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Computational Modeling (computational + modeling)
Selected AbstractsIndividual-based Computational Modeling of Smallpox Epidemic Control StrategiesACADEMIC EMERGENCY MEDICINE, Issue 11 2006Donald S. Burke MD In response to concerns about possible bioterrorism, the authors developed an individual-based (or "agent-based") computational model of smallpox epidemic transmission and control. The model explicitly represents an "artificial society" of individual human beings, each implemented as a distinct object, or data structure in a computer program. These agents interact locally with one another in code-represented social units such as homes, workplaces, schools, and hospitals. Over many iterations, these microinteractions generate large-scale macroscopic phenomena of fundamental interest such as the course of an epidemic in space and time. Model variables (incubation periods, clinical disease expression, contagiousness, and physical mobility) were assigned following realistic values agreed on by an advisory group of experts on smallpox. Eight response scenarios were evaluated at two epidemic scales, one being an introduction of ten smallpox cases into a 6,000-person town and the other an introduction of 500 smallpox cases into a 50,000-person town. The modeling exercise showed that contact tracing and vaccination of household, workplace, and school contacts, along with prompt reactive vaccination of hospital workers and isolation of diagnosed cases, could contain smallpox at both epidemic scales examined. [source] Computational Modeling of Statistical Learning: Effects of Transitional Probability Versus Frequency and Links to Word LearningINFANCY, Issue 5 2010Daniel Mirman Statistical learning mechanisms play an important role in theories of language acquisition and processing. Recurrent neural network models have provided important insights into how these mechanisms might operate. We examined whether such networks capture two key findings in human statistical learning. In Simulation 1, a simple recurrent network (SRN) performed much like human learners: it was sensitive to both transitional probability and frequency, with frequency dominating early in learning and probability emerging as the dominant cue later in learning. In Simulation 2, an SRN captured links between statistical segmentation and word learning in infants and adults, and suggested that these links arise because phonological representations are more distinctive for syllables with higher transitional probability. Beyond simply simulating general phenomena, these models provide new insights into underlying mechanisms and generate novel behavioral predictions. [source] An Overview of Computational Modeling in Agricultural and Resource EconomicsCANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 4 2009James Nolan First page of article [source] Modeling and simulation of bioheat transfer in the human eye using the 3D alpha finite element method (,FEM)INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 8 2010Eric Li Abstract Computational modeling is an effective tool for the detection of eye abnormalities and a valuable assistant to hyperthermia treatments. In all these diagnoses and treatments, predicting the temperature distribution accurately is very important. However, the standard finite element method (FEM) currently used for such purposes has strong reliance on element meshes and the discretized system exhibits the so-called ,overly stiff' behavior. To overcome this shortcoming, this paper formulates an alpha finite element method (,FEM) to compute two-dimensional (2D) and three-dimensional (3D) bioheat transfer in the human eyes. The ,FEM can produce much more accurate results using triangular (2D) and tetrahedron (3D) elements that can be generated automatically for complicated domains and hence is particularly suited for modeling human eyes. In the ,FEM, a scaling factor ,,[0, 1] is introduced to combine the ,overly stiff' FEM model and ,overly soft' node-based finite element method (NS-FEM) model. With a properly chosen ,, the ,FEM can produce models with very ,close-to-exact' stiffness of the continuous system. Numerical results have shown that the present method gives much more accurate results compared with the standard FEM and the NS-FEM. Copyright © 2010 John Wiley & Sons, Ltd. [source] If We Produce Discrepancies, Then How?JOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 9 2010Testing a Computational Process Model of Positive Goal Revision Within the self-regulation literature on goals, both discrepancy reduction and discrepancy production are considered important theoretical and practical processes. Yet, discrepancy production has only been examined in a limited number of goal-striving contexts, and the analytical strategies employed (e.g., difference scores) are difficult to interpret. This study extends discrepancy production research to multiple goal contexts where the goals are in conflict. Computational modeling and an organizational simulation were used to test a control theory explanation of discrepancy production. The occurrence of discrepancy production in the computational model and