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Dyslexia is an impairment of reading and spelling that affects both children and adults even after many years of schooling. Dyslexic readers have deficits in the integration of auditory and visual inputs but the neural mechanisms of the deficits are still unclear. This fMRI study examined the neural processing of auditorily presented German numbers 0–9 and videos of lip movements of a German native speaker voicing numbers 0–9 in unimodal (auditory or visual) and bimodal (always congruent) conditions in dyslexic readers and their matched fluent readers. We confirmed results of previous studies that the superior temporal gyrus/sulcus plays a critical role in audiovisual speech integration: fluent readers showed greater superior temporal activations for combined audiovisual stimuli than auditory-/visual-only stimuli. Importantly, such an enhancement effect was absent in dyslexic readers. Moreover, the auditory network (bilateral superior temporal regions plus medial PFC) was dynamically modulated during audiovisual integration in fluent, but not in dyslexic readers. These results suggest that superior temporal dysfunction may underly poor audiovisual speech integration in readers with dyslexia. [ABSTRACT FROM AUTHOR]

During the acquisition of a sensorimotor sequence error monitoring as reflected by the error-related negativity (ERN) of the event-related brain potential was studied in normal human subjects. The central, imperative letter in an Eriksen-like flanker task either followed a repeating sequence or was determined randomly. ‘Explicit learners’ were informed about the presence of a sequence, whereas ‘implicit learners’ were not. Both groups learned the sequential structure inherent in the material as indicated by a speed-up in response time for structured compared to random trials. Most importantly, the ERN was larger for explicit compared to implicit learners. Thus, explicitly searching for a sequential regularity led to a more intensive engagement of the error monitoring system as reflected by the ERN. [Copyright &y& Elsevier]

Objective: Differences in recognition memory for unfamiliar faces between adult developmental dyslexic (n=12) and normal readers (n=12) were studied by means of event-related brain potentials.Methods: Subjects performed a continuous face recognition task, in which 240 unfamiliar faces were presented on a computer screen, 100 of which were repetitions. For each face, subjects had to indicate whether it was presented before or not. Performance did not differ between normal and dyslexic readers. Old/repeated faces elicited more positive event-related potentials (ERPs) starting 250 ms poststimulus. These were analyzed in two time-windows encompassing the early (250–450 ms) and the late phase (450–750 ms) of the old/new effect.Results: No group difference in amplitude or topography of the old/new effect emerged. However, ERPs for all faces were more positive for normal compared with those of dyslexic readers.Conclusions: These results show that a previously described recognition memory deficit for words in dyslexic readers is likely to be specific for verbal material. [Copyright &y& Elsevier]

About 7.5 million adults in Germany cannot read and write properly despite attending school for several years. They are considered to be functional illiterates. Since the ability to read and write is crucial for being employed and socially accepted, we developed a literacy training to overcome these deficits. In this study, we investigate the structural changes induced by the training. A group of 20 functional illiterates and 20 adult normal readers participated in the study. Group differences as well as intervention-related changes in gray (voxel-based morphometry, VBM) and white matter (Tract-Based Spatial Statistics, TBSS, applied to fractional anisotropy, FA, obtained with diffusion tensor imaging, DTI) were assessed in functional illiterates and normal reading controls. VBM analyses revealed decreased gray matter intensities in functional illiterates compared to normal readers before training in several reading-related brain regions such as the superior temporal gyrus, supramarginal gyrus, and angular gyrus. Using TBSS, functional illiterates showed reduced FA values in the genu of the corpus callosum. After training, both the gray matter intensities and FA values increased in functional illiterates and were no longer statistically different from controls’ pre-test data. Moreover, the increase was positively correlated with reading and writing skills. The findings suggest that poor literacy skills are associated with several structural abnormalities in reading-related brain areas. In addition, we showed that while literacy skills of functional illiterates improved after training, the structural differences to controls disappeared. [ABSTRACT FROM AUTHOR]

Abstract: The present study investigates whether performance monitoring and its electrophysiological indices in a choice reaction time task are modulated by affective information presented briefly prior to the critical stimuli. A flanker task known to elicit a sufficient number of performance errors was used and prior to each flanker stimulus a neutral, pleasant or unpleasant picture from the International Affective Picture System (IAPS) was shown. While behavioral performance to the flanker stimuli was hardly affected by the preceding affective information, the error-related negativity (ERN) of the event-related potential was modulated by affective information: Unpleasant IAPS pictures preceding a performance error led to an increased ERN amplitude compared to trials with neutral and pleasant IAPS pictures. These trial-by-trial modulations of electrophysiological markers of performance monitoring are discussed in terms of the possible influence of affective stimuli on monaminergic neuromodulatory transmitter systems. [Copyright &y& Elsevier]

Objectives: The present investigation explored the electrophysiological correlates of working memory during sentence comprehension.Methods: Event-related brain potentials (ERP) were recorded from 29 channels in 22 subjects, while they read German sentences having subject-first (canonical) or object-first (non-canonical) word orders.Results: Three different ERP effects were observed: a negativity (maximum at Fc5) differentiating unambiguous object-first and subject-first sentences, interpreted as reflecting the demands of the object-first sentences on working memory; a second negativity (maximum at F7) to the subject noun-phrase in object-first sentences, interpreted as indicating retrieval of verbal material. Finally, a parietal positivity was found for ambiguous sentences that turned out to have a non-canonical word order, which was interpreted as indicating revision and reevaluation processes.Conclusions: The present data underscore the different roles of working memory in comprehension. [Copyright &y& Elsevier]