48 research outputs found
Non-classical behavior of atoms in an interferometer
We have studied the properties of the non-classical behavior of atoms in a
double-slit interferometer. An indication of this behavior for metastable
helium was reported by Kurtsiefer, Pfau and Mlynek [Nature 386, 150 (1997)]
showing distinctive negative values of the Wigner function, which was
reconstructed from the measured diffraction data. Our approach to explain this
non-classical behavior is based on the de Broglie-Bohm-Vigier-Selleri
understanding of the wave-particle duality and compatible statistical
interpretation of the atomic wave function. It follows from the results that
the atomic motion is non-classical because it does not obey the laws of
classical mechanics. However, there is no evidence that this atomic behavior
violates the classical probability law of the addition of probabilities.Comment: 10 pages, 9 figure
Decompositional Representation of Morphological Complexity: Multivariate fMRI Evidence from Italian.
Derivational morphology is a cross-linguistically dominant mechanism for word formation, combining existing words with derivational affixes to create new word forms. However, the neurocognitive mechanisms underlying the representation and processing of such forms remain unclear. Recent cross-linguistic neuroimaging research suggests that derived words are stored and accessed as whole forms, without engaging the left-hemisphere perisylvian network associated with combinatorial processing of syntactically and inflectionally complex forms. Using fMRI with a "simple listening" no-task procedure, we reexamine these suggestions in the context of the root-based combinatorially rich Italian lexicon to clarify the role of semantic transparency (between the derived form and its stem) and affix productivity in determining whether derived forms are decompositionally represented and which neural systems are involved. Combined univariate and multivariate analyses reveal a key role for semantic transparency, modulated by affix productivity. Opaque forms show strong cohort competition effects, especially for words with nonproductive suffixes (ventura, "destiny"). The bilateral frontotemporal activity associated with these effects indicates that opaque derived words are processed as whole forms in the bihemispheric language system. Semantically transparent words with productive affixes (libreria, "bookshop") showed no effects of lexical competition, suggesting morphologically structured co-representation of these derived forms and their stems, whereas transparent forms with nonproductive affixes (pineta, pine forest) show intermediate effects. Further multivariate analyses of the transparent derived forms revealed affix productivity effects selectively involving left inferior frontal regions, suggesting that the combinatorial and decompositional processes triggered by such forms can vary significantly across languages.This research was supported by an Advanced Investigator grant to WMW from the European Research Council (AdG 230570 NEUROLEX) and by MRC Cognition and Brain Sciences Unit (CBSU) funding to WMW (U.1055.04.002.00001.01). Computing resources were provided by the MRC CBSU.This is the author accepted manuscript. The final version is available from MIT Press via http://dx.doi.org/10.1162/jocn_a_0100
Cross-linguistic parallels in processing derivational morphology: evidence from Polish.
Neuroimaging evidence in English suggests that the neurocognitive processing of derivationally complex words primarily reflects their properties as whole forms. The current experiment provides a cross-linguistic examination of these proposals by investigating the processing of derivationally complex words in the rich morphological system of Polish. Within the framework of a dual language system approach, we asked whether there is evidence for decompositional processing of derivationally complex Polish stems - reflected in the activation of a linguistically specific decompositional system in the left hemisphere - or for increased competition between the derived stem and its embedded base stem in the bilateral system. The results showed activation in the bilateral system and no evidence for selective engagement of the left hemisphere decompositional system. This provides a cross-linguistic validation for the hypothesis that the neurocognitive processing of derived stems primarily reflects their properties as stored forms
Brain Network Connectivity During Language Comprehension: Interacting Linguistic and Perceptual Subsystems.
The dynamic neural processes underlying spoken language comprehension require the real-time integration of general perceptual and specialized linguistic information. We recorded combined electro- and magnetoencephalographic measurements of participants listening to spoken words varying in perceptual and linguistic complexity. Combinatorial linguistic complexity processing was consistently localized to left perisylvian cortices, whereas competition-based perceptual complexity triggered distributed activity over both hemispheres. Functional connectivity showed that linguistically complex words engaged a distributed network of oscillations in the gamma band (20-60 Hz), which only partially overlapped with the network supporting perceptual analysis. Both processes enhanced cross-talk between left temporal regions and bilateral pars orbitalis (BA47). The left-lateralized synchrony between temporal regions and pars opercularis (BA44) was specific to the linguistically complex words, suggesting a specific role of left frontotemporal cross-cortical interactions in morphosyntactic computations. Synchronizations in oscillatory dynamics reveal the transient coupling of functional networks that support specific computational processes in language comprehension.This work was supported by an EPSRC grant to W.M.-W. (EP/F030061/1), an ERC Advanced Grant (Neurolex) to W.M.-W., and by MRC Cognition and Brain Sciences Unit (CBU) funding to
W.M.-W. (U.1055.04.002.00001.01). Computing resources were provided by the MRC-CBU. Funding to pay the Open Access publication charges for this article was provided by the Advanced Investigator Grant (Neurolex) to W.D.M.-W.This is the final published version which appears at http://dx.doi.org/10.1093/cercor/bhu28
Grammatical analysis as a distributed neurobiological function.
