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Information Processing (information + processing)
Kinds of Information Processing Terms modified by Information Processing Selected AbstractsInformation Processing and Firm-Internal Environment Contingencies: Performance Impact on Global New Product DevelopmentCREATIVITY AND INNOVATION MANAGEMENT, Issue 3 2010Elko Kleinschmidt Innovation in its essence is an information processing activity. Thus, a major factor impacting the success of new product development (NPD) programs, especially those responding to global markets, is the firm's ability to access, share and apply NPD information, which is often widely dispersed, functionally, geographically and culturally. To this end, an IT-communication strength is essential, one that is nested in an internal organizational environment that ensures its effective functioning. Using organizational information processing (OIP) theory as a framework, superior global NPD program performance is shown to result from an effective IT/Communication strength and the commitment components of the firm's internal environment, which are hypothesized to moderate this relationship. IT/Communication strength is identified in this study in terms of two components including the IT/Comm Infrastructure and IT/Comm Capability of the firm, whereas the moderating internal environment of the firm incorporates Resource Commitment and Senior Management Involvement. Data from a major empirical study of international NPD programs (382 SBUs) are used to develop and test this model. Based on a hierarchical regression analysis, the results are substantially supportive, with some unexpected findings. These shed light on the complex relationships of the firm's internal environment, OIP competency, and global NPD program performance. [source] The Distinctive and Inclusive Domain of Entrepreneurial Cognition ResearchENTREPRENEURSHIP THEORY AND PRACTICE, Issue 6 2004Ronald K. Mitchell Through mapping both distinctive and inclusive elements within the domain of entrepreneurial cognition research, we accomplish our task in this introductory article to Volume 2 of the Special Issue on Information Processing and Entrepreneurial Cognition: to provide a fitting backdrop that will enhance the articles you will find within. We develop and utilize a "boundaries and exchange" concept to provide a lens through which both distinctive and inclusive aspects of the entrepreneurship domain are employed to frame this special issue. [source] Infants' Use of Constraints to Speed Information Processing and to Anticipate EventsINFANCY, Issue 4 2002Thomas M. Dougherty Two experiments were conducted with 28-week-old infants using a modification of the Visual Expectation Paradigm. The first sought to determine whether speed of information processing (SIP) could be assessed in infants using a reaction time (RT) measure and approach that is widely used to measure SIP in adults. Infants saw a center fixation cue followed by a peripheral target that could appear in 1, 2, or 4 locations. There was a linear increase in RT of eye movements as the number of locations increased from 1 to 2 and to 4 targets, suggesting that the paradigm does measure SIP. The second experiment asked whether varying the number of cue-target pairings would augment or impair infant's SIP in the trade-off between the benefit of additional information and the liability of additional memory load. The findings showed that the presence of cue information can eliminate the difference in RT between the 1- and 2-location conditions, whereas no benefit of cue was obtained for the 4-location condition. [source] Spin-Based Optical Quantum Information ProcessingISRAEL JOURNAL OF CHEMISTRY, Issue 4 2006Ehoud Pazy We shall present a review of semiconductor spin-based implementation schemes for the realization of quantum information/computation solid-state devices. After briefly describing the fundamentals of quantum computation theory, we shall introduce and discuss potential implementation schemes based on the spin degrees of freedom in semiconductor nanostructures. More specifically, we shall describe an implementation scheme for quantum information processing in which the spin degrees of freedom of electrons confined to a quantum dot are the computational degrees of freedom, and spins are manipulated/controlled through interaction between trionic states created by interband optical transitions by ultrafast sequences of multicolor laser pulses. We will also review briefly an adiabatic method for operating the two-qubit gate that avoids the main imperfections present in real quantum dots: exciton decay, hole mixing, and phonon decoherence. [source] The Effects of Negativity and Motivated Information Processing During a Political CampaignJOURNAL OF COMMUNICATION, Issue 1 2006Michael F. Meffert This research investigated how voters select, process, are affected by, and recall political information in a dynamic campaign environment. It