The N400 in readers with dyslexia: A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to assess whether (i) significant differences exist in the N400 response to lexico-semantic tasks between typically developing (TD) readers and readers with dyslexia, and (ii) whether these differences are moderated by the modality of task presentation (visual vs. auditory), the type of task, age, or opaque orthography (shallow and transparent alphabets vs Chinese morpho-syllabary). Twenty studies were included in the meta-analysis, and the analysis did not demonstrate strong evidence of publication bias. An overall effect size of Hedge's g = 0.66, p < .001, was found between typically developing readers and readers with dyslexia. All moderators were found to be significant; larger effects were associated with visual modality (g = 0.692, p < .001), semantically incongruent sentence tasks (g = 0.948, p < .001), pseudowords/characters tasks (g = 0.971, p < .001), and orthography [Chinese (g = 1.015, p < .001) vs. alphabets (g = 0.539, p < .001)]. Analysis of reaction time showed Hedge's g = 1.613, p < .001. Results suggest that the N400 reliably differentiated between typically developing readers and readers with dyslexia. Implications for future research and practice are discussed.

Characterizing Attention Resource Capacity in Autism: A Multiple Object Tracking Study.

The extant literature aimed at characterizing attentional capability in autistics has presented inconsistent findings. This inconsistency and uncertainty may be the product of different theoretical and methodological approaches used to define attention in autism. In the current study, we investigate whether the allocation of attentional resources to task demands, and attention resource capacity, differs between autistics with no comorbid attention-deficit diagnosis (n = 55) and age-matched neurotypicals (n = 55). We compared differences in capacity and the allocation of resources by manipulating attentional load in a Multiple Object-Tracking (MOT) task, a robust, versatile, and ecological measure of selective, sustained, and distributed attention. While autistics demonstrated lower MOT performance, this difference disappeared when we accounted for fluid reasoning intelligence. Additionally, the similarity in the trend of MOT performance at increasing levels of attentional load between autistics and neurotypicals suggests no differences in the allocation of attentional resources to task demands. Taken together, our study suggests that higher-order cognitive abilities, such as intelligence, should be considered when characterizing attention across the autistic population in research. Similarly, our findings highlight the importance of considering cognitive competence when assessing attentional capabilities in autistic individuals, which could have significant implications for clinical diagnosis, treatment, and support.

Brief Report: An Exploration of Cognitive Flexibility of Autistic Adolescents with Low Intelligence Using the Wisconsin Card Sorting Task.

Cognitive flexibility (CF) is the ability to shift between concepts or rules. Difficulty with CF is associated with autism (i.e., ASD) as it contributes to repetitive behaviours. However, little is known about CF skills of autistic adolescents with low intelligence. This study uses the Wisconsin Card Sorting Task (WCST) to assess the CF of 36 adolescents, all with a Weschler full-scale IQ between 50 and 85, 14 of whom had an ASD diagnosis. The results indicated no statistically significant differences in WCST performance between those with and without ASD. It was also found that performance IQ significantly contributed to the WCST performance in the ASD group only, suggesting an autism-specific role of non-verbal cognitive functioning in CF.

Distinctive patterns of Multiple Object-Tracking performance trajectories in youth with deficits in attention, learning, and intelligence.

