Infants' reorienting efficiency depends on parental autistic traits and predicts future socio-communicative behaviors

Attentional reorienting is dysfunctional not only in children with autism spectrum disorder (ASD), but also in infants who will develop ASD, thus constituting a potential causal factor of future social interaction and communication abilities. Following the research domain criteria framework, we hypothesized that the presence of subclinical autistic traits in parents should lead to atypical infants' attentional reorienting, which in turn should impact on their future socio-communication behavior in toddlerhood. During an attentional cueing task, we measured the saccadic latencies in a large sample (total enrolled n = 89; final sample n = 71) of 8-month-old infants from the general population as a proxy for their stimulus-driven attention. Infants were grouped in a high parental traits (HPT; n = 23) or in a low parental traits (LPT; n = 48) group, according to the degree of autistic traits self-reported by their parents. Infants (n = 33) were then longitudinally followed to test their socio-communicative behaviors at 21 months. Results show a sluggish reorienting system, which was a longitudinal predictor of future socio-communicative skills at 21 months. Our combined transgenerational and longitudinal findings suggest that the early functionality of the stimulus-driven attentional network-redirecting attention from one event to another-could be directly connected to future social and communication development.

Action video games and posterior parietal cortex neuromodulation enhance both attention and reading in adults with developmental dyslexia

The impact of action video games on reading performance has been already demonstrated in individuals with and without neurodevelopmental disorders. The combination of action video games and posterior parietal cortex neuromodulation by a transcranial random noise stimulation could enhance brain plasticity, improving attentional control and reading skills also in adults with developmental dyslexia. In a double blind randomized controlled trial, 20 young adult nonaction video game players with developmental dyslexia were trained for 15 h with action video games. Half of the participants were stimulated with bilateral transcranial random noise stimulation on the posterior parietal cortex during the action video game training, whereas the others were in the placebo (i.e. sham) condition. Word text reading, pseudowords decoding, and temporal attention (attentional blink), as well as electroencephalographic activity during the attentional blink, were measured before and after the training. The action video game + transcranial random noise stimulation group showed temporal attention, word text reading, and pseudoword decoding enhancements and P300 amplitude brain potential changes. The enhancement in temporal attention performance was related with the efficiency in pseudoword decoding improvement. Our results demonstrate that the combination of action video game training with parietal neuromodulation increases the efficiency of visual attention deployment, probably reshaping goal-directed and stimulus-driven fronto-parietal attentional networks interplay in young adults with neurodevelopmental conditions.

Action video games normalise the phonemic awareness in pre-readers at risk for developmental dyslexia

Action video-games (AVGs) could improve reading efficiency, enhancing not only visual attention but also phonological processing. Here we tested the AVG effects upon three consolidated language-based predictors of reading development in a sample of 79 pre-readers at-risk and 41 non-at-risk for developmental dyslexia. At-risk children were impaired in either phonemic awareness (i.e., phoneme discrimination task), phonological working memory (i.e., pseudoword repetition task) or rapid automatized naming (i.e., RAN of colours task). At-risk children were assigned to different groups by using an unequal allocation randomization: (1) AVG (n = 43), (2) Serious Non-Action Video Game (n = 11), (3) treatment-as-usual (i.e., speech therapy, n = 11), and (4) waiting list (n = 14). Pre- and post-training comparisons show that only phonemic awareness has a significantly higher improvement in the AVG group compared to the waiting list, the non-AVG, and the treatment-as-usual groups, as well as the combined active groups (n = 22). This cross-modal plastic change: (i) leads to a recovery in phonemic awareness when compared to the not-at-risk pre-readers; (ii) is present in more than 80% of AVG at-risk pre-readers, and; (iii) is maintained at a 6-months follow-up. The present findings indicate that this specific multisensory attentional training positively affects how phonemic awareness develops in pre-readers at risk for developmental dyslexia, paving the way for innovative prevention programs.

