Efectos diferenciales de la frecuencia silábica: dependencia del tipo de prueba y características de los estímulos

Resumen

La frecuencia silábica posicional es una variable de reciente utilización en nuestro idioma. Por su carácter fonológico ha sido utilizada en este trabajo tanto para estudiar su papel en la lectura como para obtener algunas pistas sobre diferencias interlingüísticas entre nuestro idioma y otros que como el inglÉs son más opacos a la hora de traducir a sonidos su ortografía. Se utilizaron dos tipos de pruebas: decisión lÉxica y lectura que presumiblemente implican diferentes demandas cognitivas. Los resultados de la tarea de decisión lÉxica (Experimentos 1 y 3) muestran, en general, que la frecuencia silábica enlentece la respuesta del sujeto tanto en las palabras como en las pseudopalabras, confirmando algunos estudios previos (De Vega et al., 1990). Por el contrario, en la tarea de lectura (Experimentos 2 y 4) la frecuencia silábica tiende a acelerar la respuesta en la mayoría de los estímulos. Este comportamiento diferencial de los sujetos en función de la tÉcnica utilizada sugiere que mientras la decisión lÉxica exige el ascenso hasta el nivel de palabra, la lectura puede realizarse con Éxito desde un nivel prelÉxico silábico.     

Emotional distraction in boys with ADHD: Neural and behavioral correlates

Although, in everyday life, patients with attention deficit hyperactivity disorder (ADHD) are frequently distracted by goal-irrelevant affective stimuli, little is known about the neural and behavioral substrates underlying this emotional distractibility. Because some of the most important brain responses associated with the sudden onset of an emotional distracter are characterized by their early latency onset and short duration, we addressed this issue by using a temporally agile neural signal capable of detecting and distinguishing them. Specifically, scalp event-related potentials (ERPs) were recorded while 20 boys with ADHD combined type and 20 healthy comparison subjects performed a digit categorization task during the presentation of three types of irrelevant, distracting stimuli: arousing negative (A−), neutral (N) and arousing positive (A+). Behavioral data showed that emotional distracters (both A− and A+) were associated with longer reaction times than neutral ones in the ADHD group, whereas no differences were found in the control group. ERP data revealed that, compared with control subjects, boys with ADHD showed larger anterior N2 amplitudes for emotional than for neutral distracters. Furthermore, regression analyses between ERP data and subjects’ emotional ratings of distracting stimuli showed that only in the ADHD group, emotional arousal (ranging from calming to arousing) was associated with anterior N2: its amplitude increased as the arousal content of the visual distracter increased. These results suggest that boys with ADHD are more vulnerable to the distracting effects of irrelevant emotional stimuli than control subjects. The present study provides first data on the neural substrates underlying emotional distractibility in ADHD.     

Third International Conference on Spatial Cognition: “Dynamics in Spatial Interactions”. Rome - Perugia, Italy: September 12th–15th 2006. www.icsc2006.org - committee@icsc2006.org

Call for Papers

Third International Conference on Spatial Cognition: “Dynamics in Spatial Interactions”. Rome - Perugia, Italy: September 12th–15th 2006. www.icsc2006.org - committee@icsc2006.org     

From models to rules: mechanization of reasoning as a way to cope with cognitive overloading in combinatorial problems

It is hypothesized that the transition from unfamiliar problems to familiar, well-learned problems coincides with the transition from a model-based style of reasoning to a rule-based style of reasoning; model-based style of reasoning helps understanding the problem structure, but can overload working memory when the number of models required increases; rule-based style of reasoning avoids cognitive overloading, at the cost of making individuals liable to mechanization errors. In Experiment 1, the number of models required to respond to a verification task affected response latencies with unfamiliar problems, but not with familiar problems, supporting the initial hypothesis. In Experiment 2, participants were prone to mechanization errors when confronted with slightly modified problems in the late stages of the experiment, supporting the hypothesis that they had developed a reasoning rule in the early stages and were blindly applying it. The findings suggest that model-based reasoning and rule-based reasoning serve different purposes and have different costs and benefits, are both available to human reasoners, and familiarization with a problem may induce the transition from the former to the latter. The findings also suggest that mechanization of reasoning may be the first step along a gradient of decreasing cognitive load, whose end-point is automatization, as discussed in theories of automatization of information processing.     

