Word associations in deep dyslexia

Deep dyslexia is an acquired reading disorder resulting in the production of semantic errors during oral reading and an inability to read aloud nonwords. Several researchers have postulated that patients with deep dyslexia have both phonological and semantic access impairments but the data supporting these claims are not convincing. In fact, the hallmark feature of deep dyslexia--the semantic errors--strongly implies that these patients can access semantic information from printed words. We test the integrity of the semantic system in two such patients through auditory and visual word association tasks. The data support the notion that semantics remains intact and that the disorder and associated errors arise through a selection impairment related to failure of inhibitory connections in the phonological lexicon.     

The Tourette's Disorder Scale (TODS): development, reliability, and validity

To address the lack of a simple and standardized instrument to assess overall illness severity of Tourette's disorder (TD), the authors developed and tested a 15-item scale to measure a broad range of common symptoms including tics, inattention, hyperactivity, obsessions, compulsions, aggression, and emotional symptoms. Independent investigators used the 15-item Tourette's Disorder Scale (TODS) to assess 60 TD patients who were taking part in a double-blind placebo-controlled multicenter 8-week treatment study. Interrater reliability, internal consistency, convergent and discriminant validity, and sensitivity to change were examined. The TODS was associated with good interrater reliability, excellent internal consistency, and favorable levels of validity and sensitivity to change. Individual TODS items showed good convergent and discriminant validity against other measures. The TODS is a simple, efficient way for clinicians and parents to rate the severity of multiple symptoms commonly found in patients with Tourette's disorder.     

Visual perspective taking for avatars in a Simon task

In modern digital applications, users often interact with virtual representations of themselves or others, called avatars. We examined how these avatars and their perspectives influence stimulus–response compatibility in a Simon task. Participants responded to light/dark blue stimuli with left/right key presses in the presence of a task-irrelevant avatar. Changes in stimulus–response compatibility were used to quantify changes in the mental representation of the task and perspective taking toward this avatar. Experiments 1 and 2 showed that perspective taking for an avatar occurred in orthogonal stimulus–response mappings, causing a compatibility effect from the avatar’s point of view. In the following two experiments we introduced a larger variety of angular disparities between the participant and avatar. In Experiment 3, the Simon effect with lateralized stimulus positions remained largely unaffected by the avatar, pointing toward an absence of perspective taking. In Experiment 4, after avatar hand movements were added in order to strengthen the participants’ sense of agency over the avatar, a spatial compatibility effect from the avatar’s perspective was observed again, and hints of the selective use of perspective taking on a trial-by-trial basis were found. Overall, the results indicate that users can incorporate the perspective of an avatar into their mental representation of a situation, even when this perspective is unnecessary to complete a task, but that certain contextual requirements have to be met.     

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.     

The puzzle of language evolution

Linguistics must again concentrate on the evolutionary nature of language, so that language models are more realistic with respect to human natural languages and have a greater explanatory force. Multi-agent systems are proposed as a possible route to develop such evolutionary models and an example is given of a concrete experiment in the origins and evolution of word-meaning based on a multi-agent approach.     

Psychological Distress and Symptoms of Posttraumatic Stress Disorder in Jewish Adolescents Following a Brief Exposure to Concentration Camps

We investigated the psychological impact of an organized visit to Polish concentration camps on Jewish-American adolescents. Eighty-seven adolescents who participated in a B'nai B'rith memorial visit to concentration camps in Poland completed measures of general psychological adjustment and posttraumatic stress disorder (PTSD) at four time-points: pretest, posttest, 6-month follow-up and 12-month follow-up. Measures included the SCL-90-R, the Mississippi Scale for PTSD, and the Impact of Events Scale (IES) for PTSD. On the SCL-90-R, changes in somatization, interpersonal sensitivity, obsessive-compulsive tendencies, depression, anxiety, and phobic anxiety were observed over time, with peak symptom scores at posttest and 6-month follow-up. Scores on the Mississippi Scale for PTSD and the IES Intrusion subscale also increased at 6-months. Predictors of PTSD symptoms on the Mississippi Scale included previous psychiatric treatment and SCL-90-R symptoms of paranoia, depression, and psychosis. Elevated psychotic symptoms on the SCL-90-R predicted PTSD symptoms on the IES. Jewish adolescents with preexisting symptoms of generalized distress or psychoticism appeared at increased risk for PTSD symptoms following exposure to Holocaust stimuli. This study contributes a prospective, multi-measure assessment of trauma reactions in adolescents.     

Wisdom and Life Experience: How Grandfathers Mentor Their Grandchildren

This exploratory study uses qualitative methods to focus on the largely unexamined role of the grandfather and to examine men's experiences as grandfathers. We gathered information through both surveys and individual interviews to explore men's feelings and attitudes toward the grandfather role. Of the 51 grandfathers that completed a survey, 20 participated in interviews. Our examination of the data collected reveals the life lessons men teach their grandchildren. The grandfathers in this study expressed strong desires for purposeful involvement in their grandchildren's lives and indicated desires for transferring values to grandchildren and teaching interpersonal relationships. Through this involvement, they educate through life experiences and serve as mentors for their grandchildren. We suggest that this mentoring role makes a positive contribution to the lives of grandchildren and to the identity of grandfathers.     

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.