participants was assessed using hierarchical linear modeling. Comparing the data from the computational model with participants' data indicated a good fit. Implications of the findings and methods are discussed. [source] Computational modeling of tetrahydroimidazo-[4,5,1-jk][1,4]-benzodiazepinone derivatives: An atomistic drug design approach using Kier-Hall electrotopological state (E-state) indicesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 11 2008Nitin S. Sapre Abstract Quantitative structure-activity relationships (QSAR), based on E-state indices have been developed for a series of tetrahydroimidazo-[4,5,1-jk]-benzodiazepinone derivatives against HIV-1 reverse transcriptase (HIV-1 RT). Statistical modeling using multiple linear regression technique in predicting the anti-HIV activity yielded a good correlation for the training set (R2 = 0.913, R = 0.897, Q2 = 0.849, MSE = 0.190, F -ratio = 59.97, PRESS = 18.05, SSE = 0.926, and p value = 0.00). Leave-one-out cross-validation also reaffirmed the predictions (R2 = 0.850, R = 0.824, Q2 = 0.849, MSE = 0.328, and PRESS = 18.05). The predictive ability of the training set was also cross-validated by a test set (R2 = 0.812, R = 0.799, Q2 = 0.765, MSE = 0.347, F -ratio = 64.69, PRESS = 7.37, SSE = 0.975, and p value = 0.00), which ascertained a satisfactory quality of fit. The results reflect the substitution pattern and suggest that the presence of a bulky and electropositive group in the five-member ring and electron withdrawing groups in the seven-member ring will have a positive impact on the antiviral activity of the derivatives. Bulky groups in the six-member ring do not show an activity-enhancing impact. Outlier analysis too reconfirms our findings. The E-state descriptors indicate their importance in quantifying the electronic characteristics of a molecule and thus can be used in chemical interpretation of electronic and steric factors affecting the biological activity of compounds. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008 [source] Performance of DFT in modeling electronic and structural properties of cobalaminsJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 12 2006Jadwiga Kuta Abstract Computational modeling of the enzymatic activity of B12 -dependent enzymes requires a detailed understanding of the factors that influence the strength of the CoC bond and the limits associated with a particular level of theory. To address this issue, a systematic analysis of the electronic and structural properties of coenzyme B12 models has been performed to establish the performance of three different functionals including B3LYP, BP86, and revPBE. In particular the cobalt,carbon bond dissociation energies, axial bond lengths, and selected stretching frequencies have been analyzed in detail. Current analysis shows that widely used B3LYP functional significantly underestimates the strength of the CoC bond while the nonhybrid BP86 functional produces very consistent results in comparison to experimental data. To explain such different performance of these functionals molecular orbital analysis associated with axial bonds has been performed to show differences in axial bonding provided by hybrid and nonhybrid functionals. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1429,1437, 2006 [source] Heat transfer during microwave combination heating: Computational modeling and MRI experimentsAICHE JOURNAL, Issue 9 2010Vineet Rakesh Abstract Combination of heating modes such as microwaves, convection, and radiant heating can be used to realistically achieve the quality and safety needed for cooking processes and, at the same time, make the processes faster. Physics-based computational modeling used in conjunction with MRI experimentation can be used to obtain critical understanding of combination heating. The objectives were to: (1) formulate a fully coupled electromagnetics - heat transfer model, (2) use magnetic resonance imaging (MRI) experiments to determine the 3D spatial and temporal variation of temperatures and validate the numerical model, (3) use the insight gained from the model and experiments to understand the combination heating process and to optimize it. The different factors that affect heating patterns during combination heating such as the type of heating modes used, placement of sample, and microwave cycling were considered. Objective functions were defined and minimized for design and optimization. The use of such techniques can lead to greater control and automation of combination heating process benefitting the food process and product developers immensely. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source] Computational modeling of supercontinuum generation in fused silica by a femtosecond laser pulse of a few optical cyclesMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2004David Hovhannisyan Abstract The numerical solution of a wave equation describing the propagation of the laser pulse of a few optical cycles in fused silica is obtained. Our numerical simulations closely follow the published experimental data. A shifting of the spectrum peak of the broadened pulse, depending on the input-pulse central wavelength, is observed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 60,64, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20207 [source] Cadaveric and Engineering Analysis of the Septal L-Strut,THE LARYNGOSCOPE, Issue 11 2007Ted Mau MD Abstract Objectives: To identify patterns of failure of the L-strut, to identify elements of the nasal framework that support the L-strut, and to investigate the effect of altering L-strut design on its stability. Study Design: Laboratory study with human cadaveric heads and computational modeling. Methods: Directional forces were applied to cadaveric L-struts and patterns of failure with incremental force were noted. Computational modeling using the finite element method (FEM) was employed to determine quantitatively the effect of various modifications on the stability of the L-strut. Results: The L-strut was found to respond to frontal force initially by buckling. This buckling was reversible until the force exceeded a certain threshold when the L-strut broke at the bony-cartilaginous junction. The threshold force varied depending on the length of the overlap with the bony vault. Intact mucoperichondrium provided significant stability. Modeling with FEM showed that the preservation of a triangular piece of cartilage at the dorsal anchor of a narrowed L-strut can offset some of the loss in mechanical stability. Conclusions: Intrinsic elasticity of the septal cartilage, the mucoperichondrial flap, and overlap with the bony vault all contribute to the stability of the L-strut, which is enhanced by preserving a small segment of cartilage at the bony-cartilaginous junction of the dorsal L-strut. [source] Edited by K. Morokuma and D. Musaev Computational modeling for homogeneous and enzymatic catalysis: a knowledge-base for designing efficient catalysts Wiley,VCH, 2008, 398 pp. (hardover) ISBN 978-3-527-31843-8APPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2009Hans Martin Senn No abstract is available for this article. [source] Potential and Bottlenecks of Bioreactors in 3D Cell Culture and Tissue ManufacturingADVANCED MATERIALS, Issue 32-33 2009David Wendt Abstract Over the last decade, we have witnessed an increased recognition of the importance of 3D culture models to study various aspects of cell physiology and pathology, as well as to engineer implantable tissues. As compared to well-established 2D cell-culture systems, cell/tissue culture within 3D porous biomaterials has introduced new scientific and technical challenges associated with complex transport phenomena, physical forces, and cell,microenvironment interactions. While bioreactor-based 3D model systems have begun to play a crucial role in addressing fundamental scientific questions, numerous hurdles currently impede the most efficient utilization of these systems. We describe how computational modeling and innovative sensor technologies, in conjunction with well-defined and controlled bioreactor-based 3D culture systems, will be key to gain further insight into cell behavior and the complexity of tissue development. These model systems will lay a solid foundation to further develop, optimize, and effectively streamline the essential bioprocesses to safely and reproducibly produce appropriately scaled tissue grafts for clinical studies. [source] Circuitry of nuclear factor ,B signalingIMMUNOLOGICAL REVIEWS, Issue 1 2006Alexander Hoffmann Summary:, Over the past few years, the transcription factor nuclear factor (NF)-,B and the proteins that regulate it have emerged as a signaling system of pre-eminent importance in human physiology and in an increasing number of pathologies. While NF-,B is present in all differentiated cell types, its discovery and early characterization were rooted in understanding B-cell biology. Significant research efforts over two decades have yielded a large body of literature devoted to understanding NF-,B's functioning in the immune system. NF-,B has been found to play roles in many different compartments of the immune system during differentiation of immune cells and development of lymphoid organs and during immune activation. NF-,B is the nuclear effector of signaling pathways emanating from many receptors, including those of the inflammatory tumor necrosis factor and Toll-like receptor superfamilies. With this review, we hope to provide historical context and summarize the diverse physiological functions of NF-,B in the immune system before focusing on recent advances in elucidating the molecular mechanisms that mediate cell type-specific and stimulus-specific functions of this pleiotropic signaling system. Understanding the genetic regulatory circuitry of NF-,B functionalities involves system-wide measurements, biophysical studies, and computational modeling. [source] Towards a comprehensive computational model for the respiratory system,INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 7 2010Wolfgang A. Wall Abstract This paper is concerned with computational modeling of the respiratory system against the background of acute lung diseases and mechanical ventilation. Conceptually, we divide the lung into two major subsystems, namely the conducting airways and the respiratory zone represented by lung parenchyma. Owing to their