There is a significant overlap in symptomology between individuals with deficits in attention and learning, which is explained by the co-dependent dynamic between the two cognitive constructs. Within this dynamic, attentional resources are allocated to salient stimuli while learning mechanisms distinguish relevant from irrelevant information. Moreover, individuals with deficits in higher-order cognition (i.e., intelligence) can demonstrate difficulties in attention and learning. The Multiple Object-Tracking (MOT) task is a sensitive and versatile measure of attention that has characterized individual differences in attention as a function of higher-order cognition. Exploiting the traditional MOT task's ability to characterize the allocation of attentional resources to task demands, the current study compared learning exhibited on an attention-based task across neurodevelopmental conditions defined by deficits in attention (attention-deficit/hyperactivity disorder; ADHD), learning (specific learning disorder; SLD), and intelligence (intellectual developmental disorder; IDD). Children and adolescents (N = 101) completed 15 sessions on a Multiple Object-Tracking (MOT) task where performance trajectories were analyzed using latent growth curve modeling and conditioned by the presence of ADHD, SLD, or IDD while controlling for performance on a separate measure of attention, age, and sex. The sample, characterized by below-average IQ and problematic levels of attention, exhibited an effect of learning on MOT. However, individuals with an IDD diagnosis demonstrated decreased baseline MOT capability while ADHD and SLD profiles exhibited decreased slopes, relative to other neurodevelopmental conditions. Taken together, the results demonstrate distinct linear performance trajectories between neurodevelopmental conditions defined by deficits in attention, learning, and intelligence. The current study provides additional evidence to repurpose the traditional MOT task as a descriptor of attention and discusses alternative uses for the paradigm. Overall, these results suggest an eclectic approach that considers attention, learning, and higher-order cognition when diagnosing ADHD, SLD, or IDD.

Audiovisual temporal binding window narrows with age in autistic individuals.

Atypical sensory perception has been recognized in autistic individuals since its earliest descriptions and is now considered a key characteristic of autism. Although the integration of sensory information (multisensory integration; MSI) has been demonstrated to be altered in autism, less is known about how this perceptual process differs with age. This study aimed to assess the integration of audiovisual information across autistic children and adolescents. MSI was measured using a non-social, simultaneity judgment task. Variation in temporal sensitivity was evaluated via Gaussian curve fitting procedures, allowing us to compare the width of temporal binding windows (TBWs), where wider TBWs indicate less sensitivity to temporal alignment. We compared TBWs in age and IQ matched groups of autistic (n = 32) and neurotypical (NT; n = 73) children and adolescents. The sensory profile of all participants was also measured. Across all ages assessed (i.e., 6 through 18 years), TBWs were negatively correlated with age in the autistic group. A significant correlation was not found in the NT group. When compared as a function of child (6-12 years) and adolescent (13-18 years) age groups, a significant interaction of group (autism vs NT) by age group was found, whereby TBWs became narrower with age in the autistic, but not neurotypical group. We also found a significant main effect of age and no significant main effect of group. Results suggest that TBW differences between autistic and neurotypical groups diminishes with increasing age, indicating an atypical developmental profile of MSI in autism which ameliorates across development.

Development of static and dynamic perception for luminance- and texture-defined information from school-ages to adulthood.

Few studies have assessed the visual development of static and dynamic information processing at different levels of processing during typical development from the school-age years to adulthood. The implication of non-visual factors on visual development, such as cognitive (e.g., IQ) and attentional abilities, has yet to be systematically assessed with regard to spanning such a large age range. To address these voids, 203 typically-developing participants (aged 6 to 31 years) identified the orientation or direction of a static or moving grating defined by either luminance- or texture-contrast. An adaptive staircase procedure was used to measure contrast sensitivity in all four conditions. Cognitive (Wechsler IQ) and attentional ability (CPT-3) were also measured for all participants. Different developmental rates of contrast sensitivity were found between static and dynamic conditions when defined by more complex, texture-defined information, with the difference in sensitivity starting after the age of 9.71 years. However, static and dynamic profiles for luminance-defined information developed similarly with age. In addition, IQ did not correlate with nor predict the sensitivity across any condition. These results suggest age significantly explains the variance in the developmental profiles of contrast sensitivity above and beyond non-visual factors such as IQ and the CPT-3 attentional scores. Moreover, the neural pathways processing static and dynamic visual information continue to develop through late childhood and adolescence for the processing of texture-defined information only.

Sleep and daytime behavior in individuals with Christianson Syndrome.

