El "Fedro" de Platón: un ejercicio de buena retórica engañosa

En este artículo me propongo mostrar que lo que Sócrates hace con Fedro a lo largo de toda la obra no es otra cosa que utilizar la auténtica retórica (con su doble carga, dialéctica y psicológica) que es descrita en la segunda parte del diálogo. Las tensiones, rivalidades y celos de la situación inicial entre ellos expone un perfil representativo de relaciones entre interlocutores con perspectivas intelectuales opuestas. Es preciso disolver la resistencia emocional por medio de una serie de pasos graduales, estratégicos, y ‘engañosos’ (no se puede develar el propio juego desde el principio). Hay que partir de acuerdos, siquiera parciales, para continuar dialogando. Sin embargo, Sócrates también introduce nociones nuevas acerca del amor, pero éstas pasan desapercibidas a un Fedro obsesionado con la imitación de su enamorado Lisias. Hasta que Sócrates decide cortar el juego y cruzar el río. Este corte provoca un giro en ambos personajes: Fedro se dispone a escuchar lo que Sócrates quiere contarle (el mito del carro alado) y Sócrates se revela ante sí mismo como un personaje capaz de ‘encantar’ a Fedro con la belleza rapsódica del relato y superar su propio temor de convertirse en una bestia devoradora. Al final Sócrates muestra su juego a Fedro y le enseña cómo ha sido posible llegar a un auténtico diálogo filosófico, donde pueda tener lugar la enseñanza y el aprendizaje recíprocos.

Do development and learning really decrease memory? On similarity and category-based induction in adults and children

In a recently published study, Sloutsky and Fisher [Sloutsky, V. M., & Fisher, A.V. (2004a). When development and learning decrease memory: Evidence against category-based induction in children. Psychological Science, 15, 553-558; Sloutsky, V. M., & Fisher, A. V. (2004b). Induction and categorization in young children: A similarity-based model. Journal of Experimental Psychology: General, 133, 166-188.] demonstrated that children have better memory for the items that they generalise to than do adults. On the basis of this finding, they claim that children and adults use different mechanisms for inductive generalisations;whereas adults focus on shared category membership, children project properties on the basis of perceptual similarity. Sloutsky & Fisher attribute children's enhanced recognition memory to the more detailed processing required by this similarity-based mechanism. In Experiment I we show that children look at the stimulus items for longer than adults. In Experiment 2 we demonstrate that although when given just 250 ms to inspect the items children remain capable of making accurate inferences, their subsequent memory for those items decreases significantly. These findings suggest that there are no necessary conclusions to be drawn from Sloutsky & Fisher's results about developmental differences in generalisation strategy. (C) 2007 Elsevier B.V. All rights reserved.

Using time-to-contact information to assess potential collision modulates both visual and temporal prediction networks

Accurate estimates of the time-to-contact (TTC) of approaching objects are crucial for survival. We used an ecologically valid driving simulation to compare and contrast the neural substrates of egocentric (head-on approach) and allocentric (lateral approach) TTC tasks in a fully factorial, event-related fMRI design. Compared to colour control tasks, both egocentric and allocentric TTC tasks activated left ventral premotor cortex/frontal operculum and inferior parietal cortex, the same areas that have previously been implicated in temporal attentional orienting. Despite differences in visual and cognitive demands, both TTC and temporal orienting paradigms encourage the use of temporally predictive information to guide behaviour, suggesting these areas may form a core network for temporal prediction. We also demonstrated that the temporal derivative of the perceptual index tau (tau-dot) held predictive value for making collision judgements and varied inversely with activity in primary visual cortex (V1). Specifically, V1 activity increased with the increasing likelihood of reporting a collision, suggesting top-down attentional modulation of early visual processing areas as a function of subjective collision. Finally, egocentric viewpoints provoked a response bias for reporting collisions, rather than no-collisions, reflecting increased caution for head-on approaches. Associated increases in SMA activity suggest motor preparation mechanisms were engaged, despite the perceptual nature of the task.

Optic variables used to judge future ball arrival position in expert and novice soccer players

Although many studies have looked at the perceptual-cognitive strategies used to make anticipatory judgments in sport, few have examined the informational invariants that our visual system may be attuned to. Using immersive interactive virtual reality to simulate the aerodynamics of the trajectory of a ball with and without sidespin, the present study examined the ability of expert and novice soccer players to make judgments about the ball's future arrival position. An analysis of their judgment responses showed how participants were strongly influenced by the ball's trajectory. The changes in trajectory caused by sidespin led to erroneous predictions about the ball's future arrival position. An analysis of potential informational variables that could explain these results points to the use of a first-order compound variable combining optical expansion and optical displacement.