respective complexity, both parts are themselves out of range for a direct numerical simulation resolving all relevant length scales. Therefore, we develop detailed individual models for parts of the subsystems as a basis for novel multi-scale approaches taking into account the unresolved parts appropriately. In the tracheobronchial region, CT-based geometries up to a maximum of approximately seven generations are employed in fluid,structure interaction simulations, considering not only airway wall deformability but also the influence of surrounding lung tissue. Physiological outflow boundary conditions are derived by considering the impedance of the unresolved parts of the lung in a fully coupled 3D-1D approach. In the respiratory zone, an ensemble of alveoli representing a single ventilatory unit is modeled considering not only soft tissue behavior but also the influence of the covering surfactant film. Novel nested multi-scale procedures are then employed to simulate the dynamic behavior of lung parenchyma as a whole and local alveolar ensembles simultaneously without resolving the alveolar micro-structure completely. Copyright © 2010 John Wiley & Sons, Ltd. [source] The musculotendinous system of an anguilliform swimmer: Muscles, myosepta, dermis, and their interconnections in Anguilla rostrataJOURNAL OF MORPHOLOGY, Issue 1 2008Nicole Danos Abstract Eel locomotion is considered typical of the anguilliform swimming mode of elongate fishes and has received substantial attention from various perspectives such as swimming kinematics, hydrodynamics, muscle physiology, and computational modeling. In contrast to the extensive knowledge of swimming mechanics, there is limited knowledge of the internal body morphology, including the body components that contribute to this function. In this study, we conduct a morphological analysis of the collagenous connective tissue system, i.e., the myosepta and skin, and of the red muscle fibers that sustain steady swimming, focusing on the interconnections between these systems, such as the muscle-tendon and myosepta-skin connections. Our aim is twofold: (1) to identify the morphological features that distinguish this anguilliform swimmer from subcarangiform and carangiform swimmers, and (2) to reveal possible pathways of muscular force transmission by the connective tissue in eels. To detect gradual morphological changes along the trunk we investigated anterior (0.4L), midbody (0.6L), and posterior body positions (0.75L) using microdissections, histology, and three-dimensional reconstructions. We find that eel myosepta have a mediolaterally oriented tendon in each the epaxial and hypaxial regions (epineural or epipleural tendon) and two longitudinally oriented tendons (myorhabdoid and lateral). The latter two are relatively short (4.5,5% of body length) and remain uniform along a rostrocaudal gradient. The skin and its connections were additionally analyzed using scanning electron microscopy (SEM). The stratum compactum of the dermis consists of ,30 layers of highly ordered collagen fibers of alternating caudodorsal and caudoventral direction, with fiber angles of 60.51 ± 7.05° (n = 30) and 57.58 ± 6.92° (n = 30), respectively. Myosepta insert into the collagenous dermis via fiber bundles that pass through the loose connective tissue of the stratum spongiosum of the dermis and either weave into the layers of the stratum compactum (weaving fiber bundles) or traverse the stratum compactum (transverse fiber bundles). These fiber bundles are evenly distributed along the insertion line of the myoseptum. Red muscles insert into lateral and myorhabdoid myoseptal tendons but not into the horizontal septum or dermis. Thus, red muscle forces might be distributed along these tendons but will only be delivered indirectly into the dermis and horizontal septum. The myosepta-dermis connections, however, appear to be too slack for efficient force transmission and collagenous connections between the myosepta and the horizontal septum are at obtuse angles, a morphology that appears inadequate for efficient force transmission. Though the main modes of undulatory locomotion (anguilliform, subcarangiform, and carangiform) have recently been shown to be very similar with respect to their midline kinematics, we are able to distinguish two morphological classes with respect to the shape and tendon architecture of myosepta. Eels are similar to subcarangiform swimmers (e.g., trout) but are substantially different from carangiform swimmers (e.g., mackerel). This information, in addition to data from kinematic and hydrodynamic studies of swimming, shows that features other than midline kinematics (e.g., wake patterns, muscle activation patterns, and morphology) might be better for describing the different swimming modes of fishes. J. Morphol., 2008. © 2007 Wiley-Liss, Inc. [source] Dynamic Compressive Failure of AlON Under Controlled Planar ConfinementJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2008Bhasker Paliwal An experimental technique is developed to impose a planar lateral confinement in a prismatic specimen (with a rectangular cross section); the setup enabled a controlled and homogeneous stress state with high