was hypothesized that voters' information selection, processing, and recall are subject to a negativity bias (i.e., negative information dominates over positive information), a congruency bias (i.e., positive information about the preferred candidate and negative information about the opponent candidate dominate over negative information about the preferred candidate and positive information about the opponent), and a candidate bias (i.e., information about the preferred candidate dominates over information about the opponent). Motivated by an initial candidate preference, participants were also expected to develop more polarized candidate evaluations over time. Participants were exposed to quickly changing information in the form of newspaper-style headlines on a dynamic, computer-based information board. The results generally supported negativity bias and candidate bias, whereas congruency bias was only found during information recall. At the information selection and processing stages, participants with a strong initial candidate preference showed a disproportionate preference for negative information about the preferred candidate. However, they developed more positive attitudes at the evaluation and recall stage. This finding suggests that participants were engaged in motivated information processing by counterarguing negative information about their preferred candidate. [source] Information Processing of Sexual Abuse in EldersJOURNAL OF FORENSIC NURSING, Issue 3 2006Ann W. Burgess Sexual abuse is considered to be a pandemic contemporary public health issue, with significant physical and psychosocial consequences for its victims. However, the incidence of elder sexual assault is difficult to estimate with any degree of confidence. A convenience sample of 284 case records were reviewed for Post-Traumatic Stress Disorder (PTSD) symptoms. The purpose of this paper is to present the limited data noted on record review on four PTSD symptoms of startle, physiological upset, anger, and numbness. A treatment model for information processing of intrapsychic trauma is presented to describe domain disruption within a nursing diagnosis of rape trauma syndrome and provide guidance for sensitive assessment and intervention. [source] Information Processing in the Hypothalamus: Peptides and Analogue ComputationJOURNAL OF NEUROENDOCRINOLOGY, Issue 6 2006G. Leng Abstract ,Lovers and madmen have such seething brains,/Such shaping fantasies, that apprehend/More than cool reason ever comprehends'(A Midsummer Night's Dream, Act V Scene I) Peptides in the hypothalamus are not like conventional neurotransmitters; their release is not particularly associated with synapses, and their long half-lives mean that they can diffuse to distant targets. Peptides can act on their cells of origin to facilitate the development of patterned electrical activity, they can act on their neighbours to bind the collective activity of a neural population into a coherent signalling entity, and the co-ordinated population output can transmit waves of peptide secretion that act as a patterned hormonal analogue signal within the brain. At their distant targets, peptides can re-programme neural networks, by effects on gene expression, synaptogenesis, and by functionally rewiring connections by priming activity-dependent release. [source] Frontiers of Remote Sensing Information ProcessingTHE PHOTOGRAMMETRIC RECORD, Issue 111 2005I. Dyras No abstract is available for this article. [source] Social Information Processing, Moral Reasoning, and Emotion Attributions: Relations With Adolescents' Reactive and Proactive AggressionCHILD DEVELOPMENT, Issue 6 2009William F. Arsenio Connections between adolescents' social information processing (SIP), moral reasoning, and emotion attributions and their reactive and proactive aggressive tendencies were assessed. One hundred mostly African American and Latino 13- to 18-year-olds from a low-socioeconomic-status (SES) urban community and their high school teachers participated. Reactive aggression was uniquely related to expected ease in enacting aggression, lower verbal abilities, and hostile attributional biases, and most of these connections were mediated by adolescents' attention problems. In contrast, proactive aggression was uniquely related to higher verbal abilities and expectations of more positive emotional and material outcomes resulting from aggression. Discussion focused on the utility of assessing both moral and SIP-related cognitions, and on the potential influence of low-SES, high-risk environments on these findings. [source] Aggression and Moral Development: Integrating Social Information Processing and Moral Domain ModelsCHILD DEVELOPMENT, Issue 4 2004William F. Arsenio Social information processing and moral domain theories have developed in relative isolation from each other despite their common focus on intentional harm and victimization, and mutual emphasis on social cognitive processes in explaining