RECERCAT - Psicologia Bàsica

People favour imperfect catching by assuming a stable world

People favour imperfect catching by assuming a stable world López i Moliner, Joan; Keil, Matthias S. The visual angle that is projected by an object (e.g. a ball) on the retina depends on the object's size and distance. Without further information, however, the visual angle is ambiguous with respect to size and distance, because equal visual angles can be obtained from a big ball at a longer distance and a smaller one at a correspondingly shorter distance. Failure to recover the true 3D structure of the object (e.g. a ball's physical size) causing the ambiguous retinal image can lead to a timing error when catching the ball. Two opposing views are currently prevailing on how people resolve this ambiguity when estimating time to contact. One explanation challenges any inference about what causes the retinal image (i.e. the necessity to recover this 3D structure), and instead favors a direct analysis of optic flow. In contrast, the second view suggests that action timing could be rather based on obtaining an estimate of the 3D structure of the scene. With the latter, systematic errors will be predicted if our inference of the 3D structure fails to reveal the underlying cause of the retinal image. Here we show that hand closure in catching virtual balls is triggered by visual angle, using an assumption of a constant ball size. As a consequence of this assumption, hand closure starts when the ball is at similar distance across trials. From that distance on, the remaining arrival time, therefore, depends on ball's speed. In order to time the catch successfully, closing time was coupled with ball's speed during the motor phase. This strategy led to an increased precision in catching but at the cost of committing systematic errors.

Unifying Time to Contact Estimation and Collision Avoidance across Species

Unifying Time to Contact Estimation and Collision Avoidance across Species Keil, Matthias Sven; López i Moliner, Joan The -function and the -function are phenomenological models that are widely used in the context of timing interceptive actions and collision avoidance, respectively. Both models were previously considered to be unrelated to each other: is a decreasing function that provides an estimation of time-to-contact (ttc) in the early phase of an object approach; in contrast, has a maximum before ttc. Furthermore, it is not clear how both functions could be implemented at the neuronal level in a biophysically plausible fashion. Here we propose a new framework
the corrected modified Tau function
capable of predicting both -type ("") and -type ("") responses. The outstanding property of our new framework is its resilience to noise. We show that can be derived from a firing rate equation, and, as , serves to describe the response curves of collision sensitive neurons. Furthermore, we show that predicts the psychophysical performance of subjects determining ttc. Our new framework is thus validated successfully against published and novel experimental data. Within the framework, links between -type and -type neurons are established. Therefore, it could possibly serve as a model for explaining the co-occurrence of such neurons in the brain.

Knowing What to Respond in the Future Does Not Cancel the Influence of Past Events

Knowing What to Respond in the Future Does Not Cancel the Influence of Past Events Tubau Sala, Elisabet; López i Moliner, Joan Everyday tasks seldom involve isolate actions but sequences of them. We can see whether previous actions influence the current one by exploring the response time to controlled sequences of stimuli. Specifically, depending on the response-stimulus temporal interval (RSI), different mechanisms have been proposed to explain sequential effects in two-choice serial response tasks. Whereas an automatic facilitation mechanism is thought to produce a benefit for response repetitions at short RSIs, subjective expectancies are considered to replace the automatic facilitation at longer RSIs, producing a cost-benefit pattern: repetitions are faster after other repetitions but they are slower after alternations. However, there is not direct evidence showing the impact of subjective expectancies on sequential effects. By using a fixed sequence, the results of the reported experiment showed that the repetition effect was enhanced in participants who acquired complete knowledge of the order. Nevertheless, a similar cost-benefit pattern was observed in all participants and in all learning blocks. Therefore, results of the experiment suggest that sequential effects, including the cost-benefit pattern, are the consequence of automatic mechanisms which operate independently of (and simultaneously with) explicit knowledge of the sequence or other subjective expectancies.

Absence of flash-lag when judging global shape from local positions

Absence of flash-lag when judging global shape from local positions Linares, D.; López i Moliner, Joan When a flash is presented aligned with a moving stimulus, the former is perceived to lag behind the latter (the flash-lag effect). We study whether this mislocalization occurs when a positional judgment is not required, but a veridical spatial relationship between moving and flashed stimuli is needed to perceive a global shape. To do this, we used Glass patterns that are formed by pairs of correlated dots. One dot of each pair was presented moving and, at a given moment, the other dot of each pair was flashed in order to build the Glass pattern. If a flash-lag effect occurs between each pair of dots, we expect the best perception of the global shape to occur when the flashed dots are presented before the moving dots arrive at the position that physically builds the Glass pattern. Contrary to this, we found that the best detection of Glass patterns occurred for the situation of physical alignment. This result is not consistent with a low-level contribution to the flash-lag effect.

