Knowledge level learning and the power law: A soar model of skill acquisition in scheduling

Zusammenfassung. Das hier vorgestellte Modell lernt graduell, Planungsaufgaben aus der Klasse der Maschinenbelegungsprobleme (job-shop-scheduling problems) zu lösen. Mit Hilfe des Chunking-Mechanismus von Soar wird episodisches Wissen über die Belegungsreihenfolge von Aufträgen auf Maschinen memoriert. Bei der Entwicklung des Modells wurden zahlreiche qualitative (z. B. Transfereffekte) und quantitative Befunde (z. B. Bearbeitungszeiten) aus einer früheren empirischen Untersuchung berücksichtigt. In einer Validierungsstudie wurden dieselben Aufgaben von 14 Probanden und dem Modell bearbeitet. Die Passung von Simulationsdaten und empirischen Ergebnissen fiel insgesamt gut aus. Allerdings löst das Modell die Aufgaben schneller und zeigt auch einen etwas besseren Lernverlauf als die Probanden. Das Modell liefert eine Erklärung für das Rauschen, das typischerweise bei Bearbeitungszeiten zu beobachten ist: es handelt sich um erworbenes Wissen, das mehr oder weniger gut und auch unterschiedlich häufig auf neue Situationen übertragen wird. Der Lernverlauf der Probanden entspricht nur für aggregierte Daten einer Potenzfunktion (power law). Der vorgestellte Mechanismus zeigt, wie ein symbolisches Modell der Informationsverarbeitung graduelle Verhaltensänderungen generiert und wie der offensichtliche Erwerb allgemeiner Prozeduren ohne explizites Lernen von deklarativen Regeln erfolgen kann. Es wird nahegelegt, daß es sich hier um die Modellierung einer Form impliziten Lernens handelt. Summary. The model presented here gradually learns how to perform a job-shop scheduling task. It uses Soar's chunking mechanism to acquire episodic memories about the order to schedule jobs. The model was based on many qualitative (e.g., transfer effects) and quantitative (e.g., solution time) regularities found in previously collected data. The model was tested with new data where scheduling tasks were given to the model and to 14 subjects. The model generally fit these data with the restrictions that the model performs the task (in simulated time) faster than the subjects, and its performance improves somewhat more quickly than the subjects' performance. The model provides an explanation of the noise typically found in problem solving times - it is the result of learning actual pieces of knowledge that transfer more or less to new situations but rarely by an average amount. Only when the data are averaged (i.e., over subjects) does the smooth power law appear. This mechanism demonstrates how symbolic models can exhibit a gradual change in behavior and how the apparent acquisition of general procedures can be performed without resorting to explicit declarative rule generation. We suggest that this may represent a type of implicit learning.     

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A remote-controlled device for long-term blood collection from freely moving, socially housed animals

A remote-controlled device was developed for injection of fluids and collection of blood samples from freely moving, socially housed animals via an indwelling catheter. Samples are collected at times chosen by the investigator, and the animal is not aware that sampling is occurring. This technique allows measurement of plasma catecholamines and other substances that fluctuate rapidly, are affected by psychosocial stimuli, and are altered by capture and other stressful activities that often accompany sample collection. Rapid retrieval of samples is facilitated by remote-controlled injection of an anesthetic. The device has been used to collect blood from dominant and subordinate male baboons before and during events such as chases and presentation of food treats. Heart rate and blood pressure were measured via radio telemetry, and behavior was recorded on videotapes. This technique allowed construction of multifaceted physiological profiles of social roles and behaviors.     

Knowing When Help Is Needed: A Developing Sense of Causal Complexity

Research on the division of cognitive labor has found that adults and children as young as age 5 are able to find appropriate experts for different causal systems. However, little work has explored how children and adults decide when to seek out expert knowledge in the first place. We propose that children and adults rely (in part) on “mechanism metadata,” information about mechanism information. We argue that mechanism metadata is relatively consistent across individuals exposed to similar amounts of mechanism information, and it is applicable to a wide range of causal systems. In three experiments, we show that adults and children as young as 5 years of age have a consistent sense of the causal complexity of different causal systems, and that this sense of complexity is related to decisions about when to seek expert knowledge, but over development there is a shift in focus from procedural information to internal mechanism information.     

Testing the theory underlying the success of point-of-choice prompts: A multi-component stair climbing intervention

Objectives

Point-of-choice prompts consistently increase stair climbing in public access settings. This study investigated the single and combined effects of a volitional and motivational component of a stair climbing intervention to test the theory underlying the success of point-of-choice prompts.

Design

Quasi-experimental, interrupted time series cross-over design.

Methods

Ascending stair/escalator choices were observed in a UK tram station (n = 38,187). Baseline observations (2 weeks; stage 1) preceded a 2-week point-of-choice prompt positioned alone (stage 2) followed by an additional message positioned at the top of each climb (6 weeks; stage 3). Four weeks after message removal, another baseline (2 weeks; stage 4) preceded installation of the intervention components in reverse order. Thus, the message positioned alone at the top of each climb (4 weeks, stage 5) was supplemented with the point-of-choice prompt (2 weeks, stage 6). Logistic regression analyses of stair/escalator choice included the independent variables of intervention components, gender, time of morning and pedestrian traffic volume.

