Dynamic Social Adaptation of Motion-Related Neurons in Primate Parietal Cortex

Social brain function, which allows us to adapt our behavior to social context, is poorly understood at the single-cell level due largely to technical limitations. But the questions involved are vital: How do neurons recognize and modulate their activity in response to social context? To probe the mechanisms involved, we developed a novel recording technique, called multi-dimensional recording, and applied it simultaneously in the left parietal cortices of two monkeys while they shared a common social space. When the monkeys sat near each other but did not interact, each monkey's parietal activity showed robust response preference to action by his own right arm and almost no response to action by the other's arm. But the preference was broken if social conflict emerged between the monkeys—specifically, if both were able to reach for the same food item placed on the table between them. Under these circumstances, parietal neurons started to show complex combinatorial responses to motion of self and other. Parietal cortex adapted its response properties in the social context by discarding and recruiting different neural populations. Our results suggest that parietal neurons can recognize social events in the environment linked with current social context and form part of a larger social brain network

Triadic (ecological, neural, cognitive) niche construction: a scenario of human brain evolution extrapolating tool use and language from the control of reaching actions

Hominin evolution has involved a continuous process of addition of new kinds of cognitive capacity, including those relating to manufacture and use of tools and to the establishment of linguistic faculties. The dramatic expansion of the brain that accompanied additions of new functional areas would have supported such continuous evolution. Extended brain functions would have driven rapid and drastic changes in the hominin ecological niche, which in turn demanded further brain resources to adapt to it. In this way, humans have constructed a novel niche in each of the ecological, cognitive and neural domains, whose interactions accelerated their individual evolution through a process of triadic niche construction. Human higher cognitive activity can therefore be viewed holistically as one component in a terrestrial ecosystem. The brain's functional characteristics seem to play a key role in this triadic interaction. We advance a speculative argument about the origins of its neurobiological mechanisms, as an extension (with wider scope) of the evolutionary principles of adaptive function in the animal nervous system. The brain mechanisms that subserve tool use may bridge the gap between gesture and language—the site of such integration seems to be the parietal and extending opercular cortices

Ionization induced by protons on isolated molecules of adenine: theory, modelling and experiment

We here report a comparison between semi-empirical and theoretical predictions in terms of differential and total cross sections for proton-induced ionization of isolated adenine molecules. Whereas the first ones are provided by existing analytical models, the second ones are based on two quantum-mechanical models recently developed within the 1st Born and the continuum distorted wave approximation, respectively. Besides, a large set of experimental data is also reported for comparisons. In all kinematical conditions here investigated, we have observed a very good agreement between theory and experiment whereas strong discrepancieswere reported with the semi-empirical models in particular when doubly-differential cross sections are analysed.Fil: Champion, C.. Universite de Bordeaux; FranciaFil: Galassi, Mariel Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Weck, P. F.. University of Nevada Las Vegas. Department of Chemistry and Harry Reid Center for Environmental Studies; Estados UnidosFil: Abdallah, C.. University Saint Joseph. Faculty of Sciences. Department of Physics; LíbanoFil: Francis, Z.. University Saint Joseph. Faculty of Sciences. Department of Physics; Líbano. The Open University. Faculty of Science. Department of Physical Sciences; Reino UnidoFil: Quinto, M. A.. Universite de Bordeaux; FranciaFil: Fojon, Omar Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Hanssen, Jocelyn. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); ArgentinaFil: Iriki, Y.. Kyoto University. Department of Nuclear Engineering; JapónFil: Itoh, A.. Kyoto University. Department of Nuclear Engineering; Japó

Potential role of monkey inferior parietal neurons coding action semantic equivalences as precursors of parts of speech

