Spoken word production: Processes and potential breakdown

Introduction: The processes of spoken word production have been a focus of interest for decades and this research has been summarised in several reviews (e.g., Friedmann, Biran, & Dotan, 2013; Nickels, 1997, 2001a,b; Wilshire, 2008). However, many questions remain unanswered and consequently spoken word production remains an area of research interest, informed by data from unimpaired and impaired adult language, as well as language development. Several theories of spoken language production have been proposed over the last half century, each differing slightly in levels of representation, processing steps, and activation flow. In this chapter, we focus on four of the most influential theories of spoken language production

Garlic and ginger are not like apples and oranges: Effects of mass/count information on the production of noun phrases in English

In this study a picture–word interference paradigm was used to investigate how grammatical mass/count information is processed during noun phrase production in English. Theories of lexical processing distinguish between two different types of lexical–syntactic information: variable extrinsic lexical–syntactic features, such as number (singular, plural), and fixed intrinsic lexical–syntactic properties, such as grammatical gender (e.g., masculine, feminine). Previous research using the picture–word interference paradigm has found effects of distractor lexical–syntactic congruency for grammatical gender but no congruency effects for number. We used this phenomenon to investigate whether mass/count information is processed similarly to grammatical gender. In two experiments, participants named pictures of mass or count objects using determiner noun phrases (e.g., Experiment 1 with mass and plural count nouns: “not muchmass ricemass”, “not manycount pegscount”; Experiment 2 with mass and singular count nouns: “some ricemass”, “a pegcount”), while ignoring distractors that were countability congruent or incongruent nouns. The results revealed a countability congruency effect for mass and plural count nouns in Experiment 1 and for singular count nouns, but not mass nouns in Experiment 2. This is similar to grammatical gender suggesting that countability processing is predominantly driven by a noun’s lexical–syntactic information. © 2017 The Experimental Psychology Societ

The relationship between response consistency in picture naming and storage impairment in people with semantic variant Primary Progressive Aphasia

This is the author accepted manuscript. The final version is available from the American Psychological Association via the DOI in this record.Objective. The progressive loss of stored knowledge about word meanings in semantic variant Primary Progressive Aphasia (svPPA) has been attributed to an amodal “storage” deficit of the semantic system. Performance consistency has been proposed to be a key characteristic of storage deficits but has not been examined in close detail and larger participant cohorts. Methods: We assessed whether 10 people with svPPA showed consistency in picture naming across three closely consecutive sessions. We examined item-by-item consistency of naming accuracy and specific error types, while controlling for the effects of variables such as word frequency, familiarity and age of acquisition. Results: Participants were very consistent in their accurate and inaccurate responses over and above any effects of the word-related variables. Analyses of error types that compared consistency of semantic errors, correct responses and other error types (e.g., phonologically related errors, unrelated errors) revealed lower consistency. Conclusions: Our findings support the assumption that semantic features constituting semantic representations of objects are progressively lost in people with svPPA and are therefore consistently unavailable during naming. Variability in the production of error types remains when distinctive features of an object are lost resulting in the selection of semantically or visually similar items, or in the failure to select an item and the production of a no-response. The assessment of performance consistency sheds light on the underlying impairment of people with semantic deficits (semantic storage versus access deficit). This can support the choice of an appropriate treatment technique aiming to maintain, or re-learn semantic information

The Influence of Spatial Resolution due to Hot-Wire Sensors on Measurements in Wall-Bounded Turbulence.

Reassessment of compiled data reveal that recorded scatter in the hot-wire measured near-wall peak in viscous-scaled streamwise turbulence intensity is due in large part to the simultaneous competing effects of Reynolds number and viscous-scaled wire-length l ( lUt n, where l is the wirelength, Ut is friction velocity and n is kinematic viscosity). These competing factors can explain much of the disparity in existing literature, in particular explaining how previous studies have incorrectly concluded that the inner-scaled near-wall peak is independent of Re. We also investigate the appearance of the, so-called, ‘outerpeak’ in the broadband streamwise intensity, found by some researchers to occur within the log-region of high Reynolds number boundary layers. We show that this ‘outer-peak’ is most likely a symptom of attenuation of small-scales due to large l . Fully mapped energy spectra, obtained with two different l , are presented to demonstrate this phenomena. The spatial attenuation resulting from wires with large l effectively filters small-scale fluctuations from the recorded signal

The effects of shrub encroachment on arthropod communities depend on grazing history

Unsustainable grazing is a major driver of biodiversity loss worldwide. Conservation actions such as grazing exclusion are effective strategies for halting such decline. However, we still know little how the long-term impact of grazing exclusion depends on plant–animal interactions such as those between encroaching unpalatable shrubs and ground arthropods. Here, we assessed how encroaching, unpalatable shrub species (Sarcopoterium spinosum) mediates the effects of grazing exclusion on the recovery of arthropod communities. We used a large-scale, long-term (15–25 years) grazing exclusion experiment complemented with local-scale treatments that consider the presence or absence of shrubs. We found that halting overgrazing supported the recovery of biodiversity in the long-term. Notably, the impacts of shrubs on arthropod diversity vary with grazing history. Shrubs decreased arthropod abundance by three folds, affecting particularly flies, butterflies, hymenopteran, and beetles in protected areas. Yet, shrubs had positive effects on animal diversity, particularly centipedes and millipeds in grazed areas. On the one hand, shrubs may enhance biodiversity recovery in overgrazed systems; on the other hand, shrubs may be detrimental in protected areas, in the absence of grazing. Understanding how plant–animal interactions vary with historical land-use change is key for biodiversity conservation and recovery and for integrated management of agroecosystems