Prolonged neural encoding of visual information in autism

Autism spectrum disorder (ASD) is associated with a hyper-focused visual attentional style, impacting higher-order social and affective domains. The understanding of such peculiarity can benefit from the use of multivariate pattern analysis (MVPA) of high-resolution electroencephalography (EEG) data, which has proved to be a powerful technique to investigate the hidden neural dynamics orchestrating sensory and cognitive processes. Here, we recorded EEG in typically developing (TD) children and in children with ASD during a visuo-spatial attentional task where attention was exogenously captured by a small (zoom-in) or large (zoom-out) cue in the visual field before the appearance of a target at different eccentricities. MVPA was performed both in the cue-locked period, to reveal potential differences in the modulation of the attentional focus, and in the target-locked period, to reveal potential cascade effects on stimulus processing. Cue-locked MVPA revealed that while in the TD group the pattern of neural activity contained information about the cue mainly before the target appearance, the ASD group showed a temporally sustained and topographically diffuse significant decoding of the cue neural response even after the target onset, suggesting a delayed extinction of cue-related neural activity. Crucially, this delayed extinction positively correlated with behavioral measures of attentional hyperfocusing. Results of target-locked MVPA were coherent with a hyper-focused attentional profile, highlighting an earlier and stronger decoding of target neural responses in small cue trials in the ASD group. The present findings document a spatially and temporally overrepresented encoding of visual information in ASD, which can constitute one of the main reasons behind their peculiar cognitive style.

Preoperative Carbon Ion Radiotherapy (CIRT) with Chemotherapy in Resectable and Borderline Resectable Pancreatic Adenocarcinoma (PCa): A Multicenter Prospective Phase II Clinical Study (Pioppo Study NCT 03822936)

PURPOSE/OBJECTIVE(S)

Preoperative chemoradiation and surgery may improve survival for resectable (Re) or borderline resectable (BRe) PCa. However, there is a lack of evidence regarding the feasibility of combined chemotherapy (CT) and CIRT in the neoadjuvant setting for Re/BRe PCa, especially in the Caucasian population. To assess the safety and efficacy of this challenging combination, we designed a prospective multicentric single-arm phase II trial MATERIALS/METHODS: PIOPPO trial was opened in September 2014. We prospectively treated patients with Re/BRe Pca with a neoadjuvant CT (3 cycles of FOLFIRINOX) and a short-course of CIRT (38.4 GyRBE, 8 fractions, 4 fractions per week) planned with 4D-imaging and delivered with breath-gating and rescanning. Four-6 weeks after CIRT patients (pts) received surgery followed by adjuvant-CT (FOLFIRINOX for 9 or gemcitabine for 6 cycles). After each step patients underwent a re-staging. The primary endpoint was Local Progression Free Survival (LPFS).

RESULTS

Fourteen (47%) of the foreseen 30 pts were evaluated for enrollment. There were 4 screening failures for duodenum infiltration. Ten Caucasian pts (M = 7; 70%; F = 3;30%) with a median age of 65.5 (range:46-76) started the treatment. There were four (40%) Re and 6 (60%) BRe Pca. 100% of the Re and 50% of BRe PCa completed the planned combined treatment for a total of 7 (70%) pts. Three (30%) pts developed systemic progression after CT and underwent palliative care (2 cases) or a second line of CT (1 case). With regards to toxicities, we recorded 2 (28.6%) cases of neutropenia during CT, none acute CIRT toxicity and one (14%) case of intra-operative ulceration of the gastro-enteric anastomosis. Moreover, we reported one (14%) case of fatal liver failure due to portal vein stenosis due to the combo approach (CT+CIRT+surgery). Six (86%) pts experienced Tumor Regression Grade (TRG) = 2 according to the College of American Pathologists (CAP) and 1 (14%) a TRG = 3. At the last follow-up, among pts who completed the scheme, 2 (28%) are currently alive and disease-free at 57 and 49 months, respectively. With a median follow-up of 13 months, the median LPFS was 9.4 months (range:4.9-57), with 1 case (14%) of systemic progression and 3 cases (43%) of local recurrence + systemic progression. The study was early closed due to low accrual in August 2022.

CONCLUSION

Although the small sample size limits the interpretation of the endpoints, a neoadjuvant approach combining CT and a short course of CIRT for resectable/borderline Pca seems feasible. Liver toxicity was similar to the Japanese series and needs to deepen investigation on the vascular dose constraints and surgical techniques. Considering the worse outcomes, a better selection of patients to treat also with a centralized imaging interpretation is mandatory.