Stress placement and word segmentation by Spanish speakers

Stress placement and word segmentation by Spanish speakers Toro-Soto, J.M.; Rodríguez Fornells, Antoni; Sebastián Gallés, Núria Several studies have shown that the stress pattern of one's native language is applied to new linguistic stimuli. Regarding the segmentation of artificial synthesized speech, this idea has been supported by experiments with languages where the stress pattern coincides with word boundaries (i.e. English, Finnish and Dutch). In this study, we present data on speech segmentation with native Spanish speakers whose stress pattern would mark the penultimate syllable of words. Results show that to stress the middle syllable of trisyllabic words in an artificial speech stream does not facilitate segmentation as would be predicted. Possible explanations of these results are explored as related to the interaction of statistical and stress cues in speech segmentation.

Beneficial effects of word final stress in segmenting a new language: evidence from ERPs

Beneficial effects of word final stress in segmenting a new language: evidence from ERPs Cunillera Llorente, T.; Gomila, Antoni; Rodríguez Fornells, Antoni Background: How do listeners manage to recognize words in an unfamiliar language? The physical continuity of the signal, in which real silent pauses between words are lacking, makes it a difficult task. However, there are multiple cues that can be exploited to localize word boundaries and to segment the acoustic signal. In the present study, word-stress was manipulated with statistical information and placed in different syllables within trisyllabic nonsense words to explore the result of the combination of the cues in an online word segmentation task. Results: The behavioral results showed that words were segmented better when stress was placed on the final syllables than when it was placed on the middle or first syllable. The electrophysiological results showed an increase in the amplitude of the P2 component, which seemed to be sensitive to word-stress and its location within words. Conclusion: The results demonstrated that listeners can integrate specific prosodic and distributional cues when segmenting speech. An ERP component related to word-stress cues was identified: stressed syllables elicited larger amplitudes in the P2 component than unstressed ones.

Updating Farful Memories with Extinction Training during Reconsolidation: A Human Study Using Auditory Aversive Stimuli

Updating Farful Memories with Extinction Training during Reconsolidation: A Human Study Using Auditory Aversive Stimuli Oyarzún, J.; Lopez-Barroso, D.; Fuentemilla Garriga, Lluís; Cucurell, D.; Pedraza, C.; Rodríguez Fornells, Antoni; de Diego-Balaguer, R. Learning to fear danger in the environment is essential to survival, but dysregulation of the fear system is at the core of many anxiety disorders. As a consequence, a great interest has emerged in developing strategies for suppressing fear memories in maladaptive cases. Recent research has focused in the process of reconsolidation where memories become labile after being retrieved. In a behavioral manipulation, Schiller et al., (2010) reported that extinction training, administrated during memory reconsolidation, could erase fear responses. The implications of this study are crucial for the possible treatment of anxiety disorders without the administration of drugs. However, attempts to replicate this effect by other groups have been so far unsuccessful. We sought out to reproduce Schiller et al., (2010) findings in a different fear conditioning paradigm based on auditory aversive stimuli instead of electric shock. Following a within-subject design, participants were conditioned to two different sounds and skin conductance response (SCR) was recorded as a measure of fear. Our results demonstrated that only the conditioned stimulus that was reminded 10 minutes before extinction training did not reinstate a fear response after a reminder trial consisting of the presentation of the unconditioned stimuli. For the first time, we replicated Schiller et al., (2010) behavioral manipulation and extended it to an auditory fear conditioning paradigm.

Beaming into the rat world: enabling real-time intereaction between rat and human each at their own scale