aggressive, morally relevant behaviors. This article presents a selective summary of these literatures with the goal of showing how they can be integrated into a single, coherent model. An essential aspect of this integration is Crick and Dodge's (1994) distinction between latent mental structures and online processing. It is argued that moral domain theory is relevant for describing underlying mental structures regarding the nature and boundaries of what is moral, whereas the social information processing model describes the online information processing that affects application of moral structures during peer interactions. [source] Information processing and transmission in glia: Calcium signaling and transmitter releaseGLIA, Issue 7 2006Joachim W. Deitmer No abstract is available for this article. [source] Septal networks: relevance to theta rhythm, epilepsy and Alzheimer's diseaseJOURNAL OF NEUROCHEMISTRY, Issue 3 2006Luis V. Colom Abstract Information processing and storing by brain networks requires a highly coordinated operation of multiple neuronal groups. The function of septal neurons is to modulate the activity of archicortical (e.g. hippocampal) and neocortical circuits. This modulation is necessary for the development and normal occurrence of rhythmical cortical activities that control the processing of sensory information and memory functions. Damage or degeneration of septal neurons results in abnormal information processing in cortical circuits and consequent brain dysfunction. Septal neurons not only provide the optimal levels of excitatory background to cortical structures, but they may also inhibit the occurrence of abnormal excitability states. [source] Efficient organization of information processingMANAGERIAL AND DECISION ECONOMICS, Issue 1 2007Jacek Cukrowski The paper examines the application of the concept of economic efficiency to organizational issues of collective information processing in decision making. Information processing is modeled in the framework of the dynamic parallel processing model of associative computation with an endogenous setup cost of the processors. The model is extended to include the specific features of collective information processing in the team of decision makers which may lead to an error in data analysis. In such a model, the conditions for efficient organization of information processing are defined and the architecture of the efficient structures is considered. We show that specific features of collective decision making procedures require a broader framework for judging organizational efficiency than has traditionally been adopted. In particular, and contrary to the results available in economic literature, we show that there is no unique architecture for efficient information processing structures, but a number of various efficient forms. The results indicate that technological progress resulting in faster data processing (ceteris paribus) will lead to more regular information processing structures. However, if the relative cost of the delay in data analysis increases significantly, less regular structures could be efficient. Copyright © 2007 John Wiley & Sons, Ltd. [source] Feeling, caring, knowing: different types of empathy deficit in boys with psychopathic tendencies and autism spectrum disorderTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 11 2010Alice P. Jones Background:, Empathy dysfunction is one of the hallmarks of psychopathy, but it is also sometimes thought to characterise autism spectrum disorders (ASD). Individuals with either condition can appear uncaring towards others. This study set out to compare and contrast directly boys with psychopathic tendencies and boys with ASD on tasks assessing aspects of affective empathy and cognitive perspective taking. The main aim of the study was to assess whether a distinct profile of empathy deficits would emerge for boys with psychopathic tendencies and ASD, and whether empathy deficits would be associated with conduct problems in general, rather than psychopathic tendencies or ASD specifically. Methods:, Four groups of boys aged between 9 and 16 years (N = 96) were compared: 1) psychopathic tendencies, 2) ASD, 3) conduct problems and 4) comparison. Tasks were included to probe attribution of emotions to self, empathy for victims of aggression and cognitive perspective-taking ability. Results:, Boys with psychopathic tendencies had a profile consistent with dysfunctional affective empathy. They reported experiencing less fear and less empathy for victims of aggression than comparison boys. Their cognitive perspective-taking abilities were not statistically significantly different from those of comparison boys. In contrast, boys with ASD had difficulties with tasks requiring cognitive perspective taking, but reported emotional experiences and victim empathy that were in line with comparison boys. Boys with conduct problems did not differ from comparison boys, suggesting that the affective empathy deficit