Shelley Shaul

Source localization of error negativity: additional source for corrected errors.

Error processing in corrected and uncorrected errors was studied while participants responded to a target surrounded by flankers. Error-related negativity (ERN/NE) was stronger and appeared earlier in corrected errors than in uncorrected errors. ERN neural sources for each error type were analyzed using low-resolution electromagnetic tomography method of source localization. For corrected errors, the ERN source was located at the anterior cingulate (BA 24) and the medial and superior frontal regions (presupplementary motor area, BA 6), whereas it was located at the anterior cingulate (BA 24) for uncorrected errors. It is suggested that the anterior cingulate is the main source of the ERN with the presupplementary motor area contributing to ERN initiation only if the correct response tendency is sufficiently active to allow for full execution of a correction response.

Brain activity while reading words and pseudo-words: a comparison between dyslexic and fluent readers.

In recent years many studies have focused on brain activity differences between fluent and dyslexic readers in order to understand the neural basis of dyslexia. The aim of the current study was to examine the processing of words and pseudo-words in the two hemispheres among dyslexic as compared to fluent readers, using behavioral, and electrophysiological source estimation measures. Two matched groups of university students, fluent and dyslexic readers, performed a lexical decision task in order to examine the processes of word recognition. Dyslexic readers showed overall less activity than fluent readers, mainly during late processing stages. In addition, the distinctive patterns of activity for words and pseudo-words displayed by fluent readers were not apparent in dyslexic readers. In particular, the increased activation of left-hemisphere language areas found in response to pseudo-words was absent in dyslexics. These findings are further evidence of orthographic and phonological impairments in dyslexia.

Brain activity associated with translation from a visual to a symbolic representation in algebra and geometry

This paper presents a small part of a larger interdisciplinary study that investigates brain activity (using event related potential methodology) of male adolescents when solving mathematical problems of different types. The study design links mathematics education research with neurocognitive studies. In this paper we performed a comparative analysis of brain activity associated with the translation from visual to symbolic representations of mathematical objects in algebra and geometry. Algebraic tasks require translation from graphical to symbolic representation of a function, whereas tasks in geometry require translation from a drawing of a geometric figure to a symbolic representation of its property. The findings demonstrate that electrical activity associated with the performance of geometrical tasks is stronger than that associated with solving algebraic tasks. Additionally, we found different scalp topography of the brain activity associated with algebraic and geometric tasks. Based on these results, we argue that problem solving in algebra and geometry is associated with different patterns of brain activity.

The Effects of Two Different Reading Acceleration Training Programs on Improving Reading Skills of Second Graders

It has been well established that poor reading skills in the first grades of primary school can lead to poor reading skills in all coming years. A reading acceleration program (RAP) known to improve reading skills in adults and children with and without reading difficulties (RD) was tested for its effect on children in second grade with standard reading skills. The influence of the RAP on improving all reading skills—decoding, fluency, and reading comprehension—was examined. Seventy-nine children in second grade were divided into two study groups and one control group. Each study group received a training program that emphasizes reading skills: decoding, fluency, and comprehension were trained at the levels of words and sentences in Version A and at the levels of words and paragraphs in Version B. Both programs significantly improved reading skills compared with the control group that was not trained: Group A improved word fluency whereas Group B improved accuracy measures (word, pseudo-word, and text). Both training groups showed significantly greater improvement over time than the control group on reading comprehension. We conclude that a RAP training that combines words, sentences, and paragraphs is the most effective for improving reading skills.

Different laterality patterns of the error-related negativity in corrected and uncorrected errors

While measuring event-related brain potentials, a divided visual field paradigm was used to discern laterality patterns of the error-related negativity (ERN) in healthy human participants. Two tasks of hemispheric specialty were used (bargraph judgement, lexical decision) and a flanker task. For corrected errors in all tasks, stronger ERN amplitude was found following right visual field presentation. For corrected errors in the specialised tasks, shorter ERN latency was revealed on the side to which the stimulus was presented, while for uncorrected errors it was shorter on the other side. In the flanker task, ERN latency after corrected errors was shorter over the RH regardless of the side to which the stimulus was presented. Results are interpreted to reveal patterns of hemispheric specialisation, independence, and cooperation in error detection that depend on the type of error been committed.