The anterior portion of the inferior parietal cortex possesses comprehensive representations of actions embedded in behavioural contexts. Mirror neurons, which respond to both self-executed and observed actions, exist in this brain region in addition to those originally found in the premotor cortex. We found that parietal mirror neurons responded differentially to identical actions embedded in different contexts. Another type of parietal mirror neuron represents an inverse and complementary property of responding equally to dissimilar actions made by itself and others for an identical purpose. Here, we propose a hypothesis that these sets of inferior parietal neurons constitute a neural basis for encoding the semantic equivalence of various actions across different agents and contexts. The neurons have mirror neuron properties, and they encoded generalization of agents, differentiation of outcomes, and categorization of actions that led to common functions. By integrating the activities of these mirror neurons with various codings, we further suggest that in the ancestral primates' brains, these various representations of meaningful action led to the gradual establishment of equivalence relations among the different types of actions, by sharing common action semantics. Such differential codings of the components of actions might represent precursors to the parts of protolanguage, such as gestural communication, which are shared among various members of a society. Finally, we suggest that the inferior parietal cortex serves as an interface between this action semantics system and other higher semantic systems, through common structures of action representation that mimic language syntax

Tool-Use Training in a Species of Rodent: The Emergence of an Optimal Motor Strategy and Functional Understanding

Tool use is defined as the manipulation of an inanimate object to change the position or form of a separate object. The expansion of cognitive niches and tool-use capabilities probably stimulated each other in hominid evolution. To understand the causes of cognitive expansion in humans, we need to know the behavioral and neural basis of tool use. Although a wide range of animals exhibit tool use in nature, most studies have focused on primates and birds on behavioral or psychological levels and did not directly address questions of which neural modifications contributed to the emergence of tool use. To investigate such questions, an animal model suitable for cellular and molecular manipulations is needed.) to use a rake-like tool with their forelimbs to retrieve otherwise out-of-reach rewards. Eventually, they mastered effective use of the tool, moving it in an elegant trajectory. After the degus were well trained, probe tests that examined whether they showed functional understanding of the tool were performed. Degus did not hesitate to use tools of different size, colors, and shapes, but were reluctant to use the tool with a raised nonfunctional blade. Thus, degus understood the functional and physical properties of the tool after extensive training.Our findings suggest that tool use is not a specific faculty resulting from higher intelligence, but is a specific combination of more general cognitive faculties. Studying the brains and behaviors of trained rodents can provide insights into how higher cognitive functions might be broken down into more general faculties, and also what cellular and molecular mechanisms are involved in the emergence of such cognitive functions

Neural changes in the primate brain correlated with the evolution of complex motor skills

Complex motor skills of eventual benefit can be learned after considerable trial and error. What do structural brain changes that accompany such effortful long-term learning tell us about the mechanisms for developing innovative behavior? Using MRI, we monitored brain structure before, during and after four marmosets learnt to use a rake, over a long period of 10–13 months. Throughout learning, improvements in dexterity and visuo-motor co-ordination correlated with increased volume in the lateral extrastriate cortex. During late learning, when the most complex behavior was maintained by sustained motivation to acquire the skill, the volume of the nucleus accumbens increased. These findings reflect the motivational state required to learn, and show accelerated function in higher visual cortex that is consistent with neurocognitive divergence across a spectrum of primate species

Pacifier Stiffness Alters the Dynamics of the Suck Central Pattern Generator

Variation in pacifier stiffness on non-nutritive suck (NNS) dynamics was examined among infants born prematurely with a history of respiratory distress syndrome. Three types of silicone pacifiers used in the NICU were tested for stiffness, revealing the Super Soothie™ nipple is 7 times stiffer than the Wee™ or Soothie™ pacifiers even though shape and displaced volume are identical. Suck dynamics among 20 preterm infants were subsequently sampled using the Soothie™ and Super Soothie™ pacifiers during follow-up at approximately 3 months of age. ANOVA revealed significant differences in NNS cycles/min, NNS amplitude, NNS cycles/burst, and NNS cycle periods as a function of pacifier stiffness. Infants modify the spatiotemporal output of their suck central pattern generator when presented with pacifiers with significantly different mechanical properties. Infants show a non-preference to suck due to high stiffness in the selected pacifier. Therefore, excessive pacifier stiffness may decrease ororhythmic patterning and impact feeding outcomes