seen in boys with psychopathic tendencies was specific to that group, rather than common to all boys with conduct problems. Conclusions:, Although both groups can appear uncaring, our findings suggest that the affective/information processing correlates of psychopathic tendencies and ASD are quite different. Psychopathic tendencies are associated with difficulties in resonating with other people's distress, whereas ASD is characterised by difficulties in knowing what other people think. [source] Stability of cognitive impairment in chronic schizophrenia over brief and intermediate re-test intervalsHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 2 2009Robert H. Pietrzak Abstract Objective This study examined between- and within-subject stability of cognitive performance in individuals with chronic schizophrenia. Methods Thirty individuals with schizophrenia and 20 healthy controls matched by age, sex, education, and estimated IQ underwent repeated cognitive assessments at baseline and 30 days using computerized tests of psychomotor function, visual attention/information processing, non-verbal learning, and executive function. Results Compared to healthy controls, individuals with schizophrenia scored lower on all cognitive measures and demonstrated greater variability in cognitive performance. Within-subject variability in cognitive performance in both the schizophrenia and healthy control groups remained stable at brief (i.e., hours) and intermediate (i.e., one month) assessments. Conclusions These results demonstrate the stability of between- and within-subject variability in cognitive performance in schizophrenia, and suggest that variability in cognitive performance may reflect an inherent characteristic of the disorder, rather than differences in test,retest reliability/error of cognitive measures. Copyright © 2008 John Wiley & Sons, Ltd. [source] Replica Exchange Light TransportCOMPUTER GRAPHICS FORUM, Issue 8 2009Shinya Kitaoka I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism; I.3.3 [Computer Graphics]: Picture/Image Generation Abstract We solve the light transport problem by introducing a novel unbiased Monte Carlo algorithm called replica exchange light transport, inspired by the replica exchange Monte Carlo method in the fields of computational physics and statistical information processing. The replica exchange Monte Carlo method is a sampling technique whose operation resembles simulated annealing in optimization algorithms using a set of sampling distributions. We apply it to the solution of light transport integration by extending the probability density function of an integrand of the integration to a set of distributions. That set of distributions is composed of combinations of the path densities of different path generation types: uniform distributions in the integral domain, explicit and implicit paths in light (particle/photon) tracing, indirect paths in bidirectional path tracing, explicit and implicit paths in path tracing, and implicit caustics paths seen through specular surfaces including the delta function in path tracing. The replica-exchange light transport algorithm generates a sequence of path samples from each distribution and samples the simultaneous distribution of those distributions as a stationary distribution by using the Markov chain Monte Carlo method. Then the algorithm combines the obtained path samples from each distribution using multiple importance sampling. We compare the images generated with our algorithm to those generated with bidirectional path tracing and Metropolis light transport based on the primary sample space. Our proposing algorithm has better convergence property than bidirectional path tracing and the Metropolis light transport, and it is easy to implement by extending the Metropolis light transport. [source] Geometric algebra and transition-selective implementations of the controlled-NOT gateCONCEPTS IN MAGNETIC RESONANCE, Issue 1 2004Timothy F. Havel Geometric algebra provides a complete set of simple rules for the manipulation of product operator expressions at a symbolic level, without any explicit use of matrices. This approach can be used not only to describe the state and evolution of a spin system, but also to derive the effective Hamiltonian and associated propagator in full generality. In this article, we illustrate the use of geometric algebra via a detailed analysis of transition-selective implementations of the controlled-NOT gate, which plays a key role in NMR-based quantum information processing. In the appendices, we show how one can also use geometric algebra to derive tight bounds on the magnitudes of the errors associated with these implementations of the controlled-NOT. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part A 23A: 49,62, 2004 [source] Information Processing and Firm-Internal Environment Contingencies: Performance Impact on Global New Product DevelopmentCREATIVITY AND INNOVATION MANAGEMENT, Issue 3 2010Elko Kleinschmidt Innovation in its essence is an information processing activity. Thus, a major factor impacting the success of new product development (NPD) programs, especially those responding to global markets, is the firm's ability to access, share and apply NPD information, which is often widely dispersed, functionally, geographically and culturally. To this end, an IT-communication strength is essential, one that is nested in an internal organizational environment that ensures its effective functioning. Using organizational information processing (OIP) theory as a framework, superior global NPD program performance is shown to result from an effective IT/Communication strength and the commitment components of the firm's internal environment, which are hypothesized to moderate this relationship. IT/Communication strength is identified in this study in terms of two components including the IT/Comm Infrastructure and IT/Comm Capability of the firm, whereas the moderating internal environment of the firm incorporates Resource Commitment and Senior Management Involvement. Data from a major empirical study of international NPD programs (382 SBUs) are used to develop and test this model. Based on a hierarchical regression analysis, the results are substantially supportive, with some unexpected findings. These shed light on the complex relationships of the firm's internal environment, OIP competency, and global NPD program performance. [source] Infant information processing and family history of specific language impairment: converging evidence for RAP deficits from two paradigmsDEVELOPMENTAL SCIENCE, Issue 2 2007Naseem Choudhury An infant's ability to process auditory signals presented in rapid succession (i.e. rapid auditory processing abilities [RAP]) has been shown to predict differences in language outcomes in toddlers and preschool children. Early deficits in RAP abilities may serve as a behavioral marker for language-based learning disabilities. The purpose of this study is to determine if performance on infant information processing measures designed to tap RAP and global processing skills differ as a function of family history of specific language impairment (SLI) and/or the particular demand characteristics of the paradigm used. Seventeen 6- to 9-month-old infants from families with a history of specific language impairment (FH+) and 29 control infants (FH,) participated in this study. Infants' performance on two different RAP paradigms (head-turn procedure [HT] and auditory-visual habituation/recognition memory [AVH/RM]) and on a global processing task (visual habituation/recognition memory [VH/RM]) was assessed at 6 and 9 months. Toddler language and cognitive skills were evaluated at 12 and 16 months. A number of significant group differences were seen: FH+ infants showed significantly poorer discrimination of fast rate stimuli on both RAP tasks, took longer to habituate on both habituation/recognition memory measures, and had lower novelty preference scores on the visual habituation/recognition memory task. Infants' performance on the two RAP measures provided independent but converging contributions to outcome. Thus, different mechanisms appear to underlie performance on operantly conditioned tasks as compared to habituation/recognition memory paradigms. Further, infant RAP processing abilities predicted to 12- and 16-month language scores above and beyond family history of SLI. The results of this study provide additional support for the validity of infant RAP abilities as a behavioral marker for later language outcome. Finally, this is the first study to use a battery of infant tasks to demonstrate multi-modal processing deficits in infants at risk for SLI. [source] Procedural learning and dyslexiaDYSLEXIA, Issue 3 2010R. I. Nicolson Abstract Three major ,neural systems', specialized for different types of information processing, are the sensory, declarative, and procedural systems. It has been proposed (Trends Neurosci.,30(4), 135,141) that dyslexia may be attributable to impaired function in the procedural system together with intact declarative function. We provide a brief overview of the increasing evidence relating to the hypothesis, noting that the framework involves two main claims: first that ,neural systems' provides a productive level of description avoiding the underspecificity of cognitive descriptions and the overspecificity of brain structural accounts; and second that a distinctive feature of procedural learning is its extended time course, covering from minutes to months. In this article, we focus on the second claim. Three studies,speeded single word reading, long-term response learning, and overnight skill consolidation,are reviewed which together provide clear evidence of difficulties in procedural learning for individuals with dyslexia, even when the tasks are outside the literacy domain. The educational implications of the results are then discussed, and in particular the potential difficulties