Raw eye tracking data of healthy adults reading aloud words, pseudowords and numerals.

This paper describes data from de Chambrier et al. (2023). The dataset [2] contains raw eye tracking data of 36 healthy adults, collected using an EyeLink 1000 (SR Research Ltd., ON, Canada) during an on-screen reading task. Participants read 96 items including words, pseudowords and numerals. Each item was presented at the center of the screen until the participant produced an oral response and pressed the keyboard's space bar. Part of the data were analyzed to extract key metrics such as fixation number, fixation duration, saccade number, and saccade amplitude identified by the EyeLink 1000 [1]. Reuse potential includes (but is not limited to) pupil diameter data analysis, identification of fixations and saccades using custom algorithms, and secondary analyses using participant demographics (age, gender) as independent variables.

Reading numbers is harder than reading words: An eye-tracking study.

We recorded the eye movements of adults reading aloud short (four digit) and long (eight to 11 digit) Arabic numerals compared to matched-in-length words and pseudowords. We presented each item in isolation, at the center of the screen. Participants read each item aloud at their pace, and then pressed the spacebar to display the next item. Reading accuracy was 99 %. Results showed that adults make 2.5 times more fixations when reading short numerals compared to short words, and up to 7 times more fixations when reading long numerals with respect to long words. Similarly, adults make 3 times more saccades when reading short numerals compared to short words, and up to 9 times more saccades when reading long numerals with respect to long words. Fixation duration and saccade amplitude stay almost the same when reading short numerals with respect to short words. However, fixation duration increases by ∼50 ms when reading long numerals (∼300 ms) with respect to long words (∼250 ms), and saccade amplitude decreases up to 0.83 characters when reading long numerals with respect to long words. The pattern of findings for long numerals-more and shorter saccades as well as more and longer fixations-shows the extent to which reading long Arabic numerals is a cognitively costly task. Within the phonographic writing system, this pattern of eye movements stands for the use of the sublexical print-to-sound correspondence rules. The data highlight that reading large numerals is an unautomatized activity and that Arabic numerals must be converted into their oral form by a step-by-step process even by expert readers.

A descriptive study on reading instruction provided to students with intellectual disability.

Little is known about the content and quality of reading instruction provided to students with intellectual disability. This study aimed to describe the reading instruction provided to students with intellectual disability who were not yet readers in self-contained elementary classrooms. The teachers of 24 classrooms participated in the study. Systematic observations of reading lessons, follow-up interviews with the teachers, review of teaching material, and content analysis of students' individualized education plans were conducted. Findings indicate that phonics and phonological awareness were taught in most of the classrooms. However, phonics was taught systematically, as recommended in the research, in only less than half of the classes. Sight-word instruction and vocabulary instruction were observed in more than half of the classes. Comprehension instruction of texts read aloud by the teacher was observed in only about a third of the classrooms. Recommendations to support teachers in enhancing the quality of reading instruction are provided.

Rapid automatized naming skills of children with intellectual disability.

BACKGROUND: A deficit in Rapid Automatized Naming (RAN), acknowledged to be linked to dyslexia, has rarely been investigated as a potential explanation of the reading difficulties that children with intellectual disability (ID) often face. The existing studies mainly focused on adolescent or adults with ID matched to typically developing (TD) children on verbal mental age, or used a single RAN task. AIMS: The aim of this study was to compare the RAN pattern and skills of children with ID and low reading skills to the ones of TD children with matched reading skills. METHOD: 30 children with mild to moderate ID with mixed etiology (M = 9.4 years-old) were pair-matched to 30 TD children (M = 4.3 years-old) on phonological awareness- and reading-level. They were all administered color, object, finger, and vowel RAN tasks. OUTCOMES AND RESULTS: Results showed that children with ID had more domain-specific RAN skills and were largely slower in most of the RAN tasks than their younger TD peers. CONCLUSIONS AND IMPLICATIONS: This suggests that a deficit in RAN should be added to the explanations of their frequent reading difficulties, which might open new remediation possibilities.

Effects of a phonics-based intervention on the reading skills of students with intellectual disability.

BACKGROUND: To date, only a few studies with randomized controlled trials have been published on the effectiveness of phonics-based reading interventions to teach decoding and spelling skills to students with intellectual disability. AIMS: This study evaluated the effects of a phonics-based reading intervention program on the progress of French-speaking elementary students with intellectual disability. METHODS: A total of 48 non decoding elementary students with intellectual disability were randomly assigned to either a treatment group or a control group. Most of the participants (75 %) had nonverbal IQs below 55. The reading intervention program was implemented for seven months by the students' teachers and mainly in a small-group format (two to four students). RESULTS: Students from the treatment group made significantly more progress in word and nonword reading measured by a researcher-designed test with a medium effect size. An almost significant difference was also found on spelling (p = .058) and on word and nonword reading measured with a standardized test (p = .060) with medium effect sizes. CONCLUSIONS: These findings suggest that students with ID benefit from phonics-based programs integrating research-based approaches and techniques.

Exploring Phonological Awareness Skills in Children With Intellectual Disability.

The phonological awareness skills of 7- to 8-year-old children with intellectual disability (ID) were compared to those of 4- to 5-year-old typically developing children who were matched for early reading skills, vocabulary, and gender. Globally, children with ID displayed a marked weakness in phonological awareness. Syllable blending, syllable segmentation, and first phoneme detection appeared to be preserved. In contrast, children with ID showed a marked weakness in rhyme detection and a slight weakness in phoneme blending. Two school years later, these deficits no longer remained. Marked weaknesses appeared in phoneme segmentation and first/last phoneme detection. The findings suggest that children with ID display an atypical pattern in phonological awareness that changes with age. The implications for practice and research are discussed.

