Internalizing and externalizing syndrome in reading and writing disorders

The prevalence and comorbidity of internalizing and externalizing syndromes was investigated in a clinical sample of children (n = 77) with dyslexia. In the normoriented broadband-screening of the Child Behavior Checklist (CBCL) the rate of behavioral disorders is four times higher than in the standardisation sample. As a consequence of specific administrative prevalence the children have--in contrast to prospective studies--more internalizing than externalizing problems (according to the secondary scales of the CBCL). Psychiatric syndromes have been diagnosed in 66.2 percent: most frequently adjustment disorders, because of nonconformity to performance standards, followed by hyperkinetic disorders and anxiety. In all different diagnosis groups the scores of both secondary scales of the CBCL lie within or near the clinical range, only the priority was different. The high rate of psychiatric disorders indicates a great demand of personal or psychotherapeutic support in referred children with dyslexia, that has to be provided--besides interventions focusing on performance deficits.     

Neural mechanism of reading and writing in the Japanese language

Three Japanese patients presenting with pure alexia showed agraphia for Kanji in addition. A left angular gyrus lesion caused agraphia for both Kanji and Kana, but Kanji reading was preserved. A left posterior inferior temporal (PIT) lesion resulted in alexia and agraphia for Kanji, while the Kana function was preserved. These results imply that the semantic processing of reading Kanji words depends upon the left PIT area, while the phonological reading of Kana is mediated by the left angular gyrus. The PIT area also plays an important role in writing Kanji words.     

Cerebral localization of the center for reading and writing music

The mechanisms that underlie the ability to read and write music remain largely unclear compared to those involved in reading and writing language. We had the extremely rare opportunity to study the cerebral localization of the center for reading and writing music in the case of a professional trombonist. During rehearsal immediately before a concert, he suffered a hemorrhage that was localized to the left angular gyrus, the area that has long been known as the center for the ability to read and write. Detailed tests revealed that he showed symptoms of alexia with agraphia for both musical scores and language.     

The neural bases of attentive reading

Recent studies have suggested that attention facilitates the formation of synchronous neural assemblies in the gamma range (>40 Hz) to amplify behaviorally relevant signals. Whether this mechanism is general or confined to sensory cortices is still a matter of debate, since there is little evidence of a direct link between attention and increased gamma synchronization in high-level brain regions. We recorded the intracerebral EEG of 10 epileptic patients while manipulating their attention during reading, and compared the neural responses to attended and unattended words. Visual presentation of attended words induced gamma band responses in the major brain regions associated with reading and those responses were attenuated for unattended words. The attenuation was not uniform within the reading network but followed a gradient from the posterior visual to the frontal areas. Altogether, these results support the view that the gamma band response can be used as a quantitative marker of attention.     

Acquired mirror writing and reading: evidence for reflected graphemic representations

Mirror writing occurs when individual letters and whole word strings are produced in reverse direction. By analogy, mirror reading refers to the preference to read mirror reversed over normally written words. These phenomena appear rarely after brain damage and offer insight into the nervous system's organization of visual-spatial and visual-motor representations. We present the case of a 51-year-old patient with persistent mirror writing and reading following traumatic brain injury. She preferred to write in the mirror direction with either hand. She drew asymmetric pictures with the same directional bias as normal right-handed subjects, and she did not exhibit left-right confusion regarding other pictures. By contrast, on picture-word matching and lexical decision tasks, she was faster and more accurate with mirrored than normally written words. This pattern of performance suggests that her behavior was not accounted for by reflected motor programs, or by the mirroring of visual-spatial representations in general. Rather, we suggest that her behavior was produced by privileged access to mirrored graphemes. Furthermore, because she seemed better able to read irregular words in mirrored than in normal formats, we suggest that mirrored representations may exist at the whole word level and not simply at the letter level.     

Aphasic reading and writing: possible evidence for right hemisphere participation

Aphasic patients performed two tasks, reading aloud and writing to dictation. In both tasks, success was positively correlated to the emotionality, the imageability and the frequency of the target words. In addition, the patients made more semantic Also, the relative difficulty of words was similar for aphasic patients to read and for normal male subjects to recognize in the left visual field. These results suggest that the performance of the aphasic patients on these language tasks were mediated in part by the right hemisphere.     

