Than Typically Developing Group Research Articles

Idiosyncratic pupil regulation in autistic children.

Recent neuroimaging and eye-tracking studies have suggested that children with autism exhibit more variable and idiosyncratic brain responses and eye movements than typically developing (TD) children. Here, we extended this research to pupillometry recordings. We successfully acquired pupillometry recordings from 111 children (74 with autism), 4.5-years-old on average, who viewed three 90 s movies, twice. We extracted their pupillary time-course for each movie, capturing their stimulus evoked pupillary responses. We then computed the correlation between the time-course of each child and those of all others in their group as well as between each autistic child and all children in the TD group. This yielded an average inter-subject correlation value per child, representing how similar their pupillary responses were to all others in their group or the comparison group. Children with autism exhibited significantly weaker inter-subject correlations than TD children in all comparisons. These differences were independent of previously reported differences in gaze inter-subject correlations and were largest in responses to a naturalistic movie containing footage of a social interaction between two TD children. The results demonstrate the utility of measuring the idiosyncrasy of pupil regulation, which can be performed with passive viewing of movies even by young children with co-occurring intellectual disability. These findings reveal that a considerable number of children with autism have significantly less stable, idiosyncratic pupil regulation than TD children, indicative of more variable, weakly regulated, underlying neural activity.

Neural responses to syllable-induced P1m and social impairment in children with autism spectrum disorder and typically developing Peers.

In previous magnetoencephalography (MEG) studies, children with autism spectrum disorder (ASD) have been shown to respond differently to speech stimuli than typically developing (TD) children. Quantitative evaluation of this difference in responsiveness may support early diagnosis and intervention for ASD. The objective of this research is to investigate the relationship between syllable-induced P1m and social impairment in children with ASD and TD children. We analyzed 49 children with ASD aged 40-92 months and age-matched 26 TD children. We evaluated their social impairment by means of the Social Responsiveness Scale (SRS) and their intelligence ability using the Kaufman Assessment Battery for Children (K-ABC). Multiple regression analysis with SRS score as the dependent variable and syllable-induced P1m latency or intensity and intelligence ability as explanatory variables revealed that SRS score was associated with syllable-induced P1m latency in the left hemisphere only in the TD group and not in the ASD group. A second finding was that increased leftward-lateralization of intensity was correlated with higher SRS scores only in the ASD group. These results provide valuable insights but also highlight the intricate nature of neural mechanisms and their relationship with autistic traits.

Combined frequency-tagging EEG and eye-tracking measures provide no support for the \u201cexcess mouth/diminished eye attention\u201d hypothesis in autism

BackgroundScanning faces is important for social interactions. Difficulty with the social use of eye contact constitutes one of the clinical symptoms of autism spectrum disorder (ASD). It has been suggested that individuals with ASD look less at the eyes and more at the mouth than typically developing (TD) individuals, possibly due to gaze aversion or gaze indifference. However, eye-tracking evidence for this hypothesis is mixed. While gaze patterns convey information about overt orienting processes, it is unclear how this is manifested at the neural level and how relative covert attention to the eyes and mouth of faces might be affected in ASD.MethodsWe used frequency-tagging EEG in combination with eye tracking, while participants watched fast flickering faces for 1-min stimulation sequences. The upper and lower halves of the faces were presented at 6 Hz and 7.5 Hz or vice versa in different stimulation sequences, allowing to objectively disentangle the neural saliency of the eyes versus mouth region of a perceived face. We tested 21 boys with ASD (8–12 years old) and 21 TD control boys, matched for age and IQ.ResultsBoth groups looked longer at the eyes than the mouth, without any group difference in relative fixation duration to these features. TD boys looked significantly more to the nose, while the ASD boys looked more outside the face. EEG neural saliency data partly followed this pattern: neural responses to the upper or lower face half were not different between groups, but in the TD group, neural responses to the lower face halves were larger than responses to the upper part. Face exploration dynamics showed that TD individuals mostly maintained fixations within the same facial region, whereas individuals with ASD switched more often between the face parts.LimitationsReplication in large and independent samples may be needed to validate exploratory results.ConclusionsCombined eye-tracking and frequency-tagged neural responses show no support for the excess mouth/diminished eye gaze hypothesis in ASD. The more exploratory face scanning style observed in ASD might be related to their increased feature-based face processing style.

