Short cuts by dogs in natural surroundings

We studied the capacity of seven Alsatian dogs to use a short cut in experiments carried out in a large (3-ha) meadow. The animals' task was to find meat hidden at two points (A and B) when released from a third (D). The dogs had each been taken previously on a lead to the two baited points by a different path that led indirectly from A to B via D (line segment AD = 24 m; DB = 40 m). The experiment was carried out in two different fields, one nearly homogeneous (covered mainly in thyme), and the other heterogeneous, containing visual features such as bushes, puddles and trails. In 96% of the 224 trials, the animals took a reasonably good short cut between the baited points rather than return to the start. The animals took the shortest possible path—a straight line directly from A to B—more frequently in the homogeneous than in the heterogeneous field. In the heterogeneous field, the animals had a greater tendency to use an “inside short cut”, heading for a point that intersected the path from the start to the second baited point rather than going directly to the point or returning to the start. The trials in which the shortest path was taken suggest that dogs are capable of evaluating along a continuum the direction of an invisible goal by integrating motor and sensory cues obtained during an early but indirect visit to the same goal. Some hypotheses are presented concerning the use of the inside short cut in this experiment, especially in an heterogeneous field.     

Masked priming effects with syllabic neighbors in a lexical decision task

Four lexical decision experiments using a masked priming paradigm were conducted to analyze whether the previous presentation of a syllabic neighbor (a word sharing the same 1st syllable) influences recognition performance. The results showed an inhibitory effect of more frequent syllabic primes and some facilitation of nonword syllabic primes (Experiments 1-3). When monosyllabic pairs were used (Experiment 3), no priming effects of the 2 initial letters were found. Finally, when using only syllables as primes, latencies to words were shorter when preceded by primes that corresponded to the 1st syllable than by primes that contained 1 letter more or less than the 1st syllable (Experiment 4). Results are interpreted using activation models that take into account a syllabic level of representation.     

Power and Action in Critical Theory Across Disciplines: Implications for Critical Community Psychology

Although critical scholarship and community psychology share similar aspirations, the links between them remain unexplored and under-theorized. In this article we explore the implications of critical scholarship in various specialties for the field of community psychology. To understand the contributions of critical scholarship to a theory of power and action for social change, we conducted a systematic analysis of a ten-year period of publications in seven journals associated with the critical scholarship tradition. We created precise criteria for the concepts of power and action and applied them to the publications. Results indicate an interesting paradox at play. Whereas community psychology is more action oriented than critical scholarship, its actions fall short of challenging institutionalized power structures and the status quo; and whereas critical scholarship is more challenging of the status quo than community psychology in theory, it has failed to produce viable actions that challenge the status quo. We discuss the implications of this state of affairs for the development of a more critical community psychology.     

Updating mental models in predictive reasoning

Abstract

A mental model account for predictive judgement is proposed. According to this view, solving a predictive task involves the foundation ad updating of a mental he work as the relevant data are provided. The final model state determines the subject's predictive outcome. Two experiments examine the temporal course of reasoning in novices (Experiment 1) and experts (Experiment 2). Each task provided in succession a quantitative source (e.g. “Last year, of the vehidts that stopped at the cafe, 80% were cars and 20% were trucks”), a diagnostic source (e.g. “This vehide is mksy”) and a categorical choice (e.g. “What kind of vehicle was it?”). Two factors were manipulated: The order of sources aimed at analysing the contextual dependence of the updating processes, and the between-sources congruence (congruent or incongruent) in order to explore the integrative processes in model building. The pattern of the sources reading times, the choice times and the categorical choices suggested that: (1) the processing of a source depends on the previous one, (2) subjects try to integrste both sources into a single mental framework, and (3) experts and novices have a similar performance, although experts give more importance to the quantitative source in the diagnostic-quantitative order. These results are better accounted for by the mental model framework than both the heuristic and the formal view of prediction.     

Test anxiety and ego-threatening stress: Over- (and under-) estimation of emotional reactivity

Abstract

This study examined discrepancies between subjective and objective measures of state anxiety as a function of test anxiety in undergraduates. Under evaluative stress conditions, state anxiety was assessed in terms of (a) self-reported cognitive and somatic anxiety, (b) behavioral reactivity (motor and facial tension, avoidance comments and avoidance of eye contact), (c) physiological arousal (heart rate and skin resistance), and (d) cognitive and motor task performance. Participants high in test anxiety showed disproportionately greater self-reported than objective state anxiety. In contrast, those low in test anxiety showed lower self-reported than objective anxiety. The high- and the low-test-anxiety groups differed only in self-reported emotional reactivity. In line with current cognitive theories of anxiety, overestimation of reactivity in high-test anxiety, as well as underestimation in low-test anxiety, are conceptualized as a hypervigilance bias and an avoidance bias, respectively, in processing internal cues, i.e., prioritization and inhibition of attention to one's own behavioral and physiological signs of distress.     

Recuperación dependiente de estados afectivos en una tarea de reconocimiento

Resumen

Estudiamos los efectos de los estados afectivos de adquisición y recuperación en una tarea de reconocimiento. Los estados afectivos se indujeron por sugestiones posthipnóticas y los estímulos fueron fotografías de caras en blanco y negro. Empleamos un diseño factorial 2 (estado de adquisición) x 2 (estado de recuperación) con medidas repetidas. El intervalo entre las fases de adquisición y recuperación fue de 24 horas. El análisis de datos, basado en el modelo no-paramétrico de la teoría de detección de señales, confirma el efecto de dependencia de estados afectivos en una prueba de reconocimiento. Los resultados se discuten en relación a trabajos anteriores que no habían encontrado este efecto en pruebas similares.     

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.     

When does the brain distinguish between genuine and ambiguous smiles? An ERP study

Event-related brain potentials (ERPs) were recorded to assess the processing time course of ambiguous facial expressions with a smiling mouth but neutral, fearful, or angry eyes, in comparison with genuinely happy faces (a smile and happy eyes) and non-happy faces (neutral, fearful, or angry mouth and eyes). Participants judged whether the faces looked truly happy or not. Electroencephalographic recordings were made from 64 scalp electrodes to generate ERPs. The neural activation patterns showed early P200 sensitivity (differences between negative and positive or neutral expressions) and EPN sensitivity (differences between positive and neutral expressions) to emotional valence. In contrast, sensitivity to ambiguity (differences between genuine and ambiguous expressions) emerged only in later LPP components. Discrimination of emotional vs. neutral affect occurs between 180 and 430 ms from stimulus onset, whereas the detection and resolution of ambiguity takes place between 470 and 720 ms. In addition, while blended expressions involving a smile with angry eyes can be identified as not happy in the P200 (175–240 ms) component, smiles with fearful or neutral eyes produce the same ERP pattern as genuinely happy faces, thus revealing poor discrimination.     

Repetition and form priming interact with neighborhood density at a brief stimulus onset asynchrony

The relationships between repetition- and form-priming effects and neighborhood density were analyzed in two masked priming experiments with the lexical decision task. Given that form-priming effects appear to be influenced by a word’s orthographic neighborhood, it is theoretically important to find out whether repetition priming also differs as a function of the word’s orthographic neighborhood. Within an activation framework, repetition- and form-priming effects are just quantitatively different phenomena, whereas the two effects are qualitatively different in a serial-ordered model of lexical access (theentry-opening model). The results show that repetition- and form-priming effects were stronger forhermit words than for words with many neighbors. These results pose some problems for both activation and serial-ordered models. The implications of these results for determining how neighbors affect the identification of a word are discussed.