A neural circuit model for a contextual association task inspired by recommender systems

Behavioral data shows that humans and animals have the capacity to learn rules of associations applied to specific examples, and generalize these rules to a broad variety of contexts. This article focuses on neural circuit mechanisms to perform a context‐dependent association task that requires linking sensory stimuli to behavioral responses and generalizing to multiple other symmetrical contexts. The model uses neural gating units that regulate the pattern of physiological connectivity within the circuit. These neural gating units can be used in a learning framework that performs low‐rank matrix factorization analogous to recommender systems, allowing generalization with high accuracy to a wide range of additional symmetrical contexts. The neural gating units are trained with a biologically inspired framework involving traces of Hebbian modification that are updated based on the correct behavioral output of the network. This modeling demonstrates potential neural mechanisms for learning context‐dependent association rules and for the change in selectivity of neurophysiological responses in the hippocampus. The proposed computational model is evaluated using simulations of the learning process and the application of the model to new stimuli. Further, human subject behavioral experiments were performed and the results validate the key observation of a low‐rank synaptic matrix structure linking stimuli to responses.     

Reduced writing and reading speed and age-related changes in verbal fluency tasks

The present study examined the influence of age-related decline in psychomotor speed on verbal fluency tasks. Reading speed, handwriting speed, written fluency, oral fluency, vocabulary, and years of formal education were measured in a sample of healthy volunteers (N=101) ranging in age from 20 to 88 years. Multiple regression analyses revealed that reading and handwriting speed strongly predicted verbal fluency performance. These measures, together with vocabulary skills and mental status, were significant predictors of performance on the fluency tasks. Present results suggest that decrement in verbal fluency performance in the aged may, at least partially, be due to reduced psychomotor speed rather than to decline in linguistic or cognitive functions.     

Executive functions for reading and writing in typical literacy development and dyslexia

Experiment 1: Hierarchical linear modeling of growth trajectories of three executive functions (inhibition; rapid automatic switching, RAS; and combined inhibition/switching) in typical readers and writers showed steady improvement of inhibition but leveling of RAS and inhibition/switching about fourth grade. In multiple regressions, RAS, entered after inhibition, contributed uniquely to literacy outcomes at every grade. Improvement of executive functions over the first four grades predicted literacy outcomes at fourth grade. Experiment 2: For children with dyslexia, executive functions explained less variance in literacy outcomes, and boys were worse in inhibition and inhibition/switching. Developmental, educational, and clinical significance of findings are discussed.     

Modulation of neural connectivity during tongue movement and reading

In a functional magnetic resonance imaging (fMRI) study, a novel connectivity analysis method termed within-condition interregional covariance analysis (WICA) was introduced for investigation into brain modulation during tongue movement and reading Chinese pinyins and logographic characters. We found that performing a horizontal tongue movement task generated a specific brain module with hierarchical orders of neural computation. Such functional modularity was further examined during both overt and silent Chinese reading tasks. Our results showed that overt pinyin reading was associated with the following distributed regions involved in tongue movement: the primary motor cortex (M1), the supplementary motor area (SMA), Broca's area, and Wernicke's area. Furthermore, we have used the WICA and demonstrated task-dependent covariance patterns that are strongly associated with the M1 mouth/tongue region, in which the Broca-Wernicke pathway is implicated in a meaning access procedure based on assembled phonology, while the SMA-Broca pathway is implicated in a meaning access procedure based on addressed phonology. Our functional connectivity analysis of the neural pathway involved in language processing may provide a basis for future studies of the dynamic neural network associated with language learning and reading in both developmental and disease conditions.     

Comparison of the neural basis for imagined writing and drawing

Drawing and writing are complex processes that require the synchronization of cognition, language, and perceptual-motor skills. Drawing and writing have both been utilized in the treatment of aphasia to improve communication. Recent research suggests that the act of drawing an object facilitated naming, whereas writing the word diminished accurate naming in individuals with aphasia. However, the relationship between object drawing and subsequent phonological output is unclear. Although the right hemisphere is characteristically mute, there is evidence from split-brain research that the right hemisphere can integrate pictures and words, likely via a semantic network. We hypothesized that drawing activates right hemispheric and left perilesional regions that are spared in aphasic individuals and may contribute to semantic activation that supports naming. Eleven right-handed subjects participated in a functional MRI (fMRI) experiment involving imagined drawing and writing and 6 of the 11 subjects participated in a second fMRI experiment involving actual writing and drawing. Drawing and writing produced very similar group activation maps including activation bilaterally in the premotor, inferior frontal, posterior inferior temporal, and parietal areas. The comparison of drawing vs. writing revealed significant differences between the conditions in areas of the brain known for language processing. The direct comparison between drawing and writing revealed greater right hemisphere activation for drawing in language areas such as Brodmann area (BA) 46 and BA 37.     

