Knowledge partitioning: Context-dependent use of expertise

Although exceptional performance is a defining attribute of expertise, experts sometimes exhibit striking errors and performance limitations. This article reports two experiments in which experts predicted the spread of bush fires, a domain characterized by complex but well-understood physical dynamics. Although accuracy was typically high, large errors were observed when two primary predictor variables were in opposition. In a second study, the experts' behavior--in contrast to that of novices--was additionally shown to depend on problem context. In one context, experts again committed errors, whereas in another, equally domain-relevant context, the correct predictions were made. Critically, when comparing performance across contexts, completely opposing predictions were made under identical physical conditions. We therefore suggest that expertise may comprise separate, and sometimes even mutually exclusive, components of knowledge.     

Catatonia in affective disorder: new findings and a review of the literature

The historical development of the concept of catatonia in affective disorders and contemporary papers on this topic are reviewed. In addition, data from a current study on the frequency of catatonia in mixed mania are reported. Differences between catatonic and noncatatonic patients with mixed mania are presented and their relevance to clinical practice is discussed.     

The President’s New Freedom Commission: Capitalizing on Opportunities to Advance School-Based Mental Health Services

The report from President George W. Bush’s New Freedom Commission on Mental Health (NFC), Achieving the Promise: Transforming Mental Health Care in America(2003), proposes goals and recommendations for improving mental health services. This report has significant implications for the delivery of mental health services through the schools. A focused discussion of the potential opportunities and challenges of implementing NFC recommendations related to school-based mental health is presented. Strategies for addressing five key areas at the intersection of school mental health and the Commission’s recommendations include: stigma reduction, suicide prevention, expansion and improvement of school mental health, and screening and treatment of co-occurring mental health and substance abuse disorders.     

Population of linear experts: knowledge partitioning and function learning

Knowledge partitioning is a theoretical construct holding that knowledge is not always integrated and homogeneous but may be separated into independent parcels containing mutually contradictory information. Knowledge partitioning has been observed in research on expertise, categorization, and function learning. This article presents a theory of function learning (the population of linear experts model--POLE) that assumes people partition their knowledge whenever they are presented with a complex task. The authors show that POLE is a general model of function learning that accommodates both benchmark results and recent data on knowledge partitioning. POLE also makes the counterintuitive prediction that a person's distribution of responses to repeated test stimuli should be multimodal. The authors report 3 experiments that support this prediction.     

Error-driven knowledge restructuring in categorization

Knowledge restructuring occurs when people shift to a new strategy or representation during learning. Although knowledge restructuring can frequently be experimentally encouraged, there are instances in which people resist restructuring and continue to use an expedient but imperfect initial strategy. The authors report 3 category learning experiments that reconciled those conflicting outcomes by postulating that, for restructuring to occur, learners must be dissatisfied with their knowledge and a usable alternative must be available. In line with expectation, restructuring was elicited only when an alternative strategy was pointed out and when people's initial expedient strategy entailed performance error. Neither error nor information about the alternative strategy by itself was sufficient to induce restructuring.     

Concurrent-schedule performance in transition: changeover delays and signaled reinforcer ratios

Six pigeons were trained in experimental sessions that arranged six or seven components with various concurrent-schedule reinforcer ratios associated with each. The order of the components was determined randomly without replacement. Components lasted until the pigeons had received 10 reinforcers, and were separated by 10-s blackout periods. The component reinforcer ratios arranged in most conditions were 27:1, 9:1, 3:1, 1:1, 1:3, 1:9 and 1:27; in others, there were only six components, three of 27:1 and three of 1:27. In some conditions, each reinforcement ratio was signaled by a different red-yellow flash frequency, with the frequency perfectly correlated with the reinforcer ratio. Additionally, a changeover delay was arranged in some conditions, and no changeover delay in others. When component reinforcer ratios were signaled, sensitivity to reinforcement values increased from around 0.40 before the first reinforcer in a component to around 0.80 before the 10th reinforcer. When reinforcer ratios were not signaled, sensitivities typically increased from zero to around 0.40. Sensitivity to reinforcement was around 0.20 lower in no-changeover-delay conditions than in changeover-delay conditions, but increased in the former after exposure to changeover delays. Local analyses showed that preference was extreme towards the reinforced alternative for the first 25 s after reinforcement in changeover-delay conditions regardless of whether components were signaled or not. In no-changeover-delay conditions, preference following reinforcers was either absent, or, following exposure to changeover delays, small. Reinforcers have both local and long-term effects on preference. The former, but not the latter, is strongly affected by the presence of a changeover delay. Stimulus control may be more closely associated with longer-term, more molar, reinforcer effects.     