Beaming into the rat world: enabling real-time intereaction between rat and human each at their own scale Normand, Jean Marie; Sánchez Vives, María Victoria; Waechter, Christian; Giannopoulos, Elias; Grosswindhager, Bernhard; Spanlang, Bernhard; Guger, Christoph; Klinker, Gudrun; Srinivasan, Mandayam A.; Slater, Mel Immersive virtual reality (IVR) typically generates the illusion in participants that they are in the displayed virtual scene where they can experience and interact in events as if they were really happening. Teleoperator (TO) systems place people at a remote physical destination embodied as a robotic device, and where typically participants have the sensation of being at the destination, with the ability to interact with entities there. In this paper, we show how to combine IVR and TO to allow a new class of application. The participant in the IVR is represented in the destination by a physical robot (TO) and simultaneously the remote place and entities within it are represented to the participant in the IVR. Hence, the IVR participant has a normal virtual reality experience, but where his or her actions and behaviour control the remote robot and can therefore have physical consequences. Here, we show how such a system can be deployed to allow a human and a rat to operate together, but the human interacting with the rat on a human scale, and the rat interacting with the human on the rat scale. The human is represented in a rat arena by a small robot that is slaved to the human"s movements, whereas the tracked rat is represented to the human in the virtual reality by a humanoid avatar. We describe the system and also a study that was designed to test whether humans can successfully play a game with the rat. The results show that the system functioned well and that the humans were able to interact with the rat to fulfil the tasks of the game. This system opens up the possibility of new applications in the life sciences involving participant observation of and interaction with animals but at human scale.

What changes in the personal construct system during psychotherapy?. A naturalistic study of brief construct therapy

What changes in the personal construct system during psychotherapy?. A naturalistic study of brief construct therapy Pucurull, Olga; Feixas i Viaplana, Guillem; Aguilera Ruiz, M. del Carmen; Carrera Fernández, María Jesús

Estudio exprimental del bilinguismo: revisión histórica I

Estudio exprimental del bilinguismo: revisión histórica I Arnau Gras, Jaume; Sebastián Gallés, Núria; Sopena, Josep Maria En el presente trabajo se lleva a cabo una revisión histórica de los estudios realizados sobre el bilingiiismo, concretándose, fundamentalmente, en las dos grandes hipótesis teóricas en torno al mismo. Se analizan, a continuación, las investigaciones que apoyan tanto a la hipótesis de "sistemas lingiiisticos separados" como a la hipótesis de un "único sistema". Por último se hace una presentación de los trabajos que han sido más relevantes en la investigación actual. De esta forma se presentan los estudios de carácter psicofisiológico, la relación entre bilingiiismo y psicologia cognitiva, la medición del bilingüismo y la teoria del código dual aplicado al bilingüismo. El texto termina planteando una serie de consideraciones de carácter metodológico y la propuesta de un modelo que va a ser objeto de un segundo escrito sobre dicha temática.

Razonamiento moral y educación

Razonamiento moral y educación Sastre, Genoveva; Moreno Marimón, Montserrat; Timón Herrero, Mónica El texto se basa en el análisis del razonamiento moral a partir del marco de los modelos organizadores. A partir de la determinación de las diferentes representaciones que una serie de sujetos realizaron sobre un dilema basado en un conflicto moral entre iguales de edad, y que incluyó tres núcleos (justicia, felicidad y cuidado) se detectó que existen cuatro grandes modelos organizadores que se presentan en diferentes líneas evolutivas. La tesis que se defiende es que la inclusión de los sentimientos puede guiar el razonamiento a niveles más elevados y puede integrar las perspectivas de justicia y solidaridad a la hora de resolver conflictos interpersonales. En el artículo se afirma que todo esto son retos en los cuales es necesario trabajar para conseguir un modelo educativo integrador dentro de las escuelas.

Cultura de género y diversidad en el razonamiento moral

Cultura de género y diversidad en el razonamiento moral Sastre, Genoveva; Moreno Marimón, Montserrat; Pavon, Teo Este texto enfoca las representaciones personales de la moral en la acción centrada en el compromiso de ayudar a una persona amiga que ha quebrantado una norma social. El artículo es un resumen del trabajo de investigación sobre el análisis de las representaciones de una serie de sujetos de ambos sexos sobre la resolución de un dilema moral. Desde una perspectiva genético-constructiva y desde la teoría de los modelos mentales, los autores formulan la teoría de los modelos organizadores para explicar que la actuación de un sujeto en un momento determinado está, en parte, condicionada por la especificidad del problema y, en parte, por el nivel de desarrollo estructural obtenido mediante el ejercicio de sus competencias cognitivas en contenidos de diferente naturaleza. Dentro de este marco teórico, los autores han estudiado las diferencias de los razonamientos según la edad y el sexo de la muestra de sujetos.