lateral compressive stresses. A transparent polycrystalline aluminum oxynitride (AlON) specimen was used for the study. The statically precompressed specimen was then subjected to axial dynamic compressive loading using a modified compression Kolsky bar setup. Experimental design was performed using 3D computational modeling. Initial exploratory experiments were conducted on AlON at an average planar confinement of 400,410 MPa; the results suggested a higher compressive strength and a nonlinear stress evolution in AlON due to the confinement. A high-speed camera was used to observe the damage evolution in the specimen during the course of loading. The photographs and stress evolution are suggestive of an additional inelastic deformation mechanism, whose evolution is slower than the typical brittle-cracking type of damage apparent in the unconfined case. The TEM and high-resolution electron microscope analysis indicated dislocation plasticity in some fragments; dislocations in the slip bands were characterized to be dissociated ,110, dislocations on {111} planes. The width between two partial dislocations was about 15 nm, suggesting low stacking fault energy of AlON. Microscopic characterization also shows that the eventual fragmentation of AlON is by cleavage mainly along low-index {111} planes. [source] Language Is a Complex Adaptive System: Position PaperLANGUAGE LEARNING, Issue 2009The "Five Graces Group" Language has a fundamentally social function. Processes of human interaction along with domain-general cognitive processes shape the structure and knowledge of language. Recent research in the cognitive sciences has demonstrated that patterns of use strongly affect how language is acquired, is used, and changes. These processes are not independent of one another but are facets of the same,complex adaptive system,(CAS). Language as a CAS involves the following key features: The system consists of multiple agents (the speakers in the speech community) interacting with one another. The system is adaptive; that is, speakers' behavior is based on their past interactions, and current and past interactions together feed forward into future behavior. A speaker's behavior is the consequence of competing factors ranging from perceptual constraints to social motivations. The structures of language emerge from interrelated patterns of experience, social interaction, and cognitive mechanisms. The CAS approach reveals commonalities in many areas of language research, including first and second language acquisition, historical linguistics, psycholinguistics, language evolution, and computational modeling. [source] Structure determination of slowly exchanging conformers in solution using high-resolution NMR, computational modeling and DFT-GIAO chemical shielding: application to an erythronolide A derivativeMAGNETIC RESONANCE IN CHEMISTRY, Issue 11 2009Dieter Muri Abstract We discuss and demonstrate the potential of HSQC-TOCSY and HSQC-NOESY experiments to offer solutions for overlap problems in COSY and NOESY spectra, leading to improved signals that can be unambiguously assigned to individual carbons. Direct comparison of experimental 1H and 13C chemical shielding with density functional theory (DFT)-calculated values are uninformative; in contrast, the relative differences in experimental shielding between pairs of molecules correlates well with the relative differences in DFT-GIAO shielding for the computed lowest energy conformers. A detailed application of both experimental and theoretical techniques is illustrated for slowly exchanging conformers of an erythronolide A derivative, which demonstrates that structure determination can strongly benefit from the interplay between experiment and theory. Copyright © 2009 John Wiley & Sons, Ltd. [source] Phosphoproteomics, oncogenic signaling and cancer researchPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 21 2008Poh-Kuan Chong Abstract The past 5,years have seen an explosion of phosphoproteomics methods development. In this review, using epidermal growth-factor signaling as a model, we will discuss how phosphoproteomics, along with bioinformatics and computational modeling, have impacted key aspects of oncogenic signaling such as in the temporal fine mapping of phosphorylation events, and the identification of novel tyrosine kinase substrates and phosphorylation sites. We submit that the next decade will see considerable exploitation of phosphoproteomics in cancer research. Such a phenomenon is already happening as exemplified by its use in promoting the understanding of the molecular etiology of cancer and target-directed therapeutics. [source] Cadaveric and Engineering Analysis of the Septal L-Strut,THE LARYNGOSCOPE, Issue 11 2007Ted Mau MD Abstract Objectives: To identify patterns of failure of the L-strut, to identify elements of the nasal framework that support the L-strut, and to investigate the effect of altering L-strut design on its stability. Study Design: Laboratory study with human cadaveric heads and computational modeling. Methods: Directional forces were applied to cadaveric L-struts and patterns of failure with incremental force were noted. Computational modeling using the finite