BACKGROUND: The objectives of this study were to: 1) characterize the sleep behaviors and symptoms of individuals with Christianson Syndrome (CS) by means of validated questionnaires; and 2) determine their associations with daytime emotional and behavioral symptoms in this population. METHODS: Participants included 16 boys genetically diagnosed with CS, between 2.5 and 40 years of age (M = 14.5 ± 8.08). Parents completed questionnaires regarding the sleep, daytime behavior, and health of their child. RESULTS: Of the participants, 31% did not obtain the recommended amount of sleep for their age, 43% experienced a prolonged sleep latency, and 88% had a clinical or sub-clinical score for at least one subscale of the Sleep Disturbance Scale for Children (SDSC). Specific problems detected included insomnia, sleep-wake transition disorders, periodic limb movements in sleep, and sleep related breathing disorders. About half of the participants manifested emotional and behavioral problems at clinical levels. Higher levels of sleep disturbances were associated with higher levels of behavioral and emotional daytime symptoms. CONCLUSIONS: Sleep problems are common in individuals with CS and are associated with daytime behavioral and emotional symptoms.

Category learning in autism: Are some situations better than others?

Autism is diagnosed according to atypical social-communication and repetitive behaviors. However, autistic individuals are also distinctive in the high variability of specific abilities such as learning. Having been characterized as experiencing great difficulty with learning, autistics have also been reported to learn spontaneously in exceptional ways. These contrasting accounts suggest that some situations may be better than others for learning in autism. We tested this possibility using a probabilistic category learning task with four learning situations differing either in feedback intensity or information presentation. Two learning situations compared high- versus low-intensity feedback, while two other learning situations without external feedback compared isolated sequentially presented information versus arrays of simultaneously presented information. We assessed the categorization and generalization performance of 54 autistic and 52 age-matched typical school-age children after they learned in different situations. We found that children in both groups were able to learn and generalize novel probabilistic categories in all four learning situations. However, across and within groups, autistic children were advantaged by simultaneously presented information while typical children were advantaged by high-intensity feedback when learning. These findings question some common aspects of autism interventions (e.g., frequent intense feedback, minimized simplified information), and underline the importance of improving our current understanding of how and when autistics learn optimally. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Assessing the feasibility of a classroom-based visual attention training program targeting academics for students with extremely low IQ.

BACKGROUND: This feasibility study investigated the viability of implementing a cognitive-based training program (NeuroTracker) and assessing its potential effects on academic performance for adolescents with extremely low IQ. METHODS: Twenty-six adolescents aged between 11 and 16 years with a Wechsler-based IQs in the extremely low range (MIQ = 56.00, SDIQ = 13.89) completed 15 training sessions on either the NeuroTracker or an active control task; math and reading performance were assessed using clinically validated instruments before and after training. Recruitment and retention rates, adherence, and properties of the academic measures were assessed. RESULTS: All recruited participants completed 15 training sessions within a 6-week period. Eighty-three percent of participants meeting initial inclusion criteria completed all stages of the study from baseline to post-intervention assessments. Some limitations of the academic measures were identified. CONCLUSIONS: Results suggest that implementing NeuroTracker as a classroom-based intervention and using clinically validated outcome measures is feasible with this population.

Reduced multisensory facilitation exists at different periods of development in autism.