The effects of bilateral posterior parietal cortex tRNS on reading performance

According to established cognitive neuroscience knowledge based on studies on disabled and typically developing readers, reading is based on a dual-stream model in which a phonological-dorsal stream (left temporo-parietal and inferior frontal areas) processes unfamiliar words and pseudowords, whereas an orthographic-ventral stream (left occipito-temporal and inferior frontal areas) processes known words. However, correlational neuroimaging, causal longitudinal, training, and pharmacological studies have suggested the critical role of visuo-spatial attention in reading development. In a double blind, crossover within-subjects experiment, we manipulated the neuromodulatory effect of a short-term bilateral stimulation of posterior parietal cortex (PPC) by using active and sham tRNS during reading tasks in a large sample of young adults. In contrast to the dual-stream model predicting either no effect or a selective effect on the stimulated phonological-dorsal stream (as well as to a general multisensory effect on both reading streams), we found that only word-reading performance improved after active bilateral PPC tRNS. These findings demonstrate a direct neural connectivity between the PPC, controlling visuo-spatial attention, and the ventral stream for visual word recognition. These results support a neurobiological model of reading where performance of the orthographic-ventral stream is boosted by an efficient deployment of visuo-spatial attention from bilateral PPC stimulation.

Visuo-spatial attention deficit in children with reading difficulties

Although developmental reading disorders (developmental dyslexia) have been mainly associated with auditory-phonological deficits, recent longitudinal and training studies have shown a possible causal role of visuo-attentional skills in reading acquisition. Indeed, visuo-attentional mechanisms could be involved in the orthographic processing of the letter string and the graphemic parsing that precede the grapheme-to-phoneme mapping. Here, we used a simple paper-and-pencil task composed of three labyrinths to measure visuo-spatial attention in a large sample of primary school children (n = 398). In comparison to visual search tasks requiring visual working memory, our labyrinth task mainly measures distributed and focused visuo-spatial attention, also controlling for sensorimotor learning. Compared to typical readers (n = 340), children with reading difficulties (n = 58) showed clear visuo-spatial attention impairments that appear not linked to motor coordination and procedural learning skills implicated in this paper and pencil task. Since visual attention is dysfunctional in about 40% of the children with reading difficulties, an efficient reading remediation program should integrate both auditory-phonological and visuo-attentional interventions.

Short-Term Effects of Video-Games on Cognitive Enhancement: the Role of Positive Emotions

According to established background knowledge, playing is essential in human development and a power remediation tool in clinical populations. In clinical interventions, the beneficial roles of playing have often been sought and investigated in the specific features of the game, rather than in the positive emotions generated by playing. However, regardless of game specifications, cognitive enhancement could be driven by the emotions linked to play. Establishing the causal connections between play and cognitive enhancement should allow us to determine how to involve play in therapy, prevention and educational programmes. Today, video-gaming is one of the most diffused forms of play. In the first crossover randomized controlled trial, we compared the short-term effects induced by shooting and puzzle video-games in visual perception, sensorimotor and reading skills in children with developmental coordination disorder and dyslexia. The funnier and more activating game enhanced breadth of visual perception and reduced sensorimotor and reading disorders. Visual perception, sensorimotor and reading improvements correlated with fun. In the second crossover randomized controlled trial, comparing the effects of the same shooting with a fighting video-game in healthy young adults, we show that regardless of game characteristics, changes in positive emotions correlated with contextual reading enhancement, while play-driven biochemical activation boosted single word and pseudoword reading. The short-term effects induced by play could be a useful clinical tool for the prevention and treatment of multiple cognitive disorders.

Action Video Games Enhance Attentional Control and Phonological Decoding in Children with Developmental Dyslexia

Reading acquisition is extremely difficult for about 5% of children because they are affected by a heritable neurobiological disorder called developmental dyslexia (DD). Intervention studies can be used to investigate the causal role of neurocognitive deficits in DD. Recently, it has been proposed that action video games (AVGs)-enhancing attentional control-could improve perception and working memory as well as reading skills. In a partial crossover intervention study, we investigated the effect of AVG and non-AVG training on attentional control using a conjunction visual search task in children with DD. We also measured the non-alphanumeric rapid automatized naming (RAN), phonological decoding and word reading before and after AVG and non-AVG training. After both video game training sessions no effect was found in non-alphanumeric RAN and in word reading performance. However, after only 12 h of AVG training the attentional control was improved (i.e., the set-size slopes were flatter in visual search) and phonological decoding speed was accelerated. Crucially, attentional control and phonological decoding speed were increased only in DD children whose video game score was highly efficient after the AVG training. We demonstrated that only an efficient AVG training induces a plasticity of the fronto-parietal attentional control linked to a selective phonological decoding improvement in children with DD.

