Learning a complex motor skill from video and point-light demonstrations

The aim of this study was to compare the learning process of a highly complex ballet skill following demonstrations of point-light and video models. 16 participants divided into point-light and video groups (ns = 8) performed 160 trials of a pirouette, equally distributed in blocks of 20 trials, alternating periods of demonstration and practice, with a retention test a day later. Measures of head and trunk oscillation, coordination disparity from the model, and movement time difference showed similarities between video and point-light groups; ballet experts' evaluations indicated superiority of performance in the video over the point-light group. Results are discussed in terms of the task requirements of dissociation between head and trunk rotations, focusing on the hypothesis of sufficiency and higher relevance of information contained in biological motion models applied to learning of complex motor skills.     

The incidence of false memories in native and non-native speakers

The current study consisted of four experiments that utilised a novel approach to investigating false memories. Each of the experiments in the current study investigated individuals with varying experience with different languages. Experiment 1 tested participants in both their native and secondary languages as well as monolingual English speakers, while Experiment 2 assessed native Spanish speakers using both English and Spanish associative lists. Experiment 3 examined the illusory memories in monolingual Spanish speakers in both English and Spanish, while Experiment 4 investigated false memories in monolingual English speakers in both English and Spanish. Results indicated that memory for list items and critical lures was greatest when the lists were presented in the participants' primary language. Results can be explained by either activation-based or fuzzy-trace theories.     

Estructura morfológica y recuperación léxica

Resumen

El objetivo principal de esta investigación es el de contribuir a un mayor conocimiento del papel que desempeña la estructura morfológica de las palabras en la organización del léxico interno y, por consiguiente, en las estrategias que emplean los sujetos para acceder a la representación mental de las palabras. Más en concreto, se trata de ver cuál es la relación existente entre la representación de la forma base de una palabra (por ej., flor) y la de formas derivadas de la misma (por ej., florero, florecer, florido) de cara a una posible simplificación del inventario mental de entradas léxicas.

Se han realizado tres experimentos, basados en una tarea de decisión léxica y en la utilización de la técnica de «priming» o presentación previa de un supuesto elemento facilitador del reconocimiento de cada estímulo. Se midió la latencia de respuesta para clasificar los estímulos como palabras o no-palabras del idioma. Los dos primeros experimentos se efectuaron bajo la modalidad visual de reconocimiento y el tercero, bajo la modalidad auditiva. En todos los casos, las comparaciones relevantes se establecen entre los TRs correspondientes a una misma palabra en condiciones experimentales diferentes: según vaya precedida por sí misma, o por una relacionada morfológicamente, o cuando no vaya precedida ni por sí misma ni por otra relacionada (condición de control).

Los resultados obtenidos bajo las dos modalidades perceptivas son coincidentes y ponen de manifiesto que: 1) se da un efecto de facilitación en el reconocimiento, tanto al presentar una palabra precedida por sí misma (repetición) como al presentarla precedida por otra relacionada morfológicamente; 2) el efecto de facilitación por repetición es significativamente superior al de facilitación por relación morfológica; y 3) dentro de este último no aparecen diferencias significativas entre la facilitación de la forma base por la derivada y la de ésta por aquélla.

Estos resultados se interpretan a la luz de los distintos modelos propuestos acerca de la representación léxica. Sin que sean cruciales para decidirse por uno de ellos en contra de los otros, sí que parecen apoyar la existencia de un código de representación abstracto que aglutina familias de palabras relacionadas morfológicamente en torno a una misma entrada léxica. En cualquier caso, y aun suponiendo que hubiera entradas léxicas distintas para cada forma particular, sería preciso postular algún mecanismo adicional que diera cuenta del papel que desempeña la información morfológica en la organización general del léxico interno.     

A relationship with Señor de Carácuaro

The present paper explores the issue of personal relationships in the context of pilgrimage. Most literature about pilgrimage in Latin America focuses on the journey, or on the alleged ‘sacred power’ located in the shrine and sought by the pilgrims. I argue that, from the perspective of the participants’ experience, pilgrimage could be understood in terms of personal relationships with particular holy beings, who are perceived as agents. Through the particular case of Marta, a young Purhépecha woman from Lake Pátzcuaro (Mexico), I will examine the modes in which people from this area relate, interact and communicate with saintly beings in the context of pilgrimage; the connection of vows with quotidian experience; and the implications of relationships with saints for people in their everyday lives.     

