Auditory Category Learning in Children With Dyslexia Roark, Casey L; Thakkar, Vishal; Chandrasekaran, Bharath ...
Journal of speech, language, and hearing research,
2024-Mar-11, Letnik:
67, Številka:
3
Journal Article
Recenzirano
Developmental dyslexia is proposed to involve selective procedural memory deficits with intact declarative memory. Recent research in the domain of category learning has demonstrated that adults with ...dyslexia have selective deficits in Information-Integration (II) category learning that is proposed to rely on procedural learning mechanisms and unaffected Rule-Based (RB) category learning that is proposed to rely on declarative, hypothesis testing mechanisms. Importantly, learning mechanisms also change across development, with distinct developmental trajectories in both procedural and declarative learning mechanisms. It is unclear how dyslexia in childhood should influence auditory category learning, a critical skill for speech perception and reading development.
We examined auditory category learning performance and strategies in 7- to 12-year-old children with dyslexia (
= 25; nine females, 16 males) and typically developing controls (
= 25; 13 females, 12 males). Participants learned nonspeech auditory categories of spectrotemporal ripples that could be optimally learned with either RB selective attention to the temporal modulation dimension or procedural integration of information across spectral and temporal dimensions. We statistically compared performance using mixed-model analyses of variance and identified strategies using decision-bound computational models.
We found that children with dyslexia have an apparent selective RB category learning deficit, rather than a selective II learning deficit observed in prior work in adults with dyslexia.
These results suggest that the important skill of auditory category learning is impacted in children with dyslexia and throughout development, individuals with dyslexia may develop compensatory strategies that preserve declarative learning while developing difficulties in procedural learning.
https://doi.org/10.23641/asha.25148519.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Learning to read requires the specialization of a region in the left fusiform gyrus known as the visual word form area (VWFA). This region, which initially responds to faces and objects, develops ...specificity for print over a long trajectory of instruction and practice. VWFA neurons may be primed for print because of their pre-literate tuning properties, becoming specialized through top-down feedback mechanisms during learning. However, much of what is known about the VWFA comes from studies of Western orthographies, whose alphabets share common visual characteristics. Far less is known about the development of the VWFA for Arabic, which is a complex orthography and is significantly more difficult to achieve fluency in in reading. In the current study, electroencephalography responses were collected from first grade children in the United Arab Emirates learning to read in both English and Arabic. Children viewed words and false font strings in English and Arabic while performing a vigilance task. The P1 and N1 responses to all stimulus categories were quantified in two occipital and two parietal electrodes as well as the alpha band signal across all four electrodes of interest. Analysis revealed a significantly stronger N1 response to English compared to Arabic and decreased alpha power to Arabic compared to English. These findings suggest a fundamental difference in neural plasticity for these two distinct orthographies, even when instruction is concurrent. Future work is needed to determine whether VWFA specialization for Arabic takes longer than more well-studied orthographies and if differences in reading instruction approaches help accelerate this process.
Expert reading acquisition is marked by fluent, effortless decoding, and adequate comprehension skills and is required for modern daily life. In spite of its importance, many individuals struggle ...with reading comprehension even when decoding skills are adequate. Unfortunately, effective reading comprehension interventions are limited, especially for adults. A growing body of research suggests that non-invasive transcutaneous stimulation of the auricular vagus nerve (taVNS) may drive neural plasticity for low-level reading skills such as speech sound perception and letter-sound learning, but it is unknown whether taVNS can improve higher level skills as well. Thus, the current pilot study was designed to evaluate the effect of taVNS paired with passage reading on reading comprehension performance. Twenty-four typically developing young adults were recruited and screened for baseline reading and working memory skills. Participants received either sham or active taVNS while reading short passages out loud. Immediately following each passage, participants answered a series of test questions that required either direct recall of passage details or more complete comprehension of the passage content. While taVNS did not improve the mechanics of reading (e.g., reading rate or accuracy), there was a significant effect of active taVNS on test performance. This effect was driven by significant improvement on accuracy for memory questions while there was no effect of taVNS on comprehension question accuracy. These findings suggest that taVNS may be beneficial for enhancing memory, but its efficacy may be limited in higher cognitive domains.