Esquema de los problemas de la Universidad en nuestro tiempo

Esquema de los problemas de la Universidad en nuestro tiempo Siguan, Miquel, 1919-2010 La Universidad está en crisis. No esta o aquella Universidad, sino la propia institución universitaria. Una afirmación a primera vista tan grave está a punto de convertirse en un lugar común a fuerza de repetirse en todas las latitudes y en los más variados contextos. El glorioso invento medieval, que ha llegado a convertirse en símbolo de nuestra cultura, parece incapaz de resistir la presión de las nuevas circunstancias y de descubrir su vocación en un mundo cambiante. La multiplicación de los proyectos de reforma y su escasa coherencia son la prueba palpable de que esta vocación no es fácil de identificar. En las páginas que siguen no pretendo proponer una reforma más. Mis pretensiones se limitan a invitar al lector a reflexionar sobre una serie de temas en torno a la Universidad actual y hacerle caer en la cuenta de su complejidad. Quizá con ello contribuiré a desanimar a los que se contentan con respuestas unilaterales o superficiales.

Textos y Documentos: La Universidad de Barcelona en 1872

Textos y Documentos: La Universidad de Barcelona en 1872 Siguan, Miquel, 1919-2010 La inaguración del curso académico 1872-73 tuvo lugar por primera vez en el edificio entonces construido para albergar la Universidad de Barcelona y que hoy continúa constituyendo su centro principal [. . .]

El carácter social según Erich Fromm

El carácter social según Erich Fromm Caparrós, Antonio, 1938-2001

La vida y la obra de Herbert Marcuse

La vida y la obra de Herbert Marcuse Siguan, Miquel, 1919-2010 El brusco descubrimiento y exaltación de MARCUSE como una de las claves de la crisis contemporánea es uno de los fenómenos más notables de nuestro tiempo. [...]

Educación y desarrollo social

Educación y desarrollo social Siguan, Miquel, 1919-2010

La selección para el ingreso en la Universidad de Barcelona

La selección para el ingreso en la Universidad de Barcelona Siguan, Miquel, 1919-2010

El tema del otro en Antonio Machado

El tema del otro en Antonio Machado Siguan, Miquel, 1919-2010

Noticia sobre Pablo Luís Lansberg

Noticia sobre Pablo Luís Lansberg Siguan, Miquel, 1919-2010 Pablo Luis Landsberg fue profesor de filosofía en nuestra Universidad en los cursos de 1934-1935 y 1935-1936. Participó así en ele períodod corto y brillante de la autonomía universitaria que he dejado un recuerdo imborrable en todos los que tuvimos la suerte de vivirlo. [...]

Nueva teoría de Andalucía

Nueva teoría de Andalucía Siguan, Miquel, 1919-2010

Los transplantes de órganos vitales. El punto de vista del psicólogo

Los transplantes de órganos vitales. El punto de vista del psicólogo Siguan, Miquel, 1919-2010

El juego-concurso de De Vries: una propuesta para la formación en competencias de trabajo en equipo en la evaluación

El juego-concurso de De Vries: una propuesta para la formación en competencias de trabajo en equipo en la evaluación Andreu Barrachina, Llorenç; Sanz Torrent, Mònica El Espacio Europeo de Enseñanza Superior (EEES) sentó las bases para la asunción de un modelo de formación basado en competencias. En este sentido, son diversas las propuestas que plantean trabajar de la competencia de trabajo en grupo en actividades de desarrollo de los contenidos de una o diferentes asignaturas. Sin embargo, no son tan frecuentes las propuestas de trabajo de esta competencia en tareas de evaluación. En este trabajo se recoge una aplicación del juego-concurso de DeVries (DeVries y Edwards, 1973) para la llevar a cabo la evaluación de una asignatura. El juego-concurso de DeVries es una alternativa a las tradicionales pruebas de evaluación o exámenes basado no en la evaluación individual sino en la preparación y colaboración grupal para la consecución de unos objetivos comunes. La aplicación de esta técnica, sus repercusiones, ventajas e inconvenientes son discutidos en el marco del Espacio Europeo de Educación Superior (EEES).

Generalization transitions in Hidden-Layer neural networks for third-order feature discrimination

Generalization transitions in Hidden-Layer neural networks for third-order feature discrimination Romeo, August Stochastic learning processes for a specific feature detector are studied. This technique is applied to nonsmooth multilayer neural networks requested to perform a discrimination task of order 3 based on the ssT-block¿ssC-block problem. Our system proves to be capable of achieving perfect generalization, after presenting finite numbers of examples, by undergoing a phase transition. The corresponding annealed theory, which involves the Ising model under external field, shows good agreement with Monte Carlo simulations.