24 research outputs found
How Learning to Read Changes the Listening Brain
Reading acquisition reorganizes existing brain networks for speech and visual processing to form novel audio-visual language representations. This requires substantial cortical plasticity that is reflected in changes in brain activation and functional as well as structural connectivity between brain areas. The extent to which a child’s brain can accommodate these changes may underlie the high variability in reading outcome in both typical and dyslexic readers. In this review, we focus on reading-induced functional changes of the dorsal speech network in particular and discuss how its reciprocal interactions with the ventral reading network contributes to reading outcome. We discuss how the dynamic and intertwined development of both reading networks may be best captured by approaching reading from a skill learning perspective, using audio-visual learning paradigms and longitudinal designs to follow neuro-behavioral changes while children’s reading skills unfold
Longitudinal changes in cortical responses to letter-speech sound stimuli in 8 – 11 year-old children
While children are able to name letters fairly quickly, the automatisation of letter-speech sound mappings continues over the first years of reading development. In the current longitudinal fMRI study, we explored developmental changes in cortical responses to letters and speech sounds across 3 yearly measurements in a sample of 18 8–11 year old children. We employed a text-based recalibration paradigm in which combined exposure to text and ambiguous speech sounds shifts participants’ later perception of the ambiguous sounds towards the text. Our results showed that activity of the left superior temporal and lateral inferior precentral gyri followed a non-linear developmental pattern across the measurement sessions. This pattern is reminiscent of previously reported inverted-u-shape developmental trajectories in children’s visual cortical responses to text. Our findings suggest that the processing of letters and speech sounds involves non-linear changes in the brain’s spoken language network possibly related to progressive automatisation of reading skills
Reading-Induced Shifts in Speech Perception in Dyslexic and Typically Reading Children
One of the proposed mechanisms underlying reading difficulties observed in developmental dyslexia is impaired mapping of visual to auditory speech representations. We investigate these mappings in 20 typically reading and 20 children with dyslexia aged 8–10 years using text-based recalibration. In this paradigm, the pairing of visual text and ambiguous speech sounds shifts (recalibrates) the participant’s perception of the ambiguous speech in subsequent auditory-only post-test trials. Recent research in adults demonstrated this text-induced perceptual shift in typical, but not in dyslexic readers. Our current results instead show significant text-induced recalibration in both typically reading children and children with dyslexia. The strength of this effect was significantly linked to the strength of perceptual adaptation effects in children with dyslexia but not typically reading children. Furthermore, additional analyses in a sample of typically reading children of various reading levels revealed a significant link between recalibration and phoneme categorization. Taken together, our study highlights the importance of considering dynamic developmental changes in reading, letter-speech sound coupling and speech perception when investigating group differences between typical and dyslexic readers
Cortical responses to letters and ambiguous speech vary with reading skills in dyslexic and typically reading children
One of the proposed issues underlying reading difficulties in dyslexia is insufficiently automatized letter-speech sound associations. In the current fMRI experiment, we employ text-based recalibration to investigate letter- speech sound mappings in 8–10 year-old children with and without dyslexia. Here an ambiguous speech sound /a?a/ midway between /aba/ and /ada/ is combined with disambiguating “aba” or “ada” text causing a perceptual shift of the ambiguous /a?a/ sound towards the text (recalibration). This perceptual shift has been found to be reduced in adults but not in children with dyslexia compared to typical readers. Our fMRI results show significantly reduced activation in the left fusiform in dyslexic compared to typical readers, despite comparable behavioural performance. Furthermore, enhanced audio-visual activation within this region was linked to better reading and phonological skills. In contrast, higher activation in bilateral superior temporal cortex was associated with lower letter-speech sound identification fluency. These findings reflect individual differences during the early stages of reading development with reduced recruitment of the left fusiform in dyslexic readers together with an increased involvement of the superior temporal cortex in children with less automatized letter-speech sound associations
Development of a test battery to diagnose specific learning disorder in reading in a multilingual education context
Development of a test battery to diagnose specific learning disorder in mathematics in a multilingual education context
Long-term treatment with the oncolytic ECHO-7 virus Rigvir of a melanoma stage IV M1c patient, a small cell lung cancer stage IIIA patient, and a histiocytic sarcoma stage IV patient-three case reports
Publisher Copyright: © 2016 International Virotherapy Center. APMIS published by John Wiley & Sons LtdOncolytic virotherapy is a recent addition to cancer treatment. Here, we describe positive treatment outcomes in three patients using Rigvir virotherapy. One of the patients is diagnosed with melanoma stage IV M1c, one with small cell lung cancer stage IIIA, and one with histiocytic sarcoma stage IV. The diagnoses of all patients are verified by histology or cytology. All patients started Rigvir treatment within a few months after being diagnosed and are currently continuing Rigvir treatment. The degree of regression of the disease has been determined by computed tomography. Safety assessment of adverse events graded according to NCI CTCAE did not show any value above grade 1 during Rigvir® treatment. Using current standard treatments, the survival of patients with the present diagnoses is low. In contrast, the patients described here were diagnosed 3.5, 7.0, and 6.6 years ago, and their condition has improved and been stabile for over 1.5, 6.5, and 4 years, respectively. These observations suggest that virotherapy using Rigvir can successfully be used in long-term treatment of patients with melanoma stage IV M1c, small cell lung cancer stage IIIA, and histiocytic sarcoma stage IV and therefore could be included in prospective clinical studies.publishersversionPeer reviewe
Draft Genome Sequences of Six Strains Isolated From the Rhizosphere of Wheat Grown In Cadmium-Contaminated Soil
This study presents high-quality draft genome assemblies of six bacterial strains isolated from the roots of wheat grown in soil contaminated with cadmium. The results of this study will help to elucidate at the molecular level how heavy metals affect interactions between beneficial rhizobacteria and crop plants