Everyday reading and writing practices of normal adults: Implications for aphasia assessment

Abstract

The everyday reading and writing practices of 50 non-neurologically damaged adults were surveyed using a semi-structured interview format. The subjects rated the elicited activities in terms of the frequency with which they were performed and their relative importance. Data analysis made it possible to rank the 131 cited activities using an index of importance. Each of the top-ranking activities was then considered in terms of its representativeness for each individual subject. They were found to represent only a small percentage of each individual's total range of activities. Group differences were considered in terms of age, sex, marital status, education and social class. Few significant differences were found between the various groups which were compared. Incidental findings regarding some subjects' use of social networks were also taken into account. The results suggest that everyday reading and writing practices typical of a normal adult cannot be predicted. The implications for existing functional assessments of acquired reading and writing disorders are discussed in the light of developments within current literacy research. An ethnographic approach is suggested as a more appropriate framework for assessment.     

The UCLA reading and writing program: an evaluation of the beginning stages

Some individuals with developmental disabilities fail to acquire functional speech despite extensive teaching efforts. To help such individuals develop functional communication skills, a "reading and writing" program was developed. This study was designed to evaluate early parts of the program. Acquisition, transfer, and maintenance of "reading and writing" skills was examined and compared with the acquisition, transfer, and maintenance of sign language. Participants were four children with autism, who scored within the mentally retarded range on standardized tests of intellectual, adaptive, and language functioning, and three 3-year-old non-disabled children. A simultaneous-treatment design was employed to compare the rate of acquisition of "reading and writing" skills to the rate at which the participants acquired receptive and expressive signs. For the participants with autism, acquisition of "reading and writing" was more successful than receptive and expressive signing on all variables assessed. All non-disabled participants acquired all of the "reading and writing" and sign language skills, but participants with autism did not. However, "reading" was acquired slightly quicker by the participants with autism than the non-disabled participants, and the participants with autism also showed some evidence of better transfer and maintenance than the non-disabled participants did.     

Peptide activation of a simple neural circuit

Pupae of the tobacco hornworm moth display a characteristic reflex response to tactile stimulation of sensory hairs located in the gin-trap. The reflex is not functional in the prepupa, but is activated abruptly as the animal enters the pupal stage by the direct action of an identified peptide hormone. The neuronal pathway between the sensory and motor neurons involved in the reflex is not direct, and the site of hormone action was localized to the connection between an interganglionic interneuron, and the motorneurons.     

Retrospective revaluation and its neural circuit in rats

Contingency learning is essential for establishing predictive or causal judgements. Retrospective revaluation captures essential aspects of the updating of this knowledge, according to new experience. In the present study, retrospective revaluation and its neural substrate was investigated in a rat conditioned magazine approach. One element of a previously food-reinforced Tone-Light compound stimulus was either further reinforced (inflation) or extinguished (extinction). These treatments affected the predictive value of the alternate stimulus (target), but only when the target was a weakly salient stimulus such as a Light, and the inflation/extinction procedure concerned the more salient element, that is the Tone. As the predictive value of the Light was decreased in comparison with a relevant control group, this revaluation was interpreted as backward blocking, and not unovershadowing. This observation challenges retrospective revaluation models focused on acquisition and prediction error detection, and is better accounted for by retrieval-based associative theories such as the comparator model (Miller and Matzel) [5]. Immunohistochemical detection of the Fos protein after the test phase revealed activation of the orbitofrontal and infralimbic cortices as well as nucleus accumbens core and shell, in rats that exhibited retrospective revaluation. Our results suggest that rats integrate successive experiences at the retrieval stage of retrospective revaluation, and that prefronto-accumbal interactions are involved in this function.     

