Brain structures associated with reading and their abnormalities in dyslexia: a whole-brain analysis

Developmental dyslexia (DD) is a highly prevalent neurodevelopmental disorder, which often has a devastating influence on the individual’s academic achievement and career. Research on the neural origins of DD has continued for half a century, yielding, however, inconsistent results. The current study was set out to determine abnormalities of grey and white matter volumes in adults with DD and to shed light on neural architectures associated with reading and related skills. To this end, we conducted a whole-brain voxel based morphometry following current recommendations on analysis approaches, coupled with rigorous neuropsychological testing, to characterize the associations between neuroanatomy and skills vital for reading in DD. We found decreased volumes of grey matter in DD, comprising a left-hemispheric network including superior temporal and inferior frontal gyri, insula, the limbic system, and basal ganglia, and white matter, including the right middle temporal gyrus and hippocampus, as well as the right precuneus. These results are both consistent with the most robust previous findings on cortical abnormalities in DD and yield novel insight to the role of subcortical structures in DD, scarcely studied so far. Crucially, areas with decreased grey matter in DD overlapped with brain areas associated with technical reading skills. This supports the conclusion that the grey matter regions that we identified to have a low volume in DD are associated with the core areas vital for reading.

Neuromagnetic speech discrimination responses are associated with reading-related skills in dyslexic and typical readers

Dyslexia is thought to result from poor phonological processing. We investigated neuromagnetic speech discrimination in dyslexic and typical readers with mismatch fields (MMF) and determined the associations between MMFs and reading-related skills. We expected weak and atypically lateralized MMFs in dyslexic readers, and associations between reading-related skills and MMF strength. MMFs were recorded to a repeating pseudoword /ta-ta/ with occasional changes in vowel identity, duration, or syllable frequency from 43 adults, 21 with confirmed dyslexia. Speech-sound changes elicited MMFs in bilateral auditory cortices, with no group differences in source strengths. MMFs to vowel identity and duration changes were left-lateralized. Better verbal working memory was associated with stronger left-hemispheric MMFs across groups, suggesting the relevance of verbal working memory for speech processing. Better technical reading was associated with stronger right-hemispheric MMFs in dyslexic readers, suggesting a right-hemispheric compensatory mechanism for language processing. In conclusion, contrary to prior work, our results did not support deficient speech discrimination in dyslexia. However, in line with previous studies, we observed left-lateralized MMFs to vowel identity and duration changes, and associations of MMFs with reading-related skills, highlighting the connection between neural speech processing and reading and promoting the use of MMFs in investigating reading-related brain processes.HighlightsSpeech-sound changes elicit comparable mismatch fields in dyslexics and controls.Mismatch fields (MMFs) to vowel identity and duration changes are left-lateralized.Stronger left MMFs are associated with better verbal working memory across groups.Stronger right MMFs are associated with better technical reading in dyslexics.Low-level neural speech discrimination is associated with reading-related skills.

Atypical MEG inter-subject correlation during listening to continuous natural speech in dyslexia

Listening to speech elicits brain activity time-locked to the speech sounds. This so-called neural entrainment to speech was found to be atypical in dyslexia, a reading impairment associated with neural speech processing deficits. We hypothesized that the brain responses of dyslexic vs. normal readers to real-life speech would be different, and thus the strength of inter-subject correlation (ISC) would differ from that of typical readers and be reflected in reading-related measures.We recorded magnetoencephalograms (MEG) of 23 dyslexic and 21 typically-reading adults during listening to ∼10 min of natural Finnish speech consisting of excerpts from radio news, a podcast, a self-recorded audiobook chapter and small talk. The amplitude envelopes of band-pass-filtered MEG source signals were correlated between subjects in a cortically-constrained source space in six frequency bands. The resulting ISCs of dyslexic and typical readers were compared with a permutation-based t-test. Neuropsychological measures of phonological processing, technical reading, and working memory were correlated with the ISCs utilizing the Mantel test.During listening to speech, ISCs were reduced in dyslexic compared to typical readers in delta (0.5–4 Hz), alpha (8–12 Hz), low gamma (25–45 Hz) and high gamma (55–90 Hz) frequency bands. In the beta (12–25 Hz) band, dyslexics had mainly enhanced ISC to speech compared to controls. Furthermore, we found that ISCs across both groups were associated with phonological processing, technical reading, and working memory.The atypical ISC to natural speech in dyslexics supports the temporal sampling deficit theory of dyslexia. It also suggests over-synchronization to phoneme-rate information in speech, which could indicate more effort-demanding sampling of phonemes from speech in dyslexia. These irregularities in parsing speech are likely some of the complex neural factors contributing to dyslexia. The associations between neural coupling and reading-related skills further support this notion.Research HighlightsMEG inter-subject correlation (ISC) of dyslexics was atypical while listening to speech.Depending on the frequency band, dyslexics had stronger or weaker ISC than controls.Reading-related measures correlated with the strength of ISC.

Influencia Del Hábito De La Lectura En La Enseñanza Aprendizaje Del Vocabulario En Estudiantes De Octavo Año De Educación Básica

The objective of the research was to determine the reasons why eighth year parallel "A" students of Primary Education at the "Maldonado High School” do not improve their vocabulary during the learning process through reading. To do so, the types of reading that the teacher uses in classes were diagnosed; we identified the techniques used to teach vocabulary and finally proceeded with the inference of reasons because students lack vocabulary when they read. The research was diagnostic and the ethnographic method was used to describe and analyze the sociocultural environment of the research context. The sample was intentional and represent twenty-eight students and one teacher. The data were obtained by means of participatory observation with an observation list, applied in May and June of 2016. The research was inductive and field, as general conclusions were obtained from observation, classification and study of facts, based on the direct collection of information from the reality in which it was investigated. The results obtained were tabulated, analyzed and interpreted and determined that students have a bad habit and do not follow a technical reading process.

The Impact of Bibliodidactics on Success in Learning to Read Among Nonnative Criminal Inmates

The main purpose of this study, based on research conducted in two randomly selected maximum-security prisons in Israel, is to explore the effectiveness of Bibliodidactics, a unique teaching reading method. The research found Bibliodidactics significantly improves the levels of technical reading among nonnative illiterate and poor-reading prisoners of Hebrew. The method is also significantly more efficient for nonnative illiterate prisoners, both in reading comprehension and in technical reading. The authors conclude that literacy instruction for struggling readers benefits from a focus on emotional processing of text, providing meaningful contexts to learning materials that motivate and sustain the readers’ interest.