Postural Requirements and Progression Velocity in Young Walkers

This article describes developmental changes in gait velocity and relates these changes to gait parameters that index postural stability (step width and lateral acceleration) and two components of velocity (cadence and step length).

Five children were observed longitudinally over a 2-year period after onset of independent walking. Their range of speed increased threefold in the first 6 months of independent walking and then remained constant. In contrast, step width decreased approximately twofold. Whereas in adults, cadence and step length contribute approximately equally to speed, when infants first begin to walk independently, increase in velocity is due mostly to increased step length. After 5 months of independent walking, the pattern reverses, and increase in velocity is due primarly to increased cadence. The pattern remains constant over the next 18 months. From a developmental point of view, the data lead us to interpret early walking (the first 5 months) as a process of integration of postural constraints into the dynamic necessities of gait movement. A second phase, beginning after 4 to 5 months of independent walking, is considered to be a tuning phase characterized by a more precise adjustment of the gait parameters.     

Coordination Dynamics of the Bipedal Galloping Pattern

A motion equation in relative phase was developed that incorporates the spatial-temporal pattern of the bipedal gallop along with the more commonplace patterns of the bipedal jump and walk-run. In 3 experiments, human participants (N = 6 per experiment) simulated the bipedal gait patterns through the rhythmic motions of hand-held pendulums. Predictions of the motion equation for coordination equilibria and their respective degrees of stability were confirmed. In particular, the gallop pattern was less stable than the fundamental in-phase and antiphase patterns but changed in qualitatively similar ways to those gaits as a function of limb asymmetry and movement frequency. The relation between the modeled coordination dynamics and the kinematic characteristics of real bipedal galloping is discussed.     

Entrevista con Jean-Paul Bronckart

RESUMEN

Bronckart comienza revisando su trayectoria científica y explicando cuáles son sus dos enfoques básicos: el análisis del contexto o de situaciones y el análisis del lenguaje en función de sus operaciones subyacentes definidas en el marco de las teorías de la enunciación. Seguidamente justifica su renuncia a posiciones estructuralistas porque no tienen en cuenta el problema de las relaciones funcionales ni prestan atención al contexto. El autor relaciona las operaciones psicológicas con universales funcionales diferenciándolos de los estructurales de Chomsky y del enfoque de Searle, defendiendo su interés por la lingüística comparativa. Seguidamente aborda el tema de análisis de textos en ambientes escolares, sugiriendo que hay que sensibilizar a los educadores sobre el hecho de que constantemente estamos en situaciones de comunicación que van cambiando y crear instrumentos para que puedan analizar su propia práctica. Con relación al aspecto cognitivo del lenguaje, enfatiza la proliferación excesiva de los enfoques representativos y seguidamente desarrolla qué entiende por especificidad de la naturaleza del lenguaje y de su carácter comunicativo. Esta entrevista aborda, además, cuestiones tales como el fenómeno presuposicional, las aportaciones de Vygotsky o las experiencias de enseñar lenguaje a chimpancés, y finaliza planteando algunos aspectos de la teoría de Culioli.     

On the relative importance of linear model and human judge(s) in combined forecasting

When and to what extent should forecasts rely on linear model or human judgment? The judgmental forecasting literature suggests that aggregating model and judge using a simple 50:50 split tends to outperform the two inputs alone. However, current research disregards the important role that the structure of the task, judges’ level of expertise, and the number of individuals providing a forecasting judgment may play. Ninety-two music industry professionals and 88 postgraduate students were recruited in a field experiment to predict chart entry positions of pop music singles in the UK and Germany. The results of a lens model analysis show how task structure and domain-specific expertise moderate the relative importance of model and judge. The study also delineates an upper boundary to which aggregating multiple judgments in model-expert combinations adds predictive accuracy. It is suggested that ignoring the characteristics of task and/or judge may lead to suboptimal forecasting performance.     

