Bayesian modeling of human performance in a visual processing training software

International audienceDyslexia is a deficit of the identification of words, which is thought to be a consequence of different possible cognitive impairments. Recent data suggest that one of these might be a specific deficit of the visual attention span (VAS). We are developing a remediation software for dyslexic children that focuses on the VAS and its training. A central component of this software is the estimation of the performance of a given participant for all possible exercises. We describe a preliminary probabilistic model of participant performance, based on Bayesian modeling and inference. We mathematically define the model, making explicit underlying generalization hypotheses. The model yields a computation of the most probable predicted performance space, and, as a direct extension, an exercise selection strategy

Isolation and characterization of novel glycoproteins from fish epidermal mucus: correlation between their pore-forming properties and their antibacterial activities

AbstractIn fish, a layer of mucus covers the external body surface contributing therefore, among other important biological functions, to the defense system of fish. The prevention of colonization by aquatic parasites, bacteria and fungi is mediated both by immune system compounds (IgM, lysozyme, etc.) and by antibacterial peptides and polypeptides. We have recently shown that only the hydrophobic components of crude epidermal mucus of fresh water and sea water fish exhibit strong pore-forming properties, which were well correlated with antibacterial activity [N. Ebran, S. Julien, N. Orange, P. Saglio, C. Lemaitre, G. Molle, Comp. Biochem. Physiol. 122 (1999)]. Here, we have isolated novel glycosylated proteins from the hydrophobic supernatant of tench (Tinca tinca), eel (Anguilla anguilla) and rainbow trout (Oncorhynchus mykiss) mucus. The study of their secondary structure was performed by circular dichroism and revealed structures in random coil and α-helix in the same proportions. When reconstituted in planar lipid bilayer, they induced the formation of ion channels. This pore-forming activity was well correlated with a strong antibacterial activity (minimal inhibitory concentration<1 μM for the three proteins) against both Gram-negative and Gram-positive bacteria. Our results suggest that fish secrete antibacterial glycoproteins able to kill bacteria by forming large pores (several hundreds to thousands of pS) in the target membrane

Microbial Dysbiosis in Colorectal Cancer (CRC) Patients

The composition of the human intestinal microbiota is linked to health status. The aim was to analyze the microbiota of normal and colon cancer patients in order to establish cancer-related dysbiosis

Combined mutations of ASXL1, CBL, FLT3, IDH1, IDH2, JAK2, KRAS, NPM1, NRAS, RUNX1, TET2 and WT1 genes in myelodysplastic syndromes and acute myeloid leukemias

<p>Abstract</p> <p>Background</p> <p>Gene mutation is an important mechanism of myeloid leukemogenesis. However, the number and combination of gene mutated in myeloid malignancies is still a matter of investigation.</p> <p>Methods</p> <p>We searched for mutations in the <it>ASXL1, CBL, FLT3, IDH1, IDH2, JAK2, KRAS, NPM1, NRAS, RUNX1, TET2 </it>and <it>WT1 </it>genes in 65 myelodysplastic syndromes (MDSs) and 64 acute myeloid leukemias (AMLs) without balanced translocation or complex karyotype.</p> <p>Results</p> <p>Mutations in <it>ASXL1 </it>and <it>CBL </it>were frequent in refractory anemia with excess of blasts. Mutations in <it>TET2 </it>occurred with similar frequency in MDSs and AMLs and associated equally with either <it>ASXL1 </it>or <it>NPM1 </it>mutations. Mutations of <it>RUNX1 </it>were mutually exclusive with <it>TET2 </it>and combined with <it>ASXL1 </it>but not with <it>NPM1</it>. Mutations in <it>FLT3 (</it>mutation and internal tandem duplication), <it>IDH1</it>, <it>IDH2</it>, <it>NPM1 </it>and <it>WT1 </it>occurred primarily in AMLs.</p> <p>Conclusion</p> <p>Only 14% MDSs but half AMLs had at least two mutations in the genes studied. Based on the observed combinations and exclusions we classified the 12 genes into four classes and propose a highly speculative model that at least a mutation in one of each class is necessary for developing AML with simple or normal karyotype.</p

Probabilistic modeling of orthographic learning based on visuo-attentional dynamics

International audienc

Lecteurs, votre attention s’il vous plait ! Le rôle de l’attention visuelle en lecture

International audienc

How do action video games improve reading performance? Theoretical framework and design principles of an educational software, based on visuo-attentional training

International audienceRecent studies suggest that dyslexic children who have action video game experience have improved visual attention and, consequently, improved reading skills. Moreover, some studies show that the visuo-attentional abilities of pre-readers strongly predict their future reading level. Action video games could therefore be an efficient training tool to improve reading acquisition, and an appropriate one thanks to their natural motivational quality. However, despite substantial research about the development of visual attention through video games, the attentional dimensions they train remain to be identified. Therefore, our objective is to identify what attentional dimensions are involved in reading acquisition and to design a video game to train them specifically. We target two attentional components: the visuo-attentional span and attentional shift, which we aim to enlarge and accelerate, respectively. We will both present a theoretical framework and design principles for the implementation of an educational video game. Its gameplay is based on visual identification and search tasks and its difficulty level is adaptively set to user performance. Our game is designed for grade 1 to grade 3 classes, and will be tested in a longitudinal study

Reconciling opposite neighborhood frequency effects in lexical decision: Evidence from a novel probabilistic model of visual word recognition

International audienc

Comparing online and post-processing pronunciation correction during orthographic incidental learning: A computational study with the BRAID-Acq model

Reading acquisition primarily relies on orthographic learning. Behavioral studies show that familiarity with a novel word’s pronunciation facilitates learning, particularly in semantically meaningful contexts. Two main components of orthographic learning are commonly described: perceptual processing of the visual stimulus, to infer corresponding phonological rep- resentations, and “pronunciation correction”, to correct errors from perceptual processing. Currently, pronunciation correc- tion has not been featured in reading acquisition computa- tional models. This study uses BRAID-Acq, a reading ac- quisition model, to implement and compare two pronunciation correction mechanisms (an “online” and a “post-processing” variant). We simulated learning of words with and without prior phonological knowledge and explored the impact of con- text strength and size on learning. Results indicate that both mechanisms improve decoding. However, the post-processing mechanism induced implausible lexicalization for words with- out prior phonological knowledge, while the online mecha- nism did not. Overall, our simulation results suggest that pro- nunciation correction could be construed as an online process