Atypical sensory processing is now recognised as a key component of an autism diagnosis. The integration of multiple sensory inputs (multisensory integration (MSI)) is thought to be idiosyncratic in autistic individuals and may have cascading effects on the development of higher-level skills such as social communication. Multisensory facilitation was assessed using a target detection paradigm in 45 autistic and 111 neurotypical individuals, matched on age and IQ. Target stimuli were: auditory (A; 3500 Hz tone), visual (V; white disk 'flash') or audiovisual (AV; simultaneous tone and flash), and were presented on a dark background in a randomized order with varying stimulus onset delays. Reaction time (RT) was recorded via button press. In order to assess possible developmental effects, participants were divided into younger (age 14 or younger) and older (age 15 and older) groups. Redundancy gain (RG) was significantly greater in neurotypical, compared to autistic individuals. No significant effect of age or interaction was found. Race model analysis was used to compute a bound value that represented the facilitation effect provided by MSI. Our results revealed that MSI facilitation occurred (violation of the race model) in neurotypical individuals, with more efficient MSI in older participants. In both the younger and older autistic groups, we found reduced MSI facilitation (no or limited violation of the race model). Autistic participants showed reduced multisensory facilitation compared to neurotypical participants in a simple target detection task, void of social context. This remained consistent across age. Our results support evidence that autistic individuals may not integrate low-level, non-social information in a typical fashion, adding to the growing discussion around the influential effect that basic perceptual atypicalities may have on the development of higher-level, core aspects of autism.

Different luminance- and texture-defined contrast sensitivity profiles for school-aged children.

Our current understanding of how the visual brain develops is based largely on the study of luminance-defined information processing. This approach, however, is somewhat limiting, since everyday scenes are composed of complex images, consisting of information characterized by physical attributes relating to both luminance and texture. Few studies have explored how contrast sensitivity to texture-defined information develops, particularly throughout the school-aged years. The current study investigated how contrast sensitivity to luminance- (luminance-modulated noise) and texture-defined (contrast-modulated noise) static gratings develops in school-aged children. Contrast sensitivity functions identified distinct profiles for luminance- and texture-defined gratings across spatial frequencies (SFs) and age. Sensitivity to luminance-defined gratings reached maturity in childhood by the ages of 9-10 years for all SFs (0.5, 1, 2, 4 and 8 cycles/degree or cpd). Sensitivity to texture-defined gratings reached maturity at 5-6 years for low SFs and 7-8 years for high SFs (i.e., 4 cpd). These results establish that the processing of luminance- and texture-defined information develop differently as a function of SF and age.

Modulation of Slow-Wave Sleep: Implications for Psychiatry.

PURPOSE OF REVIEW: The objectives of this review are to examine and integrate existing empirical evidence regarding the impact of slow-wave sleep (SWS) modulation on memory and executive function performance in individuals with psychiatric disorders, and to examine the feasibility of integrating SWS modulation into psychiatric care. RECENT FINDINGS: SWS modulation in individuals with psychiatric disorders resulted in changes to SWS across multiple psychiatric disorders, using all stimulation methods. SWS stimulation was associated with improved cognitive performance. SWS modulation using acoustic stimulation resulted in improved cognitive performance in children with ADHD, and the use of transcranial stimulation was associated with improved cognitive performance in individuals with mild cognitive impairment. Significant relationships between changes in SWS and cognitive improvement were found for individual with mild cognitive impairment following the use of acoustic or transcranial stimulation night. Our review reveals partial support to the potential efficacy of SWS modulation as a transdiagnostic intervention that uses sleep to improve cognitive functions of individuals diagnosed with psychiatric disorders and cognitive deficits. It further highlights multiple barriers pertaining to the feasibility of integrating SWS modulation into clinical practice and proposes ways to improve it.

Multiple object-tracking isolates feedback-specific load in attention and learning.

Feedback is beneficial for learning. Nevertheless, it remains unclear whether (i) feedback draws attentional resources when integrated and (ii) the benefits of feedback for learning can be demonstrated using an attention-based task. We therefore (i) isolated feedback-specific load from task-specific load via individual differences in attention resource capacity and (ii) examined the effect of trial-by-trial feedback (i.e., present vs. absent) on learning a multiple object-tracking (MOT) paradigm. We chose MOT because it is a robust measure of attention resource capacity. In Study 1 participants tracked one (i.e., lowest attentional load condition) through four target items (i.e., highest load condition) among eight total items. One group (n = 32) received trial-by-trial feedback whereas the other group (n = 32) did not. The absence of feedback resulted in better MOT performance compared with the presence of feedback. Moreover, the difference in MOT capability between groups increased as the task-specific attentional load increased. These findings suggest that feedback integration requires attentional resources. Study 2 examined whether the absence (n = 19) or presence (n = 19) of feedback affects learning on the same MOT task across four testing days. When holding task-specific load constant, improvement in MOT was greater with feedback than without. Although this study is the first to isolate feedback-specific load in attention with MOT, more evidence is needed to demonstrate how the benefits of feedback translate to improvement on an attention-based task. These findings encourage future research to further explore the interaction between feedback, attention and learning.