Internistische Psychosomatik

Zusammenfassung Die psychische Komorbidität internistischer Patienten im Sinne einer ICD-Diagnose des Kapitels F beträgt mehr als 35%: Neurotische, besonders somatoforme, Schmerz-, affektive Störungen und Suchterkrankungen sind häufig. Die Liegedauer ist bei psychischer Komorbidität deutlich erhöht. Es benötigen 5% der internistischen Patienten ein psychosomatisches Konsil. Neue, komplexe Behandlungsstrategien, wie Transplantationen, Kardioverter-Defibrillatoren, Medikamentenpumpen, erfordern häufig spezifische psychosoziale Interventionen. Ältere Patienten haben Erkrankungen, die zunehmend chronifizieren und komplexer werden. Damit werden Lebensqualität und psychische Komorbidität zu zentralen Outcomevariablen der Volkskrankheiten. Das zweite große Aufgabenfeld internistischer Psychosomatik ist die Untersuchung und die Behandlung psychosomatischer Patienten im engeren Sinne (Essstörungen, Schmerz- und somatoforme Störungen), weil internistische Diagnostik und Therapie erforderlich oder die Motivation der Patienten primär somatisch ist. Organisationsmodelle reichen von Konsil-/Liaisondiensten bis zu integrierten psychosomatischen Abteilungen oder Fachabteilungen an Allgemeinkrankenhäusern. Aussichtsreiche Forschungsstrategien werden neben der Erforschung psychosomatischer Mechanismen in der Entwicklung pragmatischer Behandlungsprogramme, ihrer Überprüfung in klinischen Studien und der Versorgungsforschung gesehen. Darüber hinaus sollte eine Intensivierung nationaler und internationaler Forschungsnetze erfolgen, wenn immer möglich unter Beteiligung anderer Disziplinen, um auch im Bereich der Forschung konkurrenzfähig zu bleiben.Herrn Prof. Dr. Ernst Richard Petzold zum 65. Geburtstag gewidmet.     

Anaphor resolution as a function of spatial distance and priming: exploring the spatial distance effect in situation models

Anaphor resolution has been found to depend on the spatial distance between the reader's focus of attention and the location of the anaphor referent in a spatially organized situation model (spatial distance effect; Rinck & Bower, 1995). This effect implies that a) the situation model is spatially organized and b) spatial distance has a stronger effect on the resolution of anaphoric reference than the text priming the anaphor referent. In three experiments, adult participants read 12 short narratives about protagonists moving around a building. Mentionning the location of the anaphor referent in text prior to the anaphoric sentence facilitated anaphor resolution. Decreased spatial distance consistently facilitated anaphor resolution, even when priming the anaphor referent affected anaphor resolution more strongly than spatial distance. Results are discussed with regard to the interpretation and reliability of the spatial distance effect and the interaction of different representational levels in the context of multi-level theories of text comprehension.     

Three Assistants on Boltzmann

The three demi-articles presented here would give a brief biographical account of Ludwig Boltzmann’s life plus some details about his Vienna laboratories first in the 1860’s in the Erdberg and second in Türkenstrasse from 1894. Josef Nabl’s account discusses J. J. Thomson’s Laboratory in Cambridge, which allows a provisional comparison between two different largely contemporary institutes. Nabl’s second letter also mentions Lord Kelvin’s late rejection of the kinetic gas theory of Maxwell and Boltzmann, rejection which on top of the negative attitude of Mach, Zermelo, and Poincaré probably did not benefit Boltzmann’s state of mind and may have contributed to the extreme character of Boltzmann’s anti-philosophical counterattack starting in 1903. This revised version was published online in June 2006 with corrections to the Cover Date.