Processing of musical structure by high-functioning adolescents with autism spectrum disorders

Enhanced pitch perception and memory have been cited as evidence of a local processing bias in autism spectrum disorders (ASD). This bias is argued to account for enhanced perceptual functioning (Mottron &; Burack, 2001 Mottron, L. and Burack, J. A. 2001. “Enhanced perceptual functioning in the development of autism”. In The development of autism: Perspectives from theory to research, Edited by: Burack, J. A., Charman, T., Yirmiya, N. and Zelazo, P. R. 131–147. Mahwah, NJ: Lawrence Erlbaum.  [Google Scholar]; Mottron, Dawson, Soulières, Hubert, &; Burack, 2006 Mottron, L., Dawson, M., Soulières, I., Hubert, B. and Burack, J. 2006. Enhanced perceptual functioning in autism: An update, and eight principles of autistic perception. Journal of Autism and Developmental Disorders, 36(1): 27–43. doi:10.1007/s10803-005-0040-7[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and central coherence theories of ASD (Frith, 1989 Frith, U. 1989. Autism: Explaining the enigma, Oxford: United Kingdom: Blackwell.  [Google Scholar]; Happé &; Frith, 2006 Happé, F. and Frith, U. 2006. The weak coherence account: Detail-focused cognitive style in autism spectrum disorders. Journal of Autism and Developmental Disorders, 36(1): 5–25. doi:10.1007/s10803-005-0039-0[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). A local processing bias confers a different cognitive style to individuals with ASD (Happé, 1999 Happé, F. 1999. Autism: Cognitive deficit or cognitive style?. Trends in Cognitive Sciences, 3(6): 216–222. doi:10.1016/S1364-6613(99)01318-2[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]), which accounts in part for their good visuospatial and visuoconstructive skills. Here, we present analogues in the auditory domain, audiotemporal or audioconstructive processing, which we assess using a novel experimental task: a musical puzzle. This task evaluates the ability of individuals with ASD to process temporal sequences of musical events as well as various elements of musical structure and thus indexes their ability to employ a global processing style. Musical structures created and replicated by children and adolescents with ASD (10–19 years old) and typically developing children and adolescents (7–17 years old) were found to be similar in global coherence. Presenting a musical template for reference increased accuracy equally for both groups, with performance associated to performance IQ and short-term auditory memory. The overall pattern of performance was similar for both groups; some puzzles were easier than others and this was the case for both groups. Task performance was further found to be correlated with the ability to perceive musical emotions, more so for typically developing participants. Findings are discussed in light of the empathizing-systemizing theory of ASD (Baron-Cohen, 2009 Baron-Cohen, S. 2009. Autism: The Empathizing-Systemizing (E-S) Theory. Annals of the New York Academy of Sciences, 1156: 68–80. doi:10.1111/j.1749-6632.2009.04467.x[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and the importance of describing the strengths of individuals with ASD (Happé, 1999 Happé, F. 1999. Autism: Cognitive deficit or cognitive style?. Trends in Cognitive Sciences, 3(6): 216–222. doi:10.1016/S1364-6613(99)01318-2[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Heaton, 2009 Heaton, P. 2009. Assessing musical skills in autistic children who are not savants. Philosophical Transactions of the Royal Society Biological Sciences, 364: 1443–1447. doi:10.1098/rstb.2008.0327[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]).     

Modeling Nonlinear Change via Latent Change and Latent Acceleration Frameworks: Examining Velocity and Acceleration of Growth Trajectories

A general equadion is presented, covering all arbitrary values for the true population splits, for obtaining the true population phi, given observed cell frequencies for a selected sample, and true population splits. A nongeneral solution is also offered, based on the use of the G Index. Demonstrations with hypothetical data are given.     

Incidental emotions associated with uncertainty appraisals impair decisions in the Iowa Gambling Task

With the Appraisal Tendency Framework, it has been established that (un)certainty appraisals associated with incidental emotions trigger the kind of information processing to cope with situation. We tested the impact of (un)certainty-associated emotions on a sequential task, the Iowa Gambling Task. In this task, intuitive processing is necessary to lead participants to rely on emotional cues arising from previous decisions and to making advantageous decisions. We predicted that certainty-associated emotions would engage participants in intuitive processing, whereas uncertainty-associated emotions would engage them in deliberative processing and lead them to make disadvantageous decisions. As expected, we observed in two distinct experiments, that participants induced to feel uncertainty (fear, sadness) were found to decide less advantageously than participants induced to feel certainty (anger, happiness, disgust).