Priming the mental time-line: effects of modality and processing mode

The notion of a mental time-line (i.e., past corresponds to left and future corresponds to right) supports the conceptual metaphor view assuming that abstract concepts like “time” are grounded in cognitively more accessible concepts like “space.” In five experiments, we further investigated the relationship between temporal and spatial representations and examined whether or not the spatial correspondents of time are unintentionally activated. We employed a priming paradigm, in which visual or auditory prime words (i.e., temporal adverbs such as yesterday, tomorrow) preceded a colored square. In all experiments, participants discriminated the color of this square by responding with the left or the right hand. Although the temporal reference of the priming adverb was task irrelevant in Experiment 1, visually presented primes facilitated responses to the square in correspondence with the direction of the mental time-line. This priming effect was absent in Experiments 2, 3, and 5, in which the primes were presented auditorily and the temporal reference of the words could be ignored. The effect, however, emerged when attention was oriented to the temporal content of the auditory prime words in Experiment 4. The results suggest that task demands differentially modulate the activation of the mental time-line within the visual and auditory modality and support a flexible association between conceptual codes.     

Attentional capture by emotional faces in adolescence

Poor decision making during adolescence occurs most frequently when situations are emotionally charged. However, relatively few studies have measured the development of cognitive control in response to emotional stimuli in this population. This study used both affective (emotional faces) and non-affective (letter) stimuli in two different flanker tasks to assess the ability to ignore task-irrelevant but distracting information, in 25 adults and 25 adolescents. On the non-emotional (letter) flanker task, the presence of incongruent flanking letters increased the number of errors, and also slowed participants’ ability to identify a central letter. Adolescents committed more errors than adults, but there were no age-related differences for the reaction time interference effect in the letter condition. Post-hoc testing revealed that age-related differences on the task were driven by the younger adolescents (11-14 years); adults and older adolescents (15-17 years) were equally accurate in the letter condition. In contrast, on the emotional face flanker task, not only were adolescents less accurate than adults but they were also more distracted by task-irrelevant fearful faces as evidenced by greater reaction time interference effects. Our findings suggest that the ability to self-regulate in adolescents, as evidenced by the ability to suppress irrelevant information on a flanker task, is more difficult when stimuli are affective in nature. The ability to ignore irrelevant flankers appears to mature earlier for non-affective stimuli than for affective stimuli.     

Time-dependent impairment of inhibitory avoidance retention in rats by posttraining infusion of a mitogen-activated protein kinase kinase inhibitor into cortical and limbic structures

Mitogen-activated protein kinase (MAPK) is abundantly expressed in postmitotic neurons of the developed nervous system. MAPK is activated and required for induction of long-term potentiation (LTP) in the CA1 area of the hippocampus, which is blocked by the specific inhibitor of the MAPK kinase, PD 098059. Recently it was demonstrated that MAPK is activated in the hippocampus after training and is necessary for contextual fear conditioning learning. The present work tests the role of the MAPK cascade in step-down inhibitory avoidance (IA) retention. PD 098059 (50 microM) was bilaterally injected (0.5 microl/side) into the CA1 region of the dorsal hippocampus or entorhinal cortex at 0, 90, 180, or 360 min, or into the amygdala or parietal cortex at 0, 180, or 360 min after IA training in rats using a 0.4-mA foot shock. Retention testing was carried out 24 h after training. PD 098059 impaired retention when injected into the dorsal hippocampus at 180 min, but not 0, 90, and 360 min after training. When infused into the entorhinal cortex, PD 098059 was amnestic at 0 and 180 min, but not at 90 and 360 min after training. The MAPKK inhibitor also impairs IA retention when infused into the parietal cortex immediately after training, but not at 180 or 360 min. Infusions performed into amygdala were amnestic at 180 min, but not at 0 and 360 min after training. Our results suggest a time-dependent involvement of the MAPK cascade in the posttraining memory processing of IA; the time dependency is different in the hippocampus, amygdala, entorhinal cortex, or parietal cortex of rats.     

Is “Latin American Thought” Philosophy?

Abstract: A durable question in Latin American thought is whether it could amount to a characteristically Latin American philosophy. I argue that if, as is now widely conceded, there is a role for philosophical analysis in thinking about problems that arise in applied subjects, such as bioethics, environmental ethics, and feminism, then why not also in Latin American thought? After all, the focus of Hispanic thinkers has often been upon the issues that arise in their own experiences of the world, and they make up a diverse group of peoples related by very idiosyncratic ethnic and historical connections. I believe that, given some appropriate criteria, the existing corpus of works by Latin American thinkers is a part of a distinctive philosophy.