Neural Mechanisms of Verb Argument Structure Training in Agrammatic Aphasia

In four speakers with agrammatic aphasia, we examined the effects of training verbs with complex argument structure in sentence contexts, behaviorally and with respect to the neural mechanisms of recovery. It was hypothesized that training ditransitive verbs would result in generalization to less-complex verb types (transitive and intransitive) in both verb naming and sentence production and that these behavioral changes would be associated with observable shifts in fMRI brain activation patterns from pre- to post-treatment. Results showed different behavioral and neural activation patterns of pre-post change across participants, which will be discusse

Noun and Verb Production and Comprehension in Stroke-Induced and Primary Progressive Aphasia: An Introduction to the Northwestern Naming Battery

This study examined production and comprehension of nouns and verbs using the Northwestern Naming Battery (NNB), a new test designed to assess naming ability in individuals with stroke-induced or primary progressive aphasia (PPA). Scores derived from the NNB were also compared to scores from published, standardized tests to evaluate the NNB’s validity. Dissociations between word classes in production were observed for participants with stroke-induced anomic and Broca’s aphasia with agrammatism and individuals with logopenic and agrammatic variants of PPA, with the two agrammatic groups showing greater impairment for verb compared to noun naming. Clinical and theoretical implications will be discussed

The role of category ambiguity in normal and impaired lexical processing: can you paint without the paint?

IntroductionMany words are categorially ambiguous and can be used as a verb (to paint) or as a noun (the paint) due to the presence of unpronounced morphology or “zero morphology”. On this account, the verb “paint” is derived from the noun “paint” through the addition of a silent category-changing morpheme. Past studies have uncovered the syntactic and semantic properties of these categorially ambiguous words, but no research has been conducted on how people process them during normal or impaired lexical processing. Are these two different uses of “paint” processed in the same way? Does this morphosyntactic structure have an effect on online sentence processing?MethodsThis study presents two experiments that investigate the effect of morphosyntactic complexity in categorially ambiguous words presented in isolation (experiment 1) and in a sentential context (experiment 2). The first experiment tested the ability to process categorially unambiguous and ambiguous nouns and verbs in 30 healthy older adults and 12 individuals with aphasia, using a forced choice phrasal-completion task, in which individuals choose whether the or to is most compatible with target words.ResultsHealthy controls and individuals with fluent aphasia all showed: (1) a bias toward the base category in selection rates for the and to, where the was selected more frequently for words identified to be base nouns, and to was selected more frequently for base verbs, and (2) longer reaction times for ambiguous (over unambiguous) words. However, individuals with non-fluent agrammatic aphasia showed a base-category effect only for nouns, with chance performance for verbs. The second experiment, using an eye-tracking while reading paradigm with 56 young healthy adults, showed a reading time slowdown for derived forms (to paint) compared to their base-category counterparts (the paint) in sentence contexts.DiscussionThese findings suggest that categorially ambiguous words likely share a common root, and are related by zero-derivation, and that impaired access to the base-category (i.e., verbs like to visit) precludes associated morphological processes and therefore the retrieval of the derived-category (i.e., nouns like the visit) in non-fluent agrammatic aphasia. This study provides insights into the theory of zero morphology, and the principles that need to be accounted for in models of the lexicon

Noviji rezultati oplemenjivanja voćaka u Institutu za voćarstvo, Čačak

The Fruit Research Institute Čačak has seventy years long tradition in breeding of continental fruit species. The continual multi-disciplinary scientific and research work conducted so far has resulted in the releasing of 41 different cultivars. In addition to the named and released cultivars, for promising candidate cultivars have been selected (three plums and one peach) and entered for releasing, while there is also a large number of promising genotypes that are currently under intense evaluation. The paper presents an overview of the most significant biological and productive characteristic of the 12 new cultivars of pome and stone fruits, including seven plum cultivars (Boranka, Timočanka, Zlatka, Nada, Mildora, Krina and Pozna plava), two pear cultivars (Julijana and Anđelija) and three sour cherry cultivars (Sofija, Nevena and Iskra).Institut za voćarstvo, Čačak ima sedamdeset godina dugu tradiciju oplemenjivačkog rada na stvaranju novih sorti kontinentalnih vrsta voćaka. Do sada je kao rezultat kontinuiranog, multidisciplinarnog naučnoistraživačkog rada priznata 41 sorta različitih vrsta voćaka. Pored priznatih sorti, izdvojene su četiri kandidat sorte (tri šljive i jedna breskve) koje su u postupku priznavanja, kao i veliki broj perspektivnih genotipova koji se intenzivno proučavaju. U radu je prikazan pregled najznačajnijih bioloških i proizvodnih osobina 12 novije priznatih sorti jabučastih i koštičavih vrsta voćaka, i to: sedam sorti šljive (Boranka, Timočanka, Zlatka, Nada, Mildora, Krina i Pozna plava), dve sorte kruške (Julijana i Anđelija) i tri sorte višnje (Sofija, Nevena i Iskra)