An ERP study of simple addition: The semantics and syntax of arithmetic operation sign

The aim of the current study was to examine brain activity of adult regular calculators while processing addition sums with different types of answers. The task was a verification task, the incorrect answers were divided into two types: one was comprised of three numbers that do not belong to any additive triplet (such as 2, 4, 7) and it was always near the correct result (± 1); the other was a number which is related to the two numbers which appear in the stimulus but belongs to an incorrect competing triplet of numbers and it was always in a greater distance from the correct answer. Differences were found between the different types of answers in the behavioral reaction time with longest reaction time for the competing triplet and the shortest reaction time for the correct answer. In addition, differences in the latency and amplitude of the N170, N270, N400 and P600 components were found among the different types of answers. It can be concluded from these results that the effect of the interference of the competing triplets is greater than the split effect (distance effect), and that there is a different time zone for coding the numbers and coding of other more general syntactic-semantic arithmetic signs.

The Basis of Reading Fluency in First Grade of Hebrew Speaking Children

The present study examines the contributions of several different cognitive and literacy skills to reading fluency in Hebrew among Grade 1 students. The main objective of the study was to examine what predicts word reading fluency at two crucial points during Grade 1: mid-year, before a multi-tiered intervention, and again 12 weeks later at the end of the year, after the intervention. A total of 47 first graders in Israel were assessed on cognitive and literacy tasks before and after an implementation of intervention. Our preliminary results demonstrate that in Hebrew orthography, there is a rapid growth in word reading fluency during Grade 1. One skill, syllable deletion, predicts reading fluency by the middle of Grade 1. By the end of Grade 1, two skills predict word reading fluency: RAN and syllable deletion. The results call attention to the pedagogical need to monitor this skill in Hebrew and emphasize the need to include fluency theoretically in models of reading as well as in related practice of early reading development in Hebrew orthography.

A Cognitive and Linguistic Approach to Predicting and Remediating Word Reading Difficulties in Young Readers

Most research on the development of reading has focused on linguistic abilities, such as naming and phonological awareness, and their role in reading, recent studies have found several specific cognitive dimensions to be associated with the development of early decoding and word recognition skills such as visual attention span, working memory and executive functions. The current study examined the connection between cognitive abilities and reading at the beginning of first grade and at the end of first grade after an intervention program. As well as the cognitive and linguistic profile of children who benefited most from the intervention.

A Model of Brain Activity of Young as Compared to Adult Dyslexic Readers and Outcomes After Intervention

The chapter examines whether the cognitive deficits that young dyslexic’s (4th graders) exhibit are similar to those of adult university students dyslexics, in addition to their outcomes of intervention. This question was investigated with the use of behavioral, electrophysiological and source estimation of brain activation measures. The results revealed a different pattern of the behavioral profile and brain activity among the dyslexic in both age groups. This may indicate that compensatory mechanisms developed among adult dyslexics during their years of print exposure, and they manage to overcome some of their difficulties. In spite of their differences in the behavioral measures both age groups of dyslexic share similar characteristics, mainly in brain activity patterns. Both age groups benefited from the intervention although the different outcomes in each age group.

Visual Processing as Revealed by ERPS: Dyslexic and Normal Readers

Although perceptual processes during reading are activated by the visual and auditory modalities the activation itself starts with visual identification and perception of printed materials. The basic question of interest in this chapter is whether visual processing among dyslexics is impaired when compared with that of regular readers. The focus of this chapter is to review electrophysiological studies pertaining to the visual modality and the table summarizing the research results of these studies indicates a clear difference in cerebral cortical activation during visual processing among dyslexic and regular readers. An in-depth-analysis of various studies indicates differences resulting from different research populations, subjects’ age as well from design of the various experimental paradigms.