that impaired overnight procedural consolidation would entail. It is proposed that response to intervention could be better predicted if diagnostic tests on the different forms of learning were first undertaken. Copyright © 2010 John Wiley & Sons, Ltd. [source] Development of microreactor array chip-based measurement system for massively parallel analysis of enzymatic activityELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 4 2009Yosuke Hosoi Abstract Microarray chip technology such as DNA chips, peptide chips, and protein chips is one of the promising approaches for achieving high-throughput screening (HTS) of biomolecule function since it has great advantages in feasibility of automated information processing due to one-to-one indexing between array position and molecular function as well as massively parallel sample analysis as a benefit of downsizing and large-scale integration. Mostly, however, the function that can be evaluated by such microarray chips is limited to affinity of target molecules. In this paper, we propose a new HTS system and enzymatic activity based on microreactor array chip technology. A prototype of the automated and massively parallel measurement system for fluorometric assay of enzymatic reactions was developed by the combination of microreactor array chips and a highly sensitive fluorescence microscope. Design strategy of microreactor array chips and an optical measurement platform for the high-throughput enzyme assay are discussed. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(4): 35,41, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10056 [source] An integrated map of the murine hippocampal proteome based upon five mouse strainsELECTROPHORESIS, Issue 13 2006Daniela D. Pollak Abstract With the advent of proteomics technologies it is possible to simultaneously demonstrate the expression of hundreds of proteins. The information offered by proteomics provides context-based understanding of cellular protein networks and has been proven to be a valuable approach in neuroscience studies. The mouse hippocampus has been a major target of analysis in the search for molecular correlates to neuronal information storage. Although human and rat hippocampal samples have been successfully subjected to proteomic profiling, no elaborate analysis providing the fundamental experimental basis for protein-expression studies in the mouse hippocampus has been carried out as yet. This led us to construct a master map generated from the individual hippocampal proteomes of five different mouse strains. A proteomic approach, based upon 2-DE coupled to MS (MALDI-TOF/TOF) has been chosen in an attempt to establish a comprehensive reference database of proteins expressed in the mouse hippocampus. 469 individual proteins, represented by 1156 spots displaying various functional states of the respective gene products were identified. Proteomic profiling of the hippocampus, a brain region with a pivotal role for neuronal information processing and storage may provide insight into the characteristics of proteins serving this highly sophisticated function. [source] Entrepreneurial Scripts and the New Transaction Commitment Mindset: Extending the Expert Information Processing Theory Approach to Entrepreneurial Cognition ResearchENTREPRENEURSHIP THEORY AND PRACTICE, Issue 4 2009J. Brock Smith In this study, we extend the expert information processing theory approach to entrepreneurial cognition research through an empirical exploration of the new transaction commitment mindset among business people in Canada, Mexico, and the United States. Using analysis of covariance, multivariate analysis of variance, and hierarchical regression analysis of data from a cross-sectional sample of 417 respondents, our results provide a foundation for additional cross-level theory development, with related implications for increasing the practicality of expert information processing theory-based entrepreneurial cognition research. Specifically, this paper: (1) clarifies the nature of the relationship between entrepreneurial expert scripts and constructs that might represent an entrepreneurial mindset at the individual level of analysis; (2) identifies analogous relationships at the economy level of analysis, where the structure found at the individual level informs an economy-level problem; (3) presents a North American Free Trade Agreement-based illustration analysis to demonstrate the extent to which cognitive findings at the individual level can be used to explain economy-level phenomena; and (4) extrapolates from our analysis some of the ways in which script-based comparisons across country or culture can inform the more general task of making information processing-based comparisons among entrepreneurs across other contexts. [source] The Relationship Among Biases, Misperceptions, and the Introduction of Pioneering Products: Examining Differences in Venture Decision ContextsENTREPRENEURSHIP THEORY AND PRACTICE, Issue 2 2002Mark