This is the final version of the article. It first appeared from [publisher] via http://dx.doi.org/10.1002/hbm.22696Language processing engages large-scale functional networks in both hemispheres. Although it is widely accepted that left perisylvian regions have a key role in supporting complex grammatical computations, patient data suggest that some aspects of grammatical processing could be supported bilaterally. We investigated the distribution and the nature of grammatical computations across language processing networks by comparing two types of combinatorial grammatical sequences--inflectionally complex words and minimal phrases--and contrasting them with grammatically simple words. Novel multivariate analyses revealed that they engage a coalition of separable subsystems: inflected forms triggered left-lateralized activation, dissociable into dorsal processes supporting morphophonological parsing and ventral, lexically driven morphosyntactic processes. In contrast, simple phrases activated a consistently bilateral pattern of temporal regions, overlapping with inflectional activations in L middle temporal gyrus. These data confirm the role of the left-lateralized frontotemporal network in supporting complex grammatical computations. Critically, they also point to the capacity of bilateral temporal regions to support simple, linear grammatical computations. This is consistent with a dual neurobiological framework where phylogenetically older bihemispheric systems form part of the network that supports language function in the modern human, and where significant capacities for language comprehension remain intact even following severe left hemisphere damage.Computing resources were provided by the MRC-CBU. Li
Su was partly supported by the Cambridge Dementia
Biomedical Research Unit
Neurobiological systems for lexical representation and analysis in English.
Current research suggests that language comprehension engages two joint but functionally distinguishable neurobiological processes: a distributed bilateral system, which supports general perceptual and interpretative processes underpinning speech comprehension, and a left hemisphere (LH) frontotemporal system, selectively tuned to the processing of combinatorial grammatical sequences, such as regularly inflected verbs in English [Marslen-Wilson, W. D., & Tyler, L. K. Morphology, language and the brain: The decompositional substrate for language comprehension. Philosophical Transactions of the Royal Society: Biological Sciences, 362, 823-836, 2007]. Here we investigated how English derivationally complex words engage these systems, asking whether they selectively activate the LH system in the same way as inflections or whether they primarily engage the bilateral system that support nondecompositional access. In an fMRI study, we saw no evidence for selective activation of the LH frontotemporal system, even for highly transparent forms like bravely. Instead, a combination of univariate and multivariate analyses revealed the engagement of a distributed bilateral system, modulated by factors of perceptual complexity and semantic transparency. We discuss the implications for theories of the processing and representation of English derivational morphology and highlight the importance of neurobiological constraints in understanding these processes
Eksploatacioni parametri kombajna za ubiranje semenskog kukuruza
Maize is one of the most important crops and one of the most significant
naturally renewable energy source, but also numerous very different products. The maize
seed production is much more complex, sensitive and expense than the commercial
maize production. Therefore a special attention should be paid during the whole process
of the seed production, in order to achieve higher yields and better seed quality.
The aim of this study was to reveal the effects of harvest methods on maize hybrid
seed production and on losses. Paper presents comparison of different technological
designs of maize seed harvesters.Kukuruz je jedna od najznačajnijih gajenih biljaka i jedan od najznačajnijih
prirodno obnovljivih izvora energije i velikog broja proizvoda. Proizvodnja semena
kukuruza je veoma složena, osetljiva i znatno skuplja od merkantilne proizvodnje. Zbog
toga se ovoj proizvodnji posvećuje posebna pažnja u cilju ostvarivanja većih prinosa i
kvalitetnijeg semena.
Cilj rada je da se pokaže kako načini ubiranja utiču na proizvodnju hibridnog
semena kukuruza kao i na gubitke. Prikazana su različita tehnološka rešenja kombajna za
ubiranje semenskog kukuruza
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Bilingualism and language similarity modify the neural mechanisms of selective attention.
Learning and using multiple languages places major demands on our neurocognitive system, which can impact the way the brain processes information. Here we investigated how early bilingualism influences the neural mechanisms of auditory selective attention, and whether this is further affected by the typological similarity between languages. We tested the neural encoding of continuous attended speech in early balanced bilinguals of typologically similar (Dutch-English) and dissimilar languages (Spanish-English) and compared them to results from English monolinguals we reported earlier. In a dichotic listening paradigm, participants attended to a narrative in their native language while ignoring different types of interference in the other ear. The results revealed that bilingualism modulates the neural mechanisms of selective attention even in the absence of consistent behavioural differences between monolinguals and bilinguals. They also suggested that typological similarity between languages helps fine-tune this modulation, reflecting life-long experiences with resolving competition between more or less similar candidates. The effects were consistent over the time-course of the narrative and suggest that learning a second language at an early age triggers neuroplastic adaptation of the attentional processing system.Cambridge Language Sciences Incubator grant
Experimental Psychology Society Small Gran
Early decomposition in visual word recognition: Dissociating morphology, form, and meaning
The role of morphological, semantic, and form-based factors in the early stages of visual word recognition was investigated across different SOAs in a masked priming paradigm, focusing on English derivational morphology. In a first set of experiments, stimulus pairs co-varying in morphological decomposability and in semantic and orthographic relatedness were presented at three SOAs (36, 48, and 72 ms). No effects of orthographic relatedness were found at any SOA. Semantic relatedness did not interact with effects of morphological decomposability, which came through strongly at all SOAs, even for pseudo-suffixed pairs such as archer-arch. Derivational morphological effects in masked priming seem to be primarily driven by morphological decomposability at an early stage of visual word recognition, and are independent of semantic factors. A second experiment reversed the order of prime and target (stem-derived rather than derived-stem), and again found that morphological priming did not interact with semantic relatedness. This points to an early segmentation process that is driven by morphological decomposability and not by the structure or content of central lexical representations