Results

There was no change in stair climbing percentages when only one intervention component was used, i.e. only the point-of-choice or the message at the top of each climb. In contrast, stair climbing increased when both components of the intervention were installed. Additionally, men took the stairs more than women and stair climbing was more common earlier in the morning and at higher pedestrian traffic volumes.

Conclusions

A motivational component targeting intentions increased the effectiveness of a volitional point-of-choice prompt for stair climbing in a setting where choice of the stairs incurred a time penalty for pedestrians due to the site layout.     

A right visual field advantage for visual processing of manipulable objects

Information about object-associated manipulations is lateralized to left parietal regions, while information about the visual form of tools is represented bilaterally in ventral occipito-temporal cortex. It is unknown how lateralization of motor-relevant information in left-hemisphere dorsal stream regions may affect the visual processing of manipulable objects. We used a lateralized masked priming paradigm to test for a right visual field (RVF) advantage in tool processing. Target stimuli were tools and animals, and briefly presented primes were identical to or scrambled versions of the targets. In Experiment 1, primes were presented either to the left or to the right of the centrally presented target, while in Experiment 2, primes were presented in one of eight locations arranged radially around the target. In both experiments, there was a RVF advantage in priming effects for tool but not for animal targets. Control experiments showed that participants were at chance for matching the identity of the lateralized primes in a picture?Cword matching experiment and also ruled out a general RVF speed-of-processing advantage for tool images. These results indicate that the overrepresentation of tool knowledge in the left hemisphere affects visual object recognition and suggests that interactions between the dorsal and ventral streams occurs during object categorization.     

Spatial reference in multiple object tracking

Spatial reference in multiple object tracking is available from configurations of dynamic objects and static reference objects. In three experiments, we studied the use of spatial reference in tracking and in relocating targets after abrupt scene rotations. Observers tracked 1, 2, 3, 4, and 6 targets in 3D scenes, in which white balls moved on a square floor plane. The floor plane was either visible thus providing static spatial reference or it was invisible. Without scene rotations, the configuration of dynamic objects provided sufficient spatial reference and static spatial reference was not advantageous. In contrast, with abrupt scene rotations of 20°, static spatial reference supported in relocating targets. A wireframe floor plane lacking local visual detail was as effective as a checkerboard. Individually colored geometric forms as static reference objects provided no additional benefit either, even if targets were centered on these forms at the abrupt scene rotation. Individualizing the dynamic objects themselves by color for a brief interval around the abrupt scene rotation, however, did improve performance. We conclude that attentional tracking of moving targets proceeds within dynamic configurations but detached from static local background.     

Therapeutic immediacy across long-term psychodynamic psychotherapy: an evidence-based case study

C. E. Hill (2004) recently developed the concept of therapist immediacy to capture discussion by the therapist about the therapeutic relationship that occurs in the here-and-now of a therapy session. This concept has been expanded to include discussion about the therapeutic relationship by both the client and therapist, captured by the term therapeutic immediacy (K. Kuutmann & M. Hilsenroth, 2011). Although prior research has examined the use of therapeutic immediacy across short-term treatment, the present study is the first to examine the use of immediacy across a long-term (4 years) psychotherapy. Also, this is the first study to assess the interrater reliability of therapeutic immediacy, which was found to achieve good to excellent levels across raters. The most frequently used categories of client and therapist immediacy are presented. Finally, the authors provide an in-depth qualitative examination of 5 therapeutic immediacy segments across the treatment judged by the raters to have high levels of depth/intensity (4.5 or higher out of 5) to examine the role of therapeutic immediacy in exploring meaningful treatment issues. Clinical utility, potential limitations, and future research on therapeutic immediacy are discussed.     

Symmetry axiom of Haken–Kelso–Bunz coordination dynamics revisited in the context of cognitive activity

We present an axiomatic derivation of a model proposed by Haken, Kelso, and Bunz (1985) that describes dynamical aspects of the rhythmic coordination between two limbs. Elaboration of this model has included a symmetry parameter that captures the coordination consequences of an inherent or imposed frequency difference between the limbs. We modified one of the axioms involved in the model derivation, a symmetry axiom, in order to incorporate a new symmetry parameter. This new parameter defines a shift between (a) the laboratory coordinate system, in which the behavior is observed, and (b) a second, postulated coordinate system. It is this second coordinate system, in which the relevant state dynamics is assumed to take place and in which the state dynamics evolves under the impact of an attractor. The state dynamics as described in the attractor coordinate system is then mapped by means of the new symmetry parameter to the laboratory coordinate system. We discuss analytically the bifurcation diagram of the model and determine main effects and interaction effects of manipulations related to the symmetry parameters and related to the mode of coordination (in-phase and anti-phase). The theoretical results are brought to bear on the challenging experimental observation that concurrent cognitive activity (counting, encoding, retrieving, sentence analysis) changes the location of the bimanual coordination attractor but not its strength. The theoretical results suggest that cognitive activity may have the effect it has because it shifts the attractor coordinate system relative to the laboratory coordinate system.