•taVNS was applied to the left posterior tragus during reading of short passages.•The active taVNS group exhibited better passage recall than sham taVNS.•taVNS was not associated with better performance on comprehension questions.•Baseline memory was significantly correlated with memory recall performance.
The ability to predict and respond to upcoming stimuli is a critical skill for all animals, including humans. Prediction operates largely below conscious awareness to allow an individual to recall ...previously encountered stimuli and prepare an appropriate response, especially in language. The ability to predict upcoming words within typical speech patterns aids fluent comprehension, as conversational speech occurs quickly. Individuals with certain neurodevelopmental disorders such as autism and dyslexia have deficits in their ability to generate and use predictions. Rodent models are often used to investigate specific aspects of these disorders, but there is no existing behavioral paradigm that can assess prediction capabilities with complex stimuli like speech sounds. Thus, the present study modified an existing rapid speech sound discrimination paradigm to assess whether rats can form predictions of upcoming speech sound stimuli and utilize them to improve task performance. We replicated prior work showing that rats can discriminate between speech sounds presented at rapid rates. We also saw that rats responded exclusively to the target at slow speeds but began responding to the predictive cue in anticipation of the target as the speed increased, suggesting that they learned the predictive value of the cue and adjusted their behavior accordingly. This prediction task will be useful in assessing prediction deficits in rat models of various neurodevelopmental disorders through the manipulation of both genetic and environmental factors.
•Sprague-Dawley rats can predict upcoming speech sounds using a cue.•Rats anticipate the target in the presence of a predictive cue.•Novel behavioral task could be used for rat models of prediction impairment.
Reading is a critical skill in modern society but is significantly more difficult to acquire during adulthood. Many adults are required to learn a new orthography after this window closes for ...personal or vocational reasons and while many programs and training methods exist for learning to read in adulthood, none result in native-like fluency. Implantable cervical vagus nerve stimulation is capable of driving neural plasticity but is invasive and not practical as a reading intervention.
The goal of the current study was to evaluate whether non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) is effective at enhancing novel orthography acquisition in young adults.
We enrolled 37 typically developing participants and randomly assigned them to a computer control, device sham control, earlobe stimulation control, or experimental transcutaneous auricular stimulation (taVNS) group. Participants then learned novel letter-sound correspondences in Hebrew over five training lessons. Performance was assessed using three measures to evaluate various aspects of reading: Letter ID, Automaticity, and Decoding.
The taVNS group significantly outperformed the three control groups on both the Automaticity and Decoding tasks. There was no difference on the Letter ID task.
These results demonstrate, for the first time, that taVNS is capable of improving aspects of reading acquisition in adults. These findings have potential implications for a wide range of cognitive tasks.
•Typical readers learned novel letter-sound correspondences well in five days.•There was no benefit of sham or earlobe stimulation on orthography learning.•taVNS paired with training improved performance on speed and decoding measures.
•Cerebellar activation was highest for rapid, semantically-plausible sentences.•Activation correlated with sub-lexical, word, and passage-level fluency performance.•Semantic context modulated the ...cerebellar response to sentence presentation rates.•Cerebellar activation was associated with reading fluency skills rather than age.
A functional region of left fusiform gyrus termed “the visual word form area” (VWFA) develops during reading acquisition to respond more strongly to printed words than to other visual stimuli. Here, ...we examined responses to letters among 5‐ and 6‐year‐old early kindergarten children (N = 48) with little or no school‐based reading instruction who varied in their reading ability. We used functional magnetic resonance imaging (fMRI) to measure responses to individual letters, false fonts, and faces in left and right fusiform gyri. We then evaluated whether signal change and size (spatial extent) of letter‐sensitive cortex (greater activation for letters versus faces) and letter‐specific cortex (greater activation for letters versus false fonts) in these regions related to (a) standardized measures of word‐reading ability and (b) signal change and size of face‐sensitive cortex (fusiform face area or FFA; greater activation for faces versus letters). Greater letter specificity, but not letter sensitivity, in left fusiform gyrus correlated positively with word reading scores. Across children, in the left fusiform gyrus, greater size of letter‐sensitive cortex correlated with lesser size of FFA. These findings are the first to suggest that in beginning readers, development of letter responsivity in left fusiform cortex is associated with both better reading ability and also a reduction of the size of left FFA that may result in right‐hemisphere dominance for face perception.