Simon Although biases influence the decision to take entrepreneurial actions, studies have not differentiated among entrepreneurial decision environments. These environments vary greatly and affect which biases arise and their context-specific consequences. Focusing on the role of firm size, age, and type of product introduction, we propose that entrepreneurs in smaller, younger, firms, who are considering pioneering, are more likely to exhibit illusion of control, law of small numbers, and reasoning by analogy. These biases contribute to underestimating competition, overestimating demand, and overlooking requisite assets. We hope to spur researchers to examine information processing across different types of entrepreneurial firms and actions. [source] Metagenomic approach studying the taxonomic and functional diversity of the bacterial community in a mesotrophic lake (Lac du Bourget , France)ENVIRONMENTAL MICROBIOLOGY, Issue 9 2009Didier Debroas Summary The main goals of this work were to identify the metabolic pathways of the bacterial community in a lacustrine ecosystem and to establish links between taxonomic composition and the relative abundances of these metabolic pathways. For this purpose, we analysed a 16S rRNA gene library obtained by gene amplification together with a sequence library of both insert ends on c. 7700 fosmids. Whatever the library used, Actinobacteria was the most abundant bacterial group, followed by Proteobacteria and Bacteroidetes. Specific aquatic clades such as acI and acIV (Actinobacteria) or LD12 and GOBB-C201 (Alphaproteobacteria) were found in both libraries. From comparative analysis of metagenomic libraries, the metagenome of this lake was characterized by overrepresentation of genes involved in the degradation of xenobiotics mainly associated with Alphaproteobacteria. Actinobacteria were mainly related to metabolic pathways involved in nucleotide metabolism, cofactors, vitamins, energy, replication and repair. Betaproteobacteria appeared to be characterized by the presence of numerous genes implicated in environmental information processing (membrane transport and signal transduction) whereas glycan and carbohydrate metabolism pathways were overrepresented in Bacteroidetes. These results prompted us to propose hypotheses on the ecological role of these bacterial classes in lacustrine ecosystems. [source] Drifting grating stimulation reveals particular activation properties of visual neurons in the caudate nucleusEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2008Attila Nagy Abstract The role of the caudate nucleus (CN) in motor control has been widely studied. Less attention has been paid to the dynamics of visual feedback in motor actions, which is a relevant function of the basal ganglia during the control of eye and body movements. We therefore set out to analyse the visual information processing of neurons in the feline CN. Extracellular single-unit recordings were performed in the CN, where the neuronal responses to drifting gratings of various spatial and temporal frequencies were recorded. The responses of the CN neurons were modulated by the temporal frequency of the grating. The CN units responded optimally to gratings of low spatial frequencies and exhibited low spatial resolution and fine spatial frequency tuning. By contrast, the CN neurons preferred high temporal frequencies, and exhibited high temporal resolution and fine temporal frequency tuning. The spatial and temporal visual properties of the CN neurons enable them to act as spatiotemporal filters. These properties are similar to those observed in certain feline extrageniculate visual structures, i.e. in the superior colliculus, the suprageniculate nucleus and the anterior ectosylvian cortex, but differ strongly from those of the primary visual cortex and the lateral geniculate nucleus. Accordingly, our results suggest a functional relationship of the CN to the extrageniculate tecto-thalamo-cortical system. This system of the mammalian brain may be involved in motion detection, especially in velocity analysis of moving objects, facilitating the detection of changes during the animal's movement. [source] Adult gaze influences infant attention and object processing: implications for cognitive neuroscienceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2005Vincent M. Reid Abstract Infants follow others' gaze toward external objects from early in ontogeny, but whether they use others' gaze in processing information about objects remains unknown. In Experiment 1, 4-month-old infants viewed a video presentation of an adult gazing toward one of two objects. When presented with the same objects alone a second time, infants looked reliably less at the object to which the adult had directly gazed (cued object). This suggests that the uncued object was perceived as more novel than the object previously cued by the adult's gaze. In Experiment 2, adult gaze was not directed towards any object. In this control