Within- and Cross-Modal Integration and Attention in the Autism Spectrum.

Although impairment in sensory integration is suggested in the autism spectrum (AS), empirical evidences remain equivocal. We assessed the integration of low-level visual and tactile information within and across modalities in AS and typically developing (TD) individuals. TD individuals demonstrated increased redundancy gain for cross-modal relative to double tactile or visual stimulation, while AS individuals showed similar redundancy gain between cross-modal and double tactile conditions. We further observed that violation of the race model inequality for cross-modal conditions was observed over a wider proportion of the reaction times distribution in TD than AS individuals. Importantly, the reduced cross-modal integration in AS individuals was not related to atypical attentional shift between modalities. We conclude that AS individuals displays selective decrease of cross-modal integration of low-level information.

Reduced multisensory facilitation in adolescents and adults on the Autism Spectrum.

Individuals with autism are reported to integrate information from visual and auditory channels in an idiosyncratic way. Multisensory integration (MSI) of simple, non-social stimuli (i.e., flashes and beeps) was evaluated in adolescents and adults with (n = 20) and without autism (n = 19) using a reaction time (RT) paradigm using audio, visual, and audiovisual stimuli. For each participant, the race model analysis compares the RTs on the audiovisual condition to a bound value computed from the unimodal RTs that reflects the effect of redundancy. If the actual audiovisual RTs are significantly faster than this bound, the race model is violated, indicating evidence of MSI. Our results show that the race model violation occurred only for the typically-developing (TD) group. While the TD group shows evidence of MSI, the autism group does not. These results suggest that multisensory integration of simple information, void of social content or complexity, is altered in autism. Individuals with autism may not benefit from the advantage conferred by multisensory stimulation to the same extent as TD individuals. Altered MSI for simple, non-social information may have cascading effects on more complex perceptual processes related to language and behaviour in autism.

A Developmental Perspective of Global and Local Visual Perception in Autism Spectrum Disorder.

Individuals with autism spectrum disorder (ASD) demonstrate superior performances on visuo-spatial tasks emphasizing local information processing; however, findings from studies involving hierarchical stimuli are inconsistent. Wide age ranges and group means complicate their interpretability. Children and adolescents with and without ASD completed a Navon task wherein they identified global and local stimuli composed of either consistent or inconsistent letters. Trajectories of reaction time in global and local conditions were similar within and between groups when consistent and inconsistent stimuli were considered together, but the effect of local-to-global interference was significantly higher in participants with than without ASD. Age was not a significant predictor of local-to-global interference, suggesting that this effect emerges in childhood and persists throughout adolescence in ASD.

Training with a three-dimensional multiple object-tracking (3D-MOT) paradigm improves attention in students with a neurodevelopmental condition: a randomized controlled trial.

The efficacy of attention training paradigms is influenced by many factors, including the specificity of targeted cognitive processes, accuracy of outcome measures, accessibility to specialized populations, and adaptability to user capability. These issues are increasingly significant when working with children diagnosed with neurodevelopmental conditions that are characterized by attentional difficulties. This study investigated the efficacy of training attention in students with neurodevelopmental conditions using a novel three-dimensional Multiple Object-Tracking (3D-MOT) task. All students (ages 6-18 years) performed the Conners Continuous Performance Task (CPT-3) as a baseline measure of attention. They were then equally and randomly assigned to one of three groups: a treatment group, (3D-MOT); an active control group (visual strategy/math-based game, 2048); and a treatment as usual group. Students were trained on their respective tasks for a total of 15 training sessions over a five-week period and then reassessed on the CPT-3. Results showed that post-training CPT-3 performance significantly improved from baseline for participants in the treatment group only. This improvement indicates that training with 3D-MOT increased attentional abilities in students with neurodevelopmental conditions. These results suggest that training attention with a non-verbal, visual-based task is feasible in a school setting and accessible to atypically developing students with attentional difficulties.

