kappa analysis were used to assess the reliability of the observations of the therapists and patients. RESULTS: The overall percent of agreement between the observers on the SFI was 93%. The overall percent of agreement between observer 1 and patients on the SFI was 66% and between observer 2 and patients was 67%. The overall inter-observer reliability measured by the Pearson coefficient was 0.91 and by Cohen's kappa was 0.86. Between observer 1 and the patients the Pearson was r = 0.53 and kappa = 0.39. For observer 2 the Pearson was r = 0.52 and kappa 0.39. CONCLUSIONS: We consider the agreement and reliability between observers to be high. The agreement and inter-observer reliability was poor between observers and patients. The SFI, as enhanced for use in this study to assess change in functional ability of patients with spondylitis, demonstrated high reliability when used by trained observers.     

Effector-Dependent Learning by Observation of a Finger Movement Sequence.

Can observational learning be effector dependent? In 3 experiments, observers watched a model respond to a 6-item unique sequence in a serial reaction time task. Their sequence knowledge was then compared with that of controls who had performed an unrelated task or observed a model responding to random targets. Observational learning was indicated when the introduction of a new sequence was associated with more reaction time elevation in observers than in controls. The authors found evidence of observational learning only when observers used the finger movement sequence that they observed during training, not when they responded at the same sequence of locations using different digits. Free generation and recognition tests also detected observational learning. These results imply that observational learning can be both explicit and effector dependent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of the Neer system of classification of proximal humeral fractures with computerized tomographic scans and plain radiographs

The intraobserver reliability and inter-observer reproducibility of the Neer classification system were assessed on the basis of the plain radiographs and computerized tomographic scans of twenty fractures of the proximal part of the humerus. To determine if the observers had difficulty agreeing only about the degree of displacement or angulation (but could determine which segments were fractured), a modified system (in which fracture lines were considered but displacement was not) also was assessed. Finally, the observers were asked to recommend a treatment for the fracture, and the reliability and re-producibility of that decision were measured. The radiographs and computerized tomographic scans were viewed on two occasions by four observers, including two residents in their fifth year of postgraduate study and two fellowship-trained shoulder surgeons. Kappa coefficients then were calculated. The mean kappa coefficient for intraobserver reliability was 0.64 when the fractures were assessed with radiographs alone, 0.72 when they were assessed with radiographs and computerized tomographic scans, 0.68 when they were classified according to the modified system in which displacement and angulation were not considered, and 0.84 for treatment recommendations; the mean kappa coefficients for interobserver reproducibility were 0.52, 0.50, 0.56, and 0.65, respectively. The interobserver reproducibility of the responses of the attending surgeons regarding diagnosis and treatment did not change when the fractures were classified with use of computerized tomographic scans in addition to radiographs or with use of the modified system in which displacement and angulation were not considered; the mean kappa coefficient was 0.64 for all such comparisons. Over-all, the addition of computerized tomographic scans was associated with a slight increase in intraobserver reliability but no increase in interobserver reproducibility. The classification of fractures of the shoulder remains difficult because even experts cannot uniformly agree about which fragments are fractured. Because of this underlying difficulty, optimum patient care might require the development of new imaging modalities and not necessarily new classification systems.     

Interobserver variability in the diagnosis of high-grade prostatic intraepithelial neoplasia and adenocarcinoma

High-grade prostatic intraepithelial neoplasia (PIN) is a strong predictor of carcinoma when identified in small-needle biopsy specimens. However, the diagnostic variability of PIN is unknown. Eight pathologists reviewed 321 prostatic biopsy specimens to assess the variability of the diagnosis of high-grade PIN and carcinoma. All of the specimens were classified as negative, high-grade PIN, suspicious for high-grade PIN, carcinoma, or suspicious for carcinoma, more than one diagnosis was permitted, except for negative. We compared diagnoses made by two observers by pairing them for negative versus high-grade PIN, negative versus carcinoma, high-grade PIN versus carcinoma, and all diagnostic categories together. Mean kappa coefficient values for 28 interobserver combinations were 0.451, 0.845, 0.669, and 0.482, respectively, for each of the four comparison combinations considered. Our results indicate a high level of agreement, "almost perfect" (kappa = 0.81-1.0) for carcinoma, "moderate" (kappa = 0.41-0.60) for high-grade PIN, and "substantial" (kappa = 0.61-0.81) for high-grade PIN versus carcinoma. We found that variability was related to the level of interest in prostatic pathology, the conditions of the study, the subjective application of diagnostic criteria, and the influence of peers and clinical colleagues.     