Out of mind, out of sight? Investigating abnormal face scanning in autism spectrum disorder using gaze-contingent paradigm.

Diminished social motivation is hypothesized to explain abnormal face scanning pattern in individuals with autism spectrum disorder (ASD), especially reduced eye-looking time in ASDs than typically developing (TD) people. Here, we tested an alternative explanation that children with ASD may use a compensatory strategy to avoid direct eye contact by processing the eyes through peripheral vision. We compared the face scanning patterns of children with and without ASD in two conditions: in the clear condition, the face was completely visible; in the blur condition, by using the gaze-contingent paradigm, the whole face was blurred except for a small region being fixated at, thus children could not rely on the peripheral information to process the eyes. We found that children with ASD fixated less on the eyes than TD children in both conditions. Temporal-course analyses further revealed the possible motivation-based guidance of attention to process the eyes in the TD group but not in the ASD group. Additionally, we found that children with ASD scanned faces more randomly and less strategically than TD children. These results have ruled out the alternative hypothesis that the abnormal face scanning pattern in ASDs was due to their compensatory strategy to process eyes through peripheral vision, furthering our understanding of the mechanisms underlying their abnormal face scanning.

Why do children with language impairment have difficulties with narrative macrostructure?

BackgroundResearch has produced conflicting findings about the effects of language impairment (LI) on narrative macrostructure outcomes. AimsThe present study investigated if children with LI perform weaker than typically developing (TD) controls on narrative macrostructure in different tasks, whether this changes over time and if between-group differences stem from linguistic or cognitive factors. Methods and proceduresA group of monolingual Dutch children with LI (n=84) and a TD control group (n=45) were tested with a story comprehension and a story generation task. All children were five or six at wave 1 and six or seven at wave 2. Information was collected on vocabulary, grammar, verbal memory and sustained attention. Outcomes and resultsAt wave 1, the LI group performed weaker than the TD group in both tasks. At wave 2, the groups performed similarly on story comprehension. On story generation, the TD group still outperformed the LI group. Sustained attention mediated the relationship between group and story generation. Conclusions and implicationsEffects of LI on narrative macrostructure are moderated by age and task and may stem from sustained attention weaknesses. These findings have implications for using narrative tasks in educational and diagnostic settings and may direct future interventions.

Epistemic uncertainty: Turkish children with specific language impairment and their comprehension of tense and aspect.

Impairments in tense morphology are characteristic of English-speaking children with specific language impairment (SLI). Recent studies have investigated the role that aspect plays in the difficulties found in tense morphology. It has been suggested that children with SLI are less sensitive to aspect and its interaction with tense than typically developing (TD) children. Profound impairment in past tense morphology compared with the present in this population was explained by a breakdown in the association between event completion information and past tense. To date, research on tense morphology in this population has not examined all three tense conditions in a single study. To examine whether monolingual Turkish-speaking children with SLI exhibit deficits in comprehending tense and aspect morphology, and, if so, whether these deficits are restricted to completed events (past tense) or also occur for incomplete non-past events (future and present tense). A sentence-picture matching task was administered to 36 monolingual Turkish-speaking children: 13 with SLI (mean age = 6;9 years) and 23 age-matched TD children (mean age = 6;5 years). Upon hearing a sentence, each child had to select between a target (past, present or future) and a distracter picture. Tense and aspect information could only be established from verb morphology. The SLI group had lower accuracy than the TD group on all test conditions. For both groups, present tense had the highest accuracy scores. Performance scores within the SLI group showed the following hierarchy from easy to difficult: present > future > past. Turkish children with SLI have deficits in comprehending tense and aspect morphology. Although comprehending past was more difficult than non-past (present and future), future was more difficult to comprehend than the present. This disassociation between two non-past incomplete events indicates that the underlying difficulties comprehending (past) tense-aspect is not restricted to event completion in past tense contexts. This finding raises the possibility that in children with SLI, non-temporal epistemic functions of verb morphology (i.e., certainty, probability or possibility of an event occurring) might play a role in efficient understanding of tense and aspect morphology. If so, children with SLI may benefit from language therapy focused on the epistemic functions of verb morphology to improve comprehension of tense and aspect.

Increased Surface Area, but not Cortical Thickness, in a Subset of Young Boys With Autism Spectrum Disorder.