Myelinated axon physiology and regulation of neural circuit function

The study of structural and functional plasticity in the central nervous system (CNS) to date has focused primarily on that of neurons and synapses. However, more recent studies implicate glial cells as key regulators of neural circuit function. Among these, the myelinating glia of the CNS, oligodendrocytes, have been shown to be responsive to extrinsic signals including neuronal activity, and in turn, tune neurophysiological function. Due to the fact that myelin fundamentally alters the conduction properties of axons, much attention has focused on how dynamic regulation of myelination might represent a form of functional plasticity. Here, we highlight recent research that indicates that it is not only myelin, but essentially all the function-regulating components of the myelinated axon that are responsive to neuronal activity. For example, the axon initial segment, nodes of Ranvier, heminodes, axonal termini, and the morphology of the axon itself all exhibit the potential to respond to neuronal activity, and in so doing might underpin specific functional outputs. We also highlight emerging evidence that the myelin sheath itself has a rich physiology capable of influencing axonal physiology. We suggest that to fully understand nervous system plasticity we need to consider the fact that myelinated axon is an integrated functional unit and adaptations that influence the entire functional unit are likely to underpin modifications to neural circuit function.     

Cognitive and neural mechanisms underlying reading and naming: Evidence from letter-by-letter reading and optic aphasia

We report detailed analysis of language performance in a patient, RMI, a 55-year-old man who presented with a homonymous hemianopsia, optic aphasia, and alexia without agraphia (with letter-by-letter reading) acutely after stroke. MRI showed infarct in the left occipital and medial temporal lobe and hypoperfusion of the entire posterior cerebral artery territory, including the splenium. Extensive language testing revealed severely impaired picture naming and oral reading, with relatively spared tactile naming and recognition of orally spelled words, consistent with impaired access to lexical and semantic representations from vision. In addition, he had a milder deficit in accessing lexical representations for output from all input modalities. RMI’s execution of various language tasks provided considerable insight into the mechanisms that underlie oral reading. His performance indicated that both semantic access and orthographic to phonologic conversion mechanisms were partially intact. When information from these two impoverished systems was coupled (the picture of an object presented with its written name), his ability to read/name improved significantly, consistent with the hypothesis that partially accessed semantic information from vision can combine with partially accessed sublexical orthographic to phonologic conversion mechanisms to access phonological representations for output. Furthermore, his written word and picture recognition improved to normal at a time when magnetic resonance perfusion imaging demonstrated reperfusion of the splenium. We interpret these results, as well as results from previous studies in the literature, within a model of the neural regions critical for various cognitive processes underlying reading.     

Classes of feedforward neural networks and their circuit complexity

This paper aims to place neural networks in the context of boolean circuit complexity. We define appropriate classes of feedforward neural networks with specified fan-in, accuracy of computation and depth and using techniques of communication complexity proceed to show that the classes fit into a well-studied hierarchy of boolean circuits. Results cover both classes of sigmoid activation function networks and linear threshold networks. This provides a much needed theoretical basis for the study of the computational power of feedforward neural networks.     

Cognitive and neural mechanisms underlying reading and naming: evidence from letter-by-letter reading and optic aphasia

We report detailed analysis of language performance in a patient, RMI, a 55-year-old man who presented with a homonymous hemianopsia, optic aphasia, and alexia without agraphia (with letter-by-letter reading) acutely after stroke. MRI showed infarct in the left occipital and medial temporal lobe and hypoperfusion of the entire posterior cerebral artery territory, including the splenium. Extensive language testing revealed severely impaired picture naming and oral reading, with relatively spared tactile naming and recognition of orally spelled words, consistent with impaired access to lexical and semantic representations from vision. In addition, he had a milder deficit in accessing lexical representations for output from all input modalities. RMI's execution of various language tasks provided considerable insight into the mechanisms that underlie oral reading. His performance indicated that both semantic access and orthographic to phonologic conversion mechanisms were partially intact. When information from these two impoverished systems was coupled (the picture of an object presented with its written name), his ability to read/name improved significantly, consistent with the hypothesis that partially accessed semantic information from vision can combine with partially accessed sublexical orthographic to phonologic conversion mechanisms to access phonological representations for output. Furthermore, his written word and picture recognition improved to normal at a time when magnetic resonance perfusion imaging demonstrated reperfusion of the splenium. We interpret these results, as well as results from previous studies in the literature, within a model of the neural regions critical for various cognitive processes underlying reading.