element method (FEM) was employed to determine quantitatively the effect of various modifications on the stability of the L-strut. Results: The L-strut was found to respond to frontal force initially by buckling. This buckling was reversible until the force exceeded a certain threshold when the L-strut broke at the bony-cartilaginous junction. The threshold force varied depending on the length of the overlap with the bony vault. Intact mucoperichondrium provided significant stability. Modeling with FEM showed that the preservation of a triangular piece of cartilage at the dorsal anchor of a narrowed L-strut can offset some of the loss in mechanical stability. Conclusions: Intrinsic elasticity of the septal cartilage, the mucoperichondrial flap, and overlap with the bony vault all contribute to the stability of the L-strut, which is enhanced by preserving a small segment of cartilage at the bony-cartilaginous junction of the dorsal L-strut. [source] A series of molecular dynamics and homology modeling computer labs for an undergraduate molecular modeling courseBIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 4 2010Donald E. Elmore Abstract As computational modeling plays an increasingly central role in biochemical research, it is important to provide students with exposure to common modeling methods in their undergraduate curriculum. This article describes a series of computer labs designed to introduce undergraduate students to energy minimization, molecular dynamics simulations, and homology modeling. These labs were created as part of a one-semester course on the molecular modeling of biochemical systems. Students who completed these activities felt that they were an effective component of the course, reporting improved comfort with the conceptual background and practical implementation of the computational methods. Although created as a component of a larger course, these activities could be readily adapted for a variety of other educational contexts. As well, all of these labs utilize software that is freely available in an academic environment and can be run on fairly common computer hardware, making them accessible to teaching environments without extensive computational resources. [source] Better library design: data-driven protein engineeringBIOTECHNOLOGY JOURNAL, Issue 2 2007Javier F. Chaparro-Riggers Abstract Data-driven protein engineering is increasingly used as an alternative to rational design and combinatorial engineering because it uses available knowledge to limit library size, while still allowing for the identification of unpredictable substitutions that lead to large effects. Recent advances in computational modeling and bioinformatics, as well as an increasing databank of experiments on functional variants, have led to new strategies to choose particular amino acid residues to vary in order to increase the chances of obtaining a variant protein with the desired property. Strategies for limiting diversity at each position, design of small sub-libraries, and the performance of scouting experiments, have also been developed or even automated, further reducing the library size. [source] Influence of Intermolecular Interactions on the Formation of Tetra(carbomethoxy)-tetrathiafulvalene AssembliesCHEMPHYSCHEM, Issue 10 2007Núria Crivillers Abstract We study the assemblies that tetra(carbomethoxy)tetrathiafulvalene (TCM,TTF) forms in solution and when deposited on a surface depending on intermolecular interactions and on the interactions with the substrate and the solvent. Its organization on graphite and mica substrates was studied by atomic force microscopy, and different molecular assemblies were observed depending on the prevailing interactions. The promotion of molecule,molecule interactions gave rise to the formation of molecular fibers. The investigation of the influence of the solvent,molecule interactions on TCM,TTF molecular organizations was carried out by UV/Vis spectroscopy, and a new TCM,TTF polymorph was obtained by changing the nature of the solvent. Finally, an explanation for all these phenomena, supported by computational modeling, is put forward. [source] How Infants Learn About the Visual WorldCOGNITIVE SCIENCE - A MULTIDISCIPLINARY JOURNAL, Issue 7 2010Scott P. Johnson Abstract The visual world of adults consists of objects at various distances, partly occluding one another, substantial and stable across space and time. The visual world of young infants, in contrast, is often fragmented and unstable, consisting not of coherent objects but rather surfaces that move in unpredictable ways. Evidence from computational modeling and from experiments with human infants highlights three kinds of learning that contribute to infants' knowledge of the visual world: learning via association, learning via active assembly, and learning via visual-manual exploration. Infants acquire knowledge by observing objects move in and out of sight, forming associations of these different views. In addition, the infant's own self-produced behavior,oculomotor patterns and manual experience, in particular,is an important means by which infants discover and construct their visual world. [source] | ||||||||||||||||||||||||||||