The Autism Phenome Project is the largest, single site, longitudinal magnetic resonance imaging (MRI) study of young children with autism spectrum disorder (ASD). Previous analyses from this cohort have shown that the children with autism have a total brain volume at time 1 (∼3 years of age) that is 6% larger than typically developing (TD) children. This finding is driven primarily by 15% of the boys with ASD that have disproportionate megalencephaly (ASD-DM) or brain size that is 1.5 standard deviations above what would be expected for the child's height. In the current study, cerebral cortical grey matter volume, thickness, and surface area were assayed from MRI scans of 112, 3-year-old boys with ASD and 50 age-matched TD boys. The boys with ASD-DM (n = 17) were analyzed separately from the boys with normal brain size (ASD-N, n = 95). Previous studies of cortical thickness and surface area for ASD children in this age range have come to diametrically different conclusions concerning the significance of cortical thickness vs. surface area. Current analyses indicate that cortical thickness was comparable across the ASD and TD groups. However, surface area was significantly greater in the ASD group compared to the TD group. This result was driven largely by the children with ASD-DM. Even in the ASD-DM group, not all cortical regions demonstrated increased surface area. These results provide strong evidence that the early cortical overgrowth associated with ASD is due primarily to increased surface area and not to increased cortical thickness.

Speed and complexity characterize attention problems in children with localization-related epilepsy.

Children with epilepsy (EPI) have a higher rate of attention-deficit/hyperactivity disorder (ADHD; 28-70%) than typically developing (TD) children (5-10%); however, attention is multidimensional. Thus, we aimed to characterize the profile of attention difficulties in children with epilepsy. Seventy-five children with localization-related epilepsy ages 6-16 years and 75 age-matched controls were evaluated using multimodal, multidimensional measures of attention including direct performance and parent ratings of attention as well as intelligence testing. We assessed group differences across attention measures, determined if parent rating predicted performance on attention measures, and examined if epilepsy characteristics were associated with attention skills. The EPI group performed worse than the TD group on timed and complex attention aspects of attention (p < 0.05), whereas performance on simple visual and simple auditory attention tasks was comparable. Children with EPI were 12 times as likely as TD children to have clinically elevated symptoms of inattention as rated by parents, but ratings were a weak predictor of attention performance. Earlier age of onset was associated with slower motor speed (p < 0.01), but no other epilepsy-related clinical characteristics were associated with attention skills. This study clarifies the nature of the attention problems in pediatric epilepsy, which may be under-recognized. Children with EPI had difficulty with complex attention and rapid response, not simple attention. As such, they may not exhibit difficulty until later in primary school when demands increase. Parent report with standard ADHD screening tools may under-detect these higher-order attention difficulties. Thus, monitoring through direct neuropsychological performance is recommended.

Hemodynamic response of children with attention-deficit and hyperactive disorder (ADHD) to emotional facial expressions

Children with attention-deficit/hyperactivity disorder (ADHD) have difficulty recognizing facial expressions. They identify angry expressions less accurately than typically developing (TD) children, yet little is known about their atypical neural basis for the recognition of facial expressions. Here, we used near-infrared spectroscopy (NIRS) to examine the distinctive cerebral hemodynamics of ADHD and TD children while they viewed happy and angry expressions. We measured the hemodynamic responses of 13 ADHD boys and 13 TD boys to happy and angry expressions at their bilateral temporal areas, which are sensitive to face processing. The ADHD children showed an increased concentration of oxy-Hb for happy faces but not for angry faces, while TD children showed increased oxy-Hb for both faces. Moreover, the individual peak latency of hemodynamic response in the right temporal area showed significantly greater variance in the ADHD group than in the TD group. Such atypical brain activity observed in ADHD boys may relate to their preserved ability to recognize a happy expression and their difficulty recognizing an angry expression. We firstly demonstrated that NIRS can be used to detect atypical hemodynamic response to facial expressions in ADHD children.

