Universidad de La LagunaNuestras categorías del mundo físico son relativamente objetivas y con escasas diferencias interindividuales, dado que corresponden a conglomerados de atributos de nuestra experiencia sensorial inmediata. No obstante, nuestras representaciones del mundo social están menos guiadas por los datos sensoriales inmediatos y depende más de propiedades y sucesos de carácter inferencial (estatus, inteligencia, agresividad, tristeza, etc.). Para entender y planificar nuestro comportamiento en el mundo social llegamos a elaborar marcos interpretativos relativamente idiosincrásicos que podrían considerarse como verdaderas teorías espontáneas o implícitas. Por ejemplo, aquellos que comparten la teoría de los grupos marginales (alcohólicos, drogadictos, etc.), como «enfermos» sin duda perciben e interpretan los comportamientos de estos grupos de modo Muy diferente a los que mantienen la teoría de la marginalidad como «vicio».

Several decades of research on conceptual change, from both developmental and instructional approaches, lead us to assume that this change should not be conceived as the progressive replacement of poor forms of knowledge by more powerful ones. Recent studies have shown that in order to understand this change in conceptual knowledge, we must know how multiple representations about the same domain, or even the same task, can coexist in interpersonal as well as intrapersonal analyses. This paper studies the acquisition and development of conceptual knowledge in terms of representational changes. Based on implicit theories that people use to interpret their social and natural world, it analyses the relationships between episodic and semantic knowledge in these implicit representations. We suggest that representational change can be understood through four related dimensions: (a) the transition from realism to epistemological perspectivism; (b) the hierarchical or heterogeneous nature of representational change; (c) the consistency and coherence of these representations; and (d) the role of specific-domain codes and languages in the representation of knowledge. Finally, we consider that research into this representational variability also requires diverse yet convergent methodological approaches.

This investigation examined the neural and personality correlates of processing infant facial expressions in mothers with substantiated neglect of a child under 5 years old. Event-related potentials (ERPs) were recorded from 14 neglectful and 14 control mothers as they viewed and categorized pictures of infant cries, laughs, and neutral faces. Maternal self-reports of anhedonia and empathy were also completed. Early (negative occipitotemporal component peaking at around 170 ms on the scalp [N170] and positive electrical potential peaking at about 200 ms [P200]) and late positive potential (LPP) components were selected. Both groups of mothers showed behavioral discrimination between the different facial expressions via reaction time and accuracy measures. Neglectful mothers did not exhibit increased N170 amplitude at temporal leads in response to viewing crying versus laughing and neutral expressions compared to control mothers. Both groups had greater P200 and LPP amplitudes at centroparietal leads in response to viewing crying versus neutral facial expressions. However, neglectful mothers displayed an overall attenuated brain response in LPP that was related to their higher scores in social anhedonia but not to their empathy scores. The ERP data suggest that the brain's failures in the early differentiation of cry stimuli and in the sustained processing of infant expressions related to social anhedonia may underlie the insensitive responding in neglectful mothers. The implications of these results for the design and evaluation of preventive interventions are discussed.

Developing axons must control their growth rate to follow the appropriate pathways and establish specific connections. However, the regulatory mechanisms involved remain elusive. By combining live imaging with transplantation studies in mice, we found that spontaneous calcium activity in the thalamocortical system and the growth rate of thalamocortical axons were developmentally and intrinsically regulated. Indeed, the spontaneous activity of thalamic neurons governed axon growth and extension through the cortex in vivo. This activity-dependent modulation of growth was mediated by transcriptional regulation of Robo1 through an NF-κB binding site. Disruption of either the Robo1 or Slit1 genes accelerated the progression of thalamocortical axons in vivo, and interfering with Robo1 signaling restored normal axon growth in electrically silent neurons. Thus, modifications to spontaneous calcium activity encode a switch in the axon outgrowth program that allows the establishment of specific neuronal connections through the transcriptional regulation of Slit1 and Robo1 signaling.