This study evaluated the time course for print vs. face development in the fusiform gyrus by measuring fMRI responses to letters and false fonts in pre‐readers aged 5 years. We found that specificity to print in the left fusiform was correlated with word reading in this young population and that there was a relationship between the size of the VWFA and the fusiform face area in left‐hemisphere.
In utero RNAi of the dyslexia-associated gene Kiaa0319 in rats (KIA-) degrades cortical responses to speech sounds and increases trial-by-trial variability in onset latency. We tested the hypothesis ...that KIA- rats would be impaired at speech sound discrimination. KIA- rats needed twice as much training in quiet conditions to perform at control levels and remained impaired at several speech tasks. Focused training using truncated speech sounds was able to normalize speech discrimination in quiet and background noise conditions. Training also normalized trial-by-trial neural variability and temporal phase locking. Cortical activity from speech trained KIA- rats was sufficient to accurately discriminate between similar consonant sounds. These results provide the first direct evidence that assumed reduced expression of the dyslexia-associated gene KIAA0319 can cause phoneme processing impairments similar to those seen in dyslexia and that intensive behavioral therapy can eliminate these impairments.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Dyslexia is a common neurobiological disorder in which a child fails to acquire typical word reading skills despite adequate opportunity and intelligence. The visual word form area (VWFA) is a region ...within the left fusiform gyrus that specializes for print over the course of reading acquisition and is often hypoactivated in individuals with dyslexia. It is currently unknown whether atypicalities in this brain region are already present in kindergarten children who will subsequently develop dyslexia. Here, we measured fMRI activation in response to letters and false fonts in bilateral fusiform gyrus in children with and without risk for dyslexia (defined by family history or low scores on assessments of pre-reading skills, such as phonological awareness). We then followed these children longitudinally through the end of second grade to evaluate whether brain activation patterns in kindergarten were related to second-grade reading outcomes. Compared to typical readers who exhibited no risk factors for reading impairment in kindergarten, there was significant hypoactivation to both letters and false-fonts in the left fusiform gyrus in at-risk children who subsequently developed reading impairment, but not in at-risk children who developed typical reading skills. There were no significant differences in letter- or false-font responses in the right fusiform gyrus among the groups. The finding that hypoactivation to print in the VWFA is present in children who subsequently develop reading impairment even prior to the onset of formal reading instruction suggests that atypical responses to print play an early role in the development of reading impairments such as dyslexia.
•Compared visual word form area (VWFA) activation in children ages 7–14vs. adults.•Children showed adult-like sensitivity to words vs. faces in VWFA.•Children did not show adult-like specificity in ...activation for words vs. nameable objects.•Developmental specialization of VWFA extends into at least early adolescence.
An area near the left lateral occipito-temporal sulcus that responds preferentially to print has been designated as the visual word form area (VWFA). Research suggests that specialization in this brain region increases as reading expertise is achieved. Here we aimed to characterize that development in terms of sensitivity (response to printed words relative to non-linguistic faces) versus specificity (response to printed words versus line drawings of nameable objects) in typically reading children ages 7–14 versus young adults as measured by functional magnetic resonance imaging (fMRI). Relative to adults, children displayed equivalent sensitivity but reduced specificity. These findings suggest that sensitivity for print relative to non-linguistic stimuli develops relatively early in the VWFA in the course of reading development, but that specificity for printed words in VWFA is still developing through at least age 14.
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