Approximate additions and working memory in individuals with Down syndrome

There is some evidence that individuals with Down syndrome (DS) may have a poorer mathematical performance and a poorer working memory (WM) than typically developing (TD) children of the same mental age. In both typical and atypical individuals, different aspects of arithmetic and their relationships with WM have been largely studied, but the specific contribution of WM to the representation and elaboration of non-symbolic quantities has received little attention. The present study examined whether individuals with DS are as capable as TD children matched for fluid intelligence of estimating numerosity both of single sets and of added sets resulting when two sequentially presented sets are added together, also considering how these tasks related to verbal and visuospatial WM. Results showed that the DS group's performance was significantly worse than the TD group's in numerosity estimation involving one set, but not when estimating the numerosity resulting from the addition. Success in the addition task was related to success in the working memory tasks, but only for the group with DS; this applied especially to the visuospatial component, which (unlike the verbal component) was not impaired in the group with DS. It is concluded that the two numerosity tasks involve different processes. It is concluded that the arithmetical and working memory difficulties of individuals with DS are not general, and they can draw on their WM resources when estimating the numerosity of additions.

Altered automatic face processing in individuals with high-functioning autism spectrum disorders: Evidence from visual evoked potentials

Individuals with autism spectrum disorders (ASDs) have different automatic responses to faces than typically developing (TD) individuals. We recorded visual evoked potentials (VEPs) in 10 individuals with high-functioning ASD (HFASD) and 10 TD individuals. Visual stimuli consisted of upright and inverted faces (fearful and neutral) and objects presented subliminally in a backward-masking paradigm. In all participants, the occipital N1 (about 100ms) and P1 (about 120ms) peaks were major components of the evoked response. We calculated “subliminal face effect (SFE)” scores by subtracting the N1/P1 amplitudes and latencies of the object stimuli from those of the face stimuli. In the TD group, the SFE score for the N1 amplitude was significantly higher for upright fearful faces but not neutral faces, and this score was insignificant when the stimuli were inverted. In contrast, the N1 amplitude of the HFASD subjects did not show this SFE in the upright orientation. There were no significant group differences in SFE scores for P1 amplitude, latency, or N1 latency. Our findings suggest that individuals with HFASD have altered automatic visual processing for emotional faces within the lower level of the visual cortex. This impairment could be a neural component of the disrupted social cognition observed in individuals with HFASD.

Abnormal social reward processing in autism as indexed by pupillary responses to happy faces

BackgroundIndividuals with Autism Spectrum Disorders (ASD) typically show impaired eye contact during social interactions. From a young age, they look less at faces than typically developing (TD) children and tend to avoid direct gaze. However, the reason for this behavior remains controversial; ASD children might avoid eye contact because they perceive the eyes as aversive or because they do not find social engagement through mutual gaze rewarding.MethodsWe monitored pupillary diameter as a measure of autonomic response in children with ASD (n = 20, mean age = 12.4) and TD controls (n = 18, mean age = 13.7) while they looked at faces displaying different emotions. Each face displayed happy, fearful, angry or neutral emotions with the gaze either directed to or averted from the subjects.ResultsOverall, children with ASD and TD controls showed similar pupillary responses; however, they differed significantly in their sensitivity to gaze direction for happy faces. Specifically, pupillary diameter increased among TD children when viewing happy faces with direct gaze as compared to those with averted gaze, whereas children with ASD did not show such sensitivity to gaze direction. We found no group differences in fixation that could explain the differential pupillary responses. There was no effect of gaze direction on pupil diameter for negative affect or neutral faces among either the TD or ASD group.ConclusionsWe interpret the increased pupillary diameter to happy faces with direct gaze in TD children to reflect the intrinsic reward value of a smiling face looking directly at an individual. The lack of this effect in children with ASD is consistent with the hypothesis that individuals with ASD may have reduced sensitivity to the reward value of social stimuli.

Motor coordination and health-related physical fitness of children with developmental coordination disorder: A three-year follow-up study

Health-related physical fitness is an important risk factor of cardiovascular disease. While previous studies have identified children with developmental coordination disorder (DCD) to be less physically fit than typically developing (TD) peers, there is limited longitudinal research in this area. This study was undertaken to evaluate concomitant changes in motor coordination and health-related physical fitness of Taiwanese children with and without DCD over a three-year period. The Movement Assessment Battery for Children (Movement ABC) test was used to evaluate motor coordination, while health-related physical fitness included several core components: (1) body mass index (BMI), (2) sit and reach forward, (3) long jump, (4) sit-ups, and (5) 800-m run. Both the Movement ABC and fitness tests were implemented once each a year for three years. Twenty-five children with DCD and 25 TD children, matched by age and gender participated in this study. The TD group showed significant long-term changes in BMI and long jump while the DCD group showed significant increases in BMI values and decreases in flexibility, measured by the sit and reach task. In general, children with DCD performed worse on the items of flexibility, muscle strength and muscle endurance after the first year. Compared to age- and gender-matched norms, children with DCD not only were less physically fit, but showed a significant long-term decline in flexibility and abdominal or core strength (sit-ups). In years two and three, there was a significant negative correlation between poor fitness and motor coordination. Based on the results of this longitudinal study, greater attention should be paid to monitoring and improving physical fitness of children with DCD to prevent further health-related problems while intervention.