The Mediation Role of Dynamic Multisensory Processing Using Molecular Genetic Data in Dyslexia

Although substantial heritability has been reported and candidate genes have been identified, we are far from understanding the etiopathogenetic pathways underlying developmental dyslexia (DD). Reading-related endophenotypes (EPs) have been established. Until now it was unknown whether they mediated the pathway from gene to reading (dis)ability. Thus, in a sample of 223 siblings from nuclear families with DD and 79 unrelated typical readers, we tested four EPs (i.e., rapid auditory processing, rapid automatized naming, multisensory nonspatial attention and visual motion processing) and 20 markers spanning five DD-candidate genes (i.e., DYX1C1, DCDC2, KIAA0319, ROBO1 and GRIN2B) using a multiple-predictor/multiple-mediator framework. Our results show that rapid auditory and visual motion processing are mediators in the pathway from ROBO1-rs9853895 to reading. Specifically, the T/T genotype group predicts impairments in rapid auditory and visual motion processing which, in turn, predict poorer reading skills. Our results suggest that ROBO1 is related to reading via multisensory temporal processing. These findings support the use of EPs as an effective approach to disentangling the complex pathways between candidate genes and behavior.

Local perception impairs the lexical reading route

Human perception of a visual scene is hierarchically organized. Such rapid, albeit coarse, global processing allows people to create a useful context in which local details can be successively allocated. Lack of the typical hierarchical global-to-local visual processing is longitudinally predictive of future reading difficulties in pre-readers, which suggests that an atypical local perception can interfere with reading skill acquisition. Global and local Navon tasks were used to induce a transient perceptual priming before a reading-aloud task. We tested the effect of an atypical local perception on lexical and sublexical reading routes in typical adult readers. Local (vs. global) priming resulted in a slower phonological access to irregular, relative to regular, words. By contrast, pseudoword reading was not affected by local (vs. global) perceptual priming. Our findings demonstrate that, in typical adult readers, local priming impairs the fast processing of the letter string useful for lexical reading.

Caffeine improves text reading and global perception

BACKGROUND

Reading is a unique human skill. Several brain networks involved in this complex skill mainly involve the left hemisphere language areas. Nevertheless, nonlinguistic networks found in the right hemisphere also seem to be involved in sentence and text reading. These areas do not deal with phonological information, but are involved in verbal and nonverbal pattern information processing. The right hemisphere is responsible for global processing of a scene, which is needed for developing reading skills.

AIMS

Caffeine seems to affect global pattern processing specifically. Consequently, our aim was to discover if it could enhance text reading skill.

METHODS

In two mechanistic studies (n=24 and n=53), we tested several reading skills, global and local perception, alerting, spatial attention and executive functions, as well as rapid automatised naming and phonological memory, using a double-blind, within-subjects, repeated-measures design in typical young adult readers.

RESULTS

A single dose of 200 mg caffeine improved global processing, without any effect on local information processing, alerting, spatial attention and executive or phonological functions. This improvement in global processing was accompanied by faster text reading speed of meaningful sentences, whereas single word/pseudoword or pseudoword text reading abilities were not affected. These effects of caffeine on reading ability were enhanced by mild sleep deprivation.

CONCLUSIONS

These findings show that a small quantity of caffeine could improve global processing and text reading skills in adults.

Brief Report: When Large Becomes Slow: Zooming-Out Visual Attention Is Associated to Orienting Deficits in Autism

Previous studies independently demonstrated impairments in rapid orienting/disengagement and zooming-out of spatial attention in autism spectrum disorder (ASD). These attentional mechanisms, however, are not completely independent. Aiming at a more complete picture of spatial attention deficits in ASD, we examined the relationship between orienting and zooming in participants with ASD and typically developing peers. We modified a classical spatial cuing task, presenting two small or large cues in the two visual hemifields and subsequently cueing attention to one of them. Our results demonstrate a sluggish orienting mechanism in ASD only when a large attentional focus is deployed. Moreover, only the sluggish orienting mechanism in the large cues condition predicts the severity in the social-interaction symptomatology in individuals with ASD.

Is excessive visual crowding causally linked to developmental dyslexia?