Personality disorders in patients with burning mouth syndrome

Burning Mouth Syndrome (BMS) presents high rates of comorbid Axis I disorders while no controlled studies have addressed the question of Axis II comorbidities. The aim of the present study was to examine DSM-IV (APA, 1994) Axis II comorbidity in BMS patients and to control for the specificity of this association. Seventy BMS patients were compared to a nonpsychiatric population sample and to patients with other Somatoform Disorders for the presence of personality disorders (assessed with the Structured Clinical Interview for DSM-IV Axis II Personality Disorders [SCID-II; First, Gibbon, Spitzer, & Williams, 1997). Prevalence rates were compared using the Pearson's chi square test. At least one personality disorder (PD) was found in 85.7%, 24.3%, and 88.6% of subjects in the three groups, respectively. When examining PD subgroups, significant differences emerged even between the BMS and the somatoform disorder group, with BMS patients showing more Cluster A and fewer Cluster B PDs. Our results suggest that BMS is associated with a specific pattern of Axis II comorbidity.     

Effects of direct and indirect cross-group friendships on judgments of Catholics and Protestants in Northern Ireland: the mediating role of an anxiety-reduction mechanism

Recent evidence suggests that both direct and indirect friendship with outgroup members (knowledge of ingroup members' friendship with outgroup members) can reduce prejudice toward the outgroup. Two surveys of cross-community relationships in Northern Ireland, using a student sample (N = 341) and a representative sample of the general population (N = 735), tested whether (a) direct and indirect friendships had generalized effects on both prejudice and perceived outgroup variability and (b) reduced anxiety about future encounters with outgroup members mediated such relationships. Structural equation modeling confirmed that, in both samples, direct and indirect cross-group friendships between Catholics and Protestants were associated with reduced prejudice toward the religious outgroup and increased perceived outgroup variability, via an anxiety-reduction mechanism. It is argued that emerging generalization hypotheses help to integrate both cognition and affect and interpersonal and intergroup approaches to contact.     

A Gabbay-Rule Free Axiomatization of T×W Validity

The semantical structures called T×W frames were introduced in (Thomason, 1984) for the Ockhamist temporal-modal language, _O, which consists of the usual propositional language augmented with the Priorean operators P and F and with a possibility operator . However, these structures are also suitable for interpreting an extended language, _SO, containing a further possibility operator ^s which expresses synchronism among possibly incompatible histories and which can thus be thought of as a cross-history simultaneity operator. In the present paper we provide an infinite set of axioms in _SO, which is shown to be strongly complete forT ×W-validity. Von Kutschera (1997) contains a finite axiomatization of T×W-validity which however makes use of the Gabbay Irreflexivity Rule (Gabbay, 1981). In order to avoid using this rule, the proof presented here develops a new technique to deal with reflexive maximal consistent sets in Henkin-style constructions.     

Human temporal behavior and discrimination-reversal learning

The present study demonstrates that a relationship exists between individual differences in temporal behavior and individual differences in human discrimination-reversal learning behavior. When the results of performance on a time-estimation task employing the method of reproduction are compared with the results of acquisition performance on a complex form of discrimination-reversal learning task is can be demonstrated that underestimation of time is associated with faster learning and overestimation of time is associated with slower learning of the discrimination task. The experimental design was based on the historical fact that the Sechenov-Pavlov and Spence-Hull formulations assigned a primary role in learning to excitation and inhibition as intervening variables between the input of stimulation and output of response. The present study also used the tasks of time estimation and discrimination learning as dependent variables; and the concept that underestimation of time is associated with and underlying predominance of excitatory processes as a hypothetical construct. The conclusion was reached that one of the many theoretical processes which may be used to explain discrimination learning is the concept that acquisition of the correct response may be viewed as a function of the individual rates at which excitatory processes come to be conditioned to a predominance over existing inhibitory processes.