Multisensory Integration of Low-level Information in Autism Spectrum Disorder: Measuring Susceptibility to the Flash-Beep Illusion.

Previous studies have suggested audiovisual multisensory integration (MSI) may be atypical in Autism Spectrum Disorder (ASD). However, much of the research having found an alteration in MSI in ASD involved socio-communicative stimuli. The goal of the current study was to investigate MSI abilities in ASD using lower-level stimuli that are not socio-communicative in nature by testing susceptibility to auditory-guided visual illusions. Adolescents and adults with ASD and typically-developing (TD) individuals were shown to have similar susceptibility to a fission illusion. However, the ASD group was significantly more susceptible to the fusion illusion. Results suggest that individuals with ASD demonstrate MSI on the flash-beep illusion task but that their integration of audiovisual sensory information may be less selective than for TD individuals.

Face perception develops similarly across viewpoint in children and adolescents with and without autism spectrum disorder.

Atypical face perception has been associated with the socio-communicative difficulties that characterize autism spectrum disorder (ASD). Growing evidence, however, suggests that a widespread impairment in face perception is not as common as once thought. One important issue arising with the interpretation of this literature is the relationship between face processing and a more general perceptual tendency to focus on local rather than global information. Previous work has demonstrated that when discriminating faces presented from the same view, older adolescents and adults with ASD perform similarly to typically developing individuals. When faces are presented from different views, however, they perform more poorly-specifically, when access to local cues is minimized. In this study, we assessed the cross-sectional development of face identity discrimination across viewpoint using same- and different-view conditions in children and adolescents with and without ASD. Contrary to the findings in adults, our results revealed that all participants experienced greater difficulty identifying faces from different views than from same views, and demonstrated similar age-expected improvements in performance across tasks. These results suggest that differences in face discrimination across views may only emerge beyond the age of 15 years in ASD.

The developmental trajectory of contrast sensitivity in autism spectrum disorder.

Autism Spectrum Disorder (ASD) is characterized by a detail-driven visual processing strategy, evidence for which has been based largely on cross-sectional studies in small participant groups of limited age ranges. It is therefore unknown when sensitivity to detailed information emerges and develops in ASD. Contrast sensitivity to sinusoidal gratings of different spatial frequencies (0.5, 1, 2, 4, and 8 cycles per degree (cpd)) was measured for 34 participants with ASD and 55 typically developing participants (aged 6-16 years). Cross-sectional, developmental trajectories were constructed to examine within and between group differences across the range of spatial frequencies tested. Developmental trajectories indicated that sensitivity across low (i.e., 0.5 and 1 cpd) and mid (2 and 4 cpd) spatial frequencies varied by chronological age within each group, with mid frequencies developing at a more significant rate than low frequencies. There was no overall difference between groups in terms of the relationship of sensitivity and age across spatial frequencies, yet the ASD group had an overall lower level of sensitivity. Closer examination revealed that the youngest participants with ASD had a reduced sensitivity for mid frequencies. Moreover, the ASD group showed a statistically significant developmental relationship at 8 cpd, which suggests that a trend for increased sensitivity to early detailed information may manifest beyond the ages tested. These findings demonstrate a differential development of contrast sensitivity for spatial frequencies in ASD and underscore the need to better identify what drives such differences in the "building blocks" of visual perception. Autism Res 2016, 9: 866-878. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.