For about 10% of children reading acquisition is extremely difficult because they are affected by a heritable neurobiological disorder called developmental dyslexia (DD), mainly associated to an auditory-phonological disorder. Visual crowding is a universal phenomenon that impairs the recognition of stimuli in clutter, such as a letter in a word or a word in a text. Several studies have shown an excessive crowding in individuals with DD, but the causal link between excessive crowding and DD is not yet clearly established. An excessive crowding might be, indeed, a simple effect of DD due to reduced reading experience. The results of five experiments in 181 children reveal that: (i) an excessive crowding only at unattended locations characterizes an unselected group of children with DD (Experiment 1); (ii) an extra-large spaced text increases reading accuracy by reducing crowding in an unselected group of children with DD (Experiment 2); (iii) efficient attentional action video game trainings reduce crowding and accelerate reading speed in two unselected groups of children with DD (Experiment 3 and 4), and; (iv) pre-reading crowding longitudinally predicts future poor readers (Experiment 5). Our results show multiple causal links between visual crowding and learning to read. These findings provide new insights for a more efficient remediation and prevention for DD.

Sluggish dorsally-driven inhibition of return during orthographic processing in adults with dyslexia

Dyslexia (D) is a neurodevelopmental reading disorder characterized by phonological and orthographic deficits. Before phonological decoding, reading requires a specialized orthographic system for parallel letter processing that assigns letter identities to different spatial locations. The magnocellular-dorsal (MD) stream rapidly process the spatial location of visual stimuli controlling visuo-spatial attention. To investigate the visuo-spatial attention efficiency during orthographic processing, inhibition of return (IOR) was measured in adults with and without D in a lexical decision task. IOR is the delay in responding to stimuli displayed in a cued location after a long cue-target interval. Only adults with D did not showed IOR effect during letter-string recognition, despite the typical left-hemisphere specialization for word identification. A specific deficit in coherent-dot-motion perception confirmed an MD-stream disorder in adults with D. Our results suggest that adults with D might develop an efficient visual word form area, but a dorsal-attentional dysfunction impairs their reading fluency.

Weak surround suppression of the attentional focus characterizes visual selection in the ventral stream in autism

Neurophysiological findings in the typical population demonstrate that spatial scrutiny for visual selection determines a center-surround profile of the attentional focus, which is the result of recurrent processing in the visual system. Individuals with autism spectrum disorder (ASD) manifest several anomalies in their visual selection, with strengths in detail-oriented tasks, but also difficulties in distractor inhibition tasks. Here, we asked whether contradictory aspects of perception in ASD might be due to a different center-surround profile of their attentional focus. In two experiments, we tested two independent samples of children with ASD, comparing them with typically developing (TD) peers. In Experiment 1, we used a psychophysical task that mapped the entire spatial profile of the attentional focus. In Experiment 2, we used dense-array electroencephalography (EEG) to explore its neurophysiological underpinnings. Experiment 1 results showed that the suppression, surrounding the attentional focus, was markedly reduced in children with ASD. Experiment 2 showed that the center-surround profile in TD children resulted in a modulation of the posterior N2 ERP component, with cortical sources in the lateral-occipital and medial/inferior temporal areas. In contrast, children with ASD did not show modulation of the N2 and related activations in the ventral visual stream. Furthermore, behavioural and neurophysiological measures of weaker suppression predicted more severe autistic symptomatology. The present findings, showing an altered center-surround profile during attentional selection, give an important insight to understand superior visual processing in autism as well as the experiencing of sensory overload.

A different vision of dyslexia: Local precedence on global perception

Individuals perceive the wor(l)d hierarchically. Firsty, the global visual scene is processed by the right hemisphere, and later, the local features are perceived by the left hemisphere. Based on this hierarchical analysis, humans evolved unique communication ability: reading. However, for about 10% of people reading acquisition is extremely difficult, they are affected by a heritable neurodevelopmental disorder called dyslexia. Differences in perceiving the wor(l)d might be one of the causes of reading disabilities. Here we show multiple causal links between the global before local perception and learning to read. Five behavioral experiments in 353 children reveal that: (i) a local before global perception characterizes three independent groups of unselected children with dyslexia; (ii) two global before local perception trainings improve reading skills in children with dyslexia; and stringently (iii) pre-reading local before global perception longitudinally predicts future poor readers. Challenging the uni-causal and left-lateralized phonological explanation of dyslexia, our results demonstrate that learning to read depends also on an efficient right neural network for the global analysis of the visual scene. These results provide new insights in learning strategies and pave the way for early identification and possible prevention programs.