Electron cryo-microscopy reveals mechanism of action of propranolol on artificial membranes.

The pharmacological activity of several amphiphilic drugs is often related to their ability to interact with biological membranes. Propranolol is an efficient multidrug resistance (MDR) modulator; it is a nonselective beta-blocker and is thought to reduce hypertension by decreasing the cardiac frequency and thus blood pressure. It is used in drug delivery studies in order to treat systemic hypertension. We are interested in the interaction of propranolol with artificial membranes, as liposomes of controllable size are used as biocompatible and protective structures to encapsulate labile molecules, such as proteins, nucleic acids or drugs, for pharmaceutical, cosmetic or chemical applications. We present here a study of the interaction of propranolol, a cationic surfactant, with pure egg phosphatidylcholine (EPC) vesicles. The gradual transition from liposome to micelle of EPC vesicles in the presence of propranolol was monitored by time-resolved electron cryo-microscopy (cryo-EM) under different experimental conditions. The liposome-drug interaction was studied with varying drug/lipid (D/L) ratios and different stages were captured by direct thin-film vitrification. The time-series cryo-EM data clearly illustrate the mechanism of action of propranolol on the liposome structure: the drug disrupts the lipid bilayer by perturbing the local organization of the phospholipids. This is followed by the formation of thread-like micelles, also called worm-like micelles (WLM), and ends with the formation of spherical (globular) micelles. The overall reaction is slow, with the process taking almost two hours to be completed. The effect of a monovalent salt was also investigated by repeating the lipid-surfactant interaction experiments in the presence of KCl as an additive to the lipid/drug suspension. When KCl was added in the presence of propranolol the overall reaction was the same but with slower kinetics, suggesting that this monovalent salt affects the general lipid-to-micelle transition by stabilizing the membrane, presumably by binding to the carbonyl chains of the phosphatidylcholine.

Liposome/water lipophilicity: methods, information content, and pharmaceutical applications.

This review discusses liposome/water lipophilicity in terms of the structure of liposomes, experimental methods, and information content. In a first part, the structural properties of the hydrophobic core and polar surface of liposomes are examined in the light of potential interactions with solute molecules. Particular emphasis is placed on the physicochemical properties of polar headgroups of lipids in liposomes. A second part is dedicated to three useful methods to study liposome/water partitioning, namely potentiometry, equilibrium dialysis, and (1)H-NMR relaxation rates. In each case, the principle and limitations of the method are discussed. The next part presents the structural information encoded in liposome/water lipophilicity, in other words the solutes' structural and physicochemical properties that determine their behavior and hence their partitioning in such systems. This presentation is based on a comparison between isotropic (i.e., solvent/water) and anisotropic (e.g., liposome/water) systems. An important factor to be considered is whether the anisotropic lipid phase is ionized or not. Three examples taken from the authors' laboratories are discussed to illustrate the factors or combinations thereof that govern liposome/water lipophilicity, namely (a) hydrophobic interactions alone, (b) hydrophobic and polar interactions, and (c) conformational effects plus hydrophobic and ionic interactions. The next part presents two studies taken from the field of QSAR to exemplify the use of liposome/water lipophilicity in structure-disposition and structure-activity relationships. In the conclusion, we summarize the interests and limitations of this technology and point to promising developments.

Lexical orthographic knowledge develops from the beginning of literacy acquisition.

This study reports two experiments assessing the spelling performance of French first graders after 3 months and after 9 months of literacy instruction. The participants were asked to spell high and low frequency irregular words (Experiment 1) and pseudowords, some of which had lexical neighbours (Experiment 2). The lexical database which children had been exposed to was strictly controlled. Both a frequency effect in word spelling accuracy and an analogy effect in pseudoword spelling were obtained after only 3 months of reading instruction. The results suggest that children establish specific orthographic knowledge from the very beginning of literacy acquisition.

Molecular factors influencing retention on immobilized artifical membranes (IAM) compared to partitioning in liposomes and n-octanol.

PURPOSE: To assess the effect of molecular factors influencing retention on immobilized artificial membrane (IAM) high-performance liquid chromatography columns compared to liposomal partitioning and traditional n-octanol/water partition coefficients. METHODS: IAM capacity factors were measured at pH 7.0 on an IAM.PC.DD2 stationary phase. Liposomal partitioning at pH 7.0 and n-octanol/water partition coefficients were measured using the pH metric method. Partitioning in egg-phosphatidylcholine (PhC) liposomes was also measured by equilibrium dialysis for a series of beta-blockers. RESULTS: For the ionized beta-blockers, potentiometry and equilibrium dialysis yielded consistent partitioning data. For relatively large bases. IAM retention correlated well with PhC liposome partitioning, hydrophobic forces being mainly involved. For more hydrophilic compounds and for heterogeneous solutes, in contrast, the balance between electrostatic and hydrophobic interactions was not the same in the two systems. Hydrogen bonding, an important factor in liposomes partitioning, played only a minor role in IAM retention. CONCLUSIONS: Partitioning in immobilized artificial membranes depends on size, hydrophobicity, and charge. When hydrophobic interactions dominate retention, IAM capacity factors are well correlated with liposomal partitioning. On the contary, for hydrophilic solutes, the two systems do not yield the same information and are not interchangeable.