Measurement error, instrumental variables and corrections for attenuation with applications to meta-analyses

MacMahon et al. present a meta-analysis of the effect of blood pressure on coronary heart disease, as well as new methods for estimation in measurement error models for the case when a replicate or second measurement is made of the fallible predictor. The correction for attenuation used by these authors is compared to others already existing in the literature, as well as to a new instrumental variable method. The assumptions justifying the various methods are examined and their efficiencies are studied via simulation. Compared to the methods we discuss, the method of MacMahon et al. may have bias in some circumstances because it does not take into account: (i) possible correlations among the predictors within a study; (ii) possible bias in the second measurement; or (iii) possibly differing marginal distributions of the predictors or measurement errors across studies. A unifying asymptotic theory using estimating equations is also presented.     

Is there feature-based attentional selection in visual search?

A new paradigm combines attentional cuing and rapid serial visual presentation to disentangle the effects of perceptual filtering and location selection. Observers search successive, superimposed arrays, in which feature values are alternated for a target numeral among letters. Two dimensions, size (small, large) and color (red, green) are tested. Selective attention to feature values is jointly manipulated by instructions, presentation probabilities, and payoffs. In Experiment 1, the attended feature provides temporal, not spatial, information; observers show no attentional costs or benefits in response accuracy. In Experiment 2, the attended feature indicates a unique location; observers show consistent attentional costs and benefits. Selective attention to a particular size or color does not cause perceptual exclusion or admission of items containing that feature; it acts by guiding search processes to spatial locations that contain the to-be-attended feature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanisms involved in the observational conditioning of fear.

Three experiments support the hypothesis that mechanisms involved in observational conditioning (OC) of fear are similar to those of direct classical conditioning and involve the organism attempting to detect the causal structure of its environment. Exp 1, a correlational analysis, shows that model monkeys' fear behaviors on snake trials (unconditioned stimulus [UCS]) were highly correlated with observer monkeys' fear (unconditioned response [UCR]) while watching the models' fear. In Exp 2, all observers showed distress while watching the model's fear during Session 1 of OC, but only observers who could see the snake to which the model was reacting continued to show fear during subsequent OC sessions, suggesting that the model's fear is an easily habituable UCS. In Exp 3, observers acquired significant fear of snakes after 1 OC session, indicating that the continued fear of those Exp 2 observers that could see the snake may reflect their own acquired fear of snakes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Observational skills.

Reviews reasons for the traditional neglect of observational skills in psychology in terms of misunderstandings, a problematic history of development, and persistent methodological difficulties. Persistent problems in studying observational skills have included individual differences, training failure, instructions to observers, and identification with trait psychology. Emphasis is given to emerging solutions for problems in research on nonverbal communication, social skills, and therapist skills. Suggestions are offered for legitimizing the study of observation in psychology by (1) specifying the skills of good observers, (2) specifying the situational factors that facilitate observation, and (3) formulating programs for the training of observational skills. (235 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Priming and theories of memory: A reply to Ratcliff and McKoon.

R. Ratcliff and G. McKoon (see record 1994-16298-001) attempt to buttress the case for non-spreading-activation models of associative priming by showing that first-response free association probabilities do not predict priming effects, and sequential effects in lexical decisions are predicted by at least one non-spreading-activation model. The author argues that their attempt to predict priming from free association is not informative because they did not propose a model of how association in memory is manifested in free association, these predictions depended on assumptions that are not consistent with the model tested, the compound-cue model is a poor model of sequential effects, and non-spreading-activation models still cannot explain the absence of inhibition following nonword primes when responses to the primes are not required. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The reproducibility of the results of transvaginal sonography of the uterus in patients with abnormal uterine bleeding

Our objectives were to determine the reproducibility, or interobserver agreement, of transvaginal sonographic imaging of the uterus in patients with abnormal uterine bleeding and to identify the effect of observer experience. Transvaginal ultrasound findings of 235 patients with abnormal uterine bleeding were recorded systematically on videotape. Recordings were reviewed by three observers who had different levels of experience, and who were asked to judge the endometrium/uterine cavity and myometrium separately as being normal, abnormal or inconclusive, according to predefined criteria. Reproducibility was expressed by the observed rates of interobserver agreement and by kappa statistics. The differences in agreement between observer pairs were analyzed by means of McNemar's chi 2 test. The observed rates of agreement for the judgement of the endometrium/uterine cavity varied from 0.85 to 0.89, with a kappa value ranging from 0.70 to 0.78 between observers. The judgment of the myometrium resulted in agreement rates of 0.86-0.91 and kappa values of 0.67-0.80. Although the effect of experience was evident, the differences in agreement between observers were not significant (p > 0.01). The reproducibility of the results of transvaginal sonography of the uterus in patients with abnormal uterine bleeding was good. Observations of the endometrium/ uterine cavity with a normal appearance were the most highly reproducible, with the smallest effect of observer experience. This may reduce the need for invasive diagnostic procedures in patients with abnormal uterine bleeding.