experiment, infants looked at both objects equally in the test phase. These findings show that adult eye gaze biases infant visual attention and information processing. Implications of the paradigm for cognitive neuroscience are presented and the results are discussed in terms of neural structures and change over ontogeny. [source] AMPA receptor-mediated presynaptic inhibition at cerebellar GABAergic synapses: a characterization of molecular mechanismsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2004Shin'Ichiro Satake Abstract A major subtype of glutamate receptors, AMPA receptors (AMPARs), are generally thought to mediate excitation at mammalian central synapses via the ionotropic action of ligand-gated channel opening. It has recently emerged, however, that synaptic activation of AMPARs by glutamate released from the climbing fibre input elicits not only postsynaptic excitation but also presynaptic inhibition of GABAergic transmission onto Purkinje cells in the cerebellar cortex. Although presynaptic inhibition is critical for information processing at central synapses, the molecular mechanisms by which AMPARs take part in such actions are not known. This study therefore aimed at further examining the properties of AMPAR-mediated presynaptic inhibition at GABAergic synapses in the rat cerebellum. Our data provide evidence that the climbing fibre-induced inhibition of GABA release from interneurons depends on AMPAR-mediated activation of GTP-binding proteins coupled with down-regulation of presynaptic voltage-dependent Ca2+ channels. A Gi/o -protein inhibitor, N-ethylmaleimide, selectively abolished the AMPAR-mediated presynaptic inhibition at cerebellar GABAergic synapses but did not affect AMPAR-mediated excitatory actions on Purkinje cells. Furthermore, both Gi/o -coupled receptor agonists, baclofen and DCG-IV, and the P/Q-type calcium channel blocker ,-agatoxin IVA markedly occluded the AMPAR-mediated inhibition of GABAergic transmission. Conversely, AMPAR activation inhibited action potential-triggered Ca2+ influx into individual axonal boutons of cerebellar GABAergic interneurons. By suppressing the inhibitory inputs to Purkinje cells, the AMPAR-mediated presynaptic inhibition could thus provide a feed-forward mechanism for the information flow from the cerebellar cortex. [source] Temporary inactivation of the perirhinal cortex by muscimol injections block acquisition and expression of fear-potentiated startleEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2004Brigitte Schulz Abstract The present study examined the role of the perirhinal cortex (PRh) in aversive information processing and emotional learning. Specifically, we studied the effects of temporary inactivation of the PRh on acquisition and expression of conditioned fear as measured by fear-potentiated startle in rats, as well as on shock sensitization of startle. Temporary inactivation of the PRh was induced by local injections of the GABAA agonist muscimol (0.0, 1.1, 2.2, 4.4 nmol/0.5 µL). Muscimol injections into the PRh blocked both the expression and acquisition of fear-potentiated startle, as well as shock sensitization of startle. Shock sensitivity was not affected by muscimol injections, indicating that the observed blockade of acquisition and shock sensitization was not caused by a disruption in the perception of shock. Taken together, the present data show that the PRh is critical for the processing of aversive information and is necessary for the expression of emotional learning. [source] Ascending visceral regulation of cortical affective information processingEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2003Gary G. Berntson Abstract Over a century ago, William James proposed that strong emotions represent the perceptual consequences of somato-visceral feedback. Although the strong form of this conception is no longer viable, considerable evidence has accumulated indicating a range of visceral influences on higher neurobehavioural processes. This literature has only recently begun to consolidate, because earlier reports generally remained at the demonstration level, and pathways and mechanisms for such influences were uncertain. Recently, specific effects of visceral feedback have become apparent on cortical activity, cerebral auditory-evoked responses, anxiety, memory and behavioural aspects of immunological sickness. Moreover, considerable progress has been made recently in determining the specific neural pathways and systems underlying these actions, especially the role of noradrenergic projections from the nucleus of the tractus solitarius and the locus coeruleus to the amygdala in memory processes, and to the basal forebrain in the processing of anxiety-related information. The present paper highlights selected recent findings in this area, and outlines relevant structures and pathways involved in the ascending visceral influence on higher neurobehavioural processes. 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