Simone Gori

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.

“Shall We Play a Game?”: Improving Reading Through Action Video Games in Developmental Dyslexia

Impaired linguistic-phonological processing is the most accepted explanation of developmental dyslexia (DD). However, growing literature shows that DD is the result of the combination of several neurocognitive causes. Visual attention and magnocellular-dorsal (MD) pathway deficits are now considered causes of DD. Interestingly, a large portion of literature showed that action video games (AVG) are able to improve attentional and perceptual skills in typical readers. Consequently, employing AVG trainings in individuals with DD could improve attention and perception, resulting in better reading skills. The aim of our review is to show the benefits of the AVG training on DD through the changes in the neurocognitive functions at the basis of learning to read. Since visual attentional and MD dysfunctions can be diagnosed in infancy, our review paves the way for possible early prevention programs that could use AVG training.

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.

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.

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.

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

HighlightsDyslexia is characterized not only by phonological but also orthographic deficits.Orthographic processing assigns letter identities to different spatial locations.Spatial location encoding is driven by the “where” dorsal‐attentional stream.Adults with dyslexia show impaired IOR during orthographic processing.Adults with dyslexia show a “where” dorsal‐attentional dysfunction. ABSTRACT 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.

Dyslexia prevention by action video game training: behavioural and neurophysiological evidence

For children affected by developmental dyslexia learning to read is extremely difficult. Pre-reading visual attention predicts future reading acquisition skills. Action video game (AVG) training increases attentional functioning and induces learning that transfers well beyond the task domain, such as reading. We investigated the effects of AVG training on predictors of future reading acquisition (i.e., visuo-spatial attention, auditory-phonological processing and rapid naming skills) and on the dense-array EEG resting-state in pre-reading children at risk for dyslexia. Three matched groups of pre-readers at risk for dyslexia were tested before and after they played with AVG, non-AVG (for 20 hrs) or no-treatment (Exp. 1). We found that only playing AVG improved childrens visuo-spatial attention processing. Phonemes discrimination was also increased only after AVG training. We confirmed this effect of AVG training on phonological processing in a replication study with another independent sample (Exp. 2). Two new samples of pre-schoolers at risk for dyslexia were selected (Exp. 3): half of them were trained with AVG while the other half had no training. We measured visuo-spatial attention and auditory-phonological skills. Eyes-closed resting-state EEG was also recorded in both groups. Results showed that only the AVG training improved visuo-spatial attention as well as auditory-phonological skills. A reduction of the upper alpha band (10-14 Hz) oscillatory activity in posterior areas was found only after the AVG training, showing a possible neural basis of the effect of attentional improvement on auditory-phonological processing. Our results showed, for the first time, that attention improvements can directly translate into better language abilities, providing a new, fast and fun prevention training for dyslexia.