Brain Activation of Children With Developmental Coordination Disorder is Different Than Peers

Children with developmental coordination disorder (DCD) struggle to learn new motor skills, demonstrating more variable performance than typically developing (TD) children. The purpose of this study was to determine whether patterns of brain activity differed between children with and without DCD while performing a motor task. Using functional MRI, we measured brain activation patterns in 7 children with DCD and 7 age-matched peers (aged 8-12 years) during a fine-motor, trail-tracing task. Despite similar levels of behavioral motor performance, different patterns of brain activity were noted between the 2 groups. The group with DCD showed significantly more activation than control subjects in left inferior parietal lobule, right middle frontal gyrus, right supramarginal gyrus, right lingual gyrus, right parahippocampal gyrus, right posterior cingulate gyrus, right precentral gyrus, right superior temporal gyrus, and right cerebellar lobule VI. These results suggest that the group with DCD relied on visuospatial processing to complete the task. The TD group demonstrated significantly more activation than the group with DCD in left precuneus, left superior frontal gyrus, right superior temporal gyrus/insula, left inferior frontal gyrus, and left postcentral gyrus; these regions have been associated with spatial processing, motor control and learning, and error processing. Children with DCD activate different brain regions from typical children when performing the same trail-tracing task. Despite the small sample size, our results contribute to a growing body of literature suggesting that children with DCD exhibit differences in neural networks and patterns of brain activation relative to same-age peers.

Sampling Context Affects MLU in the Language of Adolescents With Down Syndrome

The authors describe the procedures used to explain an unexpected finding that adolescents with Down syndrome (DS) had a lower mean length of utterance (MLU) than typically developing (TD) children in interviews without picture support, but not in narratives supported by wordless picture books. They hypothesize that the picture support of the narrative context increased the MLU for the group with DS alone. Adolescents with DS (n = 14) and TD children (n = 14) matched for receptive syntax narrated picture storybooks and participated in interviews. Transcription reliability, intelligibility/fluency, grammatical errors, discourse and sampling contexts, and discourse characteristics were examined for their effects on MLU. The DS group showed a greater responsiveness to adult questions than the TD group; an alternate MLU without yes/no responses showed the same interaction of group and context as the original finding. An additional comparison of MLUs, obtained from narratives present in the interview and narratives elicited using picture books, showed that picture support in narrative increased MLUs only for the group with DS. Picture support, rather than narrative context alone, increased MLUs for the group with DS. Clinical use of narratives and picture support in assessment and intervention with individuals with DS is discussed.

Neural basis of irony comprehension in children with autism: the role of prosody and context

While individuals with autism spectrum disorders (ASD) are typically impaired in interpreting the communicative intent of others, little is known about the neural bases of higher-level pragmatic impairments. Here, we used functional MRI (fMRI) to examine the neural circuitry underlying deficits in understanding irony in high-functioning children with ASD. Participants listened to short scenarios and decided whether the speaker was sincere or ironic. Three types of scenarios were used in which we varied the information available to guide this decision. Scenarios included (i) both knowledge of the event outcome and strong prosodic cues (sincere or sarcastic intonation), (ii) prosodic cues only or (iii) knowledge of the event outcome only. Although children with ASD performed well above chance, they were less accurate than typically developing (TD) children at interpreting the communicative intent behind a potentially ironic remark, particularly with regard to taking advantage of available contextual information. In contrast to prior research showing hypoactivation of regions involved in understanding the mental states of others, children with ASD showed significantly greater activity than TD children in the right inferior frontal gyrus (IFG) as well as in bilateral temporal regions. Increased activity in the ASD group fell within the network recruited in the TD group and may reflect more effortful processing needed to interpret the intended meaning of an utterance. These results confirm that children with ASD have difficulty interpreting the communicative intent of others and suggest that these individuals can recruit regions activated as part of the normative neural circuitry when task demands require explicit attention to socially relevant cues.