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Word forms such as walked or walker are decomposed into their morphological constituents (walk + -ed/-er) during language comprehension. Yet, the efficiency of morphological decomposition seems to vary for different languages and morphological types, as well as for first and second language speakers. The current study reports results from a visual masked priming experiment focusing on different types of derived word forms (specifically prefixed vs. suffixed) in first and second language speakers of German. We compared the present findings with results from previous studies on inflection and compounding and proposed an account of morphological decomposition that captures both the variability and the consistency of morphological decomposition for different morphological types and for first and second language speakers. Open Practices This article has been awarded an Open Materials badge. Study materials are publicly accessible via the Open Science Framework at . Learn more about the Open Practices badges from the Center for Open Science.
The current study investigates how bilingual children encode and produce morphologically complex words. We employed a silent-production-plus-delayed-vocalization paradigm in which event-related brain potentials (ERPs) were recorded during silent encoding of inflected words which were subsequently cued to be overtly produced. The bilingual children's spoken responses and their ERPs were compared to previous datasets from monolingual children on the same task. We found an enhanced negativity for regular relative to irregular forms during silent production in both bilingual children's languages, replicating the ERP effect previously obtained from monolingual children. Nevertheless, the bilingual children produced more morphological errors (viz. over-regularizations) than monolingual children. We conclude that mechanisms of morphological encoding (as measured by ERPs) are parallel for bilingual and monolingual children, and that the increased over-regularization rates are due to their reduced exposure to each of the two languages (relative to monolingual children).
Salt marshes filter pollutants, protect coastlines against storm surges, and sequester carbon, yet are under threat from sea level rise and anthropogenic modification. The sustained existence of the salt marsh ecosystem depends on the topographic evolution of marsh platforms. Quantifying marsh platform topography is vital for improving the management of these valuable landscapes. The determination of platform boundaries currently relies on supervised classification methods requiring near-infrared data to detect vegetation, or demands labour-intensive field surveys and digitisation. We propose a novel, unsupervised method to reproducibly isolate salt marsh scarps and platforms from a digital elevation model (DEM), referred to as Topographic Identification of Platforms (TIP). Field observations and numerical models show that salt marshes mature into subhorizontal platforms delineated by subvertical scarps. Based on this premise, we identify scarps as lines of local maxima on a slope raster, then fill landmasses from the scarps upward, thus isolating mature marsh platforms. We test the TIP method using lidar-derived DEMs from six salt marshes in England with varying tidal ranges and geometries, for which topographic platforms were manually isolated from tidal flats. Agreement between manual and unsupervised classification exceeds 94% for DEM resolutions of 1 m, with all but one site maintaining an accuracy superior to 90% for resolutions up to 3 m. For resolutions of 1 m, platforms detected with the TIP method are comparable in surface area to digitised platforms and have similar elevation distributions. We also find that our method allows for the accurate detection of local block failures as small as 3 times the DEM resolution. Detailed inspection reveals that although tidal creeks were digitised as part of the marsh platform, unsupervised classification categorises them as part of the tidal flat, causing an increase in false negatives and overall platform perimeter. This suggests our method may benefit from combination with existing creek detection algorithms. Fallen blocks and high tidal flat portions, associated with potential pioneer zones, can also lead to differences between our method and supervised mapping. Although pioneer zones prove difficult to classify using a topographic method, we suggest that these transition areas should be considered when analysing erosion and accretion processes, particularly in the case of incipient marsh platforms. Ultimately, we have shown that unsupervised classification of marsh platforms from high-resolution topography is possible and sufficient to monitor and analyse topographic evolution.
ShapeRotator
(2018)
The quantification of complex morphological patterns typically involves comprehensive shape and size analyses, usually obtained by gathering morphological data from all the structures that capture the phenotypic diversity of an organism or object. Articulated structures are a critical component of overall phenotypic diversity, but data gathered from these structures are difficult to incorporate into modern analyses because of the complexities associated with jointly quantifying 3D shape in multiple structures. While there are existing methods for analyzing shape variation in articulated structures in two-dimensional (2D) space, these methods do not work in 3D, a rapidly growing area of capability and research. Here, we describe a simple geometric rigid rotation approach that removes the effect of random translation and rotation, enabling the morphological analysis of 3D articulated structures. Our method is based on Cartesian coordinates in 3D space, so it can be applied to any morphometric problem that also uses 3D coordinates (e.g., spherical harmonics). We demonstrate the method by applying it to a landmark-based dataset for analyzing shape variation using geometric morphometrics. We have developed an R tool (ShapeRotator) so that the method can be easily implemented in the commonly used R package geomorph and MorphoJ software. This method will be a valuable tool for 3D morphological analyses in articulated structures by allowing an exhaustive examination of shape and size diversity.
Previous research has shown that high phonotactic frequencies
facilitate the production of regularly inflected verbs in English-learning
children with specific language impairment (SLI) but not with typical
development (TD). We asked whether this finding can be replicated
for German, a language with a much more complex inflectional
verb paradigm than English. Using an elicitation task, the production
of inflected nonce verb forms (3 rd person singular with -t suffix)
with either high- or low-frequency subsyllables was tested in
sixteen German-learning children with SLI (ages 4;1–5 ;1), sixteen
TD-children matched for chronological age (CA) and fourteen TD-
children matched for verbal age (VA) (ages 3;0–3 ;11). The findings
revealed that children with SLI, but not CA- or VA-children, showed
differential performance between the two types of verbs, producing
more inflectional errors when the verb forms resulted in low-frequency
subsyllables than when they resulted in high-frequency subsyllables,
replicating the results from English-learning children.
Do properties of individual languages shape the mechanisms by which they are processed? By virtue of their non-concatenative morphological structure, the recognition of complex words in Semitic languages has been argued to rely strongly on morphological information and on decomposition into root and pattern constituents. Here, we report results from a masked priming experiment in Hebrew in which we contrasted verb forms belonging to two morphological classes, Paal and Piel, which display similar properties, but crucially differ on whether they are extended to novel verbs. Verbs from the open-class Piel elicited familiar root priming effects, but verbs from the closed-class Paal did not. Our findings indicate that, similarly to other (e.g., Indo-European) languages, down-to-the-root decomposition in Hebrew does not apply to stems of non-productive verbal classes. We conclude that the Semitic word processor is less unique than previously thought: Although it operates on morphological units that are combined in a non-linear way, it engages the same universal mechanisms of storage and computation as those seen in other languages.
Editorial
(2016)
This article first outlines different ways of how psycholinguists have dealt with linguistic diversity and illustrates these approaches with three familiar cases from research on language processing, language acquisition, and language disorders. The second part focuses on the role of morphology and morphological variability across languages for psycholinguistic research. The specific phenomena to be examined are to do with stem-formation morphology and inflectional classes; they illustrate how experimental research that is informed by linguistic typology can lead to new insights.
Calcium phosphate nanofibers with a diameter of only a few nanometers and a cotton-ball-like aggregate morphology have been reported several times in the literature. Although fiber formation seems reproducible in a variety of conditions, the crystal structure and chemical composition of the fibers have been elusive. Using scanning transmission electron microscopy, low dose electron (nano)diffraction, energy-dispersive X-ray spectroscopy, and energy-filtered transmission electron microscopy, we have assigned crystal structures and chemical compositions to the fibers. Moreover, we demonstrate that the mineralization process yields true polymer/calcium phosphate hybrid materials where the block copolymer template is closely associated with the calcium phosphate.