Vapor Distribution above an Evaporating Sessile Drop

An experimental technique was developed that uses infrared tomography to measure the three-dimensional vapor distribution above an evaporating sessile drop. The technique was applied to measure the vapor distributions above evaporating drops of hexane and 3-methylpentane (3MP) at room temperature and pressure. The molecular masses of these two species are heavier than air and the vapor from the evaporating drop forms a flat, disk-shaped cloud. A Fourier transform infrared spectrometer (FTIR) was used to measure the spectral absorbance along a set of paths passing through the vapor cloud. From a set of path-averaged absorbance measurements, a two-dimensional spatial concentration distribution was determined using a computed tomography routine. A three-dimensional concentration distribution was obtained from multiple two-dimensional distributions obtained at different elevations above the drop. The vapor distributions for both hexane and 3MP differ significantly from the values predicted by the solutions for diffusion-limited evaporation and indicate the effect of buoyancy-induced convection of the vapor. These measurements are the first quantitative measurements of the vapor distribution above a sessile drop and are important for advancing the understanding of the vapor phase transport mechanisms, and thus sessile drop evaporation

Testosterone, cortisol, and status-striving personality features: A review and empirical evaluation of the dual hormone hypothesis

Decades of research in behavioral endocrinology has implicated the gonadal hormone testosterone in the reg- ulation of mating effort, often expressed in primates in the form of aggressive and/or status-striving behavior. Based on the idea that neuroendocrine axes influence each other, recent work among humans has proposed that links between testosterone and indices of status-striving are rendered conditional by the effects of glucocorti- coids. The Dual Hormone hypothesis is one particular instance of this argument, predicting that cortisol blocks the effects of testosterone on dominance, aggression, and risk-taking in humans. Support for the Dual Hormone hypothesis is wide-ranging, but considerations of theoretical ambiguity, null findings, and low statistical power pose problems for interpreting the published literature. Here, we contribute to the development of the Dual Hormone hypothesis by (1) critically reviewing the extant literature—including p-curve analyses of published findings; and, (2) “opening the file drawer” and examining relationships between testosterone, cortisol, and status-striving personality features in seven previously published studies from our laboratories (total N = 718; median N per feature = 318) that examined unrelated predictions. Results from p-curve suggest that published studies have only 16% power to detect effects, while our own data show no robust interactions between tes- tosterone and cortisol in predicting status-striving personality features. We discuss the implications of these results for the Dual Hormone hypothesis, limitations of our analyses, and the development of future research

Semantic variant primary progressive aphasia: Practical recommendations for treatment from 20 years of behavioural research

People with semantic variant primary progressive aphasia (svPPA) present with a char-acteristic progressive breakdown of semantic knowledge. There are currently no pharmacological interventions to cure or slow svPPA, but promising behavioural approaches are increasingly reported. This article offers an overview of the last two decades of research into interventions to support language in people with svPPA including recommendations for clinical practice and future research based on the best available evidence. We offer a lay summary in English, Spanish and French for education and dissemination purposes. This paper discusses the implications of right-versus left-predominant atrophy in svPPA, which naming therapies offer the best outcomes and how to capitalise on preserved long-term memory systems. Current knowledge regarding the maintenance and generalisation of language therapy gains is described in detail along with the development of compensatory approaches and educational and support group programmes. It is concluded that there is evidence to support an integrative framework of treatment and care as best practice for svPPA. Such an approach should combine rehabilitation interventions addressing the language impairment, compensatory approaches to support activities of daily living and provision of education and support within the context of dementia

tRNA is a new target for cleavage by a MazF toxin

Toxin-antitoxin (TA) systems play key roles in bacterial persistence, biofilm formation and stress responses. The MazF toxin from the Escherichia coli mazEF TA system is a sequence- and single-strand-specific endoribonuclease, and many studies have led to the proposal that MazF family members exclusively target mRNA. However, recent data indicate some MazF toxins can cleave specific sites within rRNA in concert with mRNA. In this report, we identified the repertoire of RNAs cleaved by Mycobacterium tuberculosis toxin MazF-mt9 using an RNA-seq-based approach. This analysis revealed that two tRNAs were the principal targets of MazF-mt9, and each was cleaved at a single site in either the tRNAPro14 D-loop or within the tRNALys43 anticodon. This highly selective target discrimination occurs through recognition of not only sequence but also structural determinants. Thus, MazF-mt9 represents the only MazF family member known to target tRNA and to require RNA structure for recognition and cleavage. Interestingly, the tRNase activity of MazF-mt9 mirrors basic features of eukaryotic tRNases that also generate stable tRNA-derived fragments that can inhibit translation in response to stress. Our data also suggest a role for tRNA distinct from its canonical adapter function in translation, as cleavage of tRNAs by MazF-mt9 downregulates bacterial growth