Guiding the swing in golf putting

Actions that involve making contact with surfaces often demand perceptual regulation of the impact — for example, of feet with ground when walking or of bat with ball when hitting. Here we investigate how this control of impact is achieved in golf putting, where control of the clubhead motion at ball impact is paramount in ensuring that the ball will travel the required distance. Our results from ten professional golfers indicate that the clubhead motion is spatially scaled and perceptually regulated by coupling it onto an intrinsic guide generated in the nervous system.

The photography and the motion landscape in the urban expressway

A new kind of photographic representation, called movement-image is proposed and discussed to record the visual experience of the journey through urban highways. It consists of performing long exposure photographic shots while the track is traversed, thus registering a time-panorama which includes landscape signs and inner spaces of the ways involved. This proposal is linked to the limitations of representing these expressways, if they are understood as structures of instrumental origin, where the resulting experience comes from moving at high speed through the territory. In al almost all cases the aesthetic approach or urban integration with the city and landscape are excluded. In this sense, although such structures may be an opportunity to collect, build and colonize the urban landscape, the lack of adequate representation of the phenomenon causes a difficulty in its understanding and transformation. The options for representation using photography is assumed, knowing its own particular tradition in the use of long exposures, for the expression of the mobile, and the multiple visual attention, divided or weakened.

The Rhetorical Construction of Corporate Logos

This research is set in the context of today’s societies, in which the corporate visual symbology of a business, corporation or institution constitutes an essential way to transmit its corporate image. Traditional discursive procedures can be discovered in the development of these signs. The rhetorical strategies developed by the great classical authors appear in the logo-symbols expressing the corporate values of today’s companies. Thus, rhetoric is emerging once again in the sense it had many centuries ago: A repertory of rules that, paradoxically, standardizes the deviations of language and whose control is synonymous with power. The main objective of this study is to substantiate the rhetorical construction of logos using as a model of analysis the classical process of creating discourse. This involves understanding logos as persuasive discourses addressed to a modern audience. Our findings show that the rhetorical paradigm can be considered as a creative model for the con­struction of an original logo consistent with a company’s image.

The use of cues for attention in ancient Greek art: aspects that influence concentration in the work of art and its elements

The goal of this study is to identify cues for the cognitive process of attention in ancient Greek art, aiming to find confirmation of its possible use by ancient Greek audiences and artists. Evidence of cues that trigger attention’s psychological dispositions was searched through content analysis of image reproductions of ancient Greek sculpture and fine vase painting from the archaic to the Hellenistic period - ca. 7th -1st cent. BC. Through this analysis, it was possible to observe the presence of cues that trigger orientation to the work of art (i.e. amplification, contrast, emotional salience, simplification, symmetry), of a cue that triggers a disseminate attention to the parts of the work (i.e. distribution of elements) and of cues that activate selective attention to specific elements in the work of art (i.e. contrast of elements, salient color, central positioning of elements, composition regarding the flow of elements and significant objects). Results support the universality of those dispositions, probably connected with basic competencies that are hard-wired in the nervous system and in the cognitive processes.

Los nuevos territorios de la gráfica: imagen, proceso y distribución

La gráfica se encuentra en un proceso de simbiosis con la cultura visual en el que la tecnología de la imagen, la descentralización de la matriz y la adaptación del formato expositivo se funden con el resto de las actividades artísticas. El análisis de las comunidades formadas alrededor de esta práctica configura un puzzle, aparentemente bien encajado, que se divide entre el formalismo y el conceptualismo y entre la idea y el proceso. Las bienales y trienales, a la vanguardia del discurso, cuestionan cualquier concepto que se haya podido asentar con solidez: ante la decadencia del proceso artesanal el mensaje se profundiza nutriéndose de la invectiva provocada por las contradicciones sociales, territoriales y medioambientales para convertirse en un reflejo de la sociedad contemporánea. Comprender la gráfica actual pasa por un ejercicio de aperturismo y un proceso de adaptación al cambio técnico e iconográfico de los sectores implicados. El grabado es ahora un territorio en el que la integración de todas las artes permite cruzar sus fronteras con fluidez.

Spatial Perception and Cognition in Multichannel Audio for Electroacoustic Music

Listeners experience electroacoustic music as full of significance and meaning, and they experience spatiality as one of the factors contributing to its meaningfulness. If we want to understand spatiality in electroacoustic music, we must understand how the listener’s mental processes give rise to the experience of meaning. In electroacoustic music as in everyday life, these mental processes unite the peripheral auditory system with human spatial cognition. In the discussion that follows we consider a range of the listener’s mental processes relating space and meaning from the perceptual attributes of spatial imagery to the spatial reference frames for places and navigation. When considering multichannel loudspeaker systems in particular, an important part of the discussion is focused on the distinctive and idiomatic ways in which this particular mode of sound production contributes to and situates meaning. These idiosyncrasies include the phenomenon of image dispersion, the important consequences of the precedence effect and the influence of source characteristics on spatial imagery. These are discussed in close relation to the practicalities of artistic practice and to the potential for artistic meaning experienced by the listener.