Visual motion and rapid auditory processing are solid endophenotypes of developmental dyslexia

Although a genetic component is known to have an important role in the etiology of developmental dyslexia (DD), we are far from understanding the molecular etiopathogenetic pathways. Reduced measures of neurobiological functioning related to reading (dis)ability, i.e. endophenotypes (EPs), are promising targets for gene finding and the elucidation of the underlying mechanisms. In a sample of 100 nuclear families with DD (229 offspring) and 83 unrelated typical readers, we tested whether a set of well-established, cognitive phenotypes related to DD [i.e. rapid auditory processing (RAP), rapid automatized naming (RAN), multisensory nonspatial attention and visual motion processing] fulfilled the criteria of the EP construct. Visual motion and RAP satisfied all testable criteria (i.e. they are heritable, associate with the disorder, co-segregate with the disorder within a family and represent reproducible measures) and are therefore solid EPs of DD. Multisensory nonspatial attention satisfied three of four criteria (i.e. it associates with the disorder, co-segregates with the disorder within a family and represents a reproducible measure) and is therefore a potential EP for DD. Rapid automatized naming is heritable but does not meet other criteria of the EP construct. We provide the first evidence of a methodologically and statistically sound approach for identifying EPs for DD to be exploited as a solid alternative basis to clinical phenotypes in neuroscience.

Action video games improve reading abilities and visual-to-auditory attentional shifting in English-speaking children with dyslexia

Dyslexia is characterized by difficulties in learning to read and there is some evidence that action video games (AVG), without any direct phonological or orthographic stimulation, improve reading efficiency in Italian children with dyslexia. However, the cognitive mechanism underlying this improvement and the extent to which the benefits of AVG training would generalize to deep English orthography, remain two critical questions. During reading acquisition, children have to integrate written letters with speech sounds, rapidly shifting their attention from visual to auditory modality. In our study, we tested reading skills and phonological working memory, visuo-spatial attention, auditory, visual and audio-visual stimuli localization, and cross-sensory attentional shifting in two matched groups of English-speaking children with dyslexia before and after they played AVG or non-action video games. The speed of words recognition and phonological decoding increased after playing AVG, but not non-action video games. Furthermore, focused visuo-spatial attention and visual-to-auditory attentional shifting also improved only after AVG training. This unconventional reading remediation program also increased phonological short-term memory and phoneme blending skills. Our report shows that an enhancement of visuo-spatial attention and phonological working memory, and an acceleration of visual-to-auditory attentional shifting can directly translate into better reading in English-speaking children with dyslexia.

How to Study Boron Biodistribution in Liver Metastases from Colorectal Cancer

The purpose of this study was to evaluate boron distribution for a safe and effective BNCT (Boron Neutron Capture Therapy) of liver metastases. Samples both from healthy and tumour liver parenchyma were analysed, after i.v. boron administration, by: alpha particles counting under neutron irradiation; morphological analysis by standard haematoxylin-eosin staining; neutron autoradiography. Our method was unaffected by the cytological heterogeneity inside tumour nodules; it demonstrated selective boron distribution in tumour tissue and predicted estimated mean therapeutic doses in tumour and safety doses in healthy tissue. The time interval for efficient BNCT was 2 to 4 hours after i.v. boron administration.

Visual Illusions: An Interesting Tool to Investigate Developmental Dyslexia and Autism Spectrum Disorder

A visual illusion refers to a percept that is different in some aspect from the physical stimulus. Illusions are a powerful non-invasive tool for understanding the neurobiology of vision, telling us, indirectly, how the brain processes visual stimuli. There are some neurodevelopmental disorders characterized by visual deficits. Surprisingly, just a few studies investigated illusory perception in clinical populations. Our aim is to review the literature supporting a possible role for visual illusions in helping us understand the visual deficits in developmental dyslexia and autism spectrum disorder. Future studies could develop new tools - based on visual illusions - to identify an early risk for neurodevelopmental disorders.