Network modulation during complex syntactic processing

Complex sentence processing is supported by a left-lateralized network including inferior frontal cortex and posterior superior temporal cortex. This study investigates the pattern of connectivity and information flow within this network. We used fMRI BOLD data derived from 12 healthy participants reported in and earlier study (Thompson, C. K., Den Ouden, D. B., Bonakdarpour, B., Garibaldi, K. & Parrish, T. B. (2010b). Neural plasticity and treatment-induced recovery of sentence processing in agrammatism. Neuropsychologia, 48(11), 3211-3227) to identify activation peaks associated with object-cleft over syntactically less complex subject-cleft processing. Directed Partial Correlation Analysis was conducted on time series extracted from participant-specific activation peaks and showed evidence of functional connectivity between four regions, linearly between premotor cortex, inferior frontal gyrus, posterior superior temporal sulcus and anterior middle temporal gyrus. This pattern served as the basis for Dynamic Causal Modeling of networks with a driving input to posterior superior temporal cortex, which likely supports thematic role assignment, and networks with a driving input to inferior frontal cortex, a core region associated with syntactic computation. The optimal model was determined through both frequentist and Bayesian model selection and turned out to reflect a network with a primary drive from inferior frontal cortex and modulation of the connection between inferior frontal and posterior superior temporal cortex by complex sentence processing. The winning model also showed a substantive role for a feedback mechanism from posterior superior temporal cortex back to inferior frontal cortex. We suggest that complex syntactic processing is driven by word-order analysis, supported by inferior frontal cortex, in an interactive relation with posterior superior temporal cortex, which supports verb argument structure processing

Neurocognitive Basis of Repetition Deficits in Primary Progressive Aphasia

Previous studies indicate that repetition is affected in primary progressive aphasia (PPA), particularly in the logopenic variant, due to limited auditory-verbal short-term memory (avSTM). We tested repetition of phrases varied by length (short, long) and meaning (meaningful, non-meaningful) in 58 participants (22 logopenic, 19 nonfluent, and 17 semantic variants) and 21 healthy controls using a modified Bayles repetition test. We evaluated the relation between cortical thickness and repetition performance and whether sub-scores could discriminate PPA variants. Logopenic participants showed impaired repetition across all phrases, specifically in repeating long phrases and any phrases that were non-meaningful. Nonfluent, semantic, and healthy control participants only had difficulty repeating long, non-meaningful phrases. Poor repetition of long phrases was associated with cortical thinning in left temporo-parietal areas across all variants, highlighting the importance of these areas in avSTM. Finally, Bayles repetition phrases can assist classification in PPA, discriminating logopenic from nonfluent/semantic participants with 89% accuracy

IL-33 Prevents MLD-STZ Induction of Diabetes and Attenuate Insulitis in Prediabetic NOD Mice

Type 1 diabetes is an autoimmune disease caused by the immune-mediated destruction of pancreatic β-cells. Prevention of type 1 diabetes requires early intervention in the autoimmune process against beta-cells of the pancreatic islets of Langerhans, which is believed to result from disordered immunoregulation. CD4+Foxp3+ regulatory T cells (Tregs) participate as one of the most important cell types in limiting the autoimmune process. The aim of this study was to investigate the effect of exogenous IL-33 in multiple low dose streptozotocin (MLD-STZ) induced diabetes and to delineate its role in the induction of protective Tregs in an autoimmune attack. C57BL/6 mice were treated i. p. with five doses of 40 mg/kg STZ and 0.4 μg rIL-33 four times, starting from day 0, 6, or 12 every second day from the day of disease induction. 16 weeks old NOD mice were treated with 6 injections of 0.4 μg/mouse IL-33 (every second day). Glycemia and glycosuria were measured and histological parameters in pancreatic islets were evaluated at the end of experiments. Cellular make up of the pancreatic lymph nodes and islets were evaluated by flow cytometry. IL-33 given simultaneously with the application of STZ completely prevented the development of hyperglycemia, glycosuria and profoundly attenuated mononuclear cell infiltration. IL-33 treatment was accompanied by higher number of IL-13 and IL-5 producing CD4+ T cells and increased presence of ST2+Foxp3+ regulatory T cells in pancreatic lymph nodes and islets. Elimination of Tregs abrogated protective effect of IL-33. We provide evidence that exogenous IL-33 completely prevents the development of T cell mediated inflammation in pancreatic islets and consecutive development of diabetes in C57BL/6 mice by facilitating the induction Treg cells. To extend this finding for possible relevance in spontaneous diabetes, we showed that IL-33 attenuate insulitis in prediabetic NOD mice

Network anatomy in logopenic variant of primary progressive aphasia

The logopenic variant of primary progressive aphasia (lvPPA) is a neurodegenerative syndrome characterized linguistically by gradual loss of repetition and naming skills resulting from left posterior temporal and inferior parietal atrophy. Here, we sought to identify which specific cortical loci are initially targeted by the disease (epicenters) and investigate whether atrophy spreads through predetermined networks. First, we used cross-sectional structural MRI data from individuals with lvPPA to define putative disease epicenters using a surface-based approach paired with an anatomically fine-grained parcellation of the cortical surface (i.e., HCP-MMP1.0 atlas). Second, we combined cross-sectional functional MRI data from healthy controls and longitudinal structural MRI data from individuals with lvPPA to derive the epicenter-seeded resting-state networks most relevant to lvPPA symptomatology and ascertain whether functional connectivity in these networks predicts longitudinal atrophy spread in lvPPA. Our results show that two partially distinct brain networks anchored to the left anterior angular and posterior superior temporal gyri epicenters were preferentially associated with sentence repetition and naming skills in lvPPA. Critically, the strength of connectivity within these two networks in the neurologically-intact brain significantly predicted longitudinal atrophy progression in lvPPA. Taken together, our findings indicate that atrophy progression in lvPPA, starting from inferior parietal and temporoparietal junction regions, predominantly follows at least two partially nonoverlapping pathways, which may influence the heterogeneity in clinical presentation and prognosis