Pregnant women's awareness of sensitivity to cold (hiesho) and body temperature observational study: A comparison of Japanese and Brazilian women

<p>Abstract</p> <p>Background</p> <p>Sensitivity to cold (<it>hiesho</it>) is a serious health problem in Japan, yet it is minimally understood within Western cultures. The purpose of this study was to clarify the divergence between pregnant Japanese woman living in Japan and pregnant Brazilian women living in Brazil in awareness of <it>hiesho </it>and differences between core body and peripheral temperatures.</p> <p>Methods</p> <p>The subjects of this study were 230 pregnant Japanese women living in Japan and 200 pregnant Brazilian women living in Brazil. Data was collected in June/July and November 2005 in Japan and from October 2007 to February 2008 in Brazil. The survey methods consisted of measurement of deep body temperatures and questionnaires.</p> <p>Results</p> <p>67.0% of Japanese women and 57.0% of Brazilian women were aware of <it>hiesho</it>, which showed a significant difference between the Japanese and Brazilian women (p = 0.034). The difference between forehead and sole temperatures was 2.0°C among Japanese and 2.8°C among Brazilians in June-July (p = 0.01). But in November the difference between those temperatures was 5.2°C among Japanese and 2.8°C among Brazilians (p < 0.001).</p> <p>Conclusions</p> <p>There are differences between Japanese and Brazilians both in awareness of <it>hiesho </it>and in body temperatures.</p

Respiratory treatment history predicts suck pattern stability in preterm infants

Sensory deprivation and motor restriction associated with extensive oxygen therapy may lead to poor oromotor control in preterm infants. Non-nutritive suck is one of the first complex oromotor behaviors infants perform. This study determined the spatiotemporal variability of non-nutritive suck (NNS) pressure trajectories in three preterm groups with differing oxygen histories—one control group with minimal or no O2 therapy, and two Respiratory Distress Syndrome (RDS) groups with either a mild/moderate (RDS1) or moderate/severe (RDS2) O2 history. The Non-nutritive Suck Spatiotemporal Index (NNS STI) quantifies spatial and temporal variability across kinematic trajectories, and was calculated from digital representations of infants’ suck pressure signals. An ANCOVA revealed a significant effect for group (p \u3c .001) on the NNS STI measure, with RDS2 infants showing highly variable NNS patterning, and thus relatively underdeveloped suck. Extensive oxygen therapy, which alters the oral sensory environment and reduces motor experiences, disrupts the development of coordinated NNS in preterm infants

Fake hands in action: embodiment and control of supernumerary limbs

Demonstrations that the brain can incorporate a fake limb into our bodily representations when stroked in synchrony with our unseen real hand [(the rubber hand illusion (RHI)] are now commonplace. Such demonstrations highlight the dynamic flexibility of the perceptual body image, but evidence for comparable RHI-sensitive changes in the body schema used for action is less common. Recent evidence from the RHI supports a distinction between bodily representations for perception (body image) and for action (body schema) (Kammers et al. in Neuropsychologia 44:2430–2436, 2006). The current study challenges and extends these findings by demonstrating that active synchronous stroking of a brush not only elicits perceptual embodiment of a fake limb (body image) but also affects subsequent reaching error (body schema). Participants were presented with two moving fake left hands. When only one was synchronous during active touch, ownership was claimed for the synchronous hand only and the accuracy of reaching was consistent with control of the synchronous hand. When both fake hands were synchronous, ownership was claimed over both, but only one was controlled. Thus, it would appear that fake limbs can be incorporated into the body schema as well as the body image, but while multiple limbs can be incorporated into the body image, the body schema can accommodate only one