Multiple Causal Links Between Magnocellular-Dorsal Pathway Deficit and Developmental Dyslexia

Although impaired auditory-phonological processing is the most popular explanation of developmental dyslexia (DD), the literature shows that the combination of several causes rather than a single factor contributes to DD. Functioning of the visual magnocellular-dorsal (MD) pathway, which plays a key role in motion perception, is a much debated, but heavily suspected factor contributing to DD. Here, we employ a comprehensive approach that incorporates all the accepted methods required to test the relationship between the MD pathway dysfunction and DD. The results of 4 experiments show that (1) Motion perception is impaired in children with dyslexia in comparison both with age-match and with reading-level controls; (2) pre-reading visual motion perception-independently from auditory-phonological skill-predicts future reading development, and (3) targeted MD trainings-not involving any auditory-phonological stimulation-leads to improved reading skill in children and adults with DD. Our findings demonstrate, for the first time, a causal relationship between MD deficits and DD, virtually closing a 30-year long debate. Since MD dysfunction can be diagnosed much earlier than reading and language disorders, our findings pave the way for low resource-intensive, early prevention programs that could drastically reduce the incidence of DD.

Early effects comparison of X-rays delivered at high-dose-rate pulses by a plasma focus device and at low dose rate on human tumour cells

A comparative study has been performed on the effects of high-dose-rate (DR) X-ray beams produced by a plasma focus device (PFMA-3), to exploit its potential medical applications (e.g. radiotherapy), and low-DR X-ray beams produced by a conventional source (XRT). Experiments have been performed at 0.5 and 2 Gy doses on a human glioblastoma cell line (T98G). Cell proliferation rate and potassium outward currents (IK) have been investigated by time lapse imaging and patch clamp recordings. The results showed that PFMA-3 irradiation has a greater capability to reduce the proliferation rate activity with respect to XRT, while it does not affect IK of T98G cells at any of the dose levels tested. XRT irradiation significantly reduces the mean IK amplitude of T98G cells only at 0.5 Gy. This work confirms that the DR, and therefore the source of radiation, is crucial for the planning and optimisation of radiotherapy applications.

In vivo radiobiological assessment of the new clinical carbon ion beams at CNAO

In this article, the in vivo study performed to evaluate the uniformity of biological doses within an hypothetical target volume and calculate the values of relative biological effectiveness (RBE) at different depths in the spread-out Bragg peak (SOBP) of the new CNAO (National Centre for Oncological Hadrontherapy) carbon beams is presented, in the framework of a typical radiobiological beam calibration procedure. The RBE values (relative to (60)Co γ rays) of the CNAO active scanning carbon ion beams were determined using jejunal crypt regeneration in mice as biological system at the entrance, centre and distal end of a 6-cm SOBP. The RBE values calculated from the iso-effective doses to reduce crypt survival per circumference to 10, ranged from 1.52 at the middle of the SOBP to 1.75 at the distal position and are in agreement with those previously reported from other carbon ion facilities. In conclusion, this first set of in vivo experiments shows that the CNAO carbon beam is radiobiologically comparable with the NIRS (National Institute of Radiological Sciences, Chiba, Japan) and GSI (Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany) ones.

How the visual aspects can be crucial in reading acquisition? The intriguing case of crowding and developmental dyslexia

Developmental dyslexia (DD) is the most common neurodevelopmental disorder (about 10% of children across cultures) characterized by severe difficulties in learning to read. According to the dominant view, DD is considered a phonological processing impairment that might be linked to a cross-modal, letter-to-speech sound integration deficit. However, new theories-supported by consistent data-suggest that mild deficits in low-level visual and auditory processing can lead to DD. This evidence supports the probabilistic and multifactorial approach for DD. Among others, an interesting visual deficit that is often associated with DD is excessive visual crowding. Crowding is defined as difficulty in the ability to recognize objects when surrounded by similar items. Crowding, typically observed in peripheral vision, could be modulated by attentional processes. The direct consequence of stronger crowding on reading is the inability to recognize letters when they are surrounded by other letters. This problem directly translates to reading at a slower speed and being more prone to making errors while reading. Our aim is to review the literature supporting the important role of crowding in DD. Moreover, we are interested in proposing new possible studies in order to clarify whether the observed excessive crowding could be a cause rather than an effect of DD. Finally, we also suggest possible remediation and even prevention programs that could be based on reducing the crowding in children with or at risk for DD without involving any phonological or orthographic training.