Sensory and intrinsic coordination of movement

A recently generalized theory of perceptual guidance (general tau theory) was used to analyse coordination in skilled movement. The theory posits that (i) guiding movement entails controlling closure of spatial and/or force gaps between effecters and goals, by sensing and regulating the tau s of the gaps (the time-to-closure at current closure rate), (ii) a principal way of coordinating movements is keeping the rs of different gaps in constant ratio (known as tau-coupling), and (iii) intrinsically paced movements are guided and coordinated by tau-coupling onto a tau-guide, tau(g), generated in the nervous system and described by the equation tau(g) = 0.5(t-T-2/t) where T is the duration of the body movement and t is the time from the start of the movement. Kinematic analysis of hand to mouth movements by human adults, with eyes open or closed, indicated that hand guidance was achieved by maintaining, during 80-85% of the movement, the tau-couplings tau(alpha)-tau(t) and tau(t)-tau(g), where tau(t) is tau of the hand-mouth gap, tau(alpha) is tau of the angular gap to be closed by steering the hand and tau(g) is an intrinsic tau-guide.

How information guides movement: Intercepting curved free kicks in soccer

Previous studies have shown that balls subjected to spin induce large errors in perceptual judgements (Craig et al, 2006; Craig et al 2009) due to the additional accelerative force that causes the ball’s flight path to deviate from a standard parabolic trajectory. A recent review however, has suggested that the findings from such experiments may be imprecise due to the decoupling of perception and action and the reliance on the ventral system (Van der Kamp et al, 2008). The aim of this study was to present the same curved free kick trajectory simulations from the perception only studies (Craig et al, 2006; Craig et al, 2009) but this time allow participants to move to intercept the ball. By using immersive, interactive virtual reality technology participants were asked to control the movement of a virtual effector presented in a virtual soccer stadium so that it would make contact with a virtual soccer ball as it crossed the goal-line. As in the perception only studies the direction of spin had a significant effect on the participants’ responses (F(2,12)=222.340; p

Judging the ‘passability’ of dynamic gaps in a virtual rugby environment

Affordances have recently been proposed as a guiding principle in perception–action research in sport (Fajen, Riley, & Turvey, 2009). In the present study, perception of the ’passability’ affordance of a gap between two approaching defenders in rugby is explored. A simplified rugby gap closure scenario was created using immersive, interactive virtual reality technology where 14 novice participants (attacker) judged the passability of the gap between two virtual defenders via a perceptual judgment (button press) task. The scenario was modeled according to tau theory (Lee, 1976) and a psychophysical function was fitted to the response data. Results revealed that a tau-based informational quantity could account for 82% of the variance in the data. Findings suggest that the passability affordance in this case, is defined by this variable and participants were able to use it in order to inform prospective judgments as to passability. These findings contribute to our understanding of affordances and how they may be defined in this particular sporting scenario; however, some limitations regarding methodology, such as decoupling perception and action are also acknowledged.

Automaticity, spelling, and second language learning

This study investigated the relationship between a chronometric estimate of automaticity for the spelling of French words (Automaticity) and performance on four tests of French language attainment among a sample of Year 11 students of French as a foreign language. Fifty participants each completed a computerized test of French spelling and attainment tests in four aspects of French language learning: reading comprehension, writing fluency, oral fluency, and aural comprehension. Correlations were significant between Automaticity and performance on all four tests of French language attainment as well as on overall attainment.

Rise time and formant transition duration in the discrimination of speech sounds: The Ba–Wa distinction in developmental dyslexia

Across languages, children with developmental dyslexia have a specific difficulty with the neural representation of the sound structure (phonological structure) of speech. One likely cause of their difficulties with phonology is a perceptual difficulty in auditory temporal processing (Tallal, 1980). Tallal (1980) proposed that basic auditory processing of brief, rapidly successive acoustic changes is compromised in dyslexia, thereby affecting phonetic discrimination (e.g. discriminating /b/ from /d/) via impaired discrimination of formant transitions (rapid acoustic changes in frequency and intensity). However, an alternative auditory temporal hypothesis is that the basic auditory processing of the slower amplitude modulation cues in speech is compromised (Goswami , 2002). Here, we contrast children's perception of a synthetic speech contrast (ba/wa) when it is based on the speed of the rate of change of frequency information (formant transition duration) versus the speed of the rate of change of amplitude modulation (rise time). We show that children with dyslexia have excellent phonetic discrimination based on formant transition duration, but poor phonetic discrimination based on envelope cues. The results explain why phonetic discrimination may be allophonic in developmental dyslexia (Serniclaes , 2004), and suggest new avenues for the remediation of